EP1531200A1

EP1531200A1 - Railway sleeper

Info

Publication number: EP1531200A1
Application number: EP03425734A
Authority: EP
Inventors: Claudio Pellegrini
Original assignee: Imel Srl
Current assignee: Imel Srl
Priority date: 2003-11-14
Filing date: 2003-11-14
Publication date: 2005-05-18
Anticipated expiration: 2023-11-14
Also published as: DE60303114D1; ATE315129T1; EP1531200B1

Abstract

Railway sleeper comprising a main structure (2) having a main direction of development, an upper surface (3) able to be associated to a railway track, and a lower base (4) able to be set down onto a railway ballast. The sleeper (1) further comprises at least a compensating element (5) associated to the main structure (2) in correspondence with the lower base (4), defining with the lower base (4) a lower bearing surface (6) of the sleeper (1), and movable relative to said lower base (4) at least between two operative positions, to each of which corresponds a different conformation of said lower bearing surface (6) to compensate for collapses and settling of said ballast.

Description

The present invention relates to a railway sleeper having an upper surface whereto can be fastened a railway track, and a lower base able to be set down onto the ballast of a railway line.
As is well known, the railway ballast is constituted by broken stones piled on top of one another.
One of the main problems of the railway sleepers in use today is given by the fact that if the ballast is subjected to settling phenomena because of the vibrations produced by transiting trains, or to the collapse of the underlying ground, the railway sleepers can lose, completely or partially, their bearing on the ballast, thus remaining at least partly suspended above gaps created in the ballast itself.
Generally, the settling and collapses mostly involve the sides of the ballast where it degrades, becoming thinner until it joins the underlying ground.
When the collapses involve multiple adjacent sleepers, the very stability of the track is jeopardised, and consequently the safety of the railway line as well.
To avoid this risk, it is therefore necessary periodically to inspect railway lines to verify whether any collapses and/or settling may be present.
When their presence is verified, it is necessary to intervene to restore the full safety of the railway line.
In particular, it is necessary to fill out any depressions that have been created with new crushed stones.
However, to best perform this operation, it is opportune preventively to remove the sleeper, detaching it from the track.
Obviously, this need makes any intervention of this kind on one hand very long and costly, and on the other hand inconvenient for train circulation.
In this situation, the technical task constituting the basis for the present invention is to provide a railway sleeper that overcomes the aforementioned drawbacks.
In particular, the technical task of the present invention is to provide a railway sleeper which allows a rapid restoration of the line in case of collapses and/or settling of the ballast.
The specified technical task and the indicated aims are substantially achieved by a railway sleeper as described in the appended claims.
Further features and the advantages of the invention shall become more readily apparent from the detailed description of some preferred, but not exclusive, embodiments of a railway sleeper illustrated in the accompanying drawings, in which:

Figure 1 shows a partially sectioned lateral schematic view of a railway sleeper in accordance with the present invention;
Figure 2 shows the sleeper of Figure 1 according to the trace II-II;
Figure 3 shows the sleeper of Figure 1 according to the trace III-III;
Figure 4 shows a partially sectioned schematic bottom view of the detail of a variation of the end of the sleeper of Figure 1;
Figure 5 shows a lateral view of the detail of Figure 4;
Figure 6 shows an enlarged detail of the sleeper of Figure 1;
Figure 7 shows a lateral schematic view with some parts removed of a detail of Figure 6; and
Figure 8 shows a variation of the detail of Figure 7.

With reference to the aforementioned figures, the reference number 1 globally designates a railway sleeper according to the present invention.
The railway sleeper comprises a main structure 2 having a main direction of development (perpendicular to the track in use), and in which can be identified, in traditional fashion, an upper surface 3 able to be associated to a railway track by means of appropriate coupling means, not shown herein, and a lower base 4 able to be set down onto a railway ballast.
The illustrated examples illustrate a hollow metallic sleeper 1, but the present invention can advantageously be applied also to non metallic sleepers 1, as well as to non hollow sleepers 1.
According to the present invention, the sleeper 1 further comprises at least a compensating element 5 associated to the main structure 2 in correspondence with the lower base 4.
Said compensating element 5 defines with the lower base 4 the lower bearing surface 6 of the sleeper 1 able to be associated to the railway ballast.
Moreover, the compensating element 5 is movable, relative to the lower base 4, at least between two operative position, to each of which corresponds a different conformation of the lower bearing surface 6. This characteristic assures the capability of compensating for collapses and settling of the ballast, as described below.
Advantageously, the compensating element 5 is movable between a plurality of operative positions, each corresponding to a different level of compensation.
In particular, in the illustrated embodiments, the compensating element 5 is movable with continuity between a first operative position of minimum compensation (Figure 1) and a second operative position of maximum compensation (Figure 6), through a plurality of intermediate positions.
When it is in the first operative position, the compensating element 5 is proximate to the lower base 4 and the sleeper 1 can be associated to intact ballast, similarly to a traditional sleeper 1 (Figure 1).
When instead it is in the second operative position, or in any intermediate position, the compensating element 5 projects inferiorly relative to the lower base 4, as shown in Figure 6.
In the illustrated embodiments, the compensating element 5 comprises at least a planar plate 7 applied under the lower base 4, which extends at least on part of the lower surface of the lower base 4 itself.
In particular, the planar plate 7 is pivotally engaged to the lower base 4 and can rotate between the different operative positions.
The accompanying figures illustrate railway sleepers 1 provided with two compensating elements 5, each comprising a planar plate 7 associated to the lower base 4 of the main structure 2 in correspondence with an end thereof.
Each planar plate 7 develops, along the main direction of development, from its own first end 8, positioned in correspondence with an end 9 of the lower base 4, to its own second end 10, pivotally engaged to an inner portion of the lower base 4, and covers the entire width of the sleeper 1 (Figure 4).
As shown in Figures 2 and 4, in the illustrated embodiments, the fulcrum of the planar plate 7 to the lower base 4 is obtained by means of a central bushing 11 fastened to the planar plate 7, two lateral bushings 12 fastened to the lower base 4, and a through pivot 13 inserted in the bushings 11, 12 and held in position by means of two anti-sliding elements 14 (washers, split pins, or other elements).
Whilst in the embodiment of Figures 4 and 5 the compensating element 5 comprises only the planar plant 7, in the embodiment of Figures 1 through 3 and 6, the compensating element 5 further comprises a lateral wall 15 extending upwards from the planar plate 7 and encompassing, at least in part, the lateral part 16 of the main structure 2.
In particular, said lateral wall 15 encompasses, at least in part, the lateral part of the main structure 2 in any operative position assumed by the compensating element 5, in order to prevent the accidental insertion of one or more broken stones of the ballast between the planar plate 7 and the lower base 4 of the main structure 2.
The railway sleeper 1 further comprises means 17 for actuating the compensating element 5 whose purpose is to actuate the compensating element 5 at least from an operative position to another operative position. In particular, in the illustrated embodiments, the actuating means 17 can cause the planar plate 7 to move away from the lower base 4, and can prevent it from re-approaching it.
The actuating means 17 comprise a screw 18, screwed onto the main structure 2, and having a first upper end 19 which can be operated by an operator, and a second lower end 20 operatively associated to the compensating element 5.
Said lower end 20 acts in abutment against the planar plate 7.
The screw 18 is mounted in a through hole 21, at least partly threaded, obtained in the main structure 2. Figures 7 and 8 show two variations of the through hole 21, distinguishable by the different conformation of the threaded parts 22.
Additionally, the actuating means 17 comprise at least a locking element 22 to enable and inhibit their operation selectively. In particular, in the case of the screw 18, the locking element 23 is constituted by a nut screwed onto the screw 18 in proximity to the first upper end 19.
Depending on requirements, the planar plate 7 can be connected to the lower base 4 in such a way as to be able to rotate freely relative thereto, or in such a way that it can be rotated only winning the resistance opposed by the friction between the bushings, manually or using the actuating means 17.
In other embodiments, not shown herein, the compensating element 5 can assume different shapes, provided they are suitable to assure its operation. For example, it can be constituted by a planar plate 7 able to be translated vertically relative to the lower base 4, and placed in any position relative to the lower base 4 itself.
At the time of its mounting on a well levelled ballast, the sleeper 1 is in the form shown in Figure 1, with the compensating element 5 adjacent to the lower base 4.
When, over time, the ballast collapses or settles, and gaps are created underneath the compensating element 5, if the planar plate 7 can rotate freely, it moves downwards following the collapse of the ballast.
For the worker tasked with conducting line maintenance, therefore, it is sufficient to act on the actuating means 17 or to lock the compensating element 5 in the lowered position, and thus to prop the sleeper 1 with respect to the ballast.
If, on the contrary, the planar plate 7 cannot rotate freely, and remains in the position of Figure 1, the worker has to act on the actuating means 17 both to move the planar plate 7 downwards and to prop the sleeper 1.
The present invention thus achieves important advantages.
The compensating element 5 allows to maintain a solid bearing of the sleeper on the ballast even when gaps are created.
It also allows to obtain a rapid restoration of the line in case of collapses and/or settling of the ballast, with no need to release the sleeper from the track, or to interrupt railway traffic.
It should also be noted that the present invention is relatively easy to construct and the cost connected with the implementation of the invention is not very high.
The invention thus conceived can be subject to numerous modifications and variations, without departing from the scope of the inventive concept that characterises it.
All details can be replaced with technically equivalent elements and in practice all materials employed, as well as the shapes and dimensions of the various components, may be any depending on requirements.

Claims

Railway sleeper comprising a main structure (2) having a main direction of development, an upper surface (3) able to be associated to a railway track, and a lower base (4) able to be set down onto a railway ballast, characterised in that it further comprises at least a compensating element (5) associated to said main structure (2) in correspondence with said lower base (4), defining with said lower base (4) a lower bearing surface (6) of the sleeper (1), and movable relative to said lower base (4) at least between two operative positions, to each of which corresponds a different conformation of said lower bearing surface (6) to compensate for collapses and settling of said ballast.
Railway sleeper as claimed in claim 1 characterised in that said compensating element (5) is movable between a plurality of operative positions.
Railway sleeper as claimed in claim 1 o 2 characterised in that said compensating element (5) is movable with continuity between a first operative position of minimum compensation, in correspondence with which it is proximate to the lower base (4) and the sleeper (1) can be associated to intact ballast, and a second operative position of maximum compensation in correspondence with which it projects inferiorly relative to said lower base (4).
Railway sleeper as claimed in any of the previous claims, characterised in that said compensating element (5) comprises at least a planar plate (7) applied under said lower base (4), and extending at least on part of the lower surface of said lower base (4).
Railway sleeper as claimed in claim 4 characterised in that said planar plate (7) is pivotally engaged to said lower base (4) and it can rotate between said operative positions.
Railway sleeper as claimed in claim 4 or 5 characterised in that said planar plate (7) is associated to said lower base (4) in correspondence with one of its ends.
Railway sleeper as claimed in claim 6 characterised in that said planar plate (7) develops along said main direction of development from a first end (8) located in correspondence with an end (9) of the lower base (4) to a second end (10) pivotally engaged to said lower base (4).
Railway sleeper as claimed in any of the claims 4 through 7 characterised in that said compensating element (5) further comprises a lateral wall (15) extending upwards from said planar plate (7) and encompassing at least in part the lateral part (16) of the main structure (2).
Railway sleeper as claimed in claim 8 characterised in that said lateral wall (15) encompasses at least in part said lateral part (16) in any operative position of the compensating element (5).
Railway sleeper as claimed in any of the previous claims, characterised in that it further comprises means (17) for actuating said compensating element (5) to determine its operative position.
Railway sleeper as claimed in claim 10 characterised in that said actuating means (17) comprise at least a screw (18) screwed onto said main structure (2) and having a first end (19) capable of being operated by an operator, and a second end (20) operatively associated to said compensating element (5) to determine its position relative to said lower base (4).
Railway sleeper as claimed in claim 11 characterised in that said screw (18) is mounted in a through hole (21), threaded at least in part, obtained in said main structure (2).
Railway sleeper as claimed in claim 11 or 12 characterised in that said actuating means (17) further comprise at least a locking element (23) selectively to enable and inhibit its operation.
Railway sleeper as claimed in any of the previous claims, characterised in that it comprises at least two compensating elements (5).
Railway sleeper as claimed in claim 14 characterised in that it comprises two compensating elements (5) each associated to an end of said lower base (4).