Background of the invention
1. Field of the invention
[0001] The present invention relates to conveying devices of which the components are linked
together such that the distance between them varies as well as their speed.
2. Description of the prior art
[0002] The stretchable bandconveyoris a bandconveyor made of a succesion of components sliding
into or above each other and linked to .each other by devices varying the distance
between them such that the visible length and the speed of the components vary along
their course.
[0003] The stretchable train of cars is an endless succession of cars linked to each other
by devices varying the distance between them.
[0004] The stretchable and endless train of cars is used in combination with bandconveyors
at loading/unloading stations where the speed of the cars and the distance between
them is at a minimum and is synchronized over some distance with the speed of the
bandconveyors in order to enable people to go from the bandconveyors to the cars and
vice versa.
[0005] Several variable speed bandconveyors are known in the prior art. One such device
uses components which are longer than they are wide. These components slide along
each other, while the relative direction of motion progressively changes from a direction
perpendicular to the long side. of the components to a direction parallel to it, and
therefore, the speed of the components varies proportionally to the ratio of their
length and width. Another example of a rotating-type conveying apparatus is illustrated
in U.S. Patent 3,485,182. In another existing device components are deiven by a single
threaded rod with variable pitch.
[0006] Bandconveyors are also known which operate at constant speeds and go into or out
of cars moving at the same speed. Usually, those cars are attached to a cable moving
at constant speed, and the distance between them is fixed. These prior art devices
do not utilize controllable means for coupling the components and/or cars to achieve
variable speed and variable distance operation while maintaining the components aligned,
i.e. unrotated, with respect to the closed-loop path followed by the components.
SUMMARY OF THE INVENTION
[0007] In accordance with the invention a transportation system is provided in which a continuous
succession of components and/or cars travel in a closed circuit and are linked to
each other by devices which control and vary the distance between them.
[0008] The cars are permanently moving, but before each loading/unloading station the distance
between the cars is progressively reduced to a minimum by the devices linking them
together. After each station, the distance between the cars is progressively increased
by the same linking devices up to a maximum distance.
[0009] The action of increasing or reducing the distance between the cars will automatically
increase or reduce the speed of the cars proportionally to the distance between the
cars (including the car length). Therefore the speed of the cars is at a minimum at
the station. The loading/unloading platform at the station consists of a bandconveyor
moving at a speed which is synchronized with the minimum speed of the cars.
[0010] The linking devices may include arrangements of cables and winches, nuts and threaded
rods, articulated rods or electronic distance measurement and servomechanisms as set
forth hereinafter.
[0011] The endless train of cars can be started and kept in motion by motors at each station.
These motors may also drive the bandconveyors and keep their speed synchronized with
the speed of the cars at the stations. The power can be transmitted to the cars, e.g.,
by toothed wheels which engage racks which are fixed to each car. Small motors can
be added to each car or some cars to compensate for drag due to the friction and reduce
stresses on the linking devices.
[0012] To increase the capacity of the system, without increasing the width of the cars
it is necessary to increase their minimum speed or the speed of the bandconveyors.
In the latter case a stretchable bandconveyor may be made of components having linking
means permitting the speed of the components to be progressively increased and decreased
as described in relation to the train of cars. The succession of components are made
to slide above or into each other to maintain a solid surface suitable for transport
of passengers.
[0013] Such a stretchable bandconveyor can be used separately or in combination with the
train of cars.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014]
Figure lA shows a schematic side view of a succession of cars before, within and after
a station.
Figure 1B shows a speed diagram showing the variations of the speed of the cars as
a function of their location.
Figure 2 shows a horizontal view of a station having two trains of cars going in opposite
directions and two corresponding bandconveyors used as loading/unloading platforms.
Figure 3 shows a section of the station of Figure 2.
Figure 4 shows an elevational view of the front and the rear of a car utilizing cables
and winches driven by a set of gear-wheels.
Figure 5A shows a partial view of the bottom of the car shown in Figure 4.
Figure 5B shows a partial section of the car of Figure 5A taken along the line BB'
thereof.
Figure 5C shows a modification of the embodiment of Figures 5A and 5B using a shock
absorbing device.
Figure 6A shows a partial view of the bottom of an embodiment of a stretchable bandconveyor.
Figure 6B shows a sectional view of the bandconveyor of Figure 6A taken along line
AA' thereof.
Figure 7 shows a sectional view of the bandconveyor of Figure 6A taken along line
BB' thereof.
Figure 8A shows a partial view of the bottom of another embodiment of a stretchable
bandconveyor.
Figure 8B shows a sectional view of the bandconveyor of Figure 8A taken along line
AA' thereof.
Figures 9A and 9B illustrate an arrangement of levers and springs for automatically
opening and closing the car doors at a station.
Figure 10 illustrates a measuring apparatus and an electronic servomechanism for controlling
the distance and speed of the train of cars.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Figure lA shows a lateral view of a succession of cars 1 moving from the right to
the left. Linking devices 2, e.g. cables winded around winches, interconnected the
cars to one another.
[0016] Starting from point A on the right, the cables are first completely unwound and the
distance between the cars and the speed of the cars is a maximum. Between points A
and B, the cables are progressively wound and the distance between the cars and therefore
their speed is reduced.
[0017] Between points B and C is a station where the cars are loaded and unloaded. In the
station the cables are completely wound up such that the cars are adjacent each other
and move at the same speed which is synchronized with the speed of a bandconveyor
(not shown) which moves along the cars to enable people to go into or get out of the
cars.
[0018] After point C the cables are progressively unwound again and the distance between
the cars and therefore their speed is progressively increased.
[0019] Figure 1B shows the variation of the speed of the cars as a function of their location.
[0020] Figure 2 shows a horizontal view of two trains of cars 1 going in opposite directions
between two bandconveyors 4 which enable people to go into or come out of the cars
at a station 6. The cars are linked to each other by linking devices 2 such as cables
winded around winches (not shown).
[0021] The cars have sliding doors 8 which are automatically opened and closed at the beginning
and the end of the bandconveyors. The bandconveyors are endless belts equipped with
hand rails 5 and devices 3 which prevent jamming between the station platform and
bandconveyor. Safety rails 7 prevent people from putting their hands between cars
entering into the station when the distance between them is being reduced to a minimum.
[0022] The two rows of cars are separated by a wall 9 to prevent the mixing of the two opposite
air flows in order to reduce air drag.
[0023] Figure 3 shows a section of the station wherein bandconveyors 4 are positioned on
both sides of cars 1. The cars have sliding doors 8, windows 10 and wheels 12 rolling
on rails 14.
[0024] Each car 1 has secured thereto a rack 16 driven by a toothed wheel 18 on the same
shaft 20 as other wheels 22 which are used in driving bandconveyor 4. Shaft 20 is
driven by a motor 24 which controls and synchronizes the speed of the cars 1 and bandconveyor
4 within the station 6.
[0025] Dotted lines 26 illustrate the section of a tunnel between stations, while dotted
line 28 shows the section of the roof of the station.
[0026] Figure 4 is an elevational view of two cars 1 inside a tunnel which is divided in
two parts by a wall 30. The right car is seen from the rear side showing a motor 34
driving wheels 36 located under a bench 38. Motor 34 is used mainly to compensate
for drag due to friction on the cars, since the energy of deceleration is automatically
transmitted with very little loss by the winches and cables to accelerate the cars
at the preceding station. A toothed rack 40, similar to rack 16 in Figure 3, is used
to synchronize the speed of car 1 with the speed of the bandconveyor at the station.
Reinforcements 42 and rails 44 support and guide the cars. A platform 46 can be used
as a walkway for maintenance or for emergency use.
[0027] The left car is seen from its front end showing a winch 50 with a part of a cable
52 linking the car to the next one. Two sets of toothed wheels 54 and 56 linked by
a chain 58 are shown. Set 54 is on the same shaft as the winch 50, and set 56 is on
the same shaft as two other toothed wheels 60 which are driven by a fixed rack 62
placed between the rails before a station. A third shaft supports a toothed wheel
64 driving the second shaft and two other toothed wheels 66 driven by fixed racks
(not shown) and placed between the rails after each station.
[0028] The appropriate combination of the toothed wheels enables the winch to wind and unwind
cable 52 at different speeds. If the fixed racks have in addition a variable path,
it is possible to wind and unwind the winch at any desired speed, while using or reproducing
a part of the kinetic energy of the car, regardless of the speed of the car. This
can provide a relatively constant deceleration or acceleration.
[0029] As an alternate solution, the winch can be winded and unwinded by a motor placed
on each car and started and stopped, for instance, by a reed switch carried by the
car and activated by a magnet positioned by the desired trade position.
[0030] Space 70 is provided which can be used to house devices for automatically opening
and shutting the sliding doors 8.
[0031] Figures 5A and 5B are other partial view of the same car of Figure 4. Figure 5A is
a view of the bottom, and Figure 5B is a partial view of a section of the car taken
along line BB' of Figures 4 and 5A.
[0032] In addition to the elements shown on Figure 4, Figure 5 shows a grooved pulley 72
to guide the cable 52 on the winch 50 and two small toothed wheels 74 guiding the
chain 58 on the different toothed wheels 54 and 56. Small wheels 74 are set in rods
76 of which one end 78 is articulated with the car, and the other end 80 is free to
move and is guided by rails not shown on the figure in order to automatically set
the appropriate transmission ratio between the fixed rack 62 and the winch 50. The
free ends 80 of the rods 76 are linked to the car with a spring 82 which keeps the
chains under tension.
[0033] The chain, rods and toothed wheels are, in fact, the various parts of a simple automatic
gear-box for -automatically coupling the fixed rack 62 with the mobile winch 50. Many
other existing devices can be used for the same purpose.
[0034] The fixed end 84 of the cable 52 is linked to the next car by springs 86 in order
to keep it constantly under tension. These springs also smooth the shock at the beginning
and the end of the deceleration or acceleration and during gear changes.
[0035] The purpose of the different size wheels in the automatic gear box is to wind the
winch at a relatively constant speed in order to have a relatively constant acceleration
and deceleration.
[0036] It may also be desirable to reduce the shock produced by contact of the large wheel
60 with the rack 62. To this end, the shaft of wheel 60 may be free to move in the
direction parallel to the movement of the car and be maintained in a forward biased
position by means of springs 90 as shown in Figure 5C. Additionally, a short rack
62a may be provided in front of rack 62 and biased therefrom by means of a spring
92. Both springs 90 and 92 then help to dissipate the impact shock of wheel 60 with
rack 62 or 62a.
[0037] Yet another alternative is to replace the toothed wheel 60 by a rubber wheel and
the rack 62 by a concrete beam to permit a frictional drive means.
[0038] Figure 6A is a partial view of the bottom of a bandconveyor made of a succession
of alternating components 100 and 102. Figure 6B is a cross-sectional view of the
bandconveyor taken along line AA' of Figure 6A. Each component 102 slides into the
component 100 on its left and is linked to the component 100 on its right by an articulation
103 in order to enable the bandconveyor to be bent. Each element 102 is also linked
to its left element 100 by a threaded rod 104 of which one end is attached to the
component 102, and the other end slides inside a nut 105 linked to the component 100.
The nut 105 is screwed onto or off of the threaded rod 104 by means of gear wheels
106 and 107 driven by a fixed rack 108. The turning of the nut 105 on the threaded
rod 104 decreases or increases the distance between the consecutive components 100
and 102 and makes the corresponding components 102 slide into or out of the component
100.
[0039] The bandconveyor is made of an endless succession of such components 100 and 102
and the speed of these components varies along their course proportionally to the
distance beween them. Fixed racks 108 are positioned in appropriate places along the
path of the bandconveyor to achieve the desired speed of the components and corresponding
distance therebetween.
[0040] Figure 7 is a sectional view of Figure 6B along line BB' thereof. A hand rail 109
is made of telescoping elements which are fixed on the corresponding components 100
and 102'. Car 1 such as described in Figure 3 is also illustrated along with a device
for synchronizing the speed of the car with the speed of the bandconveyor. This synchronizing
device comprises racks 111 placed under and fixed to the cars and bandconveyor components
and gear wheels 112 and 113 located in the stations. Racks 111 are similar to racks
16 of Figure 3 and 40 of Figure 4.
[0041] Figures 8A and 8B are similar to Figures 6A and 6B except that the threaded rods
104, the nuts 105, the gear wheels 106 and 107 and the fixed rack 108 are replaced
by articulated rods 204 with wheels 205 as shown, with wheels 205 guided by fixed
rails 206, having a variable gap. The gap determines the distance beween the consecutive
components 100 and 102.
[0042] The bandconveyor can be made of more than two alternating components, one sliding
into the other, if it is desired to increase the distance between the consecutive
components and therefore their speed by a factor larger than two. As an alternate
solution, the bandconveyor can be made of components sliding above each other.
[0043] It is understood that the embodiments described for controlling the speed and distance
of the train of cars are also applicable for controlling the speed and distance of
the bandconveyor components and vise-versa.
[0044] The cars 1 may also be provided with a device for automatically opening the car doors
when the cars arrive at the station. Such a device is illustrated in Figures 9A and
9B. In Figure 9A, doors 310 are shown in their closed position, whereas in Figure
9B, the doors 310 are open. Cars 311 and 312 are illustrated together with levers
301, 302, 303 and 304 and springs 307, 308 and 309. When the cars 311 and 312 approach
one another, lever 301 is pushed in thereby moving lever 302 around an axis 305. This
in turn causes lever 303 to move lever 304 around its axis 306. The ends of levers
302 and 304 are linked to springs 308 and 309 to stretch springs 308 for opening the
doors (Figure 9B) , and to stretch springs 309 to close the doors (Figure 9A) . Spring
307 biases lever 301 in the extended position (Figure 9A) when the cars are apart.
[0045] Lever 313 may be utilized to lock the doors, and thereby prevent their opening, until
the cars are sufficiently close together to insure speed synchronization with the
bandconveyor. Any number of mechanisms may be employed for this purpose such as a
single lever and lifter arrangement.
[0046] Figure 10 is a schematic diagram of means for controlling the distance and speed
of cars 401 without mechanically interconnecting the cars. The system comprises a
motor 402 contained within each car 401 for powering same. A servomechanism 404 is
also provided which is connected to sense the speed of rotation of the car wheels
403 and compare same with a reference signal from reference source 405 and to provide
an output control signal p to motor 402. Reference source 405 provides a reference
signal Vo when the cars are far apart and away from the station. At a specified point
before a station, reference source 405 provides a signal V
x which gradually reduces to a value V
1 representative of the minimum speed of cars 401 within the station. The output signal
p to motor 402 enables the motor to drive the cars to match the desired speed V
x.
[0047] Elements 406 and 407 are utiilzed for measuring the distance between the cars 401.
Element 406, for example, may be a sonar or radar transceiver which emits signals
which are reflected by mirror 407 and received on the transceiver. Alternately, a
laser beam may be utilized wherein a measure of the beam divergence angle A is proportional
to the distance between cars as shown by elements 408 and 409 in Figure 10. The output
of element 406 is proportional to the instantaneous value of the distance between
adjacent cars. This signal is fed to servomechanism 410 to be compared with a signal
L
x from distance reference source 411. The signal L
x is representative of the theoretical value of the distance between cars. L
x varies from a maximum of L
o (cars far apart- away from station) to a minimum of L
l (cars close- together-inside station).. An error signal, E, from servomechansim 410
serves as an addition correction signal for servomechanism 404.
[0048] Reference sources 405 and 411 may be activated to change the reference signal from
V
o to V
x and L
o to L
x respectively by a mechanical or electrical tripping device positioned adjacent the
car path. The electrical tripping device may, for example, be a reed switch carried
by the cars and activated by a magnet positioned adjacent the desired track position.
1. A transportation device comprising:
a plurality of successive load carrying components, .
means for moving said components along a closed-loop path, and
means for controlling the speed of said components and their distance apart, said
controlling means operable by moving said components along said closed loop path without
rotation of said components traversed to said closed-loop path.
2. A transportation device as recited in claim 1, wherein said controlling means comprises:
a plurality of sets of articulated rods;
each of said components attached to one end of at least one of said sets of articulated
rods and the next said component attached to the opposite end of the same set of articulated
rods;
two rails positioned along said path at a varying distance from one another;
at least some of the articulations of said same set of articulated rods sliding on
said rails, such that the variations of the distance of said rails varies the distance
between the ends of the same set of articulated rods and therefore the distance beween
consecutive components.
3. A transportation device as recited in claim 1, wherein said controlling means comprises:
threaded rods and nuts associated therewith;
means for attaching,at least one of said moving components to one end of at least
one threaded rod and the next component to at least one nut associated therewith;
and
means for rotating said nuts for increasing or decreasing the distance between consecutive
components.
4. A transportation device as recited in claim 3, wherein said means for rotating
said nuts comprises a set of gear wheels fixed to each of the said components, and
a fixed rack positioned along said path, and gear wheels driven by said rack.
5. A transportation device as recited in claim 1, wherein said controlling means comprises
winches and associated cables; means for attaching said components to one end of at
least one said cable and the other end to an associated winch positioned in an adjacent
component, such that the winding or unwinding of the winch reduces or increases the
distance between consecutive components.
6. A transportation device of claim 5, wherein said winches are driven by sets of
gear-wheels positioned in each said component, said gear-wheels driven by toothed
wheels on said components and racks fixed along said path.
7. A transportation device as recited in any one of claims 1-6, further comprising
spring biasing means connected between consecutive components for placing same under
tension at least over a part of said path in order to prevent or reduce the buckling
or folding of said controlling means.
8. A transportation device as recited in any one of claims 1-6, wherein said components
support a surface for conveying loads, said surface expandable or contractable in
length as said component distance increases or decreases thereby forming a bandconveyor.
9. A transportation device as recited in claim 1 further comprising a bandconveyor
positioned at a station along said path for permitting passengers to go from said
bandconveyor to said components and vice-versa; said controlling means varying the
distance between said components to a minimum at said stations, and said device further
comprising means for synchronizing the speed of said bandconveyor with the speed of
said components at said station.
10. A transportation device as recited in claim 9, wherein said bandconveyor comprises:
a plurality of load carrying elements;
means for moving said elements along a closed-loop path; and.
means for controlling the speed of said elements and their distance apart, said controlling
means operable by moving said elements along said closed-loop path without rotation
of said elements traverse to said closed-loop path.
11. A transporation device as recited in claim 10, wherein said elements support a
surface for conveying loads, said surface expandable or contractable in length as
said element distance increases or decreases thereby providing an unbroken surface
for passenger transport.
12. A transportation device as recited in claim 11, wherein said components are cars
having doors thereon and said device further comprises means for automatically opening
said doors when the distance between adjacent cars is at a minimum.
13. A transportation device as recited in claim 12, wherein said opening means comprises
at least one lever extending outside said car for contact with an adjacent car when
said cars move relatively close together and means for coupling said lever with said
doors for opening same.
14. A transportation device as recited in claim 13, further comprising means for biasing
said lever for extending outside said car and means for coupling said lever to said
doors for automatically closing same when said cars move relatively far apart.
15. A transportation device as recited in claim 1, wherein each of said components
have motor means for moving same along said path and said controlling means comprises
means for measuring the distance between adjacent components and means responsive
to said measured distance for controlling said motor means.
16. A transportation device as recited in claim 1, wherein each of said components
have motor means for moving same along said path and said controlling mean comprises
means for measuring the velocity of said component and means responsive to said measured
velocity for controlling said motor means.
17. A transportation device as recited in claim 15, further comprising means for measuring
the velocity of said components and means responsive to said measured velocity and
said measured distance for controlling said motor means whereby the distance and velocity
of each component may be individually controlled without mechanical interconnection
of adjacent components.
18. A transportation device as recited in claim 6, wherein said winches are driven
by sets of gear-wheels positioned in each said component, said gear-wheels driven
by a friction wheel on each component making contact with a rail fixed along said
path.