Patent Application
20110278366
This application is a National Stage completion of PCT/FR2008/001205 filed Aug. 22, 2008, which claims priority from French patent application serial no. 0706047 filed Aug. 29, 2007.
The present invention concerns a prefabricated track module for a self-guided urban transport vehicle traveling on tires and a track formed of a plurality of such prefabricated modules in succession.
In order to eliminate congestion in the center of cities suffering from excessive automobile traffic, current urban policies tend towards the development of public transportation. As a result, large municipalities are using more and more trams, trolley-buses, and metropolitan type vehicles.
Of these vehicles, self-guided tramways on tires are especially advantageous for small or medium size cities. They are capable at least locally of sharing the road with conventional vehicles. They require little infrastructure preparation and can travel on relatively narrow streets. Additionally, they have a much larger capacity than buses, they are fast, and they are not exposed to the problems of city traffic when traveling on their own tracks.
However, they must operate on specially prepared tracks comprising travel surfaces and a guide rail, for example, a central rail. Installing them in an urban center requires a certain amount of work.
To construct them it is generally necessary to close one or more streets for an extended time, as long as it takes to dig a large enough ditch, reroute existing channels, prepare the terrain, pour foundations, build up areas for each element constituting the track, install and connect the various elements, construct the electrical network necessary for supplying current and signals, fill in and grade the areas adjacent to the track, repair the street damaged by the work, manage crossings and signals, etc.
Obviously all this work generates problems with traffic, parking, deliveries, access to businesses, noise, dirt, causing considerable long-term disturbance to residents, trades people, and anyone wishing to use the streets closed due to construction.
Thus, it is in everyone's best interests for the track construction work to be completed in the shortest possible time in order to minimize the difficulties it causes.
The object of the invention is therefore to provide a track with a simplified installation and thus requires much quicker construction time.
To resolve this technical problem, the track according to the invention is formed of prefabricated modules each consisting of a complete track section manufactured and assembled at the factory to be placed on prepared terrain, juxtaposed one after the other, and assembled in place with adjacent modules.
Because of this, the only tasks remaining after preparation of the terrain are to connect the modules to one another and perform the work of filling, finishing, and arranging. Numerous steps, especially those entailing down time such as waiting for concrete to set, take place in the factory and no longer in the urban environment, considerably reducing construction time and the inconvenience it causes.
The track modules according to the invention can be laid directly over an existing street or, for a track that is level with the street, on a simply prepared compacted terrain without requiring any foundation, a further considerable reduction in construction time.
Furthermore, because the prefabricated track modules are made in a factory, this ensures they are of high quality that can replicated; they are not subjected to variations in climate or to technical difficulties related to terrain as with conventional tracks built on location.
Additionally, subsequent maintenance of the track is also greatly simplified. If necessary, a defective module can be simply removed and replaced by another module without encountering problems relative to track integrity as with continuous tracks of the prior art.
In order to achieve these objectives, the invention provides track modules to be juxtaposed one after the other in order to form a track for a self-guided urban transport vehicle on tires.
According to the invention, these modules are prefabricated in a factory and each comprises:
The supporting structure advantageously is either entirely or partially made of reinforced concrete for increased solidity.
The prefabricated modules according to the invention are either rectilinear elements or they may be curved elements in order to form any desired track shape when placed in linear juxtaposition.
The curved track portions may also be made of smaller size elements, generally trapezoid in shape, which, when juxtaposed successively, form a segmented bend called “faceted” to accommodate the requirements of rear wheel deviation.
According to a first embodiment of the invention, the guide rail section may be fixed to the supporting structure at each of the crossbars using immobilizing pieces adapted for this purpose. This fixation is preferably achieved by wedging the rail section between two of these immobilizing elements bolted to the corresponding crossbar.
According to a second embodiment of the invention, the integral concrete supporting structure may comprise a supplementary intermediate sill located between the two lateral sills, preferably in the middle of them, to which the guide rail section is attached.
In this case the guide rail section may be affixed to the intermediate sill using appropriate immobilizing elements.
Alternatively, it may also be embedded in a complementary shaped channel formed in the intermediate sill.
According to a preferred embodiment of the invention, the guide rail is generally shaped like a bone or an “I.” Its two extremities, e.g., a head serving as a contact surface for the vehicle guide roller or rollers and a foot, are preferably symmetrical and joined by a narrow elongated web forming the axis of the I.
This rail preferably does not have a large contact base at the lower portion and it has no significant lateral inertia. Therefore it is relatively flexible and can be made in a straight piece, then easily curved during positioning without any independent supplementary curving process occurring when manufacturing curved modules.
The lower portion of the guide rail section is preferably coated with a lining material forming a partial or complete covering that extends through at least one lateral extension defining a lateral guide groove between the extension and the head of the rail.
The lining material used is compressible, advantageously allowing any objects that might be found in the lateral guide channel to be evacuated, buried, or embedded inside when the guide roller passes.
The connection between these modules can be extremely limited and consists only of an assembly of successive guide rail portions joined with bolts or welded, with the sills simply positioned one against the other.
The guide rail can also be positioned after the supporting structure, allowing perfect curves to be formed in the guide rail and approximate curves to be formed at the level of the sills serving as travel supporting surfaces that are more tolerant.
According to an interesting embodiment, the extremities of the guide rail section and those of the lateral sills may be longitudinally offset. Then the connection between two successive sections of guide rail would not be at the end, but in the center of the sills, for example, with the guide rail then advantageously serving as the connection between modules.
The guide rail section may also be made longer than the sills on the supporting structure, especially on curves, which also allows it to serve as a connection between the sills.
Other characteristics and features of the invention will become apparent when reading the following detailed description, taken with reference to the attached drawings, in which:
Two principal embodiments of a prefabricated track module according to the invention will now be described in detailed fashion with reference to
The various attached drawings show a prefabricated track module 1 according to the invention which when assembled in succession with several of these modules 1 forms a track for a self-guided urban transport vehicle equipped with tires.
This track module 1 comprises an integral supporting structure 2 to which a guide rail section 3 is attached for guiding an urban transport vehicle.
Supporting structure 2 is a unit that is factory made in one piece. It is made of concrete, preferably reinforced, that is, reinforced with a number of metal elements or with any type of appropriate framework made of metal or other material. Supporting structure 2 may be reinforced throughout or only in certain highly stressed areas that need to be more resistant.
Supporting structure 2 comprises two lateral sills 4 that extend on either side of the structure and are generally parallel. They consist of two concrete profile elements with a generally planar upper surface 5 serving as the travel surface for the wheels of the urban transport vehicle and a lower contact surface 6 which is preferably also planar.
Lateral sills 4 are designed to provide a resistant supporting surface adapted for urban transport vehicle traffic. The upper surface 5 of lateral sills 4 is therefore structured for improved adherence of the vehicle tires to the travel surface if there are difficult climatic conditions and may have adhering ribs that are not shown.
Upper surface 5 of lateral sills 4 may also be slightly convex in order to facilitate rainwater runoff.
Lower surface 6 of the lateral sills is a ground-bearing surface for supporting structure 2. Attaching structures may even be formed on the lower surface 6 of the sills for improved anchoring of supporting structure 2 on the ground.
Lateral sills 4 are preferably substantially rectangular in shape. They may also be trapezoidal to improve seating of supporting structure 2 or to form progressively inclined slopes for lateral surfaces 7 when the module is designed for placement above ground level.
Supporting structure 2 also comprises a group of connecting crossbars 8 which join lateral sills 4 and keep them generally parallel.
Advantageously, lower surface 39 of these connecting crossbars 8 also provides a ground-bearing surface for supporting structure 2 as can be seen in
Therefore, the entire integral monobloc concrete piece 2 is a supporting unit, that is, it contacts the ground. The downward force during passage of the urban transport vehicle is distributed on the lateral sills and the group of crossbars, thereby advantageously decreasing pressure and preventing the unit from being driven into the ground.
Thanks to this original concept, supporting structure 2 can be made thin enough to permit level installation with limited excavation work and allow it to be traversed by conventional road vehicles, flexible enough to adhere to a simply compacted terrain, yet remaining rigid enough to support the weight that is advantageously distributed over the entire supporting structure.
Crossbars 8 are, for example, generally rectangular in section and they are preferably spaced at regular intervals, for example, approximately one meter.
In the first embodiment of track module 1 according to the invention shown in
Guide rail 3 as shown has a generally I-shaped section with the extremities, specifically a head 9 and a foot 10, preferably being symmetrical and joined by an elongate narrow web 11 forming the axis of the “I.”
Head 9 is shaped so as to have one or more edges 12 appropriate for use as a travel surface for the vehicle's guide roller or rollers, for example, for the two guide rollers angled in a V on a vehicle guide arm at the head of a series of tramway cars on tires.
Rail 3 as shown is rather high and has no significant contact surface at the lower portion. Therefore it is relatively flexible and adapts easily to curves along the route. Advantageously, it may be made only of straight pieces that can be curved during positioning if necessary to follow the outline of curved modules.
The conformation of guide rail 3 is preferably symmetrical relative to its median longitudinal plane in order to prevent the rail from tilting or twisting when it is being positioned on curves.
However, the shape of the guide rail may differ from the one shown as long as it is adapted for the guiding function that the guide rail must fulfill.
Advantageously the section of guide rail 3 may be coated with a lining material 13 on its lower and median portions, that is, in the variations shown, at the level of its foot 10 and its web 11.
This lining material 13 forms a covering 14 that essentially follows the contours of rail 3, but leaves its upper portion free, specifically head 9, to avoid interfering with the operational zones of guide rail 3 and with access to edges 12.
Preferably covering 14 extends, preferably upward, through a lateral extension15 of lining material 13 in which a lateral groove 16 is formed to eliminate interference with the dynamic grip of the guide rollers.
Depending upon the model of rail 3 and its application, such a lateral extension 15 may be provided on each side of rail 3.
Lining material 13 is any type of suitable synthetic material that is elastic enough to allow any objects located in the lateral guide groove to be evacuated, buried, or embedded when the guide roller passes. It is adapted for resistance to conditions of use and exterior climate conditions and advantageously, it may be electrically insulating.
The covering 14 is preferably added to or formed around the rail during or after manufacturing, for example, by extruding lining material 13 around rail 3.
Covering 14 may be reinforced, particularly at the level of its lateral extensions 15, by an internal metallic or non-metallic frame.
This frame may advantageously take the form of clamps 17, particularly similar to those shown in
The guide rail sections 3 covered with their covering layer 14 are then positioned on supporting structure 2.
For this purpose the first embodiment of track module 1 according to the invention comprises immobilizing pieces 18 for fixing guide rail section 3 to each of the connecting crossbars 8.
Immobilizing pieces 18, as shown, may be essentially angled pieces comprising a generally planar base wall 19 resting on connecting crossbar 8 and a lateral contact wall 20 lying flat against the section of guide rail 3 preferably covered with lining material 13. Lateral contact wall 20 is preferably complementarily shaped with respect to the lateral shape of preferably coated rail section 3.
The immobilizing piece is preferably completed by a reinforcing wall 21 which connects the base wall 19 to lateral contact wall 20 closing one side of the immobilizing piece like a trihedron.
Two of these immobilizing pieces 18 are located at the level of each crossbar 8, one on either side of the guide rail section 3 so as to wedge it laterally between these pieces.
If the two sides of guide rail section 3 are generally symmetrical, the immobilizing pieces 18 used on either side of the rail may advantageously be identical, one simply being turned in the opposite direction of the other one.
Rail section 3 is solidly attached by bolting each immobilizing piece 18 to corresponding crossbar 8 using one or more attaching bolts 22 through base wall 19 of immobilizing piece 18.
In the second embodiment of the invention shown in
In this case crossbars 8 do not directly connect the two lateral sills 4 to one another. Each crossbar 8 is formed of two half-crossbars 24 each joining one lateral sill 4 to intermediate sill 23.
In this embodiment guide rail section 3 is mounted on intermediate sill 23. To do this, guide rail section 3 may be attached to intermediate sill 23, for example, or embedded in a complementary shaped channel 25 formed in this intermediate sill 23.
Channel 25 is open longitudinally at the level of the upper surface of intermediate sill 23 and its depth is adapted so that head 9 of guide rail 3 is essentially level with the upper surface of supporting structure 2, so that the urban transport vehicle is guided satisfactorily.
Prefabricated track modules 1 according to the invention are formed as rectilinear sections or optionally curved sections, of varying lengths, preferably of the order of ten to twelve meters long.
These prefabricated modules 1 are joined to one another, either directly or using an appropriate interface, and form, according to the invention, a track to be traveled by a self-guided urban transport vehicle on tires.
The concrete sills of two successive modules may be connected using complementary self-blocking shaped extremities, or by means of bolted connecting plates 26 such as those shown in
According to another variation not shown the sills of two successive modules may simply be placed in juxtaposition, one in the extension of the other, without being assembled, with the connection between the two modules being limited to guide rail 3.
However, it is preferable for there to be a connection between successive modules to avoid ground shear at this level, as shearing over the long term could lead to module displacement. For this reason, a mechanical anti-shear connection is preferably provided between these sills.
At the extremity the guide rail section 3 preferably comprises a means for connection to the successive guide rail sections.
In the examples shown the two extremities 29 of the guide rail section 3 are left free, that is, with no covering 14, to facilitate connection to the adjacent sections of the guide rail. They also overlap beyond the corresponding extremity of intermediate sill 23 supporting guide rail 3, with the extremities of intermediate sill 23 set back from those of lateral sills 4.
Free extremities 29 on rail 3 are drilled to allow the bolting of two connecting strips 30 located on either side of guide rail web 11 and joining successive guide rail portion 3 by being bolted in the identical way at the level of its adjacent free end 29.
According to another possible embodiment, the successive guide rail portions 3 may be connected by welding.
The first prefabricated track module 1 is first of all placed in its implantation site as shown in
As seen in
To ensure continuity of the track, the two modules are then joined to each other. In the example shown in
The extremities of the two guide rail sections 3 are also connected to each other using two connecting strips 30 as described above.
Factory prefabricated modules 1 may advantageously be transported by truck to their installation site where they are unloaded and positioned using the appropriate lifting apparatus.
Prefabricated track modules 1 may either be immobilized in a trench 32 or positioned on top of a preexisting finished ground surface, for example, a street.
When the track according to the invention is installed in a trench 32 as in the example of
According to this exemplary embodiment, the lower portion of trench 32 is filled to a certain level with an appropriate drainage material 35, for example, untreated gravel. This material is then covered with a bed of sand 36 forming an anchor surface, flat and stable, for placement of prefabricated track modules 1.
After being connected, the track modules are buried up to a certain level in an appropriate fill material 37 to immobilize the supporting structure sufficiently. The free intermediate space between the two lateral sills 4 is also filled using fill material 37.
Advantageously, the trench depth and sill height are selected so that the upper surface 5 of lateral sills 4 serving as the travel surface and head 9 of guide rail 3 are essentially level with the ground level.
The entire installation can be completed on the surface with a decorative or technical covering 38 or landscaping such as grass or some type of planting. Covering 38 is preferably in the form of plates, for example, flagstones, stone slabs, tiled blocks or areas planted with grass, preferably also placed on a bed of sand 36.
The invention obviously is not limited to the preferred embodiments described and shown above, but additionally comprises all the numerous variations and modifications belonging to the same inventive concept that a person skilled in the art might easily imagine.
Thus, for example, two globally planar and horizontal track modules 1 have been described and shown. It is also possible to construct modules which when seen in transverse cross-section would be angled like a “circumflex accent mark” as many streets are to improve rainwater runoff and limit formation of frost.
Another imaginable variation would be the manufacture of prefabricated track modules which comprise in addition to the guide rail an electric supply rail for the urban transport vehicle, for example, a lateral rail.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0706047 | Aug 2007 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FR08/01205 | 8/22/2008 | WO | 00 | 3/16/2010 |
