Patent Application
20110192908
The present invention concerns a rail expansion device adapted to the guidance of a vehicle wheel on a track and a procedure for its installation according to the pre-characterising clauses of claims 1 and 9.
The application of the present invention concerns the public transport domain such as trains, underground trains, tram-ways, trolley buses, buses, etc. and more particularly that of vehicles guided by tyres and traction vehicles with central guidance for which the path is realised by a single central metal rail between two running tracks of pneumatic tyre wheels. Concerning traction guidance, two angled rollers, rolling directly along either side of a central rail, control for example a vehicle steering system and therefore ensure a defined path of the latter.
It should be noted that the application domain of the invention also concerns one or more railway rails adapted to the guidance of an iron type carrying wheel, instead of tyres, as for standard train vehicles.
Subjected to variations in temperature, notably in elevated sections, a rail designed using steel undergoes an expansion phenomenon, in other words a relative increase in all of its dimensions. The most notable variation being its length.
Other external phenomena can add to this:
1) Either longitudinal mechanical constraints
2) Or movements relative to one section of rail in relation to another. It may be a matter of for example:
In all of the cases cited, the presence of a rail expansion device adapted to the guidance of a vehicle wheel on a track is rendered necessary to limit, or even eliminate a concentration of constraints which are detrimental to the rail. Within an elevated context, it is common to encounter structural play of 150 mm between the different portions of the viaduct for example. The purpose of the expansion device is to correct and compensate for the play or movements relating to the structures and thus enable expansion of the rail further to the constraints (thermal) whilst guaranteeing continuity of the guidance function. This therefore allows for the prevention, in particular, of significant longitudinal constraints in the rail.
Different types of expansion device currently available ensure such correction of the constraints at a single point.
This generally relates to:
On the one hand, none of these systems responds simply to the constraints of the guidance concerned. On the other hand, these devices, as a general rule, can be quite complex to produce and particularly to install given that, considering the same guidance principle, it is necessary for the safe function of the expansion device:
1. on the one hand to respect a maximum gap of 10 mm between two track components in “expanded” mode;
2. on the other hand to ensure mechanical continuity which is symmetrical in relation to the plane of the track in order that the two guide wheels are balanced (in traction) regardless of the shape of the track and the constraints to which it is subjected.
One aim of the present invention is therefore to provide a rail expansion device adapted to the guidance of a vehicle wheel on a track, for which the design and installation must be simplified, whilst guaranteeing safe operation.
Such a device and installation process of said device are provided by the content of claims 1 and 9.
From the expansion device of a rail adapted to the guidance of a vehicle wheel on a track, the invention anticipates that the rail comprises a portion of track composed of a series of components in the form of transverse strips of track having an identical cross-section to that of the rail, being successively and longitudinally positioned on the portion and between which compressible modules are interspersed.
In this way, it is advantageously possible to guarantee mechanical continuity by simple expansions which are successively juxtaposed between the strips, whilst ensuring continuity of wheel guidance/movement since the maximum gaps of 10 mm between the sections/strips are easily obtained by choosing compressible modules of this maximum width.
Due to this juxtaposition of strips, it is also possible to correct significant play in the structure. In other words, by means of a suitable quantity of strips, it is possible to compensate for any foreseeable length of expansion.
The use of such compressible modules which are inserted like elastic/elastomer components or a spring simultaneously enables the expansion phenomenon to be rendered extremely safe and also to better absorb rolling vibrations and therefore to reduce noise from the rail.
The simple architecture of the expansion device is thus also planned for in order to facilitate its installation as well as its maintenance/replacement.
To this end, the invention provides for an installation process for an expansion device such as previously described, according to which:
Only the two external ends of the fittings should thus be secured simply (for example welded) to the remainder of the track for which expansion should be compensated for. No additional adjustments are necessary with regard to the installation, as expansion appropriate to a specific environment is governed by the chosen structure of a series of strips (number of strips, width/flexibility of the slits formed by the compressible modules).
A group of sub-claims also presents advantages of the invention.
Examples of embodiment and application are provided using the figures described below:
The rail susceptible to expansion on the track is thus interrupted and comprises a portion of track formed by a rail fitting (1), a series of components in the form of transverse strips (6) of track having a cross-section identical to that of the rail, being successively and longitudinally positioned on the portion and between which compressible modules are interspersed (7), only represented in
The compressible modules (7) are for example elastomer or spring type in order to provide variable adjacent widths, ideally in rest mode (free from expansion, and therefore of compression of said modules) of approximately 10 mm. This latter order of size is particularly well adapted to the size of the current wheels for standard public transport. A series of at least 15 compressible modules therefore enables the compensation, without any difficulty, of 150 mm of expansion for rails adjacent to the device according to the invention. In practice, it also turns out that 21 strips for a compensation of 150 mm of possible expansion is a sufficiently suitable number.
The transverse strips are for example simple “sections” which are transversely cut in a rail. Said transverse strips comprise at least one opening connecting its two cross-sections and adapted to allow for the positioning of an anti-friction component (5) such as a ring inside the opening in which a shaft (3, 4) is inserted longitudinally connecting the rail which is susceptible to expansion by a slide (through the two rail fittings) to the transverse strips. The rail comprises at its fittings which are substituted and positioned at the end of the portion of track for the expansion device, at least one opening for an anti-friction component (2) in which a shaft (3, 4) is inserted longitudinally connecting the rail to the transverse strips by a slide.
Ideally, the shafts (3, 4) are three in number and are inserted on either side and in the top part of the section of a traction rail (for two traction rollers) and transverse strips.
In all cases, one or more shafts simply enable sufficient rigidity to be obtained for mechanical retention of the strips in order to ensure perfect continuity of the track. Lateral gaps in the strips in relation to the direction of the track are thus, in the event of expansion, highly advantageously eliminated.
The rail susceptible to expansion may be advantageously a railway rail adapted to the guidance of an iron type wheel. In this case, the strips can also be sections of iron type rail.
Alternatively, the rail susceptible to expansion may be a flat track adapted to the guidance of an iron or concrete type pneumatic wheel. Here again, the strips may also be sections of an iron type rail or another material of which the top part ensures continuous flatness with the rail susceptible to expansion.
Finally, the rail may be a traction rail adapted to the guidance of one or two lateral wheel(s) of the traction rail on which two traction rollers are gripped (angled at approximately 45° on one or both sides of the rail). Here again perfect continuity of track is ensured for several wheels/rollers.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FR08/01197 | 8/15/2008 | WO | 00 | 4/27/2011 |
