Clamping spring for retaining a track body element

Abstract

The invention relates to a clamping spring (1) for holding a track element, such as a rail base, in place. The clamping spring comprises a main U-shaped portion having: a U-bend (2); a first leg (3) located on one side of the U-bend (2); and a second leg (4) located on the other side of the U-bend (2). In this clamping spring, an inwardly curved, hook-shaped retaining portion (5) is formed and supported by a clamping element (12) on the first leg (3), and a terminal portion (6) is bent toward or away from the retaining portion (5) on the second leg (4). The U-bend (2) forms a torsion portion so that a clamping force can be applied to the track element by means of the bent terminal portion (6).

Description

[0001] The invention relates to a tension spring for holding down a track 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 that can be attached to a base, in particular a sleeper, ribbed plate or angle guide plate, adjacent to a rail.

[0003] Publications DE 20 2015 106541 U1, CA 2 752 835 A1 and US 5,069,386 A disclose tension springs and rail fastenings relating to the subject matter of the present invention.

[0004] The installation of rails on a track bed is typically carried out using a spring element, usually referred to as a tension spring or clamp, and a suitable clamping element or hold-down device to tension the spring element. This clamping element or hold-down device is usually a screw, which tensions the spring element against the substrate so that it exerts the necessary holding forces via the section resting on the rail foot. This tensioning can be achieved, for example, by connecting the hold-down device directly to the substrate supporting 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 respective substrate.

[0005] Commonly used tension springs are those with an "e" shape and those with a "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.

[0006] Numerous embodiments of fastening systems with tension springs are known, in which the tension spring can be positioned relative to the rail foot and the anchoring elements not only in a precisely defined final assembly position, but also in a position-secured pre-assembly position. To achieve the pre-assembly position, the tension spring is mounted so that the section intended to hold down the rail foot does not rest on the rail. In this way, railway sleepers can be fitted with tension springs in the pre-assembly position and pre-tensioned at the factory. On the construction site, after the rail has been laid, the tension springs can be moved laterally into the final assembly position and tensioned with some effort, so that the section intended to hold down the rail foot overlaps it and springs down from above.

[0007] A disadvantage of tension springs from the prior art is that they are designed for only one installation direction or method. The installation direction here refers to the direction in which the tension spring, which is usually already pre-tensioned, is pushed onto the rail foot. Most commonly, tension springs are designed for transverse installation, meaning they are pushed on perpendicular to the longitudinal direction of the rail. In contrast, longitudinal installation involves bringing the tension spring into its final assembly position along the longitudinal direction of the rail. Longitudinal installation is advantageous, for example, for securing rails in the area of ​​turnouts, due to limited space.Conventional tension springs are adapted to their predetermined 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.

[0008] Other problems with conventional tension springs include breakage and loosening, resulting in a loss of tension. Loosening occurs particularly with tension springs that are tightened with a screw.

[0009] Tension springs often break when subjected to excessive stress. Conventional rail fastening systems are rarely equipped with overload protection. Overload protection serves to limit the load acting on the tension spring, which is particularly important when the rail is subjected to significant up-and-down movement or tilting relative to the sleeper as it is traversed.

[0010] The present invention therefore aims to improve a tension spring and a corresponding fastening system in such a way as to overcome the aforementioned disadvantages. In particular, a tension spring is to be created that can be held down or tensioned both by a screw and without screws, and which exhibits high elasticity. The tension spring should be universally applicable, especially for holding down rails in open track as well as in the area of ​​turnouts. Finally, installation and removal should be facilitated, and a position-secured pre-assembly position should be enabled.

[0011] To solve this problem, the invention, according to a first aspect, provides 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 retaining section bent inwards and supported on a hold-down device is formed on the first leg and an end section bent towards or away from the retaining section is formed on the second leg, wherein the U-bend forms a torsion section so that a hold-down force can be applied to the track element via the bent end section.

[0012] By having the tension spring, starting from the basic "U" shape, feature a hook-shaped retaining section on the first leg of the U-shape and an end section bent towards or away from the retaining section on the other leg, an asymmetrical shape is achieved that is easy to manufacture and allows installation in both transverse and longitudinal directions. In both longitudinal and transverse installations, the bent end section forms the part of the tension spring through which the holding force is applied to the track element or the rail foot.

[0013] 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 towards or away from the retaining section of the tension spring. Preferably, the bend extends towards the retaining section of the tension spring. According to a preferred embodiment, the bent end section extends at an angle of 80-100°, preferably approximately 90°, to the second leg, and this applies both to the design with an end section bent towards the retaining section of the tension spring and to the design with an end section bent away from the retaining section. The advantages of the bent end section become clear in both longitudinal and transverse installations in conjunction with the hold-down device, as will be explained in more detail below.

[0014] 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 almost directly into the holding section. In other embodiments, however, the first leg has a certain length, such as a length essentially corresponding to the second leg, and is particularly straight.

[0015] The hook-shaped retaining 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-shaped arc of the tension spring. The hook-shaped retaining section is bent inwards, meaning that the hook is bent between the two legs of the U-shape. Preferably, the hook-shaped retaining section forms the end of the tension spring on the side of the first leg, i.e., the free end of the section bent into a hook lies between the two legs of the U-shape.

[0016] In this context, the invention provides that the holding section has a free end area connected to the first leg via a hook arc, which is arranged between the first leg and the second leg.

[0017] According to a preferred embodiment of the invention, a hook arc of the retaining section has a substantially 180° bend, such that a free end region of the retaining section runs substantially, at least partially, parallel to the first leg. The expression "substantially 180°" means that the angle is 180°, but can also be between 175° and 185°.

[0018] The holding force is provided at least partially by a torsional load on the torsional section formed by the U-shaped bend of the tension spring, resulting in a corresponding spring 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 to be as flat as possible in order to minimize the overall height of the tension spring and the material required for its construction.

[0019] In this context, a preferred design provides that the first leg and the free end of the retaining section offer a flat bearing surface in the unloaded state. This flat bearing surface can, for example, serve as a support for the hold-down device, with the flat state referring to the unloaded state of the tension spring, since the retaining section may twist slightly when the tension spring is compressed.

[0020] The first leg and the free end region of the retaining section can, in the unloaded state, lie with their respective central axes, preferably over their entire extent, in a median plane that preferably runs parallel to the flat bearing surface. In the case of a circular cross-section, the central axis of the respective sections is, for example, the center line or axis passing through the center of the circle.

[0021] However, it can also be designed so that the first leg and the holding section lie in the same plane when unloaded, or rather, that their respective central axes lie in the central plane. This also provides a flat bearing surface and prevents any parts of the first leg and the holding section, including the hook arc, from being bent out of this plane.

[0022] The design of the U-shaped arc of the tension spring can also contribute to achieving the flattest possible construction, in that, according to the invention, the free end area of ​​the retaining section, viewed in the direction of a longitudinal extension of the free end area, at least partially, preferably completely, covers the U-shaped arc.

[0023] To ensure sufficient spring travel, the bent end section of the tension spring can be deflected from the aforementioned plane in the unloaded state. A preferred embodiment in this context provides that the bent end section, in the unloaded state, has a perpendicular distance to the central plane or to the flat bearing surface.

[0024] If the entire holding section, including the hook arc and the first leg, lies in the same plane, this means that, with regard to the overall height of the tension spring, the hook arc and the bent end section define the maximum height of the tension spring when unloaded, measured perpendicular to the central plane or the flat bearing surface. This allows for an extremely flat design of the tension spring.

[0025] In particular, the 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.

[0026] Preferably, an imaginary extension of the bent end section overlaps the hook arc in a top view. This means that the imaginary extension of the bent end section at least partially overlaps the hook arc in the top view of the tension spring. For transverse installation of the tension spring, this results in the hook arc being positioned above the rail foot in the final assembly position, thus providing overload protection.

[0027] The tension spring conventionally consists of a spring bar and can therefore be manufactured in one piece from a suitable starting material. It is manufactured by repeatedly bending an initially straight spring bar. If, as is preferably intended, the hook-shaped retaining section, the U-bend, and the folded end section are all bent in the same direction, the tension spring can be manufactured in three bending steps. In the first step, the hook-shaped retaining section is bent; in the second step, the U-bend; and in the third step, the folded end section. The three bending steps can also be performed continuously in a single operation if all three bends are in the same direction. The aforementioned bends can all be made in the same plane, or, simultaneously with the bends, individual sections can be deflected out of the common plane.

[0028] 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.

[0029] 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, tension force, and stiffness can be controlled by selecting the thickness of the spring bar. The radius of the U-bend also controls the tension and stiffness of the tension spring.

[0030] In order to exert a holding force on the rail foot by clamping the holding section using the hold-down device and the resulting torsional load on the torsion 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 to the center plane or to the flat bearing surface that increases continuously in the direction of the bent end section.

[0031] This means, in particular, that the second leg, in its unloaded state, is inclined at an acute angle relative to the central plane or the flat bearing surface. This acute angle can range from 5° to 20°. Tightening the tension spring causes it to bend, reducing the aforementioned acute angle from the unloaded state to, for example, only 0°–5° when tightened. This angle can be reduced to 5–10° in the case of fastening systems with lower holding force. In this tensioned state, a torsional moment acts on the torsional section of the tension spring, specifically about an axis perpendicular to the axis of the first leg and tangent to the U-shaped bend.

[0032] The holding force acting on the rail foot from the bent end section and the corresponding counterforce acting on the retaining section of the tension spring from the retainer form a force couple that additionally subjects the torsion section to bending about an axis perpendicular to the axis of the torsional moment, resulting in a corresponding bending about this axis. Due to this bending, the bent end section of the tension spring has a different angle to the bearing surface on the rail foot in the unloaded state than in the loaded state.To ensure that the bent end section is substantially horizontally oriented under load, thus providing a suitable bearing surface on the rail foot, a preferred embodiment of the invention provides that the bent end section has a bearing surface for resting on the track element. In the unloaded state, this bearing surface extends upwards at an acute angle relative to the central plane or the flat bearing surface. The angle between the bent end section and said plane is preferably 2°–8°, and more particularly 5°–7°. Under load, this angle decreases due to the bending moment and is preferably 0°–1°.

[0033] When the invention refers 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 respective sections, i.e., in the case of a circular cross-section, to the center line or axis passing through the center of the circle.

[0034] The tension spring according to the invention is designed to be usable with various types of hold-down devices.

[0035] In a first installation variant, the retaining 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 preferably the hook arc overlaps the rail foot in a final assembly position of the tension spring.

[0036] In a second installation variant, the retaining 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 preferably the second leg overlaps the rail foot.

[0037] In terms of design, the first and second installation variants can preferably be implemented by arranging a gap between the bent end section and the free end area of ​​the holding section in a longitudinal extension of the free end area and in a top view, i.e. in a normal projection onto the middle plane or the flat bearing surface, seen on the side of the free end area facing the second leg.

[0038] In another installation variant, a clearance can be provided between the first leg and the free end of the holding section. This clearance is traversable by the shank of a fastening screw forming the hold-down device, and the fastening screw is displaceable in the longitudinal direction of the first leg. The shank of the fastening screw has a diameter larger than the diameter of a wire forming the tension spring in the holding section, and preferably the inner radius of the hook arc is greater than or equal to the radius of the screw shank. This displaceability allows the tension spring, when held down by the fastening screw, to be moved from a pre-assembly position to a final assembly position and back. If the inner radius of the hook arc is greater than or equal to the radius of the screw shank, a maximum displacement is provided.

[0039] Overall, the invention provides a compact, low-profile, and versatile tension spring that can be manufactured cost-effectively due to the minimal material requirements. Preferably, the tension spring, when viewed from above, particularly in a normal projection onto the central plane or the flat support surface, lies within a minimal surrounding rectangle having an aspect ratio of 1:1.5 to 1:1, preferably 1:1.1 to 1:1.

[0040] 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 top view.

[0041] In particular, the bent end section lies within a square corner area of ​​a rectangle minimally surrounding the tension spring in a top view, and has a maximum area of ​​1 / 9 of the surrounding rectangle.

[0042] 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 attached to a base, in particular a sleeper, ribbed plate or angle guide plate, adjacent to a rail, on which 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 element, in particular a rail foot of the rail.

[0043] It is preferably intended that the hold-down device, in the assembled state of the tension spring, not only covers the free end area of ​​the holding section, but also at least partially covers the first leg.

[0044] As already explained in connection with the first aspect of the invention, the tension spring can be tensioned without screws or with the aid of a screw. For the implementation of the screwless alternative, a preferred embodiment provides that the retainer has or forms a tunnel-shaped recess into which the retaining section of the tension spring can be at least partially inserted.

[0045] 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 retaining 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.

[0046] In a design with a tension spring that can be inserted transversely to the longitudinal direction of the rail, the tunnel-shaped recess on the side facing the track element, in particular the rail foot, is preferably open, and the hook arc of the tension spring projects from the tunnel-shaped recess in its fully assembled state and overlaps the track element, in particular the rail foot. In this way, the hook arc, when projecting beyond the track element, forms an overload protection device. For this purpose, the hook arc is arranged such that there is a vertical gap between the track element to be held down, in particular the rail foot, and the hook arc of the tension spring. Upward movements of the track element that fall within this vertical gap are absorbed by the bent end section of the tension spring.However, should excessive upward movement occur, the track element to be held down will collide with the hook arch and thus be prevented from rising further without overloading the tension spring within its permissible spring travel.

[0047] 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 that it is securely held in the tunnel-shaped recess, but that the hooked section does not yet protrude from the tunnel-shaped recess on the side facing the track element to be held down, and that the bent end section does not yet rest on the track element. Only when assuming the final assembly position is the tension spring advanced further towards the track element until the bent end section presses down onto the track element from above.

[0048] 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 longitudinally to the rail, it is preferable to provide that the hold-down device has a ramp rising in the insertion direction, on which the bent end section rests slidingly during insertion. This results in the bent end section being continuously pre-tensioned during insertion.

[0049] The ramp preferably comprises a first rising ramp section and a second rising ramp section, with an intermediate section on which the bent end section rests in a pre-assembled position of the tension spring. The intermediate section may, for example, have a recess in which the bent end section of the tension spring can engage to remain in the pre-assembled position.

[0050] In this context, a preferred further development provides that a step is formed at the end of the ramp, over 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, with the step forming a rear stop which secures the end section against leaving the final assembly position.

[0051] In the variant with a tension spring that slides in along the rail, overload protection can be achieved by having a stop on the hold-down device that overlaps the bent end section by a distance when the tension spring is installed. Such a stop has the effect of limiting the upward movement of the bent end section.

[0052] The fastening system according to the invention can also be used in the area of ​​a turnout for fixing jaw rails, wherein the hold-down device can be combined or connected to a slide chair on the side of the jaw rail facing the tongue rail, preferably such that the hold-down device forms at least part of the sliding surface for the tongue rail. In this context, a preferred embodiment provides that the fastening system has a slide chair associated with the jaw 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 slide chair.

[0053] Preferably, the additional sliding surface, as well as the sliding chair itself, is extended in the direction of the jaw rail in such a way that the additional sliding surface overlaps the rail foot of the jaw rail by a distance.

[0054] Preferably, the hold-down associated with the sliding chair and the hold-down arranged on the opposite side of the jaw rail can be formed in one piece with a sliding chair plate.

[0055] As already mentioned, an advantage of the tension spring according to the invention lies in 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 retainer is formed by a fastening screw that can be screwed into the substrate, in particular a sleeper or plate, or by a hook screw with a nut that is hooked into the substrate, in particular a ribbed plate, wherein the shank and / or thread of the screw penetrates a gap between the first leg and the free end region of the retaining section of the tension spring in order to hold the tension spring down in the region of the retaining section and, if applicable, the first leg.

[0056] Even with this type of fastening, a pre-assembly position is easily achievable. This can be done by first screwing the tension spring down in the pre-assembly position. Then, the rail is inserted, after which the tension spring, still in its lowered position, is moved into the final assembly position. It is no longer necessary to loosen the screw after inserting the rail and then tighten it to the final torque after inserting the tension spring into the final assembly position, because even with the screw tightened to the final torque in the pre-assembly position, the tension spring can easily be moved from the pre-assembly position to the final assembly position using a hand or power tool.

[0057] To ensure that the tension spring remains movable between the pre-assembly and final assembly positions when screwed down, a preferred embodiment of the invention provides that a stop is arranged on the base and / or the retainer to limit the screw-in depth of the retainer, preferably interacting with the screw head or nut of the fastening screw, so that a holding 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 in such a way that the tension spring remains movable between the pre-assembly and final assembly positions.Preferably, the stop defines a minimum vertical distance between the hold-down and the base, which is equal to or greater than the unloaded diameter of the wire forming the tension spring in the area of ​​the hold-down, wherein the vertical distance is preferably not more than 1.2 times the wire diameter.

[0058] A deviation in the final tightening torque, or the clamping force of the screw achieved with that torque, has no further adverse effect on the desired tension state of the tension spring once it is clamped against the stop. Therefore, in the final assembly position, there is no need to check the distances between the clamping clamp and the rail foot, as is necessary with some common fastening systems using tension springs.

[0059] Furthermore, the stop can preferably compensate for a predominantly one-sided load on the screw by providing at least one support point for the screw, over which a force acting on the screw, at least partially compensating for the one-sided load on the screw, is exerted by the screw or nut being tightened with final tightening torque.

[0060] Several options are possible for repositioning the tension spring from the pre-assembly to the final assembly position. In particular, the tension spring, with its bent end section, can be rotated or displaced transversely to the longitudinal direction of the rail when the hold-down device is tightened, i.e., especially in the tension state defined by the stop described above, between the pre-assembly position and the final assembly position.

[0061] Preferably, the support in the area of ​​the contact surface over which the tension spring slips during repositioning is designed such that, when the tension spring is moved on the support from the pre-assembly position to the final assembly position along the displacement path, no or only gradual increases in the preload of the tension spring occur, so that damaging stress, especially shear stress, is prevented for all components subjected to this movement. For this purpose, one possible embodiment of the support is free of grooves and depressions on the contact surfaces over which the tension spring slips during repositioning, transversely to the displacement direction of the tension spring.

[0062] To prevent the tension spring from shifting automatically or unintentionally from the final assembly position to the pre-assembly position, it is preferably provided that the base forms a step sloping downwards in the direction of the tension spring's movement. As the tension spring is moved from the pre-assembly position to the final assembly position, the bent end section descends from this step onto the rail foot. The step thus forms a rear stop for the bent end section, preventing it from leaving the final assembly position.

[0063] The tension spring is advantageously positioned on the base in the pre-assembly position in such a way that the insertion of a rail between pre-assembled tension springs is not obstructed. This allows sleepers to be fitted 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 their final assembly position using a suitable tool. This is preferably achieved by the base having a lateral contact surface for the rail foot and by arranging the hold-down device or fastening screw such that the tension spring does not protrude beyond the contact surface in the pre-assembly position.

[0064] 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.

[0065] For safety reasons, it should be ensured that the fastening screw does not unintentionally loosen when the tension spring is moved 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 biased towards the screw head or nut on one side of the screw, while it is supported on the base on the other side of the screw, can be utilized.

[0066] 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 tightening torque. In other words, the fastening screw or the nut of the hook screw is designed so that it primarily holds down the free end of the retaining section of the tension spring, with the first leg of the tension spring bearing against the support, and the tightening direction of the thread of the fastening screw or the hook screw is designed such that, when the tension spring is displaced transversely to the longitudinal direction of the rail from the pre-assembly position to the final assembly position, the free end of the retaining section is subjected, directly or indirectly, to a tightening torque on the fastening screw or the nut of the hook screw.

[0067] For a fastening system with a tension spring that can be rotated between a pre-assembly position and a final assembly position, it is provided that the rotation from the pre-assembly position to the final assembly position takes place in the fixed direction of rotation of the fastening screw or the nut of the hook screw, so that it is thereby indirectly or directly subjected to a torque in the fixed direction of rotation.

[0068] The invention is explained in more detail below with reference to exemplary embodiments schematically illustrated in the drawing. In this 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 design 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 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 design of a rail fastening using the tension spring according to Fig. 1 , Fig. 12 a modified design of the rail fastening Fig. 11 , Fig. 13 a fourth design of a rail fastening using the tension spring according to Fig. 1 , Fig. 14 a training according to Fig. 12 with a modified angled 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 expanded representation, 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 a further cross-sectional view of the rail fastening according to Fig. 19 .

[0069] 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, wherein a retaining section 5, bent inwards in a hook shape and supported on a retainer, 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. The retaining section 5 comprises a free end region 7.

[0070] In Fig. 2 It is evident that, viewed from above, a gap x is arranged between the bent end section 6 and the free end region 7 of the retaining section 5 on the side of the free end region 7 facing the second leg 4. The gap allows the retaining section of the tension spring 1 to be inserted, hook-end first, into a tunnel-shaped recess of the hold-down (see Fig. 5-8 ))

[0071] In Fig. 3 und 4 It is evident that the first leg 3 and the retaining section 5, including the free end region 7, lie in the same plane, thus forming a flat bearing surface a. Since the tension spring 1 is bent from a wire with a circular cross-section, this also means that the central axis of the aforementioned sections lies in a common median plane b. In the unloaded state, it is further provided that the free end region 7 of the retaining 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, starting from the first leg 3, the U-bend, 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 retaining section 5 including the free end region 7.

[0072] In the further course of the U-bend 2, i.e., towards the second leg 4, the U-bend 2 is bent downwards out of plane a or b, so that the normal distance of the second leg 4 to plane a or b increases up to the bent end section 6. 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.

[0073] In Fig. 3 It is further shown that the bent end section 6 has a bearing surface d for support 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 exists between the bent end section 6 or the bearing surface d and the plane a or b of the holding section 5 and the first leg 3.

[0074] Fig. 5 Figure 8 shows a rail 8 which is fastened to a sleeper 11 by means of an intermediate plate 10 arranged on a base plate 9. The fastening is effected on each side of the rail 8 by means of a tension spring 1 as shown. Fig. 1 , which has a tunnel-shaped recess 13 of a hold-down device 12 inserted into it. In the Fig. 5 In the illustrated final assembly position of the tension spring 1, its bent end section 6 presses against the rail foot 16 of the rail 8, optionally with the intermediate arrangement 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 screwed to the sleeper 11. Alternatively, an anchor can be molded onto the underside of the plate 10, which is embedded in the concrete sleeper 11 during its casting.

[0075] Fig. 6 Figure 1 is an enlarged view of the tension spring 1 inserted into the tunnel-shaped recess 13. It can be seen that the tension spring, with its retaining section 5, was inserted into the tunnel-shaped recess 13 in the direction of arrow 14, i.e., in the longitudinal direction of the rail, 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 rising in the insertion direction 14 until it falls over a step formed at the end of the ramp 17 onto the rail foot 16. Furthermore, a stop 18 is formed on the side of the retainer 12 facing the rail foot 16, extending beyond the bent end section 6 by a distance, and together with the end section 6, it acts as an overload protection device.

[0076] 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, i.e. 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 over a step 19 formed at the end of the ramp 17 onto the rail foot 16. An insulator 15 can be arranged between the tension spring 1 and the rail foot. In the Fig. 8 In the final assembly position shown, the retaining section 5 protrudes from the tunnel-shaped recess 13 on the side facing the rail 8 and forms a stop that overlaps the rail foot 16 with optional insulator 15 by a distance, thus forming an overload protection.

[0077] The in Fig 7 und 8 The used hold-down device 12 is in the Fig. 9 und 10 shown in more detail, in which 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 without a gradient, on which the bent end section 6 of the tension spring 1 rests in a pre-assembly position. Furthermore, it is shown in Fig. 9 und 10 An anchor 31 is visible, with which the hold-down device can be embedded or cast into a concrete sleeper 11 or, for example, a plastic sleeper 11.

[0078] In Fig. 11 A modified embodiment is shown in which the tension spring 1 is tensioned by a retainer designed as a fastening screw 25. The fastening screw 25 is hooked onto the rib 24 as a hook screw or screwed into the threshold 11 in such a way that its screw shank or thread passes through a gap between the first leg 3 and the free end region 7 of the retaining section 5 of the tension spring 1. The gap between the first leg 3 and the free end region 7 of the retaining section 5 is slot-shaped, so that the tension spring 1 can be positioned between a pre-assembly position and the position shown in the figure. Fig. 12 The rail support 10 can be moved to the final assembly position shown. In the illustrated design, the rail support 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.

[0079] In the modified training according to Fig. 12 The fastening system on both sides of the rail 8 comprises an angle guide plate 26, which engages in a groove 27 of the sleeper 11 with a rib formed on the underside.

[0080] Fig. 13 Figure 1 shows the use of a rail fastening according to the invention in the area of ​​a turnout, which has a stock rail 8 and a tongue rail 28 that can be moved between a retracted and a retracted position. The tongue rail 28 slides with its rail foot on a slider 29, wherein the hold-down device 12 has a further sliding surface on its upper side that is flush with the sliding surface of the slider 29. The hold-down devices 12 arranged on both sides of the stock rail 8 can be formed integrally with a base plate 30.

[0081] The training according to Fig. 14 essentially corresponds to the training according to Fig. 12 , whereby the angle guide plate 26 is designed in two parts. The angle guide plate 26 consists, as shown in the Fig. 15 und 17 As can be seen, the assembly consists of 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 engages in the groove 27 when installed, the rib 34 preferably having a trapezoidal cross-section and at least one guide surface 38. The first and second parts 32, 33 are guided along guide surfaces 38, 39 which are inclined to the longitudinal direction of the rail. Fig. 17 ) are slidable against each other to allow adjustment to the respective track gauge. The second part 33 further comprises a plate-shaped support element 41 on which the tension spring 1 rests and which overlaps the upper surface of the first element 32. As in Fig. 17 As can be seen, the plate-shaped support element 41 has at least one inclined 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 to hold the two parts 32, 33 together, particularly in the unloaded state. It is further evident that the second part 33, in particular the plate-shaped support element 41, has a through-hole 35, which is penetrated by the screw 25 when the tension spring 1 is installed. The through-hole 35 is designed as an elongated hole perpendicular to the longitudinal direction of the rail. For lateral guidance of the tension spring 1, the second part 33, in particular the plate-shaped support element 41, has two walls 37 that extend in the insertion direction 14 of the tension spring 1. The projection 36, which is arranged between the first leg 3 and the free end 7 of the retaining section 5 of the tension spring 1, also serves to guide the tension spring 1.

[0082] The tension spring 1 can be positioned between the in Fig. 14 The tension spring 1 can be moved between the illustrated final assembly position and a pre-assembly position (not shown) in which it does not extend beyond the rail foot. The design is such that screw 25 does not need to be loosened to move the tension spring 1 from the pre-assembly position to the final assembly position. This movement can be accomplished, for example, using a lever-like tool.

[0083] Fig. 18 und 19 demonstrate based on the training according to Fig. 12 the adjustability of the tension spring 1 between the pre-assembly position ( Fig. 18 ) and the final assembly position ( Fig. 19 ), whereby, insofar as matching components are concerned, reference numerals from the Fig. 14-17 were retained. Fig. 20 und 21 each show a cross-section of the Fig. 18 or 19 along line XX or XXI.

[0084] 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 shank 43, with the screw head 42, with a washer 44 interposed, compressing the tension spring. The projection 36 of the angle guide plate 26 forms a stop 45 with which the screw head 42 or the washer 44 interacts, thus limiting the screw-in depth of the fastening screw 25. The stop 45 serves to define the compressed state of the tension spring 1 or the tightened state of the fastening screw 25 such that the tension spring 1 remains movable between the pre-assembly and final assembly positions. The stop 45 defines a minimum vertical distance h between the washer 44 and the bearing surface of the angle guide plate 26, which is equal to or greater than the unloaded diameter of the wire forming the tension spring in this area.

[0085] 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 that 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.

[0086] Furthermore, in Fig. 18 und 19 A ramp 47 formed on the angle guide plate 26 is shown, which is arranged such that the bent end section 6 of the tension spring 1 slides down on it when moved from the pre-assembly position to the final assembly position. The ramp is flat or rising towards the rail foot 16, with the end of the ramp forming a step sloping down towards the rail foot, over which the bent end section 6 descends onto the rail foot 16 when the tension spring 1 is moved from the pre-assembly position to the final assembly position.

[0087] 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. 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 clamping 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.

[0088] The rotatable stop 45, similar to the previously described sliding design, serves to define the lowered 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 and final assembly positions. The intermediate piece 48 comprises a section extending over the first leg 3 and the free end region 7, thereby clamping the tension spring when the fastening screw 25 is tightened. Here, the section of the intermediate piece 48 extending over the first leg 3 and the free end region 7, acting as a stop 45, defines a minimum vertical distance h between the bearing surface of the tension spring on the angle guide plate 26 and the opposite contact surface of the intermediate piece 48. This distance is equal to or greater than the unloaded diameter of the wire forming the tension spring in this section.Furthermore, the intermediate piece 48 includes a projection 49 that engages behind the end face of the free end region 7 of the tension spring 1 or engages in the space between the free end region 7 and the U-bend 2. The projection 49 acts as a safeguard against horizontal displacement of the tension spring 1 and as a driver to assist in transferring the rotational movement applied to the tension spring 1 by a tool acting on the intermediate piece 48 or stop 45.

[0089] The angle guide plate 26 from the Figuren 22 bis 25 is in Fig. 26 In more detail, it is shown that a projection 50 is formed on the side 46 facing the rail foot 16. This projection has a contoured edge 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 rotatably displaceable tension spring 1. Furthermore, the contact surface 46 forms a step 52 extending from its upper edge down to the rail foot. To ensure that the holding force in the final assembly position is fully transferred to the rail foot, the required vertical clearance between the second leg and the angled guide plate 26 of the tension spring 1 must be present. A recess 51 provides this clearance by lowering the upper edge of the contact surface 46 and the step 52 at the corresponding location.

[0090] Fig. 27 shows the SS cutoff through level 52 from Fig. 19. This slopes down to the rail base by a distance Y.

Claims

1. A 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 inwardly bent holding section (5) which can be braced against a hold-down device is formed on the first leg (3) and an end section (6) 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 so that a hold-down force can be applied to the track body element via the bent end section (6), wherein the holding section (5) has a free end portion (7) connected to the first leg (3) via a hook bend and arranged between the first leg (3) and the second leg (4), characterized in that the free end portion (7) of the holding section (5), as viewed in the direction of a longitudinal extension of the free end portion (7), covers the U-bend at least partially, preferably completely.

2. Tension spring according to claim 1, characterized in that the bent end section (6) extends at an angle of 80-100°, preferably about 90°, to the second leg (4).

3. Tension spring according to claim 1 or 2, characterized in that the first leg (3) and the free end portion (7) of the holding section (5) in the unloaded state provide a planar bearing surface.

4. Tension spring according to any one of claims 1 to 3, characterized in that the first leg (3) and the free end portion (7) of the holding section (5) in the unloaded state lie with their respective center axes, preferably over their entire extension, in a center plane which preferably runs parallel to the planar bearing surface.

5. Tension spring according to any one of claims 1 to 4, characterized in that the hook bend of the holding section (5) has a substantially 180° bend so that the free end portion (7) of the holding section (5), preferably in a normal projection onto the planar bearing surface or the center plane, runs essentially parallel to the first leg (3) at least in sections.

6. Tension spring according to any one of claims 1 to 5, characterized in that an imaginary extension of the bent end section (6) overlaps the hook bend in a plan view.

7. Tension spring according to any one of claims 3 to 6, characterized in that the bent end section (6) in the unloaded state has a normal distance to the center plane or to the planar bearing surface, wherein preferably the hook bend and the bent end section (6) define, in the unloaded state, the maximum overall height of the tension spring (1) measured normal to the center plane or to the planar bearing surface, wherein preferably the overall 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).

8. Tension spring according to any one of claims 3 to 7, characterized in that the second leg (4) in the unloaded state has a normal distance from the center plane or from the planar bearing surface which increases continuously in the direction towards the bent end section (6), wherein preferably the second leg (4) in the unloaded state runs at an acute angle inclined relative to the center plane or to the planar bearing surface.

9. Tension spring according to any one of claims 3 to 8, characterized in that the bent end section (6) has a bearing surface for bearing on the track body element which, in the unloaded state, extends upwardly at an acute angle relative to the center plane or to the planar bearing surface.

10. Tension spring according to any one of claims 1 to 9, characterized in that, on the side of the free end portion (7) facing the second leg, a gap (x) is arranged between the bent end section (6) and the free end portion (7) of the holding section (5), as seen in a longitudinal extension of the free end portion (7) and in a plan view.

11. Tension spring according to any one of claims 1 to 10, characterized in that the holding section (5) of the tension spring (1) can be pushed transversely to the longitudinal direction of the rail into a tunnel-shaped recess (13) of the hold-down device towards the rail, so that preferably the hook bend engages over the rail foot (16) in a final assembly position of the tension spring (1).

12. Tension spring according to any one of claims 1 to 11, characterized in that between the first leg (3) and the free end portion (7) of the holding section (5) a free space is provided which can be penetrated by a screw shank of a fastening screw (25) forming the hold-down device and in which the fastening screw (25) can be displaced in the longitudinal direction of the first leg (3), wherein the screw shank of the fastening screw (25) has a diameter which is larger 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 larger than or equal to the radius of the screw shank.

13. Rail fastening device comprising a tension spring (1) according to any one of claims 1 to 12 and a hold-down device (12) which can be fastened adjacent to a rail (8) on a base, in particular a sleeper (11), ribbed plate or angle guide plate, and against which the holding section (5) is braced in the mounted state of the tension spring (1) in such a way that the bent end section (6) can be arranged resiliently holding down a track body element, in particular a rail foot (16) of the rail.

14. Rail fastening device according to claim 13, characterized in that, in the mounted state of the tension spring (1), the hold-down device at least partially engages over both a free end portion (7) of the holding section (5) and the first leg (3).

15. Rail fastening device according to claim 13 or 14, 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, wherein preferably the holding section (5) of the tension spring (1) can be pushed transversely to the longitudinal direction of the rail into the tunnel-shaped recess (13) towards the rail, wherein preferably 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 in a final assembly position of the tension spring (1) projects out of the tunnel-shaped recess (13) and engages over the track body element, in particular the rail foot (16).

16. Rail fastening device according to claim 13 or 14, characterized in that the 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 bolt with nut which is suspended in a base, in particular a ribbed plate, the screw shank and / or thread of which passes through a free space between the first leg (3) and the free end portion (7) of the holding section (5) of the tension spring (1) in order to hold down the tension spring (1) in the region of the holding section (5) and optionally of the first leg (3), wherein preferably a stop (45) limiting the screw-in depth of the hold-down device and preferably cooperating with the screw head (42) or the nut of the fastening screw (25) is 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.

17. Rail fastening device according to claim 16, characterized in that the tension spring (1) is displaceable, in particular rotatable or displaceable transversely to the longitudinal direction of the rail, with its bent end section (6) in the tightened state of the hold-down device between a pre-assembly position and a final assembly position.

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