Clamping spring for holding down a track body element

Abstract

In a tension spring (1) for holding down a track element, such as a rail foot of a rail, comprising a U-shaped main section having a U-bend (2), a first leg (3) arranged on one side of the U-bend (2) and a second leg (4) arranged on the other side of the U-bend (2), a hook-shaped retaining section (5) bent inwards and supported on a retainer (12) is formed on the first leg (3) and an end section (6) bent towards or away from the retaining section (5) is formed on the second leg (4), wherein the U-bend (2) forms a torsion section so that a holding force can be applied to the track element via the bent end section (6).

Description

[0001] The invention relates to a tension spring for holding down a track body element, such as a rail foot of a rail.

[0002] Furthermore, the invention relates to a rail fastening comprising a tension spring according to the invention and a hold-down device which can be fastened to a base, in particular a sleeper, ribbed plate or angle guide plate, adjacent to a rail.

[0003] The installation of rails on a track bed is usually carried out using a spring element, usually referred to as a tension spring or tension clamp, and a suitable tensioning element or hold-down device to clamp the spring element. This tensioning element or hold-down device is usually a screw, which clamps the spring element against the substructure so that it exerts the required holding forces via the section resting on the rail foot. The clamping can be achieved, for example, by connecting the hold-down device directly to the substructure that supports the rail and the fastening system, or by attaching the hold-down device to an additional component, such as a plate, which is then firmly coupled to the substructure.

[0004] Commonly used tension springs are those with an "e" shape and those with an "ω" shape. An "e"-shaped tension spring is described, for example, in EP 313325 B1. The "ω" shape is described, for example, in DE 3243895 A1.

[0005] Numerous designs of fastening systems with tension springs are known in which the tension spring can be moved relative to the rail foot and the anchoring components not only into a precisely defined final assembly position, but also into a secured pre-assembly position. To achieve the pre-assembly position, the tension spring is mounted in such a way that the section intended to hold down the rail foot does not rest on the rail. In this way, railway sleepers can be provided with tension springs arranged in the pre-assembly position and pre-tensioned in the factory. With a certain amount of effort, the tension springs can be moved laterally into the final assembly position and tensioned on site after the rail has been laid in place, so that the section intended to hold down the rail foot engages over it and presses it down from above.

[0006] A disadvantage of state-of-the-art tension springs is the fact that they are only designed for a single installation direction or type. The installation direction here is the direction in which the tension spring, which is usually already pre-tensioned, is pushed onto the rail foot. The most common tension springs are those designed for transverse installation, i.e. for sliding the tension spring onto the rail at right angles to the longitudinal direction. With longitudinal installation, however, the tension spring is brought into its final assembly position in the longitudinal direction of the rail. Due to the limited space, installation in the longitudinal direction of the rail is advantageous, for example, for fastening rails in the area of ​​switches.Conventional tension springs are adapted to their specified installation direction, particularly with regard to the arrangement of areas of different stiffness, and therefore cannot easily be installed in a different direction, although in most cases a different installation direction is not even possible for geometric reasons.

[0007] Other problems with conventional tension springs include breakage and loosening of the tension springs, resulting in a loss of tension force. This loosening occurs particularly in tension springs that are tensioned with a screw.

[0008] Tension springs often break when they are subjected to excessive loads. Conventional rail fastening systems are rarely equipped with overload protection. The purpose of overload protection is to limit the load acting on the tension spring, which is particularly important when the rail is subject to significant upward and downward movement or tilting relative to the sleeper when passing over it.

[0009] The present invention therefore aims to improve a tension spring and a corresponding fastening system so that the aforementioned disadvantages can be overcome. In particular, a tension spring is to be created that can be held down or tensioned both with a screw and without a screw, and that exhibits high elasticity. The tension spring is to be universally applicable, in particular for holding down rails on open track as well as in the area of ​​switches. Finally, installation and removal are to be facilitated and a secure pre-assembly position is to be enabled.

[0010] To achieve this object, the invention provides, according to a first aspect, a tension spring comprising a U-shaped main section which has a U-bend, a first leg arranged on one side of the U-bend and a second leg arranged on the other side of the U-bend, wherein a hook-shaped holding section which is bent inwards and can be supported on a hold-down device is formed on the first leg and an end section which is bent towards or away from the holding section is formed on the second leg, wherein the U-bend forms a torsion section such that a hold-down force can be applied to the track body element via the bent end section.

[0011] The tension spring, which starts from the basic shape of a "U," has a hook-shaped holding section on the first leg of the U-shape and an end section bent toward or away from the holding section on the other leg of the U-shape, resulting in an asymmetrical shape that is easy to manufacture and allows for installation in both transverse and longitudinal directions. In both longitudinal and transverse installation, the bent end section forms the area of ​​the tension spring through which the hold-down force is applied to the track element or rail foot.

[0012] The inventive design of the tension spring is similar to that of the "e" shape known from the prior art, with the difference that the end section of the "e" shape has an additional bend. This bend can be directed toward or away from the holding section of the tension spring. Preferably, the bend runs toward the holding section of the tension spring. According to a preferred embodiment, the bent end section runs at an angle of 80-100°, preferably approximately 90°, to the second leg. This applies both to the design with an end section bent toward the holding section of the tension spring and to the design with an end section bent away from the holding section. The advantages of the bent end section become apparent in both longitudinal and transverse installation in conjunction with the hold-down device, as explained in more detail below.

[0013] In some embodiments of the invention, the U-shape formed by the U-bend, the first leg, and the second leg also includes configurations in which the first leg is reduced to a minimum, so that the U-bend transitions directly into the holding section. In other embodiments, however, the first leg has a certain length, such as a length substantially corresponding to the second leg, and is, in particular, straight.

[0014] The hook-shaped holding section extending from the first leg of the U-shape serves to be held under tension by a hold-down device when a torsional force is exerted by the bent end section on the torsional section formed by the U-bend of the tension spring. The hook-shaped holding section is bent inward, which means that the hook is bent between the two legs of the U-shape. Preferably, the hook-shaped holding section on the first leg side forms the end of the tension spring, i.e., the free end of the area bent into a hook lies between the two legs of the U-shape.

[0015] In this context, a preferred embodiment provides that the holding section has a free end region connected to the first leg via a hook bend, which is arranged between the first leg and the second leg.

[0016] According to a preferred embodiment of the invention, a hook bend of the holding section has a substantially 180° bend, so that a free end region of the holding section runs substantially parallel to the first leg, at least in sections. The term "substantially 180°" means that the angle is 180°, but can also be between 175° and 185°.

[0017] The hold-down force is provided at least partially by a torsional load on the torsion section formed by the U-bend of the tension spring, resulting in a corresponding resilient deflection of the second leg extending from the U-bend to the bent end section. While the second leg thus forms a deflectable spring arm, the remaining part of the tension spring can be designed as flat as possible to minimize the overall height of the tension spring and the material consumption for the tension spring.

[0018] In this context, a preferred design provides that the first leg and the free end area of ​​the holding section provide a flat support surface in the unloaded state. The flat support surface can serve, for example, as a support for the hold-down device, whereby the flat state refers to the unloaded state of the tension spring, since slight twisting of the holding section may occur when the tension spring is tensioned.

[0019] In the unloaded state, the first leg and the free end region of the holding section can lie with their respective central axes, preferably over their entire extent, in a central plane that preferably runs parallel to the flat support surface. The central axis of the corresponding sections, for example, in the case of a circular cross-section, is understood to be the center line or axis passing through the center of the circle.

[0020] However, it can also be provided that the first leg and the holding section lie in the same plane in the unloaded state, or with their respective center axes in the center plane. This also provides a flat support surface and prevents parts of the first leg and the holding section, including the hook bend, from being bent out of the aforementioned plane.

[0021] The design of the U-bend of the tension spring can also contribute to achieving the flattest possible construction in that the free end region of the holding section, seen in the direction of a longitudinal extension of the free end region, preferably covers the U-bend at least partially, preferably completely.

[0022] However, to ensure sufficient spring travel, the bent end section of the tension spring can be deflected out of the aforementioned plane in the unloaded state. A preferred embodiment in this context provides for the bent end section to be at a normal distance from the center plane or the flat support surface in the unloaded state.

[0023] If the entire holding section, including the hook bend, and the first leg lie in the same plane, this means that the hook bend and the bent end section define the maximum height of the tension spring in the unloaded state, measured perpendicular to the center plane or the flat support surface. This allows for an extremely flat design of the tension spring.

[0024] In particular, the overall height of the tension spring in the unloaded state can correspond to 1.5 to 3 times the diameter of the wire forming the tension spring in the holding section.

[0025] Preferably, an imaginary extension of the bent end section overlaps the hook bend in a plan view. This means that the imaginary extension of the bent end section at least partially overlaps the hook bend in the plan view of the tension spring. For transverse installation of the tension spring, this means that the hook bend lies above the rail foot in the final assembly position and can provide overload protection.

[0026] The tension spring conventionally consists of a spring rod and can therefore be manufactured in one piece from a corresponding starting product. It is manufactured by repeatedly bending an originally straight spring rod. If, as is preferably provided, the hook-shaped holding section, the U-bend and the bent end section are all bent in the same direction, the tension spring can be manufactured in three bending steps. The hook-shaped holding section is bent in the first step, the U-bend in the second step, and the bent end section in the third step. The three bending steps can also be carried out in a single circular process if all three bends occur in the same direction. These bends can all occur in the same plane, or individual sections can be deflected from the common plane at the same time as the bends.

[0027] The cross-section of the tension spring is preferably circular, although other cross-sectional shapes are also conceivable, such as oval, elliptical or the like.

[0028] Due to the relatively simple geometry of the tension spring according to the invention, its mechanical properties can be easily adapted to specific requirements by varying certain geometric parameters while maintaining the basic shape. For example, the length of the second leg of the U-shape, and thus the length of the lever arm acting on the torsion section, determines the stiffness of the tension spring. The tension, clamping force, and stiffness can be controlled by selecting the thickness of the spring rod. The radius of the U-bend also controls the tension and stiffness of the tension spring.

[0029] In order to be able to exert a holding-down force on the rail foot by clamping down the holding section by means of the hold-down device and the resulting torsional load on the torsional section of the tension spring via the bent end section, it is preferably provided that the second leg, in the unloaded state, has a normal distance from the center plane or from the flat support surface that continuously increases in the direction of the bent end section.

[0030] This means in particular that the second leg, in the unloaded state, runs at an acute angle relative to the center plane or to the flat support surface. The acute angle can be between 5° and 20°. Tightening the tension spring leads to a bending of the tension spring in such a way that the acute angle decreases from the unloaded state and is, for example, only 0°-5° in the tightened state. This angle can be reduced to 5-10° in the case of fastening systems with a lower hold-down force. In this tensioned state, a torsional moment acts on the torsional section of the tension spring, in particular about an axis that runs normal to the axis of the first leg and forms a tangent to the U-bend.

[0031] The hold-down force acting on the rail foot from the bent end section and the corresponding counterforce acting from the hold-down device on the holding section of the tension spring form a force couple that also forces the torsion section to bend around an axis perpendicular to the axis of the torsional moment, resulting in a corresponding bending around this axis. Due to this bending, the bent end section of the tension spring has a different angle to the support plane at the rail foot in the unloaded state than in the loaded state.So that the bent end section is aligned substantially horizontally in the loaded state in order to ensure a corresponding support surface on the rail foot, a preferred embodiment of the invention provides that the bent end section has a support surface for resting on the track body element, which in the unloaded state runs upwards at an acute angle relative to the center plane or the flat support surface. The angle between the bent end section and the said plane can preferably be 2°-8°, in particular 5°-7°. The angle decreases under load due to the said bending moment and is preferably 0°-1° in the loaded state.

[0032] When, in the context of the invention, reference is made to an angle between two sections of the tension spring or to a plane in which the sections lie, this refers to the center line of the corresponding sections, ie in the case of a circular cross-section to the center line or axis passing through the center of the circle.

[0033] The tension spring according to the invention is designed to be usable with various types of hold-down devices.

[0034] In a first installation variant, the holding section of the tension spring can be inserted transversely to the longitudinal direction of the rail into a tunnel-shaped recess of the hold-down device towards the rail, so that the hook bend preferably overlaps the rail foot in a final assembly position of the tension spring.

[0035] In a second installation variant, the holding section of the tension spring can be inserted parallel to the longitudinal direction of the rail into a tunnel-shaped recess of the hold-down device, so that the second leg preferably overlaps the rail foot.

[0036] From a structural point of view, the first and the second installation variant can preferably be realized in that a gap is arranged between the bent end section and the free end region of the holding section in a longitudinal extension of the free end region and in a plan view, ie in a normal projection onto the center plane or the flat support surface, on the side of the free end region facing the second leg.

[0037] In a further installation variant, a free space can be provided between the first leg and the free end region of the holding section, through which space a screw shaft of a fastening screw forming the hold-down device can pass and in which space the fastening screw can be displaced in the longitudinal direction of the first leg, wherein the screw shaft of the fastening screw has a diameter that is greater than the diameter of a wire forming the tension spring in the holding section, and wherein the inner radius of the hook bend is preferably greater than or equal to the radius of the screw shaft. This displaceability makes it possible to displace the tension spring, when held down by the fastening screw, from a pre-assembly position to a final assembly position and back. If the inner radius of the hook bend is greater than or equal to the radius of the screw shaft, a maximum displacement path is provided.

[0038] Overall, the invention provides a compact, flat, and flexibly usable tension spring that can also be manufactured cost-effectively due to its low material requirements. Preferably, the tension spring, viewed from above, in particular in a normal projection onto the center plane or the flat support surface, lies within a minimal surrounding rectangle with an aspect ratio of 1:1.5-1:1, preferably 1:1.1-1:1.

[0039] According to a further preferred embodiment, the diameter of the wire forming the tension spring is at least 1 / 7, preferably at least 1 / 6, of the shorter side of a rectangle minimally surrounding the tension spring in a plan view.

[0040] In particular, the bent end section lies within a square corner region of a rectangle minimally surrounding the tension spring in a plan view, which is at most 1 / 9 of the area of ​​the surrounding rectangle.

[0041] According to a second aspect, the invention relates to a rail fastening comprising a tension spring according to the first aspect of the invention and a hold-down device which can be fastened to a base, in particular a sleeper, ribbed plate or angle guide plate, adjacent to a rail, on which hold-down device the holding section is supported in the mounted state of the tension spring in such a way that the bent end section can be arranged to resiliently hold down a track body element, in particular a rail foot of the rail.

[0042] It is preferably provided that the hold-down device, when the tension spring is mounted, not only engages over the free end area of ​​the holding section, but also at least partially over the first leg.

[0043] As already explained in connection with the first aspect of the invention, the tension spring can be tensioned down without a screw or with the aid of a screw. To implement the screwless alternative, a preferred embodiment provides that the hold-down device has or forms a tunnel-shaped recess into which the holding portion of the tension spring can be at least partially inserted.

[0044] Depending on whether the tension spring is to be installed transversely to the longitudinal direction of the rail or in the longitudinal direction of the rail, the holding section of the tension spring can be inserted transversely to the longitudinal direction of the rail into the tunnel-shaped recess towards the rail or inserted parallel to the longitudinal direction of the rail.

[0045] In a design with a tension spring that can be inserted transversely to the longitudinal direction of the rail, the tunnel-shaped recess is preferably open on the side facing the track body element, in particular the rail base, and the hook bend protrudes from the tunnel-shaped recess in the finally assembled state of the tension spring and engages over the track body element, in particular the rail base. In this way, the hook bend, in its state projecting over the track body element, forms an overload protection device. For this purpose, the hook bend is arranged such that a vertical distance exists between the track body element to be held down, in particular the rail base, and the hook bend of the tension spring. Upward movements of the track body element that lie within the vertical distance are resiliently absorbed by the bent end section of the tension spring.However, if excessive upward movement occurs, the track element to be held down will hit the hook bend and will thus be prevented from rising further without overloading the tension spring within its permissible spring travel.

[0046] In the variant with a tension spring that can be inserted transversely to the longitudinal direction of the rail, a pre-assembly position of the tension spring can be easily achieved by initially inserting the tension spring only far enough so that it is securely accommodated in the tunnel-shaped recess, but the hook bend does not yet protrude from the tunnel-shaped recess on the side facing the track element to be held down, and the bent end section does not yet come to rest on the track element. Only when the final assembly position is assumed is the tension spring pushed further toward the track element until the bent end section presses against the track element from above.

[0047] In both the variant with a tension spring that can be inserted transversely to the longitudinal direction of the rail and the variant with a tension spring that can be inserted in the longitudinal direction of the rail, the hold-down device can preferably be provided with a ramp that rises in the insertion direction, on which the bent end section slides during insertion. This results in the bent end section being increasingly pre-tensioned during insertion.

[0048] Particularly preferably, the ramp comprises a first rising ramp section and a second rising ramp section, and an intermediate section located therebetween, on which the bent end section rests in a pre-assembly position of the tension spring. The intermediate section can, for example, have a recess in which the bent end section of the tension spring can engage to remain in the pre-assembly position.

[0049] In this context, a preferred further development provides that a step is formed at the end of the ramp, via which the bent end section reaches the final assembly position, in which the end section rests on the track body element, in particular the rail foot, wherein the step forms a rear stop which secures the end section against leaving the final assembly position.

[0050] In the variant with a tension spring that can be inserted longitudinally along the rail, overload protection can be achieved by providing the hold-down device with a stop that overlaps the bent end section at a distance when the tension spring is installed. Such a stop has the effect of limiting the upward movement of the bent end section.

[0051] The fastening system according to the invention can also be used in the area of ​​a switch for fixing stock rails, wherein the hold-down device can be combined or connected with a sliding chair on the side of the stock rail facing the tongue rail, preferably in such a way that the hold-down device forms at least part of the sliding surface for the tongue rail. A preferred embodiment in this context provides that the fastening system has a sliding chair assigned to the stock rail with a sliding surface for a tongue rail, wherein the hold-down device has a further sliding surface that is preferably flush with the sliding surface. Alternatively, the upper surface of the hold-down device can also be arranged lower than the sliding surface of the sliding chair.

[0052] Preferably, the further sliding surface, like the sliding chair itself, is extended in the direction of the stock rail in such a way that the further sliding surface overlaps the rail foot of the stock rail at a distance.

[0053] Preferably, the hold-down device associated with the sliding chair and the hold-down device arranged on the opposite side of the stock rail can be formed integrally with a sliding chair plate.

[0054] As already mentioned, one advantage of the tension spring according to the invention is its universal applicability. As already mentioned, the tension spring can be fastened not only without screws, but also with a sleeper screw. In this context, the fastening system according to the invention is preferably designed such that the hold-down device is formed by a fastening screw that can be screwed into the base, in particular a sleeper or plate, or by a hook screw with a nut that is suspended in the base, in particular a ribbed plate, the screw shaft and / or thread of which penetrates a free space between the first leg and the free end region of the holding section of the tension spring in order to hold the tension spring down in the region of the holding section and, if applicable, the first leg.

[0055] With this type of fastening, a pre-assembly position is also easily possible. This can be achieved by first screwing the tension spring down into the pre-assembly position. The rail is then inserted, and the tension spring, screwed down, is then moved into the final assembly position. This eliminates the need to loosen the screw after inserting the rail and then tighten it to the final tightening torque after inserting the tension spring into the final assembly position. This is because the tension spring can be easily moved from the pre-assembly position to the final assembly position using a hand or power tool, even if the screw is tightened to the final tightening torque in the pre-assembly position.

[0056] To ensure that the tension spring remains displaceable between the pre-assembly and final assembly positions when screwed down, a preferred embodiment of the invention provides for a stop on the base and / or on the hold-down device that limits the screw-in depth of the hold-down device and preferably interacts with the screw head or the nut of the fastening screw, so that the hold-down force on the tension spring can be limited. The stop thus serves to define the screwed-down state of the tension spring or the tightened state of the screw such that the tension spring remains displaceable between the pre-assembly and final assembly positions.Preferably, the stop defines a minimum vertical distance between the hold-down device and the base, which is equal to or greater than the unloaded diameter of the wire forming the tension spring in the region of the hold-down device, wherein the vertical distance is preferably not more than 1.2 times the wire diameter.

[0057] Any deviation from the final tightening torque or the clamping force of the screw achieved with the final tightening torque no longer has a negative impact on the desired tension state of the tension spring once it has been tightened against the stop. This eliminates the need to check the clearances between the tension clamp and the rail base in the final assembly position, as is necessary, for example, with some common fastening systems using tension springs.

[0058] The stop can further preferably enable compensation for a predominantly one-sided load on the screw in that the stop of the screw provides at least one support point via which, by means of the screw or nut tightened with the final tightening torque, a force acts on the screw which at least partially compensates for the one-sided load on the screw.

[0059] Various variants are possible for moving the tension spring from the pre-assembly to the final assembly position. In particular, the tension spring, with its bent end section, can be twistable or displaceable transversely to the longitudinal direction of the rail when the hold-down device is tightened, i.e., particularly in the tension state defined by the stop described above, between the pre-assembly and final assembly positions.

[0060] Preferably, the support is designed in the region of the contact surface over which the tension spring passes during displacement such that, when the tension spring is displaced on the support from the pre-assembly position to the final assembly position along the displacement path, there is no increase in the preload of the tension spring or only a gradual increase. Thus, damaging loading, particularly due to shear, is excluded for all components subjected to stress during displacement of the tension spring. For this purpose, one possible design of a support is free of grooves and depressions perpendicular to the displacement direction of the tension spring on the contact surfaces over which the tension spring passes on the support during displacement.

[0061] To prevent the tension spring from moving spontaneously or accidentally from the final assembly position to the pre-assembly position, the base preferably forms a step sloping in the direction of the tension spring's displacement, from which the bent end section descends onto the rail foot when the tension spring is moved from the pre-assembly position to the final assembly position. The step thus forms a rear stop for the bent end section, preventing it from leaving the final assembly position.

[0062] In the pre-assembly position, the tension spring is advantageously positioned on the support in such a way that the insertion of a rail between pre-assembled tension springs is not impeded. This allows sleepers to be provided with pre-assembled tension springs before the rails are laid, so that after the rails are laid, the tension springs only need to be moved into the final assembly position using a suitable tool. This is preferably achieved by the support having a lateral contact surface for the rail foot and by the hold-down device or fastening screw being arranged in such a way that the tension spring does not protrude beyond the contact surface in the pre-assembly position.

[0063] In particular, the distance between the screw shaft and the lateral contact surface can be equal to or greater than the diameter of the wire forming the tension spring.

[0064] For safety reasons, it should be ensured that the fastening screw does not become unintentionally loose when moving the tension spring from the pre-assembly position to the final assembly position. For this purpose, the fact that the asymmetrical tension spring according to the invention, when tensioned, is predominantly tensioned on one side of the screw toward the screw head or nut, while resting on the support on the other side of the screw, can be utilized.

[0065] If the direction of rotation of the screw thread and the installation position or asymmetry of the tension spring are coordinated, a displacement of the tension spring from the pre-assembly position to the final assembly position results in the screw being subjected to a load in the sense of tightening the screw. In other words, the fastening screw or the nut of the hook screw is intended to hold down primarily the free end area of ​​the holding section of the tension spring and the first leg of the tension spring is supported on the base. And the tightening direction of rotation of the thread of the fastening screw or the hook screw is designed such that the free end area of ​​the holding section directly or indirectly applies a torque in the tightening direction to the fastening screw or the nut of the hook screw when the tension spring is moved transversely to the longitudinal direction of the rail from the pre-assembly position to the final assembly position.

[0066] For a fastening system with a tension spring that can be rotated between a pre-assembly position and a final assembly position, it is intended that the rotation from the pre-assembly position to the final assembly position takes place in the fixed rotation direction of the fastening screw or the nut of the hook screw, so that it is directly or indirectly subjected to a torque in the fixed rotation direction.

[0067] The invention will be explained in more detail below with reference to exemplary embodiments shown schematically in the drawing. Fig. 1 a perspective view of a tension spring according to the invention, Fig. 2 a top view of the tension spring according to Fig. 1, Fig. 3 a view according to arrow III of the Fig. 2, Fig. 4 a view according to arrow IV of the Fig. 2 , Fig. 5 a first embodiment of a rail fastening using the tension spring according to Fig. 1 , Fig. 6 a detailed view of the Fig. 5 , Fig. 7 second design of a rail fastening using the tension spring according to Fig. 1 , Fig. 8 a detailed view of the Fig. 7 , Fig. 9 a hold-down device according to Fig. 7 und 8 in a perspective view, Fig. 10 a side view of the hold-down device according to Fig. 9 , Fig. 11 a third embodiment of a rail fastening using the tension spring according to Fig. 1 , Fig. 12 a modified design of the rail fastening of the Fig. 11 , Fig. 13 a fourth embodiment of a rail fastening using the tension spring according to Fig. 1 , Fig. 14 training in accordance with Fig. 12 with a modified angle guide plate, Fig. 15 a view of the angle guide plate according to Fig. 14, Fig. 16 a front view of the angle guide plate according to Fig. 14, Fig. 17 a bottom view of the angle guide plate according to Fig. 14 in an exploded view, Fig. 19 the rail fastening according to Fig. 12 in a final assembly position, Fig. 18 the rail fastening according to Fig. 12 in a pre-assembly position, Fig. 21 a cross-sectional view of the rail fastening according to Fig. 19, Fig. 20 a cross-sectional view of the rail fastening according to Fig. 18 , Fig. 22 an alternative design of the rail fastening in a pre-assembly position, Fig. 23 the rail fastening according to Fig. 22 in a final assembly position, Fig. 24 a cross-sectional view of the rail fastening according to Fig. 22, Fig. 25 a cross-sectional view of the rail fastening according to Fig. 23 , Fig. 26 a perspective view of the rail fastening according to the Fig. 22-25 used angle guide plate and Fig. 27 another cross-sectional view of the rail fastening according to Fig. 19 .

[0068] In Fig. 1 The tension spring 1 according to the invention is shown, comprising a U-shaped main section having a U-bend 2, a first leg 3 arranged on one side of the U-bend 2, and a second leg 4 arranged on the other side of the U-bend 2. A hook-shaped, inwardly bent holding section 5 that can be supported on a hold-down device is formed on the first leg 3, and an end section 6 that is bent toward or away from the holding section 5 is formed on the second leg 4. The holding section 5 comprises a free end region 7.

[0069] In Fig. 2 It can be seen that between the bent end section 6 and the free end region 7 of the holding section 5, as seen in a plan view, a gap x is arranged on the side of the free end region 7 facing the second leg 4. The gap allows the insertion of the holding section of the tension spring 1 with the hook bend first into a tunnel-shaped recess of the hold-down device (see Fig. 5-8 ))

[0070] In Fig. 3 und 4 It can be seen that the first leg 3 and the holding section 5, including the free end region 7, lie in the same plane, so that they form a flat support surface a. Since the tension spring 1 is bent from a wire with a circular cross-section, this also means that the center axes of the said sections lie in a common center plane b. In the unloaded state, it is further provided that the free end region 7 of the holding section 5, viewed in the direction of a longitudinal extension of the free end region 7 ( Fig. 3 ) completely covers the U-bend 2. In other words, the U-bend, starting from the first leg 3, at least up to the aforementioned overlap with the free end region 7, also lies in the same plane as the first leg 3 and the holding section 5, including the free end region 7.

[0071] However, in the further course of the U-bend 2, ie in the direction of the second leg 4, the U-bend 2 is bent downwards from the plane a or b, so that the normal distance of the second leg 4 to the plane a or b increases up to the bent end section 6. In Fig. 4 It can be seen that the second leg 4 with its central axis c forms an acute angle β with the plane a or b of the holding section 5 and the first leg 3.

[0072] In Fig. 3 it is further shown that the bent end section 6 has a support surface d for resting on the track body element, which in the unloaded state is slightly inclined upwards in the direction of arrow III, so that an acute angle α is present between the bent end section 6 or the support surface d and the plane a or b of the holding section 5 and the first leg 3.

[0073] Fig. 5 shows a rail 8 which is fastened to a sleeper 11 with the interposition of a plate 10 arranged on a base plate 9. The fastening is carried out on each side of the rail 8 by means of a tension spring 1 according to Fig. 1 , into which a tunnel-shaped recess 13 of a hold-down device 12 is inserted. In the Fig. 5 In the final assembly position of the tension spring 1 shown, it presses with its bent end section 6 onto the rail foot 16 of the rail 8, optionally with the interposition of an insulator. The hold-down device 12 is suitably attached to the plate 10. For example, the plate 10 and the hold-down device 12 are manufactured as a single piece and bolted to the sleeper 11. Alternatively, an anchor can be formed on the underside of the plate 10, which is encased in concrete during the casting of the concrete sleeper 11.

[0074] Fig. 6 is an enlarged view of the tension spring 1 inserted into the tunnel-shaped recess 13. It can be seen that the tension spring has been inserted with its holding section 5 in the direction of arrow 14, i.e. in the longitudinal direction of the rail, into the tunnel-shaped recess 13, so that the bent end section 6 rests on the rail foot 16. When inserted in the direction of arrow 14, the bent end section 6 slides on a ramp 17 which rises in the insertion direction 14 until it falls over a step formed at the end of the ramp 17 onto the rail foot 16. On the side of the hold-down device 12 facing the rail foot 16, there is also a stop 18 which overlaps the bent end section 6 at a distance and acts together with the end section 6 as an overload protection device.

[0075] Fig. 7 und 8 show an alternative design of the rail fastening, in which the tension spring 1 is inserted transversely to the longitudinal direction of the rail, ie in the direction of arrow 14, into the tunnel-shaped recess 13 (see Fig. 9 ) of the hold-down device 12 is inserted. When inserted in the direction of arrow 14, the bent end section 6 slides again along the ramp 17 formed on the outside of the hold-down device 12 until the bent end section 6 falls down onto the rail foot 16 via a step 19 formed at the end of the ramp 17. An insulator 15 can be arranged between the tension spring 1 and the rail foot. Fig. 8 In the final assembly position shown, the holding section 5 emerges from the tunnel-shaped recess 13 on the side facing the rail 8 and forms a stop which overlaps the rail foot 16 with the optional insulator 15 at a distance and which forms an overload protection device.

[0076] The Fig 7 und 8 The used hold-down device 12 is in the Fig. 9 und 10 shown in more detail, wherein it is particularly evident that the ramp 17 consists of three successive sections in the insertion direction 14. The ramp 17 comprises a first rising ramp section 20 and a second rising ramp section 22 and an intermediate section 21 lying therebetween without a slope, on which the bent end section 6 of the tension spring 1 rests in a pre-assembly position. Fig. 9 und 10 an anchor 31 is visible with which the hold-down device can be concreted or cast into a concrete sleeper 11 or, for example, a plastic sleeper 11.

[0077] In Fig. 11 A modified embodiment is shown in which the tension spring 1 is tensioned by a holding-down device designed as a fastening screw 25. The fastening screw 25 is hooked to the rib 24 as a hook screw or is screwed into the sleeper 11 in such a way that its screw shaft or thread penetrates a free space between the first leg 3 and the free end region 7 of the holding section 5 of the tension spring 1. The free space between the first leg 3 and the free end region 7 of the holding section 5 is designed in a slot-shaped manner, so that the tension spring 1 can be moved between a pre-assembly position and the Fig. 12 can be moved into the final assembly position shown. In the illustrated embodiment, the rail base 10 is designed as a ribbed plate, the ribs 24 of which define the position of the rail foot 16 of the rail 8 on the sleeper 11.

[0078] In the modified training according to Fig. 12 The fastening system comprises an angled guide plate 26 on each side of the rail 8, which engages with a rib formed on the underside into a groove 27 of the sleeper 11.

[0079] Fig. 13 shows the use of a rail fastening according to the invention in the area of ​​a switch, which has a stock rail 8 and a tongue rail 28 that can be moved between a remote and adjacent position. The tongue rail 28 slides with its rail base on a slide chair 29, with the hold-down device 12 having a further sliding surface on its upper side that is flush with the sliding surface of the slide chair 29. The hold-down devices 12 arranged on both sides of the stock rail 8 can be formed integrally with a base plate 30.

[0080] The training according to Fig. 14 essentially corresponds to the training according to Fig. 12 , but the angle guide plate 26 is formed in two parts. The angle guide plate 26 consists, as shown in the Fig. 15 und 17 can be seen, from a first part 32 facing away from the rail and a second part 33 facing the rail. The first part 32 carries a rib 34 which, when installed, engages in the groove 27, wherein the rib 34 preferably has a trapezoidal cross-section and has at least one guide surface 38. The first and second parts 32, 33 are arranged along guide surfaces 38, 39 ( Fig. 17 ) are displaceable relative to each other, thereby enabling adaptation to the respective track width. The second part 33 further comprises a plate-shaped support element 41, on which the tension spring 1 rests and which engages over the upper surface of the first element 32. As shown in Fig. 17 As can be seen, the plate-shaped support element 41 has at least one oblique guide groove 40 on its underside, into which guide pins or the like (not shown) formed on the upper side of the first element 32 engage in order to hold the two parts 32, 33 together, particularly in the unloaded state. Furthermore, it can be seen that the second part 33, in particular the plate-shaped support element 41, has a through-hole 35 through which the screw 25 passes when the tension spring 1 is in the assembled state. The through-hole 35 is designed as an elongated hole perpendicular to the longitudinal direction of the rail. For the lateral guidance of the tension spring 1, the second part 33, in particular the plate-shaped support element 41, has two walls 37 which run in the insertion direction 14 of the tension spring 1. The elevation 36, which is arranged between the first leg 3 and the free end 7 of the holding section 5 of the tension spring 1, also serves to guide the tension spring 1.

[0081] The tension spring 1 can be positioned between the Fig. 14 The tension spring 1 can be moved between the final assembly position shown and a pre-assembly position (not shown), in which the tension spring 1 does not overlap the rail foot. The design is such that the screw 25 does not have to be loosened to move the tension spring 1 from the pre-assembly position to the final assembly position. The movement can be achieved, for example, using a lever-like tool.

[0082] Fig. 18 und 19 demonstrate through training in accordance with Fig. 12 the displaceability of the tension spring 1 between the pre-assembly position ( Fig. 18 ) and the final assembly position ( Fig. 19 ), whereby, as far as matching components are concerned, reference symbols from the Fig. 14-17 were retained. The Fig. 20 und 21 each show a cross-section of the Fig. 18 or 19 along lines XX and XXI respectively.

[0083] In the cross-sectional view according to Fig. 20 und 21 It can be seen that the fastening screw 25 has a screw head 42 and a screw shaft 43, wherein the screw head 42, with the interposition of a washer 44, tensions the tension spring. The elevation 36 of the angled guide plate 26 forms a stop 45, with which the screw head 42 or the washer 44 interacts and which thus limits the screw-in depth of the fastening screw 25. The stop 45 serves to define the screwed-down state of the tension spring 1 or the tightened state of the fastening screw 25 such that the tension spring 1 remains displaceable between the pre-assembly and the final assembly position. The stop 45 defines a minimum vertical distance h between the washer 44 and the support surface of the angled guide plate 26, which is equal to or greater than the unloaded diameter of the wire forming the tension spring in this area.

[0084] In Fig. 20 It can be seen that the angle guide plate 26 has a lateral contact surface 46 for the rail foot 16 and the fastening screw 25 is arranged such that the tension spring 1 does not protrude beyond the contact surface 46 in the pre-assembly position.

[0085] Furthermore, in Fig. 18 und 19 A ramp 47 is shown formed on the angled guide plate 26, which is arranged such that the bent end section 6 of the tension spring 1 slides along it during displacement from the pre-assembly position to the final assembly position. The ramp is flat or ascending toward the rail foot 16, with the end of the ramp forming a step sloping toward the rail foot, over which the bent end section 6 descends onto the rail foot 16 during displacement of the tension spring 1 from the pre-assembly position to the final assembly position.

[0086] The Fig. 22 und 23 show an alternative design in which the tension spring 1 is rotated around the screw axis from the pre-assembly position ( Fig. 22 ) into the final assembly position ( Fig. 23 ) can be brought. The Fig. 24 und 25 are sectional views of the Fig. 22 und 23 . For the rotation of the tension spring 1, a rotatable intermediate piece 48 is provided as a stop 45, which is penetrated by the screw shaft 43 and engages between the first leg 3 and the free end region 7 of the tension spring 1 and is pressed there by the fastening screw 25 against the angle guide plate 26, so that the intermediate piece 48 forms a rotatable stop 45, which both limits and transmits the screw-in depth of the fastening screw 25 and its tensioning force to the tension spring 1, which is why the intermediate piece 48 could also be understood as a component of a hold-down device.

[0087] The rotatable stop 45 serves in a similar way to the previously described movable design to define the screwed-down state of the tension spring 1 or the tightened state of the fastening screw 25 such that the tension spring 1 remains rotatable between the pre-assembly position and the final assembly position. The intermediate piece 48 comprises an area that overlaps the first leg 3 and the free end region 7, whereby the tension spring is tightened when the fastening screw 25 is tightened. The area of ​​the intermediate piece 48 that overlaps the first leg 3 and the free end region 7 defines, as the stop 45, a minimum vertical distance h between the support surface of the tension spring on the angle guide plate 26 and its opposite contact surface of the intermediate piece 48, which is equal to or greater than the unloaded diameter of the wire forming the tension spring in this area.Furthermore, the intermediate piece 48 comprises an extension 49 that engages behind the end face of the free end region 7 of the tension spring 1 or engages in the free space between the free end region 7 and the U-bend 2. The extension 49 acts as a safeguard against horizontal displacement of the tension spring 1 and as a driver to support the transmission of the rotational movement applied by a tool to the intermediate piece 48 or stop 45 to the tension spring 1.

[0088] The angle guide plate 26 from the Figuren 22 bis 25 is in Fig. 26 shown in more detail and it can be seen that on the side 46 facing the rail foot 16, a raised portion 50 is formed which has a contoured edge in order to provide both a first holding surface 53 for the pre-assembly position and a second holding surface 54 for the final assembly position of a rotationally displaceable tension spring 1. Furthermore, the contact surface 46 forms a step 52 extending from the upper edge of the contact surface 46 and descending to a rail foot. In order for the hold-down force to be fully transmitted to the rail foot in the final assembly position, the required vertical freedom of movement for a tension spring 1 must be present between the second leg and the angled guide plate 26. For this purpose, a recess 51 ensures that the upper edge of the contact surface 46 or the step 52 is lowered at the appropriate location.

[0089] Fig. 27 shows the section SS through step 52 from Fig. 19. This falls to the rail foot by the distance Y.

[0090] The following embodiments of the invention are disclosed: 1. Tension spring (1) for holding down a track body element, such as a rail foot of a rail, comprising a U-shaped main section which has a U-bend (2), a first leg (3) arranged on one side of the U-bend (2) and a second leg (4) arranged on the other side of the U-bend (2), wherein a hook-shaped holding section (5) which is bent inwards and can be supported on a hold-down device is formed on the first leg (3) and an end section (6) which is bent towards or away from the holding section (5) is formed on the second leg (4), wherein the U-bend (2) forms a torsion section such that a holding-down force can be applied to the track body element via the bent end section (6). 2. Tension spring according to embodiment 1, characterized in that the bent end portion (6) extends at an angle of 80-100°, preferably approximately 90°, to the second leg (4). 3.Tension spring according to embodiment 1 or 2, characterized in that the holding section (5) has a free end region (7) connected to the first leg (3) via a hook bend, which is arranged between the first leg (3) and the second leg (4). 4. Tension spring according to embodiment 3, characterized in that the first leg (3) and the free end region (7) of the holding section (5) provide a flat support surface in the unloaded state. 5. Tension spring according to embodiment 3 or 4, characterized in that the first leg (3) and the free end region (7) of the holding section (5) lie with their respective central axes, preferably over their entire extent, in a central plane that preferably runs parallel to the flat support surface. 6.Tension spring according to embodiment 3, 4, or 5, characterized in that the hook bend of the holding section (5) has a substantially 180° bend, so that the free end region (7) of the holding section (5) runs substantially parallel to the first leg (3), preferably in a normal projection onto the flat support surface or the center plane, at least in sections. 7. Tension spring according to one of embodiments 3 to 6, characterized in that an imaginary extension of the bent end section (6) overlaps the hook bend in a plan view. 8. Tension spring according to one of embodiments 5 to 7, characterized in that the first leg (3) and the holding section (5) lie with their respective center axes in the center plane in the unloaded state. 9.Tension spring according to one of embodiments 4 to 8, characterized in that the bent end section (6) in the unloaded state has a normal distance from the center plane or the flat support surface. 10. Tension spring according to one of embodiments 4 to 9, characterized in that the hook bend and the bent end section (6) in the unloaded state define the maximum structural height of the tension spring (1), measured normal to the center plane or the flat support surface. 11. Tension spring according to embodiment 10, characterized in that the structural height of the tension spring in the unloaded state corresponds to 1.5 to 3 times the diameter of the wire forming the tension spring (1) in the holding section (5).Tension spring according to one of embodiments 4 to 10, characterized in that the second leg (4), in the unloaded state, has a normal distance from the center plane or the flat support surface that continuously increases in the direction of the bent end section (6). 13. Tension spring according to one of embodiments 4 to 12, characterized in that the second leg (4), in the unloaded state, extends inclined at an acute angle relative to the center plane or the flat support surface. 14. Tension spring according to one of embodiments 3 to 13, characterized in that the free end region (7) of the holding section (5), viewed in the direction of a longitudinal extension of the free end region (7), at least partially, preferably completely, covers the U-bend. 15.Tension spring according to one of embodiments 4 to 14, characterized in that the bent end section (6) has a support surface for resting on the track body element, which, in the unloaded state, extends upwards at an acute angle relative to the center plane or to the flat support surface. 16. Tension spring according to one of embodiments 3 to 15, characterized in that a gap (x) is arranged between the bent end section (6) and the free end region (7) of the holding section (5) in a longitudinal extension of the free end region (7) and, as seen in a plan view, on the side of the free end region (7) facing the second leg. 17.Tension spring according to one of embodiments 1 to 16, characterized in that the holding section (5) of the tension spring (1) can be inserted transversely to the longitudinal direction of the rail into a tunnel-shaped recess (13) of the hold-down device towards the rail, so that the hook bend preferably engages over the rail foot (16) in a final assembly position of the tension spring (1).Tension spring according to one of embodiments 3 to 17, characterized in that a free space is provided between the first leg (3) and the free end region (7) of the holding section (5), through which a screw shaft of a fastening screw (25) forming the hold-down device can pass and in which the fastening screw (25) is displaceable in the longitudinal direction of the first leg (3), wherein the screw shaft of the fastening screw (25) has a diameter that is greater than the diameter of a wire forming the tension spring (1) in the holding section (5), and wherein preferably the inner radius of the hook bend is greater than or equal to the radius of the screw shaft. 19.Tension spring according to one of embodiments 1 to 18, characterized in that the tension spring (1) in a plan view, in particular in a normal projection onto the central plane or the flat support surface, lies within a minimally surrounding rectangle having an aspect ratio of 1:1.5-1:1, preferably 1:1.1-1:1. 20. Tension spring according to one of embodiments 1 to 19, characterized in that the diameter of the wire forming the tension spring (1) is at least 1 / 7, preferably at least 1 / 6, of the shorter side of a rectangle minimally surrounding the tension spring (1) in a plan view. 21. Tension spring according to one of embodiments 1 to 20, characterized in that the bent end section (6) lies within a square corner region of a rectangle minimally surrounding the tension spring (1) in a plan view, which has at most 1 / 9 of the area of ​​the surrounding rectangle. 22.Rail fastening comprising a tension spring (1) according to one of embodiments 1 to 21 and a hold-down device (12) attachable to a base, in particular a sleeper (11), ribbed plate, or angled guide plate, adjacent to a rail (8), on which hold-down device the holding section (5) is supported in the mounted state of the tension spring (1) such that the bent end section (6) can be arranged to resiliently hold down a track body element, in particular a rail foot (16) of the rail. 23. Rail fastening according to embodiment 22, characterized in that the hold-down device at least partially engages over both a free end region (7) of the holding section (5) and the first leg (3) in the mounted state of the tension spring (1). 24.Rail fastening according to embodiment 22 or 23, characterized in that the hold-down device (12) has or forms a tunnel-shaped recess (13) into which the holding section (5) of the tension spring (1) can be at least partially inserted. 25. Rail fastening according to embodiment 24, characterized in that the holding section (5) of the tension spring (1) can be inserted transversely to the longitudinal direction of the rail into the tunnel-shaped recess (13) towards the rail. 26. Rail fastening according to embodiment 25, characterized in that the tunnel-shaped recess (13) is open on the side facing the track body element, in particular the rail foot (16), and the hook bend protrudes from the tunnel-shaped recess (13) in a final assembly position of the tension spring (1) and engages over the track body element, in particular the rail foot (16). 27.Rail fastening according to embodiment 24, characterized in that the holding section (5) of the tension spring (1) can be inserted into the tunnel-shaped recess (13) parallel to the longitudinal direction of the rail. 28. Rail fastening according to embodiment 25 or embodiment 26, characterized in that the hold-down device (8) has a ramp (17) rising in the insertion direction (14), on which ramp the bent end section (6) rests slidingly when the holding section (5) is inserted into the tunnel-shaped recess (13). 29. Rail fastening according to embodiment 28, characterized in that the ramp (17) has a first rising ramp section (20) and a second rising ramp section (22) and an intermediate section (21) located therebetween, on which the bent end section (6) rests in a pre-assembly position of the tension spring (1). 30.Rail fastening according to embodiment 28 or 29, characterized in that a step (19) is formed at the end of the ramp (17), via which the bent end section (6) reaches the final assembly position, in which the end section (6) rests on the track body element, in particular the rail foot (16), wherein the step (19) forms a rear stop which secures the bent end section (6) against leaving the final assembly position. 31. Rail fastening according to one of embodiments 27 to 30, characterized in that the hold-down device (12) has a stop (18) which engages the bent end section (6) at a distance in a final assembly position of the tension spring (1). 32.Rail fastening according to one of embodiments 22 to 31, further comprising a sliding chair (29) assigned to the rail (8) designed as a stock rail, said chair having a sliding surface for a tongue rail (28), wherein a hold-down device (12) is connected to the sliding chair and preferably has a further sliding surface flush with the sliding surface of the sliding chair. 33. Rail fastening according to embodiment 32, characterized in that the further sliding surface overlaps the rail foot (16) of the stock rail (8) at a distance. 34.Rail fastening according to embodiment 22 or 23, characterized in that the hold-down device is formed by a fastening screw (25) that can be screwed into the base, in particular a sleeper (11) or plate (10, 26), or by a hook screw with a nut that is suspended in a base, in particular a ribbed plate, the screw shaft and / or thread of which penetrates a free space between the first leg (3) and the free end region (7) of the holding section (5) of the tension spring (1) in order to hold the tension spring (1) down in the region of the holding section (5) and optionally the first leg (3). 35. Rail fastening according to embodiment 34, characterized in that a stop (45) is arranged on the base and / or on the hold-down device, which limits the screw-in depth of the hold-down device and preferably interacts with the screw head (42) or the nut of the fastening screw (25), so that a hold-down force on the tension spring (1) can be limited.36. Rail fastening according to embodiment 35, characterized in that the stop (45) defines a minimum vertical distance between the hold-down device and the base, which is equal to or greater than the unloaded diameter of the wire forming the tension spring (1) in the region of the hold-down device, wherein the vertical distance is preferably no more than 1.2 times the wire diameter. 37. Rail fastening according to one of embodiments 34 to 36, characterized in that the tension spring (1) with its bent end section (6) is displaceable, in particular rotatable or displaceable transversely to the longitudinal direction of the rail, between a pre-assembly position and a final assembly position when the hold-down device is tightened. 38.Rail fastening according to embodiment 37, characterized in that the base forms a step sloping in the displacement direction (14) of the tension spring (1), from which the bent end section (6) descends upon displacement of the tension spring (1) from the pre-assembly position to the final assembly position onto the rail foot (16). 39. Rail fastening according to embodiment 38, characterized in that the bent end section (6) lying on the step is arranged higher than the hook curve of the holding section (5). 40. Rail fastening according to one of embodiments 34 to 39, characterized in that the base has a lateral contact surface for the rail foot, and the hold-down device or the fastening screw (25) is arranged such that the tension spring (1) does not protrude beyond the contact surface in the pre-assembly position. 41.Rail fastening according to embodiment 40, characterized in that the distance between the screw shaft and the lateral contact surface is equal to or greater than the diameter of the wire forming the tension spring (1). 42. Rail fastening according to one of embodiments 37 to 41, characterized in that the fastening screw or the nut of the hook screw preferably predominantly holds down the free end region (7) of the holding section (5) of the tension spring (1) and the first leg (3) of the tension spring (1) is supported on the base and that the tightening direction of the thread of the fastening screw or the hook screw is designed such that the free end region (7) of the holding section (5) holds the fastening screw orthe nut of the hook screw is directly or indirectly subjected to a torque in the fixed rotation direction when the tension spring (1) is moved transversely to the longitudinal direction of the rail from the pre-assembly position to the final assembly position.

Claims

1. Rail fastening comprising a tension spring (1) for holding down a track body element, such as a rail foot of a rail, and a hold-down device (12) which can be fastened on a base, in particular a sleeper (11), ribbed plate or angled guide plate, adjacent to a rail (8), wherein the tension spring (1) has a U-shaped main section which has a U-bend (2), a first leg (3) arranged on one side of the U-bend (2) and a second leg (4) arranged on the other side of the U-bend (2), wherein on the first leg (3) a hook-shaped, inwardly bent holding section (5) which can be supported on the hold-down device is formed, and on the second leg (4) an end section (6) which is bent towards or away from the holding section (5), wherein the U-bend (2) forms a torsion section, so that a hold-down force is applied to the track body element can be applied,wherein the holding section (5) is supported on the hold-down device (12) in the assembled state of the tension spring (1) in such a way that the bent end section (6) can be arranged to resiliently hold down the track body element, in particular a rail foot (16) of the rail, wherein the holding section (5) has a free end region (7) connected to the first leg (3) via a hook bend, which is arranged between the first leg (3) and the second leg (4), and the hook bend comes to lie above the rail foot in a final assembly position and can form an overload protection.

2. Rail fastening according to claim 1, characterized in that the hold-down device, in the assembled state of the tension spring (1), at least partially overlaps both a free end region (7) of the holding section (5) and the first leg (3).

3. Rail fastening according to claim 1 or 2, characterized in thatthe hold-down device (12) has or forms a tunnel-shaped recess (13) into which the holding section (5) of the tension spring (1) can be at least partially inserted.

4. Rail fastening according to claim 3, characterized in that the holding section (5) of the tension spring (1) can be inserted transversely to the longitudinal direction of the rail into the tunnel-shaped recess (13) towards the rail.

5. Rail fastening according to claim 4, characterized in that the tunnel-shaped recess (13) is open on the side facing the track body element, in particular the rail foot (16), and the hook bend protrudes from the tunnel-shaped recess (13) in a final assembly position of the tension spring (1) and engages over the track body element, in particular the rail foot (16).

6. Rail fastening according to claim 4 or 5, characterized in thatthe hold-down device (8) has a ramp (17) which rises in the insertion direction (14) and on which the bent end section (6) slides when the holding section (5) is inserted into the tunnel-shaped recess (13), wherein a step (19) is preferably formed at the end of the ramp (17), via which the bent end section (6) reaches the final assembly position, in which the end section (6) rests on the track body element, in particular the rail foot (16), wherein the step (19) forms a rear stop which secures the bent end section (6) against leaving the final assembly position.

7. Rail fastening according to one of claims 1 to 6, further comprising a sliding chair (29) assigned to the rail (8) designed as a stock rail, said sliding chair having a sliding surface for a tongue rail (28), wherein a hold-down device (12) is connected to the sliding chair and preferably has a further sliding surface flush with the sliding surface of the sliding chair, wherein the further sliding surface preferably overlaps the rail foot (16) of the stock rail (8) at a distance.

8. Rail fastening according to claim 1 or 2, characterized in thatthe hold-down device is formed by a fastening screw (25) which can be screwed into the base, in particular a sleeper (11) or plate (10, 26), or by a hook screw with a nut which is suspended in a base, in particular a ribbed plate, the screw shaft and / or thread of which passes through a free space between the first leg (3) and the free end region (7) of the holding section (5) of the tension spring (1) in order to hold the tension spring (1) down in the region of the holding section (5) and optionally of the first leg (3), wherein a stop (45) which limits the screw-in depth of the hold-down device and preferably interacts with the screw head (42) or the nut of the fastening screw (25) is preferably arranged on the base and / or on the hold-down device, so that a hold-down force on the tension spring (1) can be limited.

9. Rail fastening according to claim 8, characterized in thatthe stop (45) defines a minimum vertical distance between the hold-down device and the base which is equal to or greater than the unloaded diameter of the wire forming the tension spring (1) in the region of the hold-down device, wherein the vertical distance is preferably not more than 1.2 times the wire diameter.

10. Rail fastening according to claim 8 or 9, characterized in that the tension spring (1) with its bent end section (6) can be displaced, in particular rotated or displaced transversely to the longitudinal direction of the rail, between a pre-assembly position and a final assembly position when the hold-down device is tightened.

11. Rail fastening according to claim 10, characterized in that the base forms a step sloping in the direction of displacement (14) of the tension spring (1), from which the bent end section (6) descends onto the rail foot (16) when the tension spring (1) is displaced from the pre-assembly position to the final assembly position.

12. Rail fastening according to claim 11, characterized in that the bent end section (6) lying on the step is arranged higher than the hook bend of the holding section (5).

13. Rail fastening according to one of claims 8 to 12, characterized in that the base has a lateral contact surface for the rail foot and the hold-down device or the fastening screw (25) is arranged such that the tension spring (1) does not protrude beyond the contact surface in the pre-assembly position.

14. Rail fastening according to claim 13, characterized in that the distance between the screw shaft and the lateral contact surface is equal to or greater than the diameter of the wire forming the tension spring (1).

15. Rail fastening according to one of claims 10 to 14, characterized in thatthe fastening screw or the nut of the hook screw preferably predominantly holds down the free end region (7) of the holding section (5) of the tension spring (1) and the first leg (3) of the tension spring (1) is supported on the base and that the fixed direction of rotation of the thread of the fastening screw or the hook screw is designed such that the free end region (7) of the holding section (5) directly or indirectly applies a torque in the fixed direction of rotation to the fastening screw or the nut of the hook screw when the tension spring (1) is moved transversely to the longitudinal direction of the rail from the pre-assembly position to the final assembly position.

Images