Note: Descriptions are shown in the official language in which they were submitted.
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TRANSPORT SYSTEM WITH BLOCKING_VALVE CONI'ROI.
BACKGROUND OF THE INVENTION
This invention relates to transport systems such as
those disclosed in United States Patents 4,017,039 of April 12,
1977; 3,724,691 of April 3, 1973; 3,797,405 of March 19, 1975;
and 3,881,A25 of May 6, 1975.
In the above systems, a wheel-supported vehicle or
a train of them moves through a conduit system through which
! air is pumped. Each vehicle incompletely Eills the cross section
of the conduit system and presents a high coefficient of drag
j 10 with respect to the air being pumped through the conduit system.
l ,- The air ~low is maintained at a high mass rate of flow and
vehicles are swept along by this flow of air.
In the development of these systems, several types
of air pumps were employed. One type, as disclosed in patent
3,797,405, may be regarded as a jet type of pump in which air
is withdrawn from the conduit,system and discharged back into
the conduit system through what is effectively a restriction
or nozzle, the resultant high velocity of the jet stream discharge
being partlally converted, downstream of the discharge region,
20, into a pressu're component which creates or maintains the requisite
momentum for the high mass rate of flow. Although this type
,of pump system is low cost and reliable, the amount of air
which can be withdrawn from the conduit system and then reirltroduce
thereinto under high. velocity, is limited to a fraction of
the total flow in the conduit system in order to avoid a "dead
spot" or any tendency for reverse flow in the conduit system
~ between the regions of air withdrawal and reintroduc:tion by
the pump. Consequently, in order to provide a.system having
hlgh total energy input with this type of pump, a large number
of them are required in series along the pipeline or conduit
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l system.
Subsequent developments involved the use of pumps
_ which develop the requisite air momentum not by a high velocity,
jet stream discharye but by directly discharging the high mass
i rate of flow into the conduit system, thereby creating a tendency
¦ for the air to flow reversely or in upstream direction from
the region of introduction. The air inducted by the pump may
either be withdrawn from the conduit system or it may be ambient
air, depending upon whether the pump is employed as a booster
along the conduit system or whether it operates as an end-of-
line pump. In any event, some physical obstruction is required
¦ immediately upstream from the region of air introduction to
prevent air reversal through the conduit. In Patent No. 3,881,425,
¦ the vehicles themselves are used for this purpose and in order
¦ to move the vehicles to a point beyond or downstream of the
¦ region of air introduction or discharge in order to get them
moving within the conduit system, a mechanical drive unit may
be employed. Although- this type of system is very efficient,
it does require the complexity and disadvantage of a mechanical
i 20 drive unit of some kind and also lmposes a program of vehicle
-movement through the system.
- In order to eliminate the constraints of the immediately
foregoing systems, a further pump arrangement was developed,
as disclosed in Patent No. 4l017~039. In such systems, the
physical obstruction required to prevent any significant re-
verse flow of air is provided by an overhead-suspended, counter-
balanced flapper valve which is responsive to the phenomenon
of an approaching vehicle automatically to swing upwardly out
of the way of the vehicle, allowing it to pass therebeyond
and back into the mainstream of the moving air mass. The valve
closes automatically behind the vehicle or train.
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1 The present invention is directed to systems using
two valves which allow still greater pressure differentials
to be employed. While Patent No. 1,753,987 describes a system
using two valves for moving a postal capsule, such a system
is unsatisfactory for moving wheeled vehicles.
~RIEF SUMMARY OF THE INVENTION
,, ~., . _ .
The present invenkion is directed to a transport
system in which two overhead-suspended flapper valves are em-
ployed to provide the physical obstruction necessary to prevent
any subs~antial reverse flow of air upstream from the region
of air discharge of a pressure pump. In contrast to my prior
arrangements, the pressure differential change across the valves
which is the phenomenon by means of which the valves are swung
upwardly to clear a vehicle is not created by an entrapped
mass of air ahead of a ~ehicle, but is instead created by a
pump-induced air flow change itsel~.
Basically, the present system employs two overhead-
suspended, openly urged valves upstream from the region of
the pressuxe pump discharge into the pipeline or conduit system,
the air flow being alternately directed against the ~alves
such that a pressure dif~erential is developed across the valves
to alternateIy close the valves in combination with sensor
means responsive to the approach of an incoming vehicle or
train~ for causing an alteration in air flow which changes the
pressure *if~erential across the valves which opens and closes
the irs~ and second valves alternateIy. The pump or air-displacing
means may be a hoos~er type pump which withdraws the full system
~air from one region of the conduit system and discharges it
back into a second region of the conduit system or ik may be
an end-of-line type o~ pump or air displacing means in which
ambient air is inducted and pressurized air is discharged into
-~ the pipeline.
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1 The air displacing means includes two discharge outlets
connec~ed to spaced regions of the pipeline, each for directing
air against the back of and actuating a swingable flapper valve.
One or the other of these discharge outlets is blocked by a
suitable air flow control valve and the two are linked together
by a common actuating mechanism such that in a normal position,
one outlet discharges into the pipeline while the other is
blocked but wherein this situation is reversed in response
to the detection of an approaching vehicleO Auxiliary pump
means having an inlet connected to the pipeline between the
first and second valves may be provided to further assist in
the movement of vehicles through the pump.
Figure 1 is a diagrammatic illustration of an embodiment
of the invention and illustrating an end-of-line system;
Figure 2 is a-view similar to Figure 1 but showing
the control means in altered positions;
Figure 3 is a view similar to Figures 1 and 2 but
showing the operation after the vehicle passes the pump section;
Figure 4 is a diagrammatic view illustrating control
valve actuation for the embodiment of Figure l;
Figure 5 is a diagrammatic vi.ew illustrating another
embodiment of the invention~ this time again in an end-o~-line
configùration;
Figures~6 and 7 are views similar to Figure 5 but
illustrating thP pa~sage o~ the vehicle through the system;
and
Figure 8 is a diagrammatic view of a further embodi-
ment of the invention.
~
With reference at this time to Figure 1 in particular,
th reference character 10 indicates in general a continuous
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l pipeline or conduit system through which wheeled vehicles pass
freely in the direction of the arrow indicated by the reference
character 12. Air-displacing means 14 which may take any con-
venient conventional ~orm is provid~d with an inlet 16 through
which air is inducted and having an outlet 20. The device
14 is adapted to displace air at a high mass rate of flow and
at a pressure differential between the inlet and outlet thereof
to establish a high mass rate air f:Low of air through the pipe-
line lO as is disclosed in my aforesaid prior patent 3,797,405
A wheeled vehicle v is shown approaching the pump
station and, as will be understood from my prior disclosures
mentioned hereinabove, this vehicle only incompletely fills
the cross section of the pipeline 10 and is so shaped as to
have a high coefficient of drag with respect to the air flowing
through the system so that even though the air flows around
and past the vehicle, the vehicle is swept along by the high
mass rate flow o~ air sweeping through the system.
Figures 1, 2 and 3 are intended to illustrate a basic
prin~iple of this invention, namely, th~ control of air flow
generated by the pump means 14 so as to allow first valve 22
and second valve 24 to move from a closed position to an out-
of the-way open position allowing unimpeded movement of the
vehicle v therepast without in the process requiring eikher
the momentum o~ the vehicle to ~uild up air pressure ahead
of it in order to open the valves or the vehicle to contact
~he valves 22 and 24. To this end, air ahead of the vehicle
v passes outwardly through a vent 18 to prevent pressure build-
up such as would slow the vehicle.
The overhead-suspended flapper valves 22 and 24 are
3a provided in order to prevent reverse flow of air from the pump
outlet 20 back in the direction of the approaching vehicle.
- Valve 22 is supported ~rom a pivot axis 26 and is connected
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1 to an arm 28, which is illustrated only in Figure 2 ~or clarity,
to which counterbalanciny means such as a weight or a spring
is attached, here shown as weight 17, for countexbalancing
the valve 22 normally to urge it or to allow it easily to swing
to an open position when the pressure differential created
normally by the pump means is altered Similarly, valve 24
is supported from pivot axis 27 and is connected to an arm
29 to which counterbalancing means such as a weight or spring,
here shown as spring l9 outside said conduit, is attached for
counterbalancing the valve 24 and urging valve 24 to swing
to an open position. The edge~ of both valves 22 and 24 are
molded to match the contour of the inside pipe wall in order
to seal against the inside of the pipeline lO when moved to
the closed position.
Referring to Figure 1, an end-of-line type of pump
station is illustrated in which air flow control means is
associated with the pump 14 for alternately directiny air against
the backs 23 and 25, respectively, of valves 22 and 24 to control
their opening and closing relative to the position of vehicle
v. The outlet 20 of the pump 14 has two branches, the first
branch 48 discharges into the region 50 of the pipeline lO
and the second branch 42 discharging into the region 44 of
the pipeline lO. It is noted that regions 50 and 44 open into
the top of pipeline lO and therefore do not interfere with
the wheeIs on vehicle v~ It is also noked that regions 50
and 44 are positioned to direct air on the back of valves 22
and 24, respectively, for closing said valves by establishing
a pressure differential across the valves which alternately
maintain them in the closed position thereby preventing any
substantial reVer;e flow of air past the valves 22 and 24.
Flow of air from the pump 14 alternately to branch 48 and 42
is controlled by any suitable means such as butterfly valves
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l 56 and 58, respectively. As shown in Figure l, butter~ly valve
56 is blocking branch 48 preventing air ~rom pump 14 flowing
into region 50 and therefore first valve 22 is urged to an
open position by its counterbalancing means 17. However, butter-
fly valve 58 i~ in the open position allowing air to flow from
pump 14 through branch 42 and into :region 44 and against the
back 25 of valve 24 thereby moving valve 24 to khe closed position.
Therefore, air flows from the pump :l4 through branch 42 and
past closed valve 24 downstream in the pipeline lO to move
any vehicles v in the line lO downstream of valve 24 through
the pipeline lO, but yet prevents reverse flow o air through
valve 24.
The pipeline end section 54 is pref~rably downwardly
inclined to let the vehicles v roll by gravity into the pipeline
and past the open valve 22 and into the section 46 of the pipe-
line between the regions 44 and 50. In order to prevent air
baing trapped ahead of the vehicle and between closed valve
24, an air vent 18 is provided. ~s soon as the vehicle approaches
s~ction 46, as in Figure 2, a detector or sensor 30 positioned
~ therein operates a suitable actuating means, which will be
more fully described hereinafter, to operate the two valves
56 and 58 from the posi~ions shown in Figure 1 to the positions
shown in Figure 2. Thus, now all of the air displaced by the
device 20 is diverted into the pipeline 10 through the branch
48, reverse flow escape thexeof being prevented by the valve
22 which has been closed by th~ air flow through branch 48
and is now held positively in the closed position. At the
same time, the pressure differential which existed across the
valve 24 in Figure 1 which tended to maintain it in the closed
position is now changed such that this changed pressure differen-
tiaI now causes the valve 24 to attain the full open position
as is illustrated in Figure 2. Thereafter, the vehicle v passes
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1 the region 44 and in so doiny passes beneath the valve 24 ultimately
to reach the position of a detector 36 which now causes the
actuator to revert the valves 56 a~ld 58 to their original positions
as is shown in Figure 3.
Figure 4 illustrates in diagrammatic form the fashion
in which the two butterfly valves 56 and 58 are actuated between
the position shown in Figures 1, 2 and 3 7 As illustrated in
Figure 4, a common actuator of any conventional form and as
is indicated by the reference character 60 is controlled by
the detectors 30 and 36 and the two valves 56 and 53 are provided
with crank arms 62 and 64 which are pivotally interconnected
by a link 66 and are also connected to the actuator rod 68
of the device 60. The device 60 is adapted to move its rod
68 back and forth in the fashion indicated by the double headed
arrow in Figure 4 correspondingly to pivot the valves 56 and
58 about their axes 70 and 72 between the positions indicated
in Figures 1 and 2. The actuator may be o~ any suitable form
and as illustrated is double acting, same being energized to
act in one direction in response to a signal from the detector
or sensor 3~ and in the opposite direction in response to a
signal from the detector or sensor 36. The detectors 30 and
36 can be of any conventional type as, for example, they may
be photodetector devices as illustrated in Figure 4 operative
to be actuated to produce an output signal when the vehicle
v passec the light beams from the lamps L normally incident
thereon. Each lamp/detector pair is staggered as shown so
that any gap between successive vehicles of a vehicle train
will not allow the light beam to pass.
In the~embodiment of Figures 5-7, the apparatus is
the same as is de~cribed in conjunction with Figures 1-3 but,
in this instance/ an auxiliary pump 74 is provided having
an inlet 76 connected between the two valves 22 and 24 in place
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1 of vent 18. The outlet 78 of this pump 74 is provided with
a valve 80 which is mov~ble between the full open position
shown in Figure 5 to the fully closed position shown in Figure
6. When the valve 80 is in the ful:Ly open position as shown
in Figure 5, the auxiliary pump 74 withdraws air from the section
between the valves 22 and 24 which, although it is less than
the flow through the branch 42, nevertheless is of sufficient
flow rate as to create a pressure differential across the valve
22 which maintains it in the upwardly swung, open position
and acts to draw vehicle v through the line 10 as is shown
in Figure 5. An approaching vehicle, then, can freely pass
beneath the valve 22. As soon as the vehicle passes the position
of the sensor 30, the actuator means for the valves 56 and
58 which is also connected to the valve 80 moves these several
valves to the position shown in Figure 6I thus discharging
air through the branch 48 and moving the vehicle along with
it and, at the same time, upsetting the pressure differential
previously across the valve 24 and now moving it to the upwardly
swung or open position as is illustrated in Figure 6 whi~e
closing valve 22.
As soon as the vehicle passes the second sensor 36,
the actuator means reverse the valves to their original positions,
as is illustrated in Figure 7.
In the embodiment shown in Figure ~, the arrangement
is generally similar to that illustrated in Figures 5-7. However,
in this case, the auxiliary pump 74' has its inlet 76' connected
between the two valves 22 and 24 but in this case its outlet
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82 discharges downstream from the branch 42, the capacity of
the pump means 74' being but a fraction o the flow of the
main pump. Thus, when the valves 56 and 58 are reversed in
their positions and flow is dow~wardly through the leg 48 of
the main pump 38, the auxiliary pump 74' cannot sustain ~he
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1 pressure differential which maintained the valve 24 closed
and, instead, the pressure differential across this valve 24
alters or changes so that it moves to the upwardly swung position
while, at the same tim~, the valve 22 swings downwardly to
the closed position behind the entering vehicle. The detectors
30 and 36 operate in the same fashion as previously described.
With the systems according to the present invention,
the main pump 14 in each case can be operated at pre~sure differ-
entials correspondingly to produce high mass rates of flow
whereby the vehicles which are heavily laden can be adequately
moved through the pipeline system. At the same time, the momentum
of the vehicle is minimally disturbed by the blocking valves
22 and 24 associated with the pumping stations and, instead,
a change of flow in the system is effective to produce the
phenomenon which alters the pressure differentials across the
blocking valves ~2 and 24 to move them back and forth between
their closed and opened positions.
It will be appreciated that the basic principle of
this invention involv~s air flow control in the vicinity of
the two openly urged flapper valves 22 and 24 which adjusts
the pressure differential alternately across the valves either
to close them or to allow them to swing to open position.
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