Patent Application
20150191876
The invention pertains to a rail arrangement for rail vehicles furnished with flanged wheels.
Rail arrangements for rail vehicles furnished with flanged wheels such as, e.g., streetcars are generally known. Corresponding examples are described in DE 100 11 468 B4, DE 103 02 521 A1, DE 44 11 833 A1, DE 198 01 583 A1 and WO 92/05313 A1. Rail arrangements of this type frequently comprise grooved rails, in which a groove that accommodates the wheel flange is formed in the rail head. Grooved rails are also known, for example, from DE 10 2004 018 914 A1, DE 10 2004 054 794 B3, DE 20 2004 017 132 U1, DE 20 2005 004 107 U1, DE 479 362, DE 499 056, DE 608 258, DE 812 674, DE 564 508 and EP 1 462 570 A1.
However, this groove represents a potential safety hazard for outside traffic participants such as, e.g., cyclists, whose tires can get caught in the groove, wherein this regularly leads to sometimes serious accidents. Pedestrians such as, e.g., women wearing shoes with tapered heels or older persons also encounter problems when crossing roads with such rails. In EP 2 298 991 A1, it is therefore proposed to bond a protective insert that preferably consists of plastic, e.g. foamed polyurethane, into the groove. DE 87 07 445 U1 furthermore proposes to fix a filler profile of rubber or rubber-like material in the groove by means of retaining lips and bonding. However, it has become apparent that such solutions are inadequate for largely precluding the risk of accidents for users of two-wheeled vehicles and pedestrians, particularly for reliably and sufficiently closing the groove for the longer term in the unstressed state despite the constantly recurring loads applied by the flanged wheels. Filler profiles of this type particularly are subject to significant wear and/or do not adequately prevent, e.g., bicycle tires from getting caught in the groove.
It is therefore the objective of the present invention to reduce the risk of accidents associated with grooved rails, particularly for users of two-wheeled vehicles and pedestrians, in a more reliable fashion than previous solutions.
This objective is attained with the subject-matter of claim 1. Advantageous embodiments of the invention are disclosed in the dependent claims.
The invention proposes a rail arrangement for rail vehicles furnished with flanged wheels that comprises
a. a rail with a rail head, a rail web and a rail foot, wherein the rail head comprises a running rail, a guide rail and a flange groove lying in between, and wherein the rail has a rail height HS, the flange groove has a groove depth TR and the groove depth TR amounts to at least 35% of the rail height HS, and
b. a filler profile arranged in the flange groove, wherein the filler profile features a part A that points toward the rail head and a part B that points toward the rail foot, and wherein the part B pointing toward the rail foot can be elastically deformed and the part A pointing toward the rail head has a greater hardness and/or rigidity than the part B pointing toward the rail foot.
The rail arrangement according to the invention solves the above-described problem with a combination of a comparatively deep groove and a filler profile that is arranged in the groove and divided into an elastically deformable part B pointing toward the rail foot and therefore toward the groove base and a comparatively hard or rigid part A pointing toward the rail head and therefore toward the groove opening and the wheel flange. When the wheel flange passes over the filler profile, the thusly generated pressure essentially only causes an elastic deformation of the lower part B of the filler profile whereas the rigid/hard part A of the filler profile essentially is merely displaced in the vertical direction. After the wheel flange has passed over the filler profile, its part A is once again pushed upward by the restoring forces of the elastically deformable part B such that the groove is reliably closed. The elastic properties of the elastically deformable part B naturally are adapted to the typical pressures or weights exerted by wheel flanges of rail vehicles and, for example, two-wheeled vehicles such that a deformation of the elastically deformable part B is in essence only caused by a rail vehicle, but not by a two-wheeled vehicle such as, for example, a bicycle and/or a pedestrian. Accordingly, the hardness/rigidity of the part A is also adapted to the occurring alternating pressures or forces.
The flank of the running rail on the groove side and the flank of the guide rail on the groove side may form an angle that slightly opens upward, i.e. toward the groove opening, such as, e.g., an angle of no more than 1-5°, preferably no more than 1-3° or no more than 1-2°. The flanks may also extend essentially parallel to one another. According to the invention, it is particularly preferred that the flank of the running rail on the groove side and the flank of the guide rail on the groove side form an angle α that opens toward the rail foot. In contrast to conventional groove designs, in which the groove flanks extend apart from one another in the direction of the rail head and form a cup-shaped groove with a comparatively wide opening, the inventive design results in a groove that widens toward the rail foot. In this way, the filler profile is reliably held in the groove and does not have to be bonded, for example, to the groove bottom, although this naturally is still possible. A minimal widening toward the rail foot suffices. The angle alpha amounts to at least 0.5°, preferably 1°, particularly 1-5°, especially 1-3°, e.g. 1°, 1.5°, 2°, 2.5° or 3°.
In order to additionally anchor the filler profile in the groove, the groove side of the running rail and/or the guide rail may be provided with one or more undercuts, recesses, projections or the like, into which the filler profile can engage with corresponding complementary projecting retaining lips or recesses.
In a preferred embodiment of the rail arrangement of the invention, the groove depth TR amounts to at least 40%, preferably at least 45%, particularly at least 50%, of the rail height HS. The rail height HS is the dimension between the bottom of the rail foot and the surface of the running rail or the horizontal tangent on the running rail surface and the groove depth TR is the dimension between the surface of the running rail or the horizontal tangent on the running rail surface and the groove bottom at the height midway between the flanks of the running rail and the guide rail on the groove side.
The part A of the filler profile pointing toward the rail head may consist of the same material as the part B pointing toward the rail foot or of a different material. For example, both parts A and B may consist of elastomeric material. Suitable elastomeric materials are, for example, materials on the basis of styrene-butadiene rubber (SBR), natural rubber (NR), a natural rubber/butyl rubber mixture (NR/BR) or ethylene-propylene-diene rubber (EPDM).
For example, one suitable material for the filler profile is SBR with the properties specified below in Table 1.
The part A of the filler profile pointing toward the rail head may consist of a harder elastomer than the part B pointing toward the rail foot, for example have a greater Shore hardness A. Alternatively or additionally, both parts A and B may consist of an elastomer with the same degree of hardness, but the part A is realized solid whereas the part B is realized with gas-filled, e.g. air-filled, cavities or in a foamlike fashion. Gas-filled microspheres may also be incorporated into the part B. The part A of the filler profile also may at least partially consist of a thermoplastic elastomer, a thermosetting polymer, metal or the like whereas the part B of the filler profile consists of an elastomer. For example, the part A may also feature an additional coating of a thermoplastic elastomer such as, e.g., a polyethylene layer, namely even if it consists of an elastomer. Although it is preferred that the part B consists of an elastomer, it would also be possible, in principle, to realize the part B in the form of a metal spring.
The part A of the filler profile is preferably realized as wear-resistant as possible such that it can withstand the loads applied by the wheel flanges as long as possible without having to be replaced or without being subjected to excessive abrasion that would cause the surface of the filler profile to be recessed deeper within the groove and therefore expose the groove. For this purpose, it would also be possible to incorporate hard particles such as, for example, metal or plastic particles into the part A.
The parts A and B preferably are rigidly connected to one another or realized in one piece. If different elastomeric materials are used, the parts A and B may be integrally connected to one another, for example, by means of coextrusion. It would naturally also be possible to produce the connection by means of bonding, threaded joints, vulcanizing, etc.
The elastically deformable part B of the filler profile pointing toward the rail foot preferably constitutes the majority of the filler profile. For example, the height HFB of the part B of the filler profile amounts to at least 60%, preferably at least 65%, for example 70%, 75%, 80% or 85%, of the overall height HF of the filler profile. The part A preferably has a minimum height, i.e. a minimum layer thickness. It is preferred that the height HFA of the part A of the filler profile pointing toward the rail head amounts to at least 15%, particularly at least 20%, especially 25%, 30% or 45%, of the overall height HF of the filler profile. Examples for suitable percental ratios between the heights of the parts A and B are 60/40, 65/35, 70/30, 75/25, 80/20 and 85/15. For example, the overall height HF of the filler profile, as well as the height ratios between the parts A and B, can be determined based on the height of the wheel flange.
The upper surface, i.e. the surface of the filler profile, over which the wheel flange passes, is preferably realized in a non-skid fashion, for example profiled or roughened. For this purpose, it would also be possible to incorporate hard particles into the surface of the filler profile.
The guide rail may be realized in one piece with the running rail or preferably in the form of a separate component. In the latter instance, the guide rail preferably is suitably connected to the running rail, for example bolted or welded to the rail web. For example, the running rail may consist of a conventional Vignol rail or crane rail, on the rail web of which a guide rail is mounted. The running rail and the guide rail preferably consist of conventional rail materials, typically of metal.
In a particularly preferred embodiment of the rail arrangement of the invention, the sides of the filler profile, i.e. the surfaces that face the flanks of the running rail and the guide rail, particularly those of the part A, are coated with an easily sliding material such as, for example, a smooth plastic material. The sides are preferably coated with polytetrafluoroethylene (PTFE). In this way, the filler profile can slide along the flanks of the running rail and the guide rail more easily when it is pushed down by the wheel flange, as well as during the restoration of the filler profile, such that the filler profile quickly reassumes its original position after the wheel flange has passed over it and the wear due to abrasion is minimized.
The filler profile preferably has a cross section that widens toward the rail foot, i.e. the filler profile widens toward the groove bottom. This makes it possible to achieve an improved seat of the filler profile, particularly in an embodiment, in which the flanks of the running rail and the guide rail on the groove side also extend apart from one another toward the rail foot such that the groove cross section widens toward the rail foot.
The filler profile may be realized in the form of a one-piece, two-piece or multipiece filler profile. In an embodiment, in which a combination of a Vignol rail and a guide rail bolted or welded to the rail web thereof is provided, for example, it may be advantageous to arrange a separate profiled part such as, e.g., a profiled part with a circular cross section in the hollow space formed on the groove side between the rail web, the guide rail and the underside of the running rail head. In this way, the installation of the filler profile is also simplified, for example, if the guide rail is welded to the running rail. In this case, a restiform profiled part can initially be placed into the aforementioned hollow space and the remainder of the filler profile can subsequently be installed. The separate profiled part may consist of the same material as the part A and/or the part B of the filler profile or of a different material or a different material combination.
In the unstressed state, the upper surface of the filler profile preferably lies essentially at the level of the guide rail head. In this way, an essentially plane surface is formed in the groove region such that cyclists and pedestrians can respectively ride or walk across the rails without increased risk of falling.
The invention is described in greater detail below with reference to the attached figures that show preferred embodiments of the invention purely for elucidative purposes. In these figures:
A groove 8 is formed between the running rail 6 and the guide rail 7 and a filler profile 9 consisting of two components 9a, 9b is inserted into said groove. The filler profile 9 consists of an upper part A that points toward the rail head 3 or the groove opening 23 and a lower part B that points toward the rail foot 5 or the groove bottom 24. In this figure, the boundary between the part A and the part B is merely indicated in the form of the broken line 20 for illustrative purposes because both parts are integrally connected to one another. The part A of the filler profile 9a consisting of elastomeric material is realized solid in this case whereas the part B of the filler profile 9a consisting of elastomeric material respectively features gas-filled or air-filled channels 25. The surface 12 of the part A is profiled. The surface 12 of the part A essentially lies at the level 15 of the guide rail head 17. The filler profile 9 engages behind the running rail head 16 with a retaining lip 31.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2012 106 138.6 | Jul 2012 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DE2013/100239 | 7/2/2013 | WO | 00 |
