US-20260125855-A1 - CLAMPING SPRING FOR HOLDING DOWN A TRACK BODY ELEMENT

Abstract

A tension spring for holding down a track body element, such as a rail foot of a rail, including 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 inwardly bent holding section which can be braced against a hold-down device is formed on the first leg and an end section bent towards or away from the holding 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 body element via the bent end section.

Inventors

• Thomas Mayer
• Wolfgang Hölzl
• Stefan BREITEGGER

Assignees

• Voestalpine Turnout Technology Zeltweg GmbH
• Voestalpine Railway Systems GmbH

Dates

Publication Date

20260507

Application Date

20251209

Priority Date

20220829

Claims (20)

1. 1 . A rail fastening device comprising: a tension spring configured to hold down a track body element; and a hold-down device configured to be fastened adjacent to a rail on a base; wherein the tension spring comprises a U-shaped main section having 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 inwardly bent holding section which can be braced against the hold-down device is formed on the first leg and an end section bent towards or away from the holding section is formed on the second leg; wherein the U-bend forms a torsion section so that a holding-down force can be applied to the track body element via the bent end section; and wherein the holding section is supported on the hold-down device in the mounted state of the tension spring so that the bent end section can be arranged to resiliently hold down the track body element when installed transversely to a longitudinal direction of the rail.
2. 2 . The rail fastening device according to claim 1 , wherein the holding section comprises a free end portion connected to the first leg by a hook bend and disposed between the first leg and the second leg.
3. 3 . The rail fastening device according to claim 2 , wherein the hook bend comes to lie above the rail foot in a final assembly position and can form an overload protection.
4. 4 . The rail fastening device according to claim 2 , wherein the hold-down device, in the mounted state of the tension spring, at least partially engages over both the free end portion of the holding section and the first leg.
5. 5 . The rail fastening device according to claim 1 , wherein the hold-down device has or forms a tunnel-shaped recess into which the holding section of the tension spring can be at least partially inserted.
6. 6 . The rail fastening device according to claim 5 , wherein the holding section of the tension spring is configured to be inserted transversely to the longitudinal direction of the rail into the tunnel-shaped recess towards the rail.
7. 7 . The rail fastening device according to claim 6 , wherein the tunnel-shaped recess is open on the side facing the track body element, and a hook bend protrudes from the tunnel-shaped recess in a final assembly position of the tension spring and engages over the track body element.
8. 8 . The rail fastening device according to claim 6 , wherein: the hold-down device has a ramp that rises in the insertion direction and on which the bent end section rests in a sliding manner during insertion of the holding section into the tunnel-shaped recess.
9. 9 . The rail fastening device according to claim 8 , wherein a step is formed at an end of the ramp, via which the bent end section reaches a final assembly position, in which the end section rests on the track body element, the step forming a rear stop which secures the bent end section against leaving the final assembly position.
10. 10 . The rail fastening device according to claim 1 , further comprising: a slide chair associated with the rail formed as a stock rail and having a slide surface for a tongue rail; wherein a hold-down device is connected to the slide chair.
11. 11 . The rail fastening device according to claim 1 , wherein the hold-down device is formed by a fastening screw which can be screwed into the base, or by a hooked bolt with nut which is suspended in another base, at least one of the screw shank and a thread of the screw shank passes through a free space between the first leg and the free end portion of the holding section of the tension spring to hold down the tension spring in a region of the holding section.
12. 12 . The rail fastening device according to claim 11 , wherein a stop limiting the screw-in depth of the hold-down device and cooperating with the screw head or the nut of the fastening screw is arranged on at least one of the base and the hold-down device, so that a hold-down force on the tension spring can be limited.
13. 13 . The rail fastening device according to claim 11 , wherein 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.
14. 14 . The rail fastening device according to claim 11 , wherein the tension spring is displaceable, with its bent end section in the tightened state of the hold-down device between a pre-assembly position and a final assembly position.
15. 15 . The rail fastening device according to claim 14 , wherein the tension spring is rotatable or displaceable transversely to the longitudinal direction of the rail.
16. 16 . The rail fastening device according to claim 14 , wherein the base forms a step which slopes in the displacement direction of the tension spring and from which the bent end section descends onto the rail foot when the tension spring is displaced from the pre-assembly position to the final assembly position.
17. 17 . The rail fastening device according to claim 16 , wherein the bent end section lying on the step is arranged higher than a hook bend of the holding section.
18. 18 . The rail fastening device according to claim 11 , wherein the base has a lateral contact surface for the rail foot and the hold-down device or the fastening screw is arranged in such a way that the tension spring does not project beyond the contact surface in the pre-assembly position.
19. 19 . The rail fastening device according to claim 18 , wherein the distance between the screw shank and the lateral contact surface is equal to or greater than the diameter of the wire forming the tension spring.
20. 20 . The rail fastening device according to claim 11 , wherein the fastening screw or the nut of the hooked bolt holds down the free end portion of the holding section of the tension spring and the first leg of the tension spring is supported on the base, and in that the tightening direction of rotation of the thread of the fastening screw or of the hooked bolt is configured so that the free end portion of the holding section directly or indirectly applies a torque in the tightening direction of rotation to the fastening screw or the nut of the hooked bolt when the tension spring is displaced transversely with respect to the longitudinal direction of the rail from the pre-assembly position into the final assembly position.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation application of U.S. patent application Ser. No. 19/106,347, filed Feb. 25, 2025, entitled “CLAMPING SPRING FOR HOLDING DOWN A TRACK BODY ELEMENT”, which is a national phase application of PCT Application No. PCT/IB 2023/058519, filed Aug. 29, 2023, which claims the benefit of European Patent Application No. 22020414.3, filed Aug. 29, 2022, each of which is incorporated by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a tension spring for holding down a track body element, such as a rail foot of a rail. Furthermore, the invention relates to a rail fastening device 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. 2. Description of the Related Art Rails of a track body are usually assembled using a spring element, usually referred to as a tension spring or tension clamp, and a suitable tensioning element or hold-down device to tension the spring element. This tensioning element or hold-down device is usually a screw by means of which the spring element is braced against the base in such a way that it applies the required holding forces via its section resting on the rail foot. Tensioning can be achieved, for example, by connecting the hold-down device directly to the base 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 base in question. Widely used tension springs are those with the “e” shape and those with a “ω” shape. A tension spring with the “e” shape is described, for example, in EP 313325 B1. The “ω” form can be found, for example, in DE 3243895 A1. Numerous embodiments of fastening systems with tension springs are known, in which the tension spring can be brought not only into a precisely defined final assembly position relative to the rail foot and to the anchoring parts, but also into a positionally secured pre-assembly position. To achieve the pre-assembly position, the tension spring is mounted in such a way that the section intended for holding down the rail foot does not rest on the rail. In this way, railroad ties can already be provided in the factory with tension springs arranged in the pre-assembly position and pretensioned, whereby the tension springs can be brought into the final assembly position and tensioned at the construction site after the rail has been laid with a certain amount of effort by lateral displacement, so that the section intended for holding down the rail foot engages over it and presses it down resiliently from above. A disadvantage of prior art tension springs is the fact that they are designed for only one installation direction or type of installation. The direction of installation is understood to be the direction in which the tension spring, which is usually already pretensioned, is pushed onto the rail foot. Most frequently, tension springs are found that are designed for transverse installation, i.e. for sliding the tension spring on transversely to the longitudinal direction of the rail. In longitudinal installation, on the other hand, the tension spring is brought into its final assembly position in the longitudinal direction of the rail. Due to the limited space available, installation in the longitudinal direction of the rails is advantageous, for example, for fastening the 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 be installed in a direction deviating from this without further ado, whereby a deviating installation direction is not even possible in most cases for geometric reasons alone. Other problems of conventional tension springs are the occurrence of fractures and the loosening of the tension springs and the associated loss of clamping force. Loosening occurs in particular with tension springs that are clamped down with a screw. Fractures often occur in tension springs when they are subjected to excessive stress. Conventional rail fastening systems are in very few cases equipped with overload protection. The purpose of overload protection is to limit the load acting on the tension spring, which is particularly effective if the rail is subject to a strong up and down movement or a strong tilting movement relative to the sleeper when it is passed over. SUMMARY OF THE INVENTION The present invention therefore aims to improve a tension spring and a corresponding fastening system to the extent that the above-mentioned disadvantages can be overcome. In particular, the aim is to create a tension spring that can be held down or tensioned both by means of a screw and without a screw, and which has high