EP2561139B1 - Rail attachment system with elastic fastener - Google Patents

Description

The invention relates to a rail fastening system with elastic attachment in which said attachment rests on a heel of said rail and is tensioned by screwing in an anchoring device such as a lag bolt or a stud. The invention relates more particularly to an improvement making it possible to envisage rapid and automatable installation of such fasteners, arranged at regular intervals along the rail.

• une semelle généralement en élastomère ou matière plastique, placée sous le rail,
• une butée latérale en matériau plastique, positionnée sur le côté du rail le long d'un talon de celui-ci,
• une attache élastique généralement en fil d'acier, et
• un dispositif d'ancrage pour appliquer sous contrainte ladite attache élastique sur ledit talon, ledit dispositif d'ancrage traversant la butée latérale et étant fixé au support de voie, typiquement une traverse en béton.

A rail fastening system is generally composed of the following elements:

• a sole generally made of elastomer or plastic material, placed under the rail,
• a lateral abutment in plastic material, positioned on the side of the rail along a heel thereof,
• an elastic tie generally made of steel wire, and
• an anchoring device for applying under stress said elastic attachment to said bead, said anchoring device passing through the lateral abutment and being fixed to the track support, typically a concrete sleeper.

The anchoring device may consist either of a sheath-bolt assembly or of a stud-nut assembly.

More specifically, the rail is wedged transversely, at a given point, by two fastening systems defined above, placed on either side of it and face to face.

The clip can assume two distinct positions, a standby position away from its mounting position on the rail and a mounting position where the elastic clip is mounted bearing against said rail heel.

The standby position is the position in which the system is assembled at the factory before delivery to the site. The attachment is then located towards the rear of the side stop. It is clear that in the rest of the text, rear or front means a location or a position remote or close to the rail, respectively. Thus, when the elastic clip is elastically fixed bearing on the rail heel, it is in the forward position.

The transition from the rear position to the front position of the elastic clip is done by unscrewing the anchoring device a little to release the elastic clip from its initial factory tightening then by moving attaches it perpendicular to the direction of the rail, i.e. forward. The lag screw or nut of the anchor device is then screwed back on.

Such a rail fastening system as defined above is known in its generality, as for example described in the patent DE 391 8091 .

However, such a system is poorly suited to automated laying. Indeed, during the translation movement to pass from the rear position to the front position, the elastic attachment can rotate freely around the axis of the anchoring device and consequently the tightening of the attachment can be done in a incorrect angular position, which can compromise the quality of the fixing and prevents any possibility of automation of the installation.

We also know of WO2009/101457 a rail fixing system having lateral guide blocks and located at the rear of the lateral abutment. The guide blocks therefore act on the outer sides of the central loop of the elastic fastener. Due to the position of these lateral guide blocks, the clip cannot be pushed to the end without the risk of damaging the base which is made of plastic material.

At the end of travel, the fastener, which is practically no longer guided, falls into a U-shaped recess. Poor guidance risks compromising the final positioning of the fastener.

In addition, there is a risk of water stagnation and/or accumulation of foreign bodies (small pebbles) in the footprint.

Water stagnation increases the risk of oxidation of metallic elements. The presence of foreign bodies disturbs the correct repositioning of the rails, that is to say their approximation end to end at the time of welding which occurs some time after the laying of the rails, after the ballast has been added. Automation is therefore difficult. In particular, the foreign bodies in the cavity cannot be evacuated and the central loop which suddenly falls therein can rest on said foreign bodies and assume a bad position that is difficult to detect.

Finally, this known system is not reversible because, when the central loop of the fastener is engaged in the cavity, it cannot be easily and automatically removed from it, at the time of welding. Manual intervention for each fastener is therefore necessary, which slows down assembly.

Moreover, we also know the document FROM 28 10 618 which describes another rail fastening system.

The invention makes it possible to overcome all these drawbacks.

To this end, the invention relates in the first place to a rail fastening system according to claim 1.

More generally, the description describes a rail fastening system intended to be mounted laterally with respect to said rail and fixed to a track support, comprising a lateral abutment, forming a base, comprising a bearing edge intended to come into contact with the edge of a rail base, an elastic clip made of metal wire and an anchoring device cooperating with said elastic clip and capable of being secured to said track support by passing through a hole in said lateral abutment, in order to under stress said elastic attachment when part of the latter rests on a rail heel, characterized in that said elastic attachment comprising a central loop substantially in the shape of a U with which said anchoring device cooperates, said lateral abutment extends in its central part from said bearing edge by a base which comprises in its middle a raised block for guiding said central loop, perpendicular to said bearing edge of the stop l lateral, in that this guide block has a width corresponding to the spacing of said central loop so that said elastic fastener is subject to move only in a direction perpendicular to said support edge while being guided by the side walls of said guide block during its passage from a standby position, away from said rail, to a mounting position where said attachment rests on a aforementioned rail pad.

In the majority of cases the track support on which the rail is installed is made of concrete, typically the track is laid on a set of concrete sleepers, regularly spaced. In this case, said support comprises a flat-bottomed groove capable of receiving a rail. This groove may be of a width somewhat greater than the width of the rail shoe. In this case, advantageously, said lateral abutment comprises a projecting marginal rib oriented downwards and capable of being inserted between an edge of the rail heel and the corresponding edge of the flat-bottomed groove. This facilitates the correct positioning of the lateral stop and consequently a good perpendicularity between the general direction of the guide block and the longitudinal direction of the rail.

Advantageously, said lateral abutment comprises a rear rib protruding from its lower surface and in that said track support comprises a trough or similar hollow extending parallel to the location of the rail, to give a positioning precise of said lateral stop in a direction perpendicular to the direction of the rail. The precise positioning of the stop is advantageous when the system is in the standby position, in the absence of a rail, when it is mounted on the crosspiece, in the factory.

According to one possibility, the anchoring device engages in a hole made in the guide block.

Under these conditions, the upper surface of said guide block can advantageously constitute a clamping limit stop of said anchoring device. This also simplifies the work of the technician since it suffices for him to screw the anchoring device fully until a lower shoulder of the head of the anchoring device rests on the upper face of said guide block, said anchoring head being shaped to also bear against the two parallel branches constituting the U-shaped loop and impose the vertical position of the latter, determining the clamping stress. Optionally, the head of the anchoring device can be equipped with a washer coming more particularly into abutment against the loop of the elastic fastener.

Advantageously, the upper face of the lateral stop also has two ramps, on the rear side, on either side of the guide block so that said elastic fastener can progress more easily towards the heel in a slightly upward path, until entering in contact with him.

Advantageously, the lateral abutment comprises lugs for positioning the elastic attachment in the waiting position, moved back towards the rear.

Finally, to ensure good guidance and facilitate the automation of assembly, it is advantageous for the height of the guide block, measured in relation to the bearing surface of the elastic clip on which the clip is positioned, to be at least equal to the diameter of the metal wire constituting the elastic fastener, preferably greater than this diameter, as will be seen later.

The head of the anchoring device mentioned above is the head of the lag screw in the case where this anchoring device consists of a lag screw and a sheath. In the case where the anchoring device consists of a stud and a nut, said anchoring head consists of the nut itself.

• la figure 1 est une vue d'une attache élastique en fil d'acier utilisable dans le cadre de l'invention ;
• la figure 2 est une vue en perspective d'une butée latérale en matière plastique conforme à l'invention ;
• la figure 3 est une vue d'un tirefond faisant partie du dispositif d'ancrage ;
• la figure 4 représente une rondelle de montage permettant à la fois le blocage du tirefond et la mise sous contrainte de l'attache élastique ;
• la figure 5 est une vue en perspective d'un tronçon de rail monté sur une traverse en béton et immobilisé par deux systèmes d'attache opposés, l'un étant représenté en position d'attente et l'autre étant représenté en position de montage sur un talon de rail ; et
• la figure 6 est une vue selon la coupe VI-VI de la figure5, les rampes de la figure 2 n'étant pas représentées pour faire apparaître le jeu de flexion de l'attache.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of a presently preferred embodiment of a fastening system in accordance with its principle, given solely by way of example and made with reference to the accompanying drawings in which:

• the figure 1 is a view of an elastic steel wire clip that can be used in the context of the invention;
• the figure 2 is a perspective view of a plastic side stop according to the invention;
• the figure 3 is a view of a lag screw forming part of the anchoring device;
• the figure 4 represents a mounting washer allowing both the blocking of the lag screw and the stressing of the elastic fastener;
• the figure 5 is a perspective view of a section of rail mounted on a concrete sleeper and immobilized by two opposing fastening systems, one being shown in the waiting position and the other being shown in the mounting position on a heel rail; and
• the figure 6 is a view according to section VI-VI of the figure5 , the ramps of the figure 2 not being shown to show the bending game of the fastener.

Referring to the drawings, it can be seen that the rail fixing system 11 is intended to be mounted laterally with respect to the rail 13 ( figure 5 ) and is attached to a track support 15 consisting here of a concrete sleeper. This fastening system comprises an elastic fastener 17 made of steel wire ( figure 1 ), a lateral stop 19, forming a base ( figure 2 ), an anchoring device 21 consisting mainly of a lag screw screwed into a sheath (not shown) located in the crosspiece and completed by a washer 23 inserted between the head 25 of the lag screw, on the one hand, and the lateral stop 19 and the elastic clip 17, on the other hand.

The anchoring device 21 is capable of being secured to the track support 15 by passing through a hole 27 of circular section of said lateral abutment. In the mounting position illustrated on the right figure 5 , the tightening of the anchoring device puts the elastic clip 17 under stress when a part of the latter rests on a rail heel 31. ci which rests on the crosspiece; so this skate is essentially consisting of two heels 31 extending on either side of the central part of the rail. Each fastening system described cooperates with such a heel 31.

The lateral stop 19, forming a base, is made of rigid plastic material and comprises a bearing edge 35 intended to come into contact with the edge of a heel 31 of the rail. From this front bearing edge, the lateral abutment is extended in its central part by a base which comprises in its middle a raised block called hereinafter guide block 39. The guide block, of constant width, is perpendicular to said bearing edge. Consequently, when the bearing edge 35 is in contact with the edge of the heel 31, the guide block 39 is perpendicular to the rail 13. Furthermore, as shown in the figure 1 , the clip 17 of steel wire has two lateral branches 41 intended to come into contact with a heel 31 of the rail and a central loop 42, directed rearward, substantially U-shaped with parallel branches 45. As will be seen later, the anchoring device 21 cooperates with this central loop 42 for the stressing of the elastic fastener 17.

On the other hand, according to an important characteristic, the guide block 39 has a width corresponding to the spacing of the two parallel branches 45 of the central loop 42 so that said elastic fastener is subject to move only in a direction perpendicular to said bearing edge 35, that is to say perpendicular to the rail, being guided by the side walls 49 of said guide block during its passage from the standby position (rear) remote from the rail to a mounting position where the two side branches 41 rest on a heel of the aforementioned rail. The hole 27 is formed vertically in the guide block 39. Advantageously, the flat upper surface 51 of said guide block constitutes a stop for limiting the tightening of the anchoring device. In the case where the head of the lag screw is completed by a washer 23 like that of the figure 4 , it is the washer which bears both against the upper face 51 of the guide block and which comes into contact with the two parallel branches 45 of the central loop.

The rear of the guide block 39 is rounded to match the shape of the central loop and to correctly determine the position of the clip when it is moved from the rear to the front.

In addition, the upper face of the lateral stop has two ramps 55a, 55b on either side of the guide block, on the rear side. These two ramps with a rounded bottom receive the two branches 45 of the central loop. In this way, the elastic fastener can progress more easily towards the heel, at the time of assembly, in a slightly upward path until it comes into contact with said heel.

Furthermore, these ramps are "open" at their ends, which prevents the accumulation of gravel or the like.

On the side of the support edge 35, towards the rear and at the ends of the latter, are defined lugs 57 for positioning the elastic fastener in the standby position. These lugs, located towards the rear with respect to the edge 35 are connected to the lateral stop by curved portions matching the branches of the elastic fastener.

In the example shown, the track support 15 is of the type comprising a flat-bottomed groove 60 capable of accommodating a rail 13. Advantageously, this groove is a little wider than the rail shoe 33 and each side stop plastic material, comprises at least one projecting marginal rib 62, oriented downwards, in the extension of the support edge and capable of being inserted between an edge of the rail heel and the corresponding edge of said flat-bottomed groove 60. This facilitates the positioning of the lateral stop 19 along the rail. Furthermore, the track support also advantageously comprises a trough 65 or similar hollow extending parallel to the location of the rail and the lateral abutment comprises a rear rib 67 projecting from its lower surface and capable of engaging in said trough to also contribute to the correct positioning of the lateral stop and consequently of the guide block 39 so that the latter is perpendicular to the direction of the rail. Of course, the concrete sleeper comprises two such chutes 65, on either side of said flat-bottomed groove 60. The rail 13 is placed at the bottom of the groove 60 and bears on said crosspiece by means of a sole 69 made of elastomer with a plastic material.

On the other hand, so that the guiding of the movement of the elastic clip is as precise as possible, it is advantageous for the height h of the guide block to be greater than or equal to the diameter of the metal wire which constitutes the elastic clip. As indicated, it is very preferable that the height h be somewhat greater than the wire diameter of the fastener so that a clearance J ( figure 6 ) remains, after tightening "block" of the lag screw, between the fastener and the lateral stop, so that the branches 45 of the fastener can work in bending and torsion. Thus, the branches 41 can elastically accompany the vertical movements of the rail during the passage of a train.

In the example shown, the washer 23 is placed under the head 25 of the lag bolt and comes into contact, after assembly, both with the upper surface 51 of the guide block and the branches 45 of the central loop of the elastic fastener. . The sole is traditionally made of plastic material, therefore insulating. In addition, the washer 23 can also be made of plastic material, which facilitates the electrical insulation of the rail.

On the figure 5 , the left fixing system is shown in the standby position, while the right fixing system is shown in the assembly position. This assembly clearly follows from the preceding description. We begin by slightly unscrewing the lag screw so as to release the elastic clip 17 which is slightly tightened on the plastic side stop. Once this clip has been released, it suffices to push it in the direction of the rail heel so that it comes into contact with it via its two side branches 41 extending on either side of the central loop 42. Then, the lag screw is again tightened "to block" until the washer 23 comes into contact both with the upper surface of the guide block and the parallel branches of the central loop, which conditions the intensity of the constraint tightening on the heel of the rail.

As shown in figure 6 , when the elastic clip 17 is mounted in the front position and tightened by means of the lag bolt, it bears against the lateral abutment 19 only on a rear surface of the latter and is applied under stress to the heel 31 of the rail, at the front. In this way, the attachment is free to work in torsion when the rail sinks slightly, as the train passes.

Claims (7)

1. Rail fastening system intended to be mounted laterally with respect to said rail (13) and fastened to a track support (15) of the type comprising a flat-bottomed groove (60) capable of accommodating a rail (13), comprising a lateral stop (19), forming a base, comprising a bearing edge (35) intended to come into contact with an edge of a rail foot (33), an elastic fastener (17) made of metal wire and an anchoring device (21, 23) cooperating with said elastic fastener (17) and capable of being secured to said track support (15) by passing through a hole (27) of said lateral stop (19), in order to stress said elastic fastener (17) when part of the latter rests on a rail heel (31),

   wherein said elastic fastener (17) comprises a substantially U-shaped central loop (42) with which said anchoring device (21, 23) cooperates,

   in which said lateral stop (19) is extended in its central part from said bearing edge (35) by a base which comprises in its middle a raised guide block (39) of said central loop (42), perpendicular to said bearing edge (35) of the lateral stop (19),

   wherein said guide block (39) has a width corresponding to the spacing of said central loop (42), so that said elastic fastener (17) is constrained to move only in a direction perpendicular to said bearing edge (35) by being guided by the side walls of said guide block (39) during its passage from a standby position, remote from said rail, to a mounting position in which said elastic fastener (17) rests on said rail heel (31),

   characterised in that said lateral stop (19) comprises a downwardly directed projecting marginal rib (62) adapted to be interposed between the edge of the rail foot (33) and the corresponding edge of said flat-bottomed groove (60) of the track support (15), and

   in that said lateral stop (19) has a rear rib (67) projecting from its lower surface, said track support (15) having a trough (65) or similar recess extending parallel to the rail location, to give an accurate positioning of said lateral stop (19) in a direction perpendicular to the rail direction.
2. Fastening system according to claim 1, characterised in that said anchoring device (21) engages in a hole (27) provided in the guide block (39).
3. Fastening system according to claim 1 or claim 2, characterized in that the upper surface (51) of said guide block (39) constitutes a clamping limitation stop of said anchoring device.
4. Fastening system according to one of the preceding claims, characterised in that the upper side of the lateral stop (19) comprises two ramps (55a, 55b) on the rear side, on either side of said guide block (39).
5. Fastening system according to one of the preceding claims, characterised in that said lateral stop (19) comprises lugs (57) for positioning the elastic fastener (17) in a waiting position, moved backwards.
6. Fastening system according to any of the preceding claims, characterised in that the height (h) of the guide block is at least equal to the diameter of said metal wire, preferably greater than this diameter.
7. Fastening system according to any of the preceding claims, characterised in that a washer (23) is placed between a head (25) of said anchoring device and said central loop (42).

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