WO2021186048A1

WO2021186048A1 - Support for railway track rails

Info

Publication number: WO2021186048A1
Application number: PCT/EP2021/057117
Authority: WO
Inventors: Boris MOUSSU
Original assignee: Baret
Priority date: 2020-03-19
Filing date: 2021-03-19
Publication date: 2021-09-23
Also published as: EP4121596C0; RS65206B1; HRP20240126T1; PL4121596T3; CN115443360A; EP4121596A1; AU2021238789B2; CA3171534A1; BR112022018438A2; FR3108344A1; JP2023517967A; PE20221877A1; FR3108344B1; US20230095797A1; MX2022011444A; AU2021238789A1; EP4121596B1; IL296061A; CL2022002497A1; ES2970560T3

Abstract

Disclosed is a support (1) for railway track rails comprising a central core (2) of parallelepiped appearance, formed of at least two strips (3) of juxtaposed materials, of thickness (e), produced from solid wood or wood-based materials, and a protective casing (4) encasing the central core (2), the protective casing (4) being produced in one piece and being formed of a peripheral wall having at least two opposite upper (6) and lower (7) faces 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 the 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 one strip (3) of the central core (2), the strips (3) comprising a plurality of slots formed through their thickness (e) and the slots of each strip being connected to the slots of the adjacent strips by pins made of plastic material filling the slots.

Description

Title of the invention: Railroad track support

The present invention relates to a support for railway rails, of the type including railroad cross member, comprising a central core of parallelepipedal appearance formed of at least two juxtaposed blades made of solid wood or materials based on wood, and a protective envelope encasing 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 to match 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 casing of protection of at least two cells each having a shape complementary to a blade of said central core.

In known manner, the rail supports, also called railroad supports, concerned by the present invention, such as railway sleepers, bridge parts, engineering structures and timber. devices, participate in the construction of railways, in which, once anchored in a ballast, beyond serving as a support for the rails, are intended to ensure a constant distance between them and to distribute the mechanical loads on the ballast when passing a convoy.

[0003] Railway engineers have always been concerned with designing infrastructures that are at the same time reliable, secure and in line with the constraints of budgetary profitability previously defined. In this context, their studies consist in particular in continuously considering new solutions making it possible to improve the mechanical performances of the constituent elements of the railways, and consequently those of the supports of railroad tracks. In this regard, various solutions have been proposed over time to overcome the problems associated with the natural aging of raw wood of which the railway track supports were made at the beginning of the railway era.

[0005] 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 mitigate biological attacks from in particular xylophagous agents, such as fungi and termites. However, although still authorized and implemented to date, creosote is currently under strong contestation because of its adverse effects on the environment and human health. The constantly evolving regulations to which the use of this substance is subject also suggests that it is doomed to phasing out. Moreover, it is clear that the same is true for the new chemical treatments, proposed as a replacement for creosote, which still represent a source of environmental pollution, in particular for aquatic environments, and for which it has been observed that granted authorizations for use may not be renewed.

[0006] Another solution has been to develop railroad track supports made of rot-proof material, such as in particular concrete, steel, plastic or composite materials.

[0007] Concrete rail supports are advantageous in terms of cost, but they prove to be heavy, complex to handle, and fragile due to their rigidity. In addition, they are non-machinable and require an elevation of the ballast, which is synonymous with additional costs. Finally, concrete railroad track supports have a high carbon footprint.

[0008] The steel track supports have a long service life. However, they generate noise when trains pass, which limits the areas where they can be used. Their high electrical conductivity and their high maintenance cost, in particular because of the corrosive risk, are also limiting.

[0009] More recently, plastic or composite material track supports are, like those made of wood, machinable and recyclable, absorb vibrations and therefore noise. Nevertheless, technical constraints remain, such as their dimensional variations, caused by thermal expansion of their constituent material. In addition, the latter may be subject to a creep phenomenon over time, which risks compromising the pull-out resistance of the lag bolts. Also, the cost of plastic or composite material track supports is high, which constitutes an additional brake on their deployment.

Still in order to overcome the problem of the putrescibility of wood, it has also been imagined to design railway rail supports in the form of a wooden core coated with a protective envelope of thermoplastic material having for aim to isolate the wood from any external contact and thus protect it from possible biological attacks.

[0011] The documents WO0158663, and WO2016105209 describe railway sleepers, in which the central core consists of a piece of solid wood. However, this configuration presents a non-negligible risk: in the event of alteration of all or part of the plastic envelope, the whole of the central core gradually breaks down 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.

[0012] 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. However, the solution described has the drawback of requiring the use of potentially harmful and polluting substances, such as formaldehyde.

The object of the present invention is to provide a support for railroad tracks, such as in particular a railroad tie, of the type consisting of a central core made of wood or wood-based materials covered with a protective envelope, having an alternative structure to those already described, making it possible both to overcome all of the drawbacks mentioned above and to improve its longevity in the face of the effects of the weight of the convoys traveling on the railway tracks, while responding the technical, budgetary and environmental criteria currently in force. More precisely, the object of the present invention is to provide a support for machinable railway rails, the service life of which is extended compared to existing rail supports, which is environmentally friendly, and whose structure and constituent materials allow easy recycling.

To this end, the present invention relates to a support for railway rails 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 lights of the adjacent blades by pins of plastic material filling said lights.

[0015] According to an advantageous embodiment of the invention, said protective envelope is made of plastic material.

[0016] According to a particular embodiment, said protective casing further comprises a pair of caps designed to cover the left and right end faces of said central core.

The present invention has also provided that the upper face of said protective casing comprises at least two recesses extending symmetrically on either side of a plane passing through the center of said protective casing and s 'extending perpendicular to its longitudinal axis.

Preferably, the recesses have threaded 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 underside of its peripheral wall. .

[0020] Optionally, the structure forming a set of reliefs and hollows can also extend over at least a portion of the opposite side faces of the peripheral wall of the protective casing, said portion extending from the face. lower part of the peripheral wall towards its upper face.

[0021] Furthermore, the present invention has also provided for the characteristic according to which said blades are each formed from a series of abutting strips. According to a possible variant 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 casing.

[0023] 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 casing also conforms to the present invention.

The advantages resulting from the present invention will become apparent on reading the following description relating to embodiments illustrated in the accompanying drawings in which:

[0025] [Fig.1] corresponds to a perspective view in transparency of an alternative embodiment of a rail support according to the invention, defined here by a railroad tie,

[0026] [Fig.2] is a perspective view of the central web of the railway sleeper of Figure 1,

[0027] [Fig. 3] corresponds to a cross-sectional view of the railway sleeper of Figure 1, taken at an alignment of through-holes formed by the blades of the central web along one of their transverse edges,

[0028] [Fig.4] illustrates a partial side view of the railway sleeper of Figure 1,

[0029] [Fig. 5] is a cross-sectional view of a second alternative embodiment of the rail support according to the invention, and

[0030] [Fig. 6] is a cross-sectional view of a third alternative embodiment of the railway rail support according to the invention.

In the variant embodiment illustrated in Figures 1 to 3, the rail support according to the invention is defined by a railroad cross member 1 comprising on the one hand a central web of parallelepipedal appearance 2, and of on the other hand a protective envelope 4 enveloping said central core 2. The latter is here formed of four blades 3, of thickness e, made of solid wood. However, other configurations can be envisaged, in which the blades 3 are formed each of a series of wooden slats assembled together, for example by their respective lateral edges, or by their respective longitudinal edges or face to face after superposition. In addition, according to still other configurations, in order to optimize the cost of wood material, 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 different types of wood. Thus, it can for example be envisaged to produce a central core 2 comprising three internal beech slats, sandwiched between two external oak slats 3, a material by definition more durable and resistant than beech. In other cases, provision may also be made to insert the central core 2 between two outer blades at least partially made of polymer material, and to coat this assembly with the outer casing 4.

According to the invention, the protective casing 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 “ejection” (registered trademark) process.

More specifically, the protective casing 4 is formed of a peripheral wall preferably having a thickness el of between 5mm and 15mm. It has two opposite faces, upper 6 and lower 7, and two opposite lateral faces 8, 9, designed to match 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 web 2.

Furthermore, the protective casing 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 partitions internal 13 have a thickness e2 of between 3mm and 10mm and delimit, with the peripheral wall of the protective casing 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 completely separated from the other blades 3. Thus, in the event of possible degradation of the peripheral wall of the protective casing 4, leading to an exposure of a wooden strip 3 to external agents, only the latter will gradually decompose, without the risk of the phenomenon spreading to the remaining 3 blades. 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 makes it possible to ensure the solidity of the anchoring of the lag bolts 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 variant embodiment illustrated in Figure 2, such that each lumen 30 of a blade 3 is aligned with a corresponding lumen 30 of the adjacent blade (s) 3. These slots 30 are filled with the plastic or thermoplastic material used to coat the blades 3 of the parallelepipedic core 2 by the protective casing 4, during the manufacture of the railway sleepers 1, for example by an injection process. plastic, extrusion or "ejection" (registered trademark). After hardening of the plastic material, the blades 3 are therefore not only each coated with an individual protective sheath, but also interconnected by pins 31 of plastic material filling said openings 30. This last characteristic makes it possible to prevent the blades 3 from being do not move with respect 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 according to the invention, the slots 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 dO between 5mm and 40mm from the longitudinal edge 18, and at a distance dl between 5mm and 70mm from their transverse edge 19. Furthermore, the slots 30 of the same blade 3 are regularly spaced from one another, 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 casing 4 comprises 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. The two recesses 15 are for example produced by machining and are designed to each accommodate a metal saddle (not shown) intended for fixing a rail. For this purpose, they are provided with threaded holes 16, extending through the blades 3 and the internal partitions 13 of the protective casing 4, intended to accommodate screws for fixing the metal saddle in the recesses 15.

[0039] It should also be noted that in the illustrated embodiment, the bottom 17 of each recess 15 has a specific inclination to allow the reception of a fixing saddle in accordance with the French standards in force. 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 be able 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 associated with the putrescible nature of the wood from which they were originally made. 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 environmentally friendly to manufacture. It also has the advantage of increased longevity over known state-of-the-art rail supports, regardless of any use of potentially toxic and polluting substances.

Furthermore, other variant embodiments than that illustrated in Figures 1 to 3 can also be provided. Thus, a variant of a rail support defining a railway sleeper 10 has been imagined (see fig. 4), in which the blades 3 form a central web 20, extending in parallel. between them and perpendicularly to the upper 6 and lower 7 faces of the protective casing 4. The variant embodiment illustrated in FIG. 5, in which the railway sleeper 100 comprises a central web 200 having two groups of blades 3 s 'extending parallel to each other and inclined relative to the upper 6 and lower 7 faces of the protective casing 4, the two groups being arranged symmetrically in the latter with respect to a plane passing through the center of the casing protection 4 and extending parallel to its longitudinal axis X, is also in accordance with the spirit of the present invention.

It should also be noted that according to the manufacturing process used to manufacture the rail support according to the invention, the protective casing 4 can be completed with a pair of caps (not shown) designed to 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 wall peripheral of the protective casing 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 face lower 7 in the direction of its upper face 6 also on at least a portion of its opposite side faces 8, 9. |

Claims

[Claim 1] Support for a railway rail (1, 10, 100), of the type in particular railway sleeper, comprising a central web (2) of parallelepipedal shape formed of at least two juxtaposed blades (3) , of thickness e, made of solid wood or of 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 upper (6) and lower (7) faces and two opposite lateral faces (8, 9), designed to match 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 said peripheral wall and delimiting with the peripheral wall of the protective casing (4) at least two cells (14) having each a shape complementary to a blade (3) of said central core (2), characterized in that q ue said slats (3) comprise a plurality of openings formed through their thickness e and in that the openings of each blade are connected to the openings of adjacent blades by pins of plastic material filling said openings.

[Claim 2] A railway rail support (1, 10, 100) according to claim 1, characterized in that said protective envelope (4) is made of plastic material.

[Claim 3] A railway rail support (1, 10, 100) according to any one of the preceding claims, characterized in that said protective casing (4) further comprises a pair of caps designed to cover the left (11) and right (12) end faces of said central core (2).

[Claim 4] A railway rail support (1, 10, 100) according to any one of the preceding claims, characterized in that the upper face (6) of said protective casing (4) comprises at least two recesses (15) extending symmetrically on either side of a plane passing through the center of said protective casing (4) and extending perpendicularly to its longitudinal axis (X).

[Claim s] Railroad rail support (1, 10, 100) according to the preceding claim, characterized in that the recesses (15) have threaded holes (16).

[Claim 6] Railroad rail support (1, 10, 100) according to any one of the preceding claims, characterized in that the peripheral wall of said protective casing (4) has a structure forming a set of reliefs and hollows extending over at least a portion of the lower face (7) of its peripheral wall.

[Claim 7] Railroad rail support (1, 10, 100) according to the preceding claim, characterized in that the structure forming a set of reliefs and hollows also extends over at least a portion of the opposite side faces (8, 9) of the peripheral wall of the protective casing (4), said portion extending from the lower face (7) of the peripheral wall, in the direction of its upper face (6).

[Claim 8] A railway rail support (1, 10, 100) according to any one of the preceding claims, characterized in that said blades (3) are each formed of a series of butted strips.

[Claim 9] A railway rail support (1, 10) according to any one of the preceding claims, characterized in that said blades (3) extend parallel to each other and parallel or perpendicular to the upper faces (6) and lower (7) of the peripheral wall of the protective casing (4).

[Claim 10] A railway rail support (100) according to any one of claims 1 to 8, characterized in that said blades (3) extend parallel to each other and inclined relative to the upper faces ( 6) and lower (7) of the peripheral wall of the protective casing (4). ]