Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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AIR-ACTUATED PIPELINE TRANSPORTATION : : -
SYST~M WITH WHEELED VEHICLES
1Background of the Invention
The use of an air-actuated pipeline system for moving
wheeled vehicles is generally old as shown in Canadian Patent
No. 940,770 which issued Januar~ 29, 1974 to M. R. Carstens and -
H. J. Bates and United States Patent No. 3,881,425 which issued
May 6, 1975 to M. R. Carstens. However, any debris in the
pipeline will tend to interfere with the movement o~ the vehicles.
Since such systems are well suited for the transportation ~ ; -
of particulate solids, there exists the possibility of inadvertent
spillage of such solids in the pipeline. One feature of the
present invention is the provision of means for removing particles
or debris from the pipeline. The wheeled vehicles have a
round cross-sectional area similar to but smaller than the
interior of the pipeline and may function as pipeline sweepers.
That is, the pressure is greater on the rear of the vehicle
than on the front and some alr flows around the vehicles to
blow smaller particles ahead of the vehicle. Those particles
which are too large to be blown ahead of the vehicle will
collide with the vehicle and will be rolled and slid ahead ~-
of the vehicle. The additional energy required to move par-
ticles by rolling and sliding by the vehicle plus the possibility
of a larger particle wedging the vehicle against the pipe
walls are incentives to remove spilled material and debris
from the pipeline as quickly as possihle.
Furthermore, in order to prevent any vehicle from ;
turning over in the pipeline and spilling its load in the
pipeline, it is desirable that the vehicles maintain an upright -~
running attitude. While vehiGles having toed out wheels for
self-righting a vehicle have been provided in the past, such
as disclosed in United States Patent No. 2,928,357, which
~- issued to McBride in ~arch of 1960, such toed out load wheels
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1 were not automatic, but required control lines connected to
the vehicle and actuated from outside the line. The present
invention provides an automatic self-righting vehicle using
toed out wheels but overcomes the objections of the prior
art.
Summary
The present invention is directed to an air-actuated
pipeline transportation system having wheeled vehicles. One
of the features of the present invention is the provision
of means for removing debris from the pipeline. The vehicles
normally move through the pipeline on load wheels adjacent
the bottom of the vehicles. The present invention includes -
' providing an opening or openings in the bottom of the pipeline -
;, which should be larger than the largest particle falling into
the line. This will generally require that the openings be
! wider than the width of a load wheel. In one embodiment,
the load wheels are spaced apart a distance greater than the
width of the openings and the wheels are toed outwardly in
the direction of movement of the vehicle whereby the vehicle ~;
will maintain an upright position and the load wheels will
then straddle the openings and the vehicle will pass over
the openings without the wheels being caught in the openings.
In another embodiment, side wheels are connected to the vehicles
and as the vehicles pass over the opening in the pipe, the
weight of the vehicle will be carried by the side wheels which
are po~itioned to straddle the openings and carry the load
, wheels over the openings without the load wheels catching in
J, the opening while the debris will be blown out of the pipeline
openings by air and by being pushed out by the vehicle. -
A still further objeGt of the present invention is
the provision of additional means to reduce any tendency of
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1 the vehicle to be jarred or bumped as it passes over the openings.
First, it is desirable that the side wheels normally extend
radially outwardly from the vehicle toward the interior of
the pipeline a distance less than the load wheels so that they
do not normally contact the pipeline and thus avoid increasing
the rolling friction of the vehicle. An elevated track i~
provided on either side of the opening positioned to engage
the side wheels as the vehicle passes over the openings and
preferably the leading and trailing edges of the tracks include
ramps between the tracks and the interior of the pipeline to
reduce any tendency of the vehicle to bump as the side wheels ;
engage the tracks. Additionally, the upstream and downstream
side of the openings may also include ramps which are positioned
to be engaged by the load wheels in the event that a load wheel
does drop slightly below the bottom of the interior of the
pipeline while passing over the openings.
A still further object of the present invention is
the provision of adjustably connecting the tracks relative -~
to the interior of the pipeline in order that the tracks may
be adjustably moved relative to the interior of the pipeline
for smoothly carrying the vehicle over the opening.
A still further object of the present invention is
the provision of spacing an opening downstream, but adjacent
to any loader or unloader in the pipeline as these are the
areas in the pipeline in which debris or material are more
likely to be located.
A stil~ further object of the present invention is
the provision of means for maintaining the vehicle in an upright
position or in an acceptable running attitude in order to prevent
the vehicle from rotating in the pipeline and dumping part
of its load into the pipeline or even turning over in the pipeline.
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1 In one embodiment, the load wheels are toed outwardly in the
direction of movement of the vehicle and act to maintain an
upright position, although this will increase the rolling resistance
of the vehicle as well as increasing the wear on the load wheels.
In another embodiment, the side wheels act to maintain the
vehicle in an upright position by toeing the side wheels outwardly
in the direction of movement of the vehicle through the pipeline.
However, by extending the side wheels outwardly from the vehicle
a distance less than the load wheels the side wheels are normally
positioned out of contact with the interior of the conduit
when the vehicle is upright and thereby avoid unnecessary rolling ~ -
resistance and wearing of the side wheels. However, one of
the toed out side wheels will engage the interior of the conduit
to act to right the vehicle when the vehicle rotates a predetermined
amount about its horizontal axis. Thus, the vehicle may include
two load wheels and two side wheels at each end of the vehicle
and preferably the plane containing each wheel extends radially
outwardly from the longitudinal axis of the vehicle.
Other and further objects, features and advantages
will be apparent from the following description of a presently
preferred embodiment, given for the purpose of disclosure and
taken in conjunction with the accompanying drawings.
Brief Description of the Drawings
Figure 1 is an elevational view of a typical air
actuated pipeline transportation system for moving wheeled
vehicles therethrough,
Figure 2 is an enlarged cross-sectional elevational
view, of one embodiment of the improved vehicle of the present
invention and means for removing debris from the pipeline,
Figure 3 is a cross-sectional view taken along the
line 3-3 of Figure 2,
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1 Figure 4 is a cross-sectional view taken along the
line 4-4 of Figure 2,
Figure 5 is a cross-sectional view taken along the
line 5-5 of Figure 4,
Figure 6 i5 a schematic elevational view of the wheel
structure, similar to Figure 3, showing the righting action
of a side wheel when the vehicle has undesirably rotated in
the pipeline, ' '
Figure 7 is a cross-sectional view taken along the '
line 7-7 of Figure 6,
Figure 8 is a schematic elevational view of the preferred
wheel structure, showing the righting action when the vehicle ;~
has undesirably rotated in the pipeline, and ~ ~
Figure 9 is a chart illustrating the righting moment ~ ' '
applied to the vehicle of Figure 8 at various toe out angles '~
versus the tilting angle of the vehicle.
Description of the Preferred Embodiment '
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Referring to the drawings, and particularly to Figure
1, the present invention may be used in any suitable air-actuated '~
pipeline system having wheeled vehicles, and for purposes of
illustration only is referred to generally by the numeral 10
and includes a tubular conduit or pipeline 12 having a suitable
pump 14 for creating a flow of air through the pipeline 12
for moving one or more wheeled vehicles 16 therethrough. Similar
pipeline systems are shown in Canadian Patent No. 940,770 and
United States Patent No. 3,881,425. Normally, such pipeline
transportation systems 10 generally include a loading station
generally indicated by the reference numeral 18 and an unloading
station generally represented by the reference numeral 20.
Such systems 10 are particularly suited for the transportation
of particulate solids and in such event the loading station
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1 18 may include a hopper 22 for filling a vehicle 16 positioned
in the loading station 18. The unloading station 20 may include
unloading means 24, such as described more fully in Canadian
Patent No. 972,337 which issued on August 5, 1975 to H. J. Bates
for receiving a vehicle, inverting the vehicle, and dumping
the transported material to a receiver 26 and then righting
the emptied vehicle.
Referring now to Figure 2, the vehicle 16 normally
includes a body 28 having a round cross-sectional area similar
in shape but smaller than the interior of the conduit 12 such
as by providing end plates 30 and 32 at the forward and rear : :
ends, respectively, of the body 16 on which the air moving
through the pipeline 12 acts to push the vehicle 16 through
the pipeline 12. Material particles or debris 15, such as
that being carried by the system 10, occasionally are present
in the pipeline 12 such as caused by inadvertent spillage when
loading or unloading the vehicle 16. The vehicle 16 functions
as a pipeline sweeper to move debris or particles in the pipeline
12 along the interior of the pipeline 12 since air flows around
the periphery of the end plates 30 and 32 sufficiently to blow
small particles along the pipeline 12, and particles which ;-:
are too large to be blown collide with the front end plate
30 and will be rolled along or slid ahead o~ the vehicle 16
as it is moved through the pipeline 12. However, debris in
the pipeline requires additional energy to move the vehicle
along the pipeline 12 and particles not removed could catch
be~ween the vehicles 16 and the interior of the pipeline 12
and wedge the vehicle 16 against the pipeline.
One feature of the present inven~ion is the provision ~
30 of one or more openings 34 positioned in the bottom of the ::
pipeline 12 to allow debris to fall through the openings 34
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1 and be discharged from the interior of the pipeline 12. Prefer-
ably, the openings 34 should be larger than the largest particle
normally carried in the system 10. However, the vehicle 16
is moved through the pipeline on a plurality of load carrying
wheels adjacent the bottom of the vehicle 16, for example two
load carrying wheels 36 and 38 at each end of the vehicle 16.
In order to make the openings 34 sufficiently large to allow
the passage of large particles, the openings 34 should be of
a width larger than the width of the load wheels 36 and 38.
10 Of course, with the openings 34 being larger than the width ~-
of the load wheels and positioned in the bottom of the pipeline
12, the load wheels could become caught in the openings 34
as the vehicle passes the openings 34.
Referring now to Figure 8, the preferred embodiment
of the pxesent invention is best seen, which shows a schematic
elevational view of the one end of a vehicle 16a, the other
end of which may be identical, having two load carr~ing wheels
36a and 38a moving through the pipeline 12a having an opening
34a therein and shown tipped at an angle B from the upright
or vertical attitude. It is important that the vehicle 16a
maintain an upright position as it moves through the pipeline
12a and does not rotate around its horizontal axis in order
to avoid spilling the load into the pipeline 12a and in order
that the wheels 36a and 38a avoid catching in the opening 34a.
To accomplish this the wheels 36a and 38a are toed outwardly
in the direction of travel of the vehicle at an angle e, similar
to that shown in Figure 7 as will be discussed later. A normal
force Nl is exerted on the wheel 36a by the pipeline and a
normal force N2 is exerted on the wheel 38a by the pipeline
12a. The wheels 36a and 38a are normally positioned an angular
distance a from the vertical axis of the vehicle 16a. If the
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1 vehicle 16a becomes undesirably tipped at an angle ~ from the
vertical as shown in Figure 8, the normal force Nl and N2 will
be unequal. The calculation for the relative forceæ is as
follows:
Nl = sin (a+B)
N2 sin (a-B)
Therefore, with the vehicle being tipped at an angle B, the
normal force Nl will be greater than the normal force N2.
The greater force acting against wheel 36a will induce an attitude
correcting moment to bring the vehicle 16a back to an upright
attitude which will not only prevent spillage from the vehicle
but will allow the wheels 36a and 38a to straddle the opening
and pass by the opening 34a without the wheels 36a and 38a
becoming caught in the opening 34a. Referring now to Figure
9, graphs 100, 102 and 104 illustrate the attitude correcting
moment versus the tilt angle B for toe out angles e in the
amounts of 0 degrees, 2 degrees, and 4 degrees, respectively,
for an angle a of 45 degrees. Generally, it has been found
that small toe out angles e such as one or two degree~ is sufficient
to maintain the vehicle in an upright position while also reducing
the undesirable wear on the toed out wheels 36a and 38a.
Preferably, the planes of the wheels 36a and 38a
extend through the horizontal axis of the vehicle 16a and prefer-
ably the angle between the wheels 36a and 38a, which is 2a,
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is approximately 90 degrees. Wide angles 2a are superior for
vehicle stability and ability to pass over debris, but are
inferior from the standpoint of increasing rolling friction.
With the angular extent of 90 between the wheels 36a and 38a,
the angular extent of opening 34a may be made as wide as 60
degrees without the likelihood of the toed out wheels catching
therein.
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1 Referring now to Figures 2, 3 and 4, another embodiment
is shown for preventing the load wheels 36 and 3~ from catching
in the openings 34 in which a pair of side wheels 40 and 42
are provided connected to the vehicle 16. One of the side :
wheels 40 is positioned on one side of both of the load wheels
36 and 38 and ~he second of the side wheels 42 is positioned ~:~
on the opposite side of both of the load wheels 36 and 38.
As best seen in Figure 4, the side wheels 40 and 42 are angularly
spaced at a distance greater than the width of the openings
34 and thus the side wheels 40 and 42 can carry the weight
of the vehicle 16 as the vehicle 16 passes over the openings
34 and the load wheels 36 and 38 will pass over the openings
34 without catching therein.
While the side wheels 40 and 42 could extend outwardly
from the vehicle 16 the same distance as the load wheels 36
and 38, it i~ preferable to avoid the additional rolling re-
sistance of the wheels 40 and 42 as well as other reasons which
will be more fully discussed hereinafter, and in~tead the outer
peripheries of the side wheels 40 and 42, as best seen in Figures
3 and 4, extend outwardly from the vehicle 16 a lesser amount
than the outer peripheries of the load wheels 36 and 38. Therefore, :
when the vehicle 16 is in its normal upright position, the
side wheels 40 and 42 do not engage the interior 13 of the
pipeline 12. In this running attitude, the shift of the weight ~ -
fxom the load wheels 36 and 38 to the side wheels 40 and 42, :.
when a vehicle 16 passes over an opening 34, may be accomplished
by providing a curved track 44 on each side of each opening
34 and positioned to engage the side wheels 40 and 42. The
added thickness of the tracks 44 should be such as to allow
the shift in load to the side wheels 40 and 42 without unde-
sirably bumping or impacting the vehicle 12 in order to avoid
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1 spillage from the vehicle 16. Preferably, the tracks 44 are
adjustably connected to the interior 13 of the pipeline 12
so that the tracks 44 may be adjusted to carry all of the wheels
smoothly over the opening 34. For example, a plurality of
bolts 46 may threadably engage the pipeline 12 to adjust the
tracks 44 inwardly and thereafter the bolts 46 are locked into
place by nuts 48. For adjusting the tracks 44 outwardly, bolts
50 are secured to the tracks and extend through the pipeline
12 and are held outwardly by nuts 52. As best seen in Figure
5, in order to avoid any bumping of the vehicle 1~ as it engages
or leaves the tracks 44, a ramp 54 is provided at the upstream
edge of each track 44 between the interior 13 of the pipeline . -:
j 12 and the leading edge of the tracks 44. Similarly, a ramp
56 is pr~vided at the downstream end of the tracks 44 joining
the interior surface 13 of the pipeline 12 and the trailing
edge of the tracks 44. ~:
Additionally, the upstream and downstream ends of
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the openings 34 may be provided with inclined ramps in the :~ :
event that the load wheel~ 36 and 38 have a tendency to sag
into the openings 34. Referring to Figures 2 and 4, an opening
ramp 58 may be provided on the upstream side of each opening . ~ .
34 leading downwardly into the opening 34, and a downstream :
ramp 60 may be provided leading upwardly from the opening 34
towards the interior 13 of the pipeline 12. Thus, the opening , :::
ramps 58 and 60 are available to provide a gradual engagement
by the load wheels 36 and 38 in the event that they move down-
wardly into the openings 34. ~ :~
If desired, exterior stiffening rings 62 and 64 may
be provided at either end of the openings 34 and secured to
the pipeline 12 to incure the dimensional integrity of the
interior 13 of the pipeline 12. -::
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1 S~hile as many openings 34 may be provided in the
pipeline 12 where desired, it is preferable that an opening
34 be located immediately downstream but adjacent to both the
loader 22 and the unloader 24 since these are the areas that
are most likely to create entrance of material into the pipeline
12. Furthermore, while not shown, a mechanical pusher may
be used at both the loading station 18 and the unloading station
20 to start a vehicle from the stop position, and therefore
this external pushing force will insure that the vehicle is
placed in motion and that the leading wheels will cross the
openings 34. Secondly, since the vehicles are started from
rest, the vehicle velocity will be small when the wheels pass
over the openings 34 which is helpful in providing for the
necessary thrust capacity of the side wheels inasmuch as bearing
capacity decreases with angular speeds.
However, as previously mentioned, it is also desirable
that the vehicles 16 maintain an upright position as they move
through the pipeline 12 and do not rotate around their horizontal
axis so ac to spill the load 15 ~nto the pipeline 12 or turn
over. United States Patent No. 2,928,357 illustrates the use
of an external control system for toeing out load wheels for
maintaining an acceptable running attitude. S~hile toed out
load wheels as shown in Figure 8 automatically act to right
the vehicle, when it undesirably rotates, the use of toed out
load wheels which are always in contact with the interior of
the pipe wall does increase the rolling resistance due to partial
skidding of the wheels and also increases wear on the wheels.
In the embodiment of Figures 3-7, the side wheels 40 and 42
are provided which do not radiall~ extend outwardly as far
as the load wheels 36 and 38 and therefore as best seen in
Figure 3 do not normally engage the interior 13 of the pipe
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1 12 if the vehicle 16 is in the upright position. Preferably,
only the side wheels 40 and 42 are toed outwardly in the direction
of movement of the vehicle 16. Therefore, the vehicle would
have to rotate to an angle greater than half the angular distance
between load wheels 36 and 38 before the vehicle 16 would be
tilted enough to bring one of the side wheels 40 or 42 into
contact with the interior 13 of the pipe 12. Referring now .
to Figure 6, the schematic view of the wheels is shown in which
the vehicle 16 is rotated sufficiently to bring side wheel
42 into engagement with the interior 13 of the pipe 12. When
the toed out side wheel 42 contacts the interior of the con~
duit 12, the wheel 42 will act to right the vehicle 16. The : -
advantage of the configuration of the present invention is :~
that the side wheels 40 and 42 do not normally contact the
interior 13 of the pipeline 12 and thus do not normally add :~
rolling friction and wear of the wheels 40 and 42 to the system -
except when they are needed to right the vehicle 16. As in- : :
dicated, it i8 preferable not to toe out the load wheels 36 .
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and 38 in this embodiment, but, if desired, the load wheels
36 and 38 may be towed out as indicated in the dotted outlines
in Figure 7 the same as in the preferred embodiment of Figure ~.
8.
In addition, the particular configuration of the
wheels shown advantageously maintains the vehicles 16 in the ~.
upright position to allow proper coaction and alignment of ~:~
the vehicles 16 with the debris openings 34. :: :
In the embodiment of Figures 3-7, it is preferable
that the planes of the wheels 36, 38, 40 and 42 extend through
the longitudinal axis 62 of the vehicle 16. In addition, all
of the wheels extend radially outwardly and downwardly from ::-
the vehicle 16 and preferably the vehicle 16 includes two load :~ .
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1 wheels 36 and 38 and two side wheels 40 and 42 at each end
of the vehicle 16~ In the preferred embodiment, the load wheels
are separated by approximately thirty angular degrees and the
side wheels are each separated approximately forty-five degrees
from a load wheel.
The present invention, therefore, is well adapted
to carry out the objects and attain the ends and advantages . .
mentioned aæ well as others inherent therein. While a presently
preferred embodiment has been given for the purpose of disclosure,
10 numerous changes may be made without departing from the spirit :
and scope of the invention as hereinafter claimed.
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