EP4121596B1 - Support for railway track rails - Google Patents

Description

The present invention relates to a support for railway rails, in particular of the railway sleeper type, comprising a central core of parallelepiped shape formed of at least two juxtaposed blades made of solid wood or materials based on wood, and a protective envelope cladding said central core, said protective envelope being made in one piece, and being formed of a peripheral wall having at least two opposite upper and lower faces and two opposite lateral faces, designed capable of marry at least the four longitudinal faces of the central core, as well as at least one internal partition extending between two opposite faces or two contiguous faces of said peripheral wall and delimiting with the peripheral wall of the protective envelope at least two cells each having a shape complementary to a blade of said central core.

In a known manner, rail supports, also called railway track supports, concerned by the present invention, such as railway sleepers, bridge parts, engineering structure parts and apparatus wood, participate to the construction of railway tracks, in which once anchored in a ballast, beyond serving as a support for the rails, are intended to ensure a constant distance between the latter and to distribute the mechanical loads on the ballast during passage of a convoy.

Railway engineers have always been constantly concerned with designing infrastructures that are reliable, secure and in line with previously defined budgetary profitability constraints. In this context, their studies consist in particular of continually considering new solutions making it possible to improve the mechanical performance of the constituent elements of the railway tracks, and consequently those of the railway rail supports.

In this regard, different solutions have been proposed over time to overcome the problems linked to the natural aging of the raw wood from which the railway track supports were made at the beginning of the railway era.

To increase their lifespan, it has thus been proposed to impregnate the supports of wooden railway rails, by definition putrescible, with a protective substance such as creosote, intended to compensate for biological attacks originating in particular from agents xylophages, such as fungi and termites. However, although still authorized and implemented to date, creosote is currently strongly contested, due to its harmful effects on the environment and human health. The constant evolution of the regulations to which the use of this substance is subject also suggests that it is doomed to gradual abandonment. Furthermore, it is clear that the same applies to the new chemical treatments, proposed to replace creosote, which still represent a source of environmental pollution, particularly for aquatic environments, and for which it has been observed that the use authorizations granted may not be renewed.

Another solution consisted of developing railway rail supports made of rot-proof material, such as concrete, steel, plastic or composite materials.

Concrete rail supports are advantageous in terms of cost, but they are heavy, complex to handle, and fragile due to their rigidity. In addition, they cannot be machined and require raising the ballast, which means additional costs. Finally, concrete railway track supports have a high carbon footprint.

Steel track supports have a long lifespan. However, they generate noise when trains pass, which limits the areas where they can be used. Their high electrical conductivity and their high maintenance costs, particularly because of the corrosive risk, are also limiting.

Appearing more recently, track supports made of plastic or composite materials are, like those made of wood, machinable and recyclable, absorbing vibrations and therefore noise. However, technical constraints remain, such as their dimensional variations, caused by the thermal expansion of their constituent material. In addition, the latter may be subject to a creep phenomenon over time, which risks compromising the resistance to tearing of the lag screws. Also, the cost of track supports made of plastic or composite materials is high, which constitutes an additional obstacle to their deployment.

Still in order to overcome the problem of the putrescibility of wood, it was further imagined to design railway rail supports in the form of a wooden core covered with a protective envelope in thermoplastic material intended to isolate the wood from any external contact and thus protect it from possible biological attacks.

The documents WO0158663 , And WO2016105209 describe railway sleepers, in which the central core consists of a solid piece of wood. However, this configuration presents a significant risk: in the event of damage to all or part of the plastic envelope, the entire central core gradually decomposes due to its one-piece structure allowing the propagation of the phenomenon of rotting of a zone towards another, which leads to the weakening of the mechanical properties of the sleepers considered.

The document US4286753 teaches the possibility of designing the central core of a railway sleeper from a juxtaposition of solid wood planks or particle boards, linked together so as to form a homogeneous block. The solution described, however, has the disadvantage of requiring the use of potentially harmful and polluting substances, such as formaldehyde.

Other examples of prior art can be found in the documents US2008/179418A1 And CN104532692A .

The aim of the present invention is to provide a support for railway rails, such as in particular a railway sleeper, of the type consisting of a central core made of wood or wood-based materials covered with a protective covering. , presenting an alternative structure to those already described, making it possible both to overcome all of the disadvantages cited above and to improve its longevity in the face of the effects of the weight of convoys traveling on the railway tracks, while meeting the technical criteria , budgetary and environmental measures currently in force. More precisely, the present invention aims to provide a machinable railway rail support, the lifespan of which is extended compared to existing rail supports, which is environmentally friendly, and whose structure and constituent materials allow easy recycling.

For this purpose, the present invention relates to a railway rail support of the type indicated in the preamble, characterized in that said blades comprise a plurality of slots formed through their thickness e and in that the slots of each blade are connected to the lumens of the adjacent blades by pins of plastic material filling said lumens.

In accordance with an advantageous embodiment of the invention, said protective envelope is made of plastic material.

According to a particular embodiment, said protective envelope further comprises a pair of caps designed capable of covering the left and right end faces of said central core.

The present invention also provides that the upper face of said protective envelope comprises at least two recesses extending symmetrically on either side of a plane passing through the center of said protective envelope and extending perpendicularly to its longitudinal axis.

Preferably, the recesses have tapped holes.

According to an advantageous embodiment of the invention, the peripheral wall of said protective envelope may have a structure forming a set of reliefs and hollows extending over at least a portion of the lower face of its peripheral wall.

Optionally, the structure forming a set of reliefs and hollows can also extend over at least one portion of the opposite side faces of the peripheral wall of the protective envelope, said portion extending from the lower face of the peripheral wall towards its upper face.

Furthermore, the present invention has also provided the characteristic according to which said blades are each formed from a series of butted blades.

According to a possible alternative embodiment, said blades extend parallel to each other and parallel or perpendicular to the upper and lower faces of the peripheral wall of the protective envelope.

Alternatively, a structure in which said blades extend parallel to each other and inclined relative to the upper and lower faces of the peripheral wall of the protective envelope is also in accordance with the present invention.

• [Fig.1] correspond à une vue en perspective et en transparence d'une variante de réalisation d'un support de rails selon l'invention, défini ici par une traverse de chemin de fer,
• [Fig.2] est une vue en perspective de l'âme centrale de la traverse de chemin de fer de la figure 1,
• [Fig. 3] correspond à une vue en coupe transversale de la traverse de chemin de fer de la figure 1, effectuée au niveau d'un alignement de lumières traversantes que comportent les lames de l'âme centrale le long d'un de leurs bords transversaux,
• [Fig.4] illustre une vue partielle de côté de la traverse de chemin de fer de la figure 1,
• [Fig. 5] est à une vue en coupe transversale d'une seconde variante de réalisation du support de rails de chemin de fer selon l'invention, et
• [Fig. 6] est une vue en coupe transversale d'une troisième variante de réalisation du support de rails de chemin de fer selon l'invention.

The advantages arising from the present invention will appear on reading the description which follows relating to exemplary embodiments illustrated in the attached drawings in which:

• [ Fig.1 ] corresponds to a perspective and transparency view of a variant embodiment of a rail support according to the invention, defined here by a railway sleeper,
• [ Fig.2 ] is a perspective view of the central core of the railway sleeper of the figure 1 ,
• [ Fig. 3 ] corresponds to a cross-sectional view of the railway sleeper of the figure 1 , carried out at the level of an alignment of through-holes that the blades of the central core have along one of their transverse edges,
• [ Fig.4 ] illustrates a partial side view of the railway tie of the figure 1 ,
• [ Fig. 5 ] is a cross-sectional view of a second alternative embodiment of the railway rail support according to the invention, and
• [ Fig. 6 ] is a cross-sectional view of a third alternative embodiment of the railway rail support according to the invention.

In the alternative embodiment illustrated in figures 1 to 3 , the rail support according to the invention is defined by a railway sleeper 1 comprising on the one hand a central core of parallelepiped shape 2, and on the other hand a protective envelope 4 coating said central core 2. This The latter is here formed of four blades 3, of thickness e, made of solid wood. However, other configurations can be considered, in which the blades 3 are formed each of a series of wooden strips assembled together, for example by their respective lateral edges, or by their respective longitudinal edges or face to face after superposition. Furthermore, according to yet other configurations, in order to optimize the wood material cost, the mechanical properties and the durability of the rail support according to the invention, the different blades 3 of the central core 2 can each be made from of different types of wood. Thus, it can for example be envisaged to produce a central core 2 comprising three internal blades of beech, sandwiched between two external blades 3 of oak, a material by definition more durable and resistant than beech. In other cases, it can still be planned to insert the central core 2 between two external blades at least partially made of polymer material, and to coat this assembly with the external envelope 4.

In accordance with the invention, the protective envelope 4 is advantageously in one piece, and is made of plastic or thermoplastic material, loaded or not with fibers and/or talc, through a process known per se. , such as for example a plastic injection, extrusion or “exjection” process (registered trademark).

More precisely, the protective envelope 4 is formed of a peripheral wall preferably having a thickness e1 of between 5mm and 15mm. It has two opposite upper 6 and lower 7 faces, and two opposite lateral faces 8, 9, designed to fit at least the four longitudinal faces of said central core 2, as well as two left and right end faces 11, 12, designed to cover the left and right end faces of the central core 2.

Furthermore, the protective envelope 4 also comprises three internal partitions 13 parallel to each other, extending between its two opposite lateral faces 8, 9, parallel to its upper 6 and lower faces 7. Preferably, the internal partitions 13 have a thickness e2 of between 3mm and 10mm and delimit, with the peripheral wall of the protective envelope 4, four cells 14 each having a shape complementary to a blade 3 of the central core 2.

In short, thanks to such a configuration of the railway sleeper 1, each wooden strip 3 of which the central core 2 is made is housed in an individual protective sheath, defined each time by a cell 14, and is thus found entirely separated from the other blades 3. Thus, in the event of possible degradation of the peripheral wall of the protective envelope 4, leading to exposure of a wooden blade 3 to external agents, only the latter will decompose gradually, without risk of propagation of the phenomenon to the remaining blades 3. Such a characteristic makes it possible to significantly improve the longevity of the railway sleeper 1. In addition, the alternation of wood and plastic leads to a structure in which the incidence of a possible creep phenomenon of the plastic material is minimized, which ensures the solidity of the anchoring of the lag screws intended to fix the rails on the railway sleeper 1.

It should also be noted that in order to create a permanent connection through the railway sleeper 1, the blades 3 comprise a plurality of slots 30, formed through their thickness e, and, in the alternative embodiment illustrated in figure 2 , in such a way that each light 30 of a blade 3 is aligned with a corresponding light 30 of the adjacent blade(s) 3. These openings 30 are filled with the plastic or thermoplastic material used to coat the blades 3 of the parallelepiped core 2 by the protective envelope 4, during the manufacture of the railway sleepers 1, for example by an injection process plastic, extrusion or “exjection” (registered trademark). After hardening of the plastic material, the blades 3 are therefore not only each coated with an individual protective sheath, but also connected together by pins 31 of plastic material filling said openings 30. This last characteristic makes it possible to prevent the blades 3 from do not move relative to each other within the protective envelope 4, in particular under the effect of the weight of the convoys traveling on the railway tracks.

It should also be noted that in accordance with the invention, the lights 30 are preferably aligned along the longitudinal edge 18 and the transverse edge 19 of each of the blades 3 and so as to be located at a distance d0 of between 5mm and 40 mm from the longitudinal edge 18, and at a distance d1 between 5mm and 70mm from their transverse edge 19. Furthermore, the slots 30 of the same blade 3 are regularly spaced between them, preferably by a distance d2 of between 50mm and 200mm.

On the other hand, with reference to figures 1 And 3 , the upper face 6 of the protective envelope 4 has two recesses 15 extending symmetrically on either side of a plane passing through the center of the protective envelope 4 and extending perpendicular to its longitudinal axis For this purpose, they are provided with tapped holes 16, extending through the blades 3 and the internal partitions 13 of the protective envelope 4, intended to accommodate screws for fixing the metal saddle in the recesses 15.

It should also be noted that in the variant embodiment illustrated, the bottom 17 of each recess 15 has an inclination suitable for accommodating a mounting saddle conforming to current French standards. Of course, the bottom 17 of the recesses 15 could have an inclination different from that illustrated and extend for example horizontally in order to accommodate other types of fixing saddles.

As is clear from the above, the rail support according to the invention, such as a railway sleeper 1, defines an alternative solution to those existing to overcome the problems linked to the putrescible nature of the wood of which they were originally constituted. Indeed, the waterproof protective envelope 4 which covers the material of which the blades 3 are made allows it to be preserved and thus guarantees durability in accordance with regulations. In addition, the rail support according to the invention is simple, economical and ecological to manufacture. It also has the advantage of increased longevity compared to rail supports known from the state of the art, regardless of any use of potentially toxic and polluting substances.

Furthermore, other alternative embodiments, not falling within the scope of the claims, than that illustrated in figures 1 to 3 can also be planned. Thus, a variant of a rail support defining a railway sleeper 10 has been imagined (cf. fig. 5 ), in which the blades 3 form a central core 20, extending parallel between them and perpendicular to the upper 6 and lower 7 faces of the protective envelope 4. The alternative embodiment illustrated in Figure 6 , in which the railway sleeper 100 comprises a central core 200 having two groups of blades 3 extending parallel to each other and inclined relative to the upper 6 and lower 7 faces of the protective envelope 4, both groups being arranged symmetrically in the latter with respect to a plane passing through the center of the protective envelope 4 and extending parallel to its longitudinal axis X, is also presented.

It should also be noted that according to the manufacturing process used to manufacture the railway rail support according to the invention, the protective envelope 4 can be completed with a pair of caps (not illustrated) designed capable of cover the left 11 and right 12 end faces of the central core 2, 20,200.

On the other hand, in order to improve the integration of a rail support according to the invention such as a railway sleeper 1, 10, 100 in the ballast of a railway track, the peripheral wall of the The protective envelope 4 can advantageously be designed in such a way that it has a structure forming a set of reliefs and hollows extending over at least a portion of its lower face 7 or, where appropriate, from its lower face 7 in direction of its upper face 6 also on at least a portion of its opposite side faces 8, 9. j

Claims (10)

1. A support for railway track rails (1, 10, 100), in particular of the railway sleeper type, comprising a central core (2) of parallelepiped appearance, formed of at least two juxtaposed strips (3) of thickness e, made of solid wood or wood-based materials, and a protective casing (4) encasing said central core (2), said protective casing (4) being in one piece and being formed of a peripheral wall having at least two opposite faces, namely one upper face (6) and one lower face (7), and two opposite lateral faces (8, 9), designed to be capable of matching at least the four longitudinal faces of the central core (2), as well as at least one internal partition (13) extending between two opposite faces or two contiguous faces of the peripheral wall and defining, with the peripheral wall of the protective casing (4), at least two cells (14) each having a shape complementary to a strip (3) of the central core (2), characterized in that the strips (3) comprise a plurality of slots (30) formed through their thickness e, and in that the slots of each strip are connected to the slots of the adjacent strips by pins (31) made of plastics material filling said slots.
2. The support for railway track rails (1, 10, 100) according to claim 1, characterized in that said protective casing (4) is made of plastics material.
3. The support for railway track rails (1, 10, 100) according to either one of the preceding claims, characterized in that said protective casing (4) further comprises a pair of caps capable of covering the left end face (11) and the right end face (12) of said central core (2).
4. The support for railway track rails (1, 10, 100) according to any one of the preceding claims, characterized in that the upper face (6) of the protective casing (4) comprises at least two recesses (15) extending symmetrically on either side of a plane passing through the center of the protective casing (4) and extending perpendicularly to its longitudinal axis (X).
5. The support for railway track rails (1, 10, 100) according to the preceding claim, characterized in that the recesses (15) comprise threaded holes (16).
6. The support for railway track rails (1, 10, 100) according to any one of the preceding claims, characterized in that the peripheral wall of the protective casing (4) has a structure forming a set of reliefs and recesses extending over at least a portion of the lower face (7) of its peripheral wall.
7. The support for railway track rails (1, 10, 100) according to the preceding claim, characterized in that the structure forming a set of reliefs and recesses also extends over at least a portion of the opposite lateral faces (8, 9) of the peripheral wall of the protective casing (4), said portion extending from the lower face (7) of the peripheral wall toward its upper face (6).
8. The support for railway track rails (1, 10, 100) according to any one of the preceding claims, characterized in that said strips (3) are each formed of a series of abutting strips.
9. The support for railway track rails (1, 10) according to any one of the preceding claims, characterized in that the strips (3) extend in parallel with one another and in parallel with or perpendicularly to the upper face (6) and lower face (7) of the peripheral wall of the protective casing (4).
10. The support for railway track rails (100) according to any one of claims 1 to 8, characterized in that the strips (3) extend in parallel with one another and at an angle to the upper face (6) and lower face (7) of the peripheral wall of the protective casing (4).

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