EP2390412A2

EP2390412A2 - Vibration isolator for continuously supported rails with an elastic shell with a preformed part provided with an integrated strip

Info

Publication number: EP2390412A2
Application number: EP20110168139
Authority: EP
Inventors: Patrick Carels
Original assignee: CDM NV
Current assignee: CDM NV
Priority date: 2010-05-28
Filing date: 2011-05-30
Publication date: 2011-11-30
Also published as: BE1019353A3

Abstract

Vibration isolator with an elastic shell for continuously supported rails which are embedded in a railway bed, whereby the elastic shell comprises at least one preformed part (1,2) which comprises a beam (11,21) which extend on one side (19,29) of the rail in a lateral cavity (7) in the longitudinal direction of the latter, an elastic strip (12,22) which extend under the rail foot (5), an elastic hinge piece (10,20) which connects the beam (11,21) to the strip (12,22) and has a groove (14,24) which extends in the longitudinal direction over practically the full length of the part (1,2) and in which the rail foot (5) extends at least partly, whereby the groove (14,24) is elastically deformed for pressing the elastic strip (12,22) against the rail foot (5).

Description

The invention concerns a vibration isolator with an elastic shell for continuously supported rails which are embedded in a railway bed, whereby the rails have a rail head and a rail foot which are connected by means of a rail body with two sides having each a lateral cavity extending over the entire length of the rail between the rail head and the rail foot.
In an operational condition, the elastic shell extends in the railway bed over practically the full length of the rail, fitting closely to this rail. The rail is hereby almost entirely enveloped, but at least the top side of the rail head is free, such that a railway vehicle can move over it.
Thus, the elastic shell comprises at least one preformed part with a beam and an elastic strip which are connected to one another by means of an elastic hinge piece which is also an integral part of this preformed part. In said operational condition, the beam extends on one side of the rail in a lateral cavity according to its longitudinal direction, whereas the elastic strip extends under the rail foot. Further, this preformed part has a slot extending in the longitudinal direction over practically the entire length of the preformed part, between the beam and the strip. In the operational condition, the rail foot extends at least partly therein.
The elastic shell makes sure that the rail is kept in place in a groove in the railway bed, which is preferably made of concrete. Thus, the rail is clamped in this groove by the elastic shell and preferably no additional fastening means are hereby required for fixing the rails to the railway bed. The elastic shell supports the rail over practically its full length and insulates the rail from the rest of the railway bed.
According to the present state of the art, said elastic shells are formed such that their inside preferably fits almost entirely to the rail. Further, the outside of the shell must fit closely to a groove in the railway bed, such that this shell prevents the rail from making direct contact with the railway bed. These continuous elastic shells are clamped onto the rail, after which they are embedded in a concrete railway bed. Alternatively, these shells are glued to one another and/or to the rails by means of an adhesive. The elastic shell can also be formed by casting the elastic material in a mould round the rail.
During the installation of the railway, the elastic shell must always fit closely to the rail. This is particularly the case, for example, with what is called the "top-down" method whereby coated rails are being suspended above a base, after which they are embedded in a concrete hardening which is cast round the coated rails.
The elastic shell may come off due to its weight, for example, thereby creating an open space between the shell and the rail. Thus, due to its weight, the shell may sag on the bottom side of the rail foot, thereby coming off the rail foot.
In order to fix the shell with the rail in the railway bed, concrete is cast round the coated rails. If the shell does not fit sufficiently onto the rail, there will be a risk of undesired open spaces being formed.
This problem rises in particular when an elastic shell is provided round the rail without any additional fastening means such as glue or clamping means.
The German Gebrauchsmusterschrift DE202008008645L11 describes for example an elastic shell made of two preformed parts having each an elastic beam and a strip. Between this beam and strip, said parts each have a preformed groove in which a far end of the rail foot fits and must extend. With these existing shells, the elastic parts are clamped round the far end of the rail foot. However, open spaces may be created at the free ends of the strips as these strips sag due to their weight.
The invention aims to remedy the aforesaid and other disadvantages by proposing a vibration isolator and a method making it possible to provide a vibration-insulating shell on the rails in a simple manner and to subsequently embed it in concrete without the use of any adhesives being required or without any separate clamping means needing to be provided and/or to be removed. The shell can hereby be easily provided on a site where the railway is being installed.
The invention hereby introduces an elastic shell which avoids that the elastic shell comes off the rail during the installation of a rail in the railway bed. In particular, an elastic shell is proposed avoiding the creation of an open space between the bottom side of the rail foot and an elastic strip of the elastic shell placed underneath it during the installation of a rail.
To this aim, the elastic shell of the vibration isolator according to the invention is designed such that, in the operational condition, the groove of the preformed part of the shell is elastically deformed, whereby the height of the groove is larger than in a non-operational state, when said groove is not deformed, as claimed in the attached claims.
Practically, in the operational condition, when the groove is elastically deformed, the strip will rotate at an angle of 3° to 30°, preferably 5° to 15°, as compared to the non-operational state when the groove is not deformed.
Preferably, the height of the groove is practically constant in a non-elastically deformed condition.
Advantageously, the elastic strip is provided with a recess having an elastic sole which fits onto the rail foot in the operational condition.
In a particularly advantageous manner, the elastic shell comprises at least two preformed parts extending opposite one another in the operational condition, each on one side of the rail, whereby the elastic strips of said two parts have free ends connecting to one another under the rail foot.
The invention also concerns a method for enveloping a rail with a vibration isolator formed of an elastic shell whereby the preformed part is made with a groove whose height, in a non-elastically deformed condition, is smaller in at least a part of the groove than the thickness of a part of the rail foot extending therein, and whereby, when the elastic shell has been provided closely fitting onto the rail, the groove is elastically deformed and the strip is pushed against the bottom side of the rail foot.
According to an advantageous method, the groove is elastically deformed by rotating the elastic strip in relation to the beam at an angle of 3° to 30°, preferably 5° to 15°.
Other particularities and advantages of the invention will become clear from the following description of a practical embodiment of the method and device according to the invention,; this description is given as an example only and does not restrict the scope of the claimed protection in any way; the figures of reference used hereafter refer to the accompanying drawings.

Figure 1 is a schematic representation of a cross section of a vibration isolator with an elastic shell according to a first embodiment of the invention in a non-operational condition, whereby the elastic shell is not elastically deformed.
Figure 2 is a schematic representation of a cross section of a rail with a vibration isolator with an elastic shell in an operational condition according to the first embodiment of the invention, as in figure 1, whereby the rail is enveloped by the elastic shell which is elastically deformed.
Figure 3 is a schematic representation of a cross section of a vibration isolator with an elastic shell according to a second embodiment of the invention in a non-operational condition, whereby the elastic shell is not elastically deformed.
Figure 4 is a schematic representation of a cross section of a rail which is enveloped by an elastic shell according to the second embodiment of the invention, as in figure 3.
Figure 5 is a schematic representation of a cross section of a vibration isolator with an elastic shell according to a third embodiment of the invention in a non-operational condition, whereby the elastic shell is not elastically deformed.
Figure 6 is a schematic representation of a cross section of a rail which is enveloped by an elastic shell according to the third embodiment of the invention, as in figure 5.
Figure 7 is a schematic representation of a cross section of a vibration isolator with an elastic shell according to a fourth embodiment of the invention in a non-operational condition, whereby the elastic shell is not clastically deformed.
Figure 8 is a schematic representation of a cross section of a vibration isolator with an elastic shell according to a fifth embodiment of the invention in a non-operational condition, whereby the elastic shell is not elastically deformed.

In the different drawings, the same reference figures refer to identical or analogous elements.
The invention generally concerns a vibration isolator comprising an elastic shell for a rail embedded in a railway bed, whereby the top side of the rail head corresponds practically to the top side of the railway bed and whereby the rails are continuously supported by the elastic shell. In particular, the invention concerns a continuous elastic shell for rails having a rail head and a rail foot which are connected to one another by means of a rail body having two sides with a lateral cavity on either side extending over the entire length of the rail between the rail head and the rail foot. The elastic shell is designed such that it envelopes the rail practically entirely, thereby leaving the rail head free, such that a railway vehicle can move over the latter. Thus, the rail is completely insulated from the railway bed by the shell, Further, the elastic material of this shell is sufficiently rigid, such that it supports the rail continuously and makes sure that the rail is kept in place in a groove in the railway bed when a railway vehicle moves over this rail. Such elastic materials are already known to the man skilled in the art and they may consist for example of rubber or recycled rubber.
The elastic shell is formed such that its inside preferably fits almost entirely onto the rail. The outside of the elastic shell further fits closely onto the groove in the railway bed. The elastic shell prevents the rail from making direct contact with the railway bed.
The material of the shell is preferably selected such that the shell not only dampens the vibrations but also electrically insulates the rails.
According to the invention, the elastic shell is preformed, such that it can fit almost perfectly onto the rails. Use is hereby made of the elastic qualities of the shell. Thus, the preformed shell is made such that it is provided with for example a groove and a pre-bent or folded strip which are elastically deformed so to envelope the rail at least partly, and whereby this elastic deformation is at least partly maintained when the shell envelopes the rail. Thanks to the elastic deformation, the shell will clamp to or round the rail. This s makes it possible to fix the shell on the rail in a simple manner without having to use any additional clamping means or adhesives. This simplifies the installation of the railway. The elastic shell according to the invention is also advantageous in that it can be built of only two parts.
A practical first embodiment of the vibration isolator according to the invention is schematically represented in figures 1 and 2. This vibration isolator consists of an elastic shell built of a first part 1 and a second part 2. These elastic parts 1 and 2 are preformed and adapted so as to fit closely onto a rail. The shape of the first part 1 is hereby adapted so as to fit onto a side 19 of the rail whereas the shape of the second part 2 is adapted to fit onto the opposite side 29 of the rail.
These parts 1 and 2 can be made according to methods known as such. Use can hereby be made of a mould, for example, in which a mix of rubber granules and polyurethane is made to cure under pressure and at a raised temperature. Thus, the parts 1 and 2 can each by made in one piece. The shape of the mould hereby corresponds to the shape of the part in a non-deformed, non-operational condition.
In an operational condition, the elastic shell of the vibration isolator is fixed to a rail and said rail is practically entirely enveloped by the latter.
The top side 3 of the rail head 4 hereby remains free, such that a railway vehicle can move over the rail head 4. In this way, the elastic shell insulates the rail from the rest of the railway bed.
The rail is preferably countersunk in the railway bed, such that the top side 3 of the rail is practically equal to the top side of the railway bed, which may be the top side of a pavement, for example.
The first part 1 of the shell comprises a first beam 11 whose shape is such that it can practically entirely fill the lateral cavity 7 between the rail foot 5 and the rail head 4 and can fit closely to the rail body 6, the top side 18 of the rail foot 5 and the bottom side 8 of the rail head 4.
In the operational condition, this beam 11 extends in a lateral cavity 7 of said rail according to the longitudinal direction of the rail.
The first part I further comprises a first strip 12 which is an integral part of this first part 1. The strip 12 has a free end 13 and defines a groove 14 between the strip 12 and the beam 11. This groove 14 extends over practically the lull length of the first part 1.
The strip 12 is connected to the beam 11 via a hinge piece 10 0 which is also an integral part of the first part 1. ..
The beam 11, the hinge piece 10 and the strip 12 are preferably made in one piece out of the same elastic material.
In a non-operational condition of the vibration isolator, the first part 1 is not elastically deformed, and the groove 14 has a certain height A. In the non-operational condition, the height A of the groove 14 is preferably practically constant over the entire groove 14. In the operational condition, the groove 14 preferably tits closely onto the rail foot, such that the height A' of the groove corresponds to the thickness C of the rail foot 5. In the operational condition, this height A' of the groove 14 hereby increases as of the hinge point 10 towards the free end 13. As a result, the strip 13 will fit closely, as of the hinge piece 10 to the free end 13, over the full length, onto the bottom side 28 of the rail foot 5.
The second part 2 of the shell, according to this first embodiment, comprises a second beam 21 whose shape is such that it can fill the lateral cavity 7 between the rail foot 5 and the rail head 4 almost entirely and can fit closely onto the rail body 6 on the side 29 of the rail opposite the side 19 of the rail onto which the first beam l of the first part 1 fits.
The rail is covered with the shell of the vibration isolator by providing the parts 1 and 2 opposite one another against the rail in the longitudinal direction of the rail. Preferably, a number of these parts 1 and 2 can be provided adjacent to one another in the longitudinal direction of the rail to thus cover the entire rail with the shell. Thus, the parts 1 and 2 could have a length of 1 to 2 metres.
When providing the first part 1 on the rail, this part 1 is elastically deformed. In particular, the groove 14 is elastically deformed by opening it up, such that it can be provided over the rail foot 5. A far end 17 of the rail foot 5 is pushed in the groove 14 until it fills the groove 14 practically entirely. The first part I will be inclined to go back to the initial non-elastically deformed condition, such that the groove 14 closes again and pushes the strip 12 against the bottom side 28 of the rail foot 5.
As the groove 14 is being opened up, the strip 12 pivots in relation to the beam 11 over an axis in the hinge piece 10 which extends in the longitudinal direction of the part 1. As a result, in the operational condition, the strip rotates at an angle between 5° and 15° in relation to the non-operational condition. Thus, the height A' of the groove 14 at the free far end 13 of the strip 12 is larger in the operational condition than the height A in the non-operational condition.
As the rail foot 5 is situated in the groove 14, the first part 1 with the strip 12 will remain elastically deformed in the operational condition.
In the operational condition, according to this first embodiment, the strip 12 extends under the rail foot 5 over the entire width of this rail foot 5, from a far end 17 of the rail foot 5 up to another far end 27 of the rail foot 5. The far end 13 of the strip 12 hereby fits onto the second part 2 of the shell. Preferably, the second part 2 is provided with a groove 9 and the far end 13 of the strip 12 is provided with a corresponding tooth which fits in the groove 9. Thus, the first part 1 is connected to the second part 2.
A practical second embodiment of the vibration isolator according to the invention is schematically represented in figures 3 and 4. This embodiment mainly differs from the first embodiment in that the second part 2 of the shell also comprises a strip 22 which is an integral part of this second part 1 2.
This second strip 22 has a free far end 23 and defines a second groove 24 between the strip 22 and the beam 21. This groove 24 extends over practically the entire length of the second part 2.
The strip 22 is connected to the beam 21 via a hinge piece 20 which is also an integral part of the second part 2.
Just as in the case of the first part 1, the beam 2L, the hinge piece 20 and the strip 22 are preferably made in one piece out of the same elastic material.
In the operational condition, the first groove 14 of the first part I is placed over a far end 17 of the rail foot 5 whereas the second groove 24 of this second part 2 is placed over the other far end 27 of the rail foot 5.
Also as in the first embodiment, when the rail foot 5 is situated in the grooves 14 and 24, these grooves 14 and 24 are elastically deformed. The height A' o£ the grooves 14 and 24 is hereby equal to the thickness C of the part of the rail foot 5 which is situated in the grooves 14 and 24. Thus, in the operational condition, the height A' of the grooves 14 and 24 will decrease towards the far ends 17 and 27 of the rail foot 5, since the thickness C of the rail foot 5 decreases towards the far ends 17 and 27 of the rail foot 5.
Preferably, the deformation of the grooves 14 and 24 is larger at the far ends 13 and 23 of the strips 12 and 22 than at the far ends 17 and 27 of the rail foot 5. If the grooves 14 and 24 have an almost constant height A in the non-operational condition, the deformation of the grooves 14 and 24 will gradually increase towards the far ends 13 and 23 of the strips 12 and 22 in the operational condition. This is due to the fact that the thickness C of the rail foot 5 decreases towards the far ends 17 and 27. As a result, the strips 12 and 22 are fit tightly onto the bottom side 28 of the rail foot 5 over their whole lengths, such that a good connection with the bottom side 28 is guaranteed.
Further, the far ends 13 and 23 of the strips 12 and 22 of two opposite parts 1 and 2 fit together on the bottom side 28 of the rail foot 5.
These far ends 13 and 23 are preferably provided with an overlap, such that they can fit together tightly. Possibly, they can also be provided with a tongue and groove joint.
A practical third embodiment of the vibration isolator according to the invention is schematically represented in figures 5 and 6. This third embodiment mainly differs from the second embodiment in that a recess 30 for an elastic sole 31 is provided in the strips 12 and 22. This recess 30 extends into the grooves 14 and 24 over the entire length of the shell. Further, the bottom side 28 of the rail foot 5 is hereby provided with an elastic sole 31. The elastic sole 31 is provided between the bottom side 28 of the rail foot 5 and the strips 12 and 22. This sole 3 L fits tightly onto the bottom side 28 of the rail foot 5 and can be selected as a function of the rail load to be provided and the required vibration isolation.
On the outer surfaces 15 and 25 of the elastic shell, the parts 1 and 2 are provided with ribs 32 which make the shell adhere well to a concrete hardening which can be provided round the shell with the rail in order to fix the rail in the railway bed.
Further, a notch 33 is provided at the hinge pieces 10 and 20 on the inside of the grooves 14 and 24. This notch 33 makes it possible to cut the shell there across the hinge pieces 10 and 20 so as to be able, for example, to remove the rail again. It is possible to provide several of these notches 33.
In the operational condition, such a notch 33 is situated at the far ends 17 and 27 of the rail foot 5. This notch 33 can also facilitate the elastic deformation required to introduce the rail foot in the grooves 14 and 24. Thus, this elastic deformation can mainly take place round the notch 33 in the hinge pieces 10 and 20.
A practical fourth embodiment of the vibration isolator according to the invention is schematically represented in figure 7. This fourth embodiment mainly differs from the second embodiment in that, in the operational condition, the beams 11 and 12 of the parts 1 and 2 cannot extend up to the bottom side 8 of the rail head 4. It is possible to provide additional beams 16 and 26 which further fill the lateral cavities 7 up against the rail head 4.
A practical fifth embodiment of the vibration isolator according to the invention is schematically represented in figure 8. This fifth embodiment mainly differs from the second embodiment in that, in the non-operational condition, the strips 12 and 22 are bent with the respective far ends 13 and 23 towards the beams 11 and 21 respectively.
As a result, the grooves 14 and 24 of the hinge pieces 10 and 20 narrow towards the far ends 13 and 23 in the non-operational condition.
In the operational condition, thanks to the elastic deformation of the strips 12 and 22, they will be pushed against the rail foot.
The invention also concerns a method for enveloping a rail with a vibration isolator formed of an elastic shell with at least one preformed part.
This preformed part is hereby formed at once in a mould. To this end, the material in the mould is hardened such that the beam, the hinge piece and the strip can be obtained out of a single piece of elastic material. The shape of the mould hereby corresponds to the shape of the part in a nondeformed, non-operational condition. The provided recess in the groove is preferably somewhat smaller than the part of the rail foot which is placed in the groove in the operational condition. Also, the strip in the mould is preferably tilted somewhat towards the beam in relation to the operational condition.
During the installation ol' the preformed part on the rail, the strip is bent such that the groove is opened. Thus, the preformed part with the groove envelopes the rail foot at least partly, and the groove is elastically deformed, such that the strip tits on the bottom side of the rail foot. The elastic strip is hereby rotated at an angle of 3' to 30°, preferably 5° to 15⁰ degrees. This makes sure that, during the installation of the rail with the elastic shell, the strip always remains pressed tightly against the rail foot.
Finally, the invention also concerns a method for installing and embedding a rail on a railway site and for manufacturing a railway bed with embedded continuously supported rails.
The method makes it possible to position the rails correctly and to then cast the hardening of the railway bed round the rails up to practically the same height as the top side 3 ot the rail head 4.
With a method according to the invention, uncovered rails are suspended via the rail head 4 over a foundation by means of an installation bridge, such that the rail body 6 and the rail foot 5 are easily accessible, not represented in the figures. The rail is hereby put in a required position on the site. It is hereby made sure that the top sides of connecting rails are situated in one and the same plane, or in other words, that successive connecting rails are aligned. Further, it is also made sure that the distance up to an adjacent rail and the height in relation to this adjacent rail is correct, such that together they form the tracks of a railway. Consequently, the rail is also aligned in relation to an adjacent rail.
A first part 1 of the elastic shell is provided on a side 19 of the rail. In an analogous manner, a second part 2 of the elastic shell is provided on an opposite side 29 of the rail. The first part 1 and the second part 2 hereby extend on either side of the rail over preferably almost the full length of this rail. Preferably, the beams 11 and 22 of these first and second parts 1 and 2 fill the lateral cavities 7 entirely and rest on the top side 1 of the rail foot 5.
Further, the grooves 14 and 24 of the parts 1 and 2 are elastically deformed and provided over the far ends 17 and 27 of the rail foot 5. To this end, the elastic strips 12 and 22 are bent or they are rotated over the hinge piece 10 and 20. Preferably, an elastic sole 31 is provided on the bottom side of the rail foot 5 between the elastic strips 12 and 22 and the rail Foot 5 as well. 1.
The elastic strips 12 and 22 hereby press the sole 31 against the rail foot 5. The parts 1 and 2 remain at least partly elastically deformed, such that they fit over the rail foot 5. Preferably, the elastic shell is fixed to the rail in this manner without any additional adhesives or clamps being required.
The far ends 13 and 23 of the strips preferably fit together. To this end, these far ends can be mitred or they may have what is called a tongue and groove joint.
The shell may consist of several analogous units provided in an analogous manner in one line round the rail. Thus, practically the entire length of the rail is covered by the shell.
Finally, material from the railway bed is provided round the rail which is enveloped by the elastic shell. This material may be concrete, for example, forming a groove in which the enveloped rail is fixed. Material from the railway bed is hereby preferably provided until the top side of the railway bed reaches practically the same height as the top side 3 of the rail head 4.
Naturally, the invention is not restricted to the above-described method and the embodiments represented in the accompanying drawings. Thus, the different characteristics of these embodiments can be mutually combined. Thus, the first embodiment can also be provided with an elastic sole fitting on the bottom side of the rail foot.
Thus, the free far ends 13 and 23 of the strips 12 and 22 can be provided with an overlap aud/or a tongue and groove joint. Thus, the groove 14 and/or 24 can be provided with a notch extending in the hinge piece 10 and/or 20.

Claims

Method for covering a rail (3) with a vibration isolator consisting of an elastic shell with preformed parts (1,2) for continuously supported rails which are embedded in a railway bed, whereby these rails have a rail head (4) and a rail foot (5) which are connected by means of a rail body (6) and which have a lateral cavity (7) on either side extending over the full length of the rail between the rail head (4) and the rail foot (5),
whereby the preformed parts (1,2) are provided closely fitting onto the rail over practically the full length of the rail, such that said shell envelopes the rail practically entirely, thereby leaving at least a top side of the rail head (4) free, such that a railway vehicle can move over the latter,
whereby at least said preformed part (1,2) of the elastic shell:
- comprises a beam (11,21) which must fit onto the rail in a lateral cavity (7) thereof,

- comprises an elastic strip (12,22) which must extend on the bottom side (28) of the rail foot (5),

- comprises an elastic hinge piece (1D,20) which connects said beam (11, 21) to said strip (12,22) and

- has a groove (14,24) extending between the beam (11,21) and the strip (12,22) according to the longitudinal direction of said part (1,2) and over practically the full length of' this part (1,2), in which groove (14,24) the rail foot (5) must extend at least partly,
characterised in that
in a non-deformed condition of said preformed part (1,2), said groove (14,24) has a height (A), in at least a part thereof, which is smaller than the thickness (C) of the corresponding part of the rail foot (5) extending in the groove (14,24) when the preformed part (1,2) has been provided closely fitting onto the rail,
whereby the rail (3) is covered by pressing the preformed part (1,2) against the rail until it fits closely onto the latter, whereby said beam (11,21) is placed in the corresponding lateral cavity (7) and whereby the rail foot (5) is pushed in said groove by elastically deforming said part (1,2), whereby the height of the groove (14,24) increases until, in an elastically deformed condition of the part (1,2), the rail foot practically entirely fills said groove, whereby this height (A') corresponds to the thickness (C) of the corresponding part of the rail foot (5) and whereby the strip (12,22) exerts, over at least part of the width thereof, a pressure force on the rail foot.
Method according to claim 1, whereby, when inserting the rail foot (5) in said groove (14,24) when covering the rail with said preformed part (1,2), the elastic strip (12,22) rotates in relation to the beam (11,21) at an angle (a) of 3° to 30°, preferably 5° to 1S°. °.
Method according to any one of claims 1 or 2, whereby an elastic sole (30) is provided between the elastic strip (12,22) and the bottom side (28) of the rail foot (5) extending over the full length of the shell, whereby this sole (30) is tightened against the bottom side (28) of the rail foot (5) by said strip (12,22).
Method according to any one of claims 1 to 3, whereby the rail is enveloped by at least two preformed parts (1,2) provided on either side of the rail opposite one another.
Method according to claim 4, whereby the elastic strips (12,22) of said preformed parts (1,2) overlap under the rail foot (5).
Method according to any one of claims 1 to 5, whereby said preformed part (1,2) is made such that, in an elastically non-deformed condition, the strip (12,22) is bent with the far end (13,23) of the strip (12,22) turned towards the beam (11,21), whereby, when covering the rail, said bent strip (12,22) is elastically deformed., such that it fits onto the bottom side (28) of the rail foot (5).
Method according to any one of claims 1 to 6, whereby
- the rail is suspended via the rail head (4), such that the rail body (6) and the rail foot (5) are freely accessible,
the rail is enveloped by the elastic shell with at least one preformed part (1,2) which is elastically deformed so as to at least partly clasp the rail foot (5),

- and whereby material from the railway bed is provided round the rail enveloped by the elastic shell, after which this material hardens and forms a groove in which the enveloped rail is fixed.
Vibration isolator with an elastic shell for continuously supported rails which are embedded in a railway bed,
whereby the rails have a rail head (4) and a rail foot (5) which are connected by means of a rail body (6) and have a lateral cavity (7) on either side extending over the full length of the rail between the rail head (4) and the rail foot (5),
whereby, in an operational condition, the elastic shell extends in the railway bed over practically the entire length of the rail, tits closely onto the rail and envelopes it practically entirely, thereby leaving at least a top side (3) of the rail head (4) free, such that a railway vehicle can move over the latter, whereby the elastic shell comprises at least one preformed part ( 1,2) which
comprises a beam (11,21) which, in the operational condition, must extend on one side (19,29) of the rail in a lateral cavity (7) in the longitudinal direction of the latter,
comprises an elastic strip (12,22) which must extend under the rail foot (5) in the operational condition,
comprises an elastic hinge piece (10,20) which connects the beam (11,21) to the strip (72,22)
has a groove (14,24) which extends in the longitudinal direction over practically the full length of the part (1,2) and in which the rail foot (5) extends at least partly in the operational condition,
characterised in that
the groove (14,24) of the preformed part (1,2) has a height (A) which, in a non-deformed condition, in at least pars of the groove (14,24), is smaller than a thickness (C) of a part of the rail foot (5) which must extend in the latter when the preformed part (1,2) is provided closely fitting onto the rail,
whereby a difference between this height (A) of the groove (14,24) and this thickness (C) of the rail foot (5) which must extend in the latter increases as of the hinge piece (10,20) towards the far end (12,23) of the strip (12,22),
such that in the operational condition, the groove (14,24) is elastically deformed and the strip (12,22) fits onto the bottom side (28) of the rail foot (5).
Vibration isolator according to claim 8, whereby in the operational condition, the strip (12,24) rotates at an angle (a) of 3° to 30°, preferably 5° to 15°, in relation to the non-deformed condition when the groove (14,24) is not deformed.
Vibration isolator according to any one of claims 8 or 9, whereby in the operational condition, the height (A') of the groove (14) at the far end (12,23) of the strip (12,22) is at least 1 to 2 times larger than the height (A) when said groove (14) is not elastically deformed.
Vibration isolator according to any one of claims 7 to 9, whereby in a non-deformed condition said height (A) of the groove (14) is almost constant.
Vibration isolator according to any one of claims 7 to 10, whereby the elastic strip (12,22) is provided with a recess (30) with an elastic sole (31) in it which fits onto the rail foot (5) in the operational condition.
Vibration isolator according to any one of claims 7 to 1 1 whereby in the operational condition the elastic shell comprises at least two preformed parts (1,2) extending each on one side of the rail opposite one another.
Vibration isolator according to claim 12, whereby in the operational condition, the strips (12,22) of two preformed parts (1,2) extending opposite one another have free far ends (13,23) which fit together.
Rail provided with a vibration isolator according to any one of claims 8 to 14.