Tension clamp and fastening point for the fastening of a rail to the ground

Abstract

The invention relates to a tension clamp for the holding of a rail for rail vehicles and a rail fastening point. The tension clamp has a central section having two legs, two torsional sections connected thereto and leading away laterally in an outwards direction having a supporting zone, and two supporting arms connected to the torsional sections. The supporting arms run to the front face of the tension clamp and have a spring section and a support section with a supporting zone. The fact that the support sections point laterally in an outwards direction such that the straight lines which in each case connect the centers of the supporting zones and the torsional section allocated to the supporting arm in an area on the rear face of the tension element increases the natural frequencies of the tension clamp such that they are outside of stimulation frequencies that occur in practice.

Claims

1. A tension clamp for elastically holding down a rail for rail vehicles, the rail comprising a foot, a web that is supported on the foot and a rail head carried by the web, the tension clamp comprising: a loop-shaped central section, with two legs and a base section that connects the legs to one another, wherein a free end face of the base section faces a front face, a free upper face of the loop-shaped central section faces an upper face of the tension clamp and the legs of the loop-shaped central section face with their ends, which face away from the base section, face a rear face of the tension clamp, two torsional sections, one of which in each case is connected to an end of one of the legs of the loop-shaped central section that faces away from the base section, wherein the two torsional sections lead away laterally in an outwards direction in each case starting from the leg that is allocated to the two torsional sections respectively and wherein the torsional sections have a supporting zone on a lower face by means of which the tension clamp is supported on a component that bears them during use; and two supporting arms, one of which in each case is connected to an end of one of the two torsional sections that faces away from the allocated leg of the loop-shaped central section, wherein the supporting arms run in the direction of a front face of the tension clamp and in each case have a spring section curved towards an upper face of the tension clamp and a support section that ends at a free end of the supporting arm, the free end of which support section has a supporting zone by means of which the supporting arm in question is supported on the foot of the rail to be fastened during use, wherein the support sections of the supporting arms and the free ends thereof each point laterally outward relative to the loop-shaped central section of the tension clamp such that when the tension clamp is viewed from above straight lines that connect the center of the supporting zones of the supporting arms to the center of the supporting zone of the torsional section allocated to the respective supporting arm intersect in an area located on the rear face of the tension clamp, and wherein for a distance, AS, measured parallel to a symmetrical axis of the tension clamp between the center of the supporting zones of the supporting arms and a point of intersection of the straight lines which connect the center of the supporting zones of the supporting arms respectively to the center of the support zones of the torsional section allocated to the respective supporting arm and for a distance, AG, that is also measured parallel to the symmetrical axis between the supporting zones of the supporting arms and the centers of the supporting zones of the torsional sections, the following applies:
1.2×AG≤AS≤1.8 AG.

2. The tension clamp according to claim 1, wherein an angle enclosed between the straight lines when the tension clamp is viewed from above is at least 60°.

3. The tension clamp according to claim 1, wherein an angle enclosed between the straight lines when the tension clamp is viewed from above is a maximum of 120°.

4. The tension clamp according to claim 1, wherein the supporting arm runs in an outwards direction from the loop-shaped central section starting from the torsion section allocated to the supporting arm when the tension clamp is viewed from above.

5. A tension clamp according to claim 1, wherein the supporting arm runs in an inwards direction in the direction of the base section of the loop-shaped central section starting from the torsion section allocated to the supporting arm when the tension clamp is viewed from above.

6. The tension clamp according to claim 5, wherein the supporting arm runs in a straight line over at least part of the length of the supporting arm's spring sections.

7. The tension clamp according to claim 1, wherein, in the case of the supporting arms, the spring section transitions into a continuous curved line in the allocated support section.

8. The tension clamp according to claim 1, wherein when the tension clamp is viewed from above, the supporting zones of the supporting arms protrude relative to the free front face of the base section of the central section in the direction of the front face of the tension clamp.

9. The tension clamp according to claim 1, wherein the following applies for the distance AG and the distance AS:
1.3×AG≤AS≤1.7 AG.

10. A fastening point in which a fastening point for a rail vehicle is fastened on a ground, wherein a tension clamp designed according to claim 1 is provided for exerting an elastic holding force on the rail.

11. The tension clamp according to claim 1, wherein an angle enclosed between the straight lines when the tension clamp is viewed from above is at least 90°.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in more detail in the following with reference to a drawing illustrating exemplary embodiments: Shown schematically is the following:

(2) FIG. 1 a view of a tension clamp according to the invention from above;

(3) FIG. 2 a perspective view of the tension clamp according to FIG. 1 from the front;

(4) FIG. 3 a lateral view of the tension clamp according to FIG. 1 and FIG. 2;

(5) FIG. 4 a view of a second tension clamp according to the invention from above;

(6) FIG. 5 a perspective view of the tension clamp according to FIG. 4 from the front;

(7) FIG. 6 a perspective view of the tension clamp according to FIG. 4 and FIG. 5 from the back;

(8) FIG. 7 a lateral view of the tension clamp according to FIGS. 4-6;

(9) FIG. 8 a diagram showing a force-path characteristic curve for a conventional tension clamp as shown in FIGS. 4-7.

DESCRIPTION OF THE INVENTION

(10) The tension clamp 1 according to the invention that is shown in FIGS. 1-3 and curved into a single piece from a spring wire with a circular cross section has a U-shaped central section 2 having a base section 3 allocated to the front face V of the tension clamp and straight legs 4, 5 connected to said base section. Flattened contact surfaces 6, 7 are provided on the upper face of the legs 4, 5 of the central section 2 allocated to the upper face O of the tension clamp 1, on which contact surfaces a sleeper screen sits with its screw head as a tensioning element to tension the tension clamp 1 during use (not shown).

(11) The legs 4, 5 of the central section 2 each pass into a torsional section 8, 9 of the tension clamp 1 on the ends that point away from the base section 3 and towards the rear face R of the tension clamp 1. The torsional sections 8, 9 are curved in the direction of the lower face U of the tension clamp 1 and lead in a lateral direction outwards from the respective allocated legs 4, 5. The lower face of each of the torsional sections 8, 9 has a supporting zone 10, 11 by means of which they sit on a contact surface of a guide plate during use.

(12) A supporting arm 12, 13 is connected to the end of the torsional sections 8, 9 that points away from the central section 2 in each case. The supporting arms 12, 13 are designed to be curved in an arch-like manner in the region of their spring sections 14, 15 in the direction of the upper face O of the tension clamp 1 and run from the respective torsional section 8, 9 in the direction of the front face V of the tension clamp 1. They are aligned such that when viewed from above (FIG. 1) the distance of the supporting arms 12, 13 starting from the torsional sections 8, 9 measured in parallel to the connection lines G between the centers Z10, Z11 of the supporting zones 10, 11 is widened in each case.

(13) The free ends 16, 17 of the supporting arms 12, 13 each end in a support section 18, 19 which connects to the respective spring section 14, 15 with which the supporting arm 12, 13 sits in the rails to be fastened in the respective rail fastening point on the foot (not shown) during use. Punctiform supporting zones 20, 21 are formed in each case on the lower face of the support sections 18, 19 allocated to the lower face U of the tension clamp 1 on the ends 16, 17 of the supporting arms 12, 13.

(14) The support sections 18, 19 are shaped in a continuous curve starting from the respective spring section 14, 15 from the central section 2 laterally in an outwards direction such that they are nestled tangentially to a straight line aligned in parallel to the connection lines G. The length of the supporting arms 12, 13 is dimensioned such that the punctiform supporting zones 20, 21, when viewed from above (FIG. 1), lie in front of the base section 3 of the central section 2 in the direction of the front face V of the tension clamp 1.

(15) As a result of the outwards-facing arrangement of the support sections 18, 19 and the corresponding lateral external punctiform supporting zones 20, 21 of the supporting arms 12, 13, the connection lines G1, G2, which on the one side (connection line G1) connect the center Z10 of the supporting zone 10 of the torsional section 8 to the punctiform supporting zone 20 which therefore also reflects the center of the supporting arm 12 connected to the torsional section 8 and on the other side (connection line G2) connects the center Z11 of the supporting zone 11 of the torsional section 9 to the punctiform supporting zone 21 which therefore also reflects the center of the supporting arm 13 connected to the torsional section 9 are arranged at an acute angle ß1 relative to the symmetrical axis S of the tension clamp 1 and enclose an angle ß2 of around 70°. Accordingly, when viewed from above (FIG. 1) they intersect at a point of intersection SG that lies behind the rear face R of the tension clamp 1.

(16) The distance AS between the punctiform supporting zones 20, 21 that form their own center of the supporting arms 12, 13 measured in parallel to the symmetrical axis S on the one side and the point of intersection SG on the other side corresponds to around 1.5 times the distance AG of the punctiform supporting zones 20, 21 from the centers Z10, Z11 of the supporting zones 10, 11 of the torsional sections 8, 9 that is also measured in parallel to the symmetrical axis S. In practice, the distance AG can for example be approximately 100 mm and the distance AS approximately 150 mm, wherein the distance AS can also be varied in a range from for example 130 mm to 170 mm if this is expedient with respect to the setting of the natural frequencies or on the basis of structural circumstances.

(17) Practical tests have shown that the tension clamp 1 has a natural frequency that is at least 50% higher than to a conventionally shaped tension clamp 101 as shown in FIGS. 4 and 5. This is so high that even under unfavorable conditions of use, for example in tunnels or on bridges, there will not be any stimulation of the tension clamp 1 in the range of its natural frequencies.

(18) The tension clamp 101 according to the invention that is shown in FIGS. 4-7 and curved into a single piece from a spring wire with a circular cross section has a U-shaped central section 102 having a base section 103 allocated to the front face V of the tension clamp 1 and straight legs 104, 105 connected to said base section. Flattened contact surfaces 106, 107 are provided on the upper face of the legs 104, 105 of the central section 102 allocated to the upper face O of the tension clamp 101, on which contact surfaces a sleeper screen sits with its screw head as a tensioning element to tension the tension clamp 101 during use (not shown).

(19) The legs 104, 105 of the central section 102 each pass into a torsional section 108, 109 of the tension clamp 101 on the ends that point away from the base section 103 and towards the rear face R of the tension clamp 101. The lower face of each of the torsional sections 108, 109 has a supporting zone 110, 111 by means of which they sit on a contact surface of a guide plate during use.

(20) The torsional sections 108, 109 are curved in the direction of the lower face U of the tension clamp 101 and lead in a lateral direction outwards from the respective allocated legs 104, 105. Starting from the respective leg 104, 105, the respective torsional section 108, 109 runs in a narrower curve than in tension 1 initially in the direction of the lower face U of the tension clamp 101 and then in a further curve in an outwards direction that is also narrower than the corresponding curve on the tension clamp 1. An area of the respective torsional section 108, 109 that extends laterally away from the allocated leg 104, 105 connects to this, which area is longer when viewed from above (FIG. 4) than the corresponding area of tension clamp 1. A further curve 108′, 109′ by means of which the torsional sections 108, 109 pass into the supporting arm 112, 113 connected to them in each case can be found in this area. The curvature radius of this angle 108′, 109′ is greater than the corresponding curve of the tension clamp 1 when viewed from above (FIG. 4) and extends over a larger angle range than in tension clamp 1. In this way, supporting arms 112, 113 of the tension clamp 101 starting from their connection to the respective allocated torsional section 108, 109 are aligned in the direction of the free, protruding base section 103 of the central section 102 of the tension clamp 101. The supporting arms 112, 113 have an area 112′, 113′ in which they are formed in a straight manner when viewed from above (FIG. 4). If a straight line is placed in the areas 112′, 113′ coaxial to the longitudinal axis of the areas 112′, 113′ when viewed from above (FIG. 4), these straight lines intersect at a point that lies on the front face V of the tension clamp 101 and the symmetrical axis S of the tension clamp 101. At the same time, the supporting arms 112, 113 are each designed to be curved in an arch-like manner in the area of their spring sections 114, 115 in the direction of the upper face O of the tension clamp 1 in each case.

(21) The free ends 116, 117 of the supporting arms 112, 113 each end in a support section 118, 119 which connects to the respective spring section 114, 115 with which the supporting arm 112, 113 sits in the rails to be fastened in the respective rail fastening point on the foot (not shown) during use. Punctiform supporting zones 120, 121 are formed in each case on the lower face of the support sections 118, 119 allocated to the lower face U of the tension clamp 101 on the ends 116, 117 of the supporting arms 112, 113.

(22) The support sections 118, 119 are shaped in a continuous curve starting from the respective spring section 114, 115 from the central section 102 laterally in an outwards direction such that they are nestled tangentially to a straight line aligned in parallel to the connection lines G. The length of the supporting arms 112, 113 is dimensioned such that the punctiform supporting zones 120, 121, when viewed from above (FIG. 4), lie in front of the base section 103 of the central section 102 in the direction of the front face V of the tension clamp 101

(23) As a result of the outwards-facing arrangement of the support sections 118, 119 and the corresponding lateral external punctiform supporting zones 120, 121 of the supporting arms 112, 113, the connection lines G1, G2, which on the one side (connection line G1) connect the center Z110 of the supporting zone 110 of the torsional section 108 to the punctiform supporting zone 120 which therefore also reflects the center of the supporting arm 112 connected to the torsional section 108 and on the other side (connection line G2) connects the center Z111 of the supporting zone 111 of the torsional section 109 to the punctiform supporting zone 121 which therefore also reflects the center of the supporting arm 113 connected to the torsional section 109 are arranged at an acute angle ß1 relative to the symmetrical axis S of the tension clamp 101 and enclose an angle ß2 of around 60°. Accordingly, when viewed from above (FIG. 4) they intersect at a point of intersection SG that lies behind the rear face R of the tension clamp 101.

(24) The distance AS between the punctiform supporting zones 120, 121 that form their own center of the supporting arms 112, 113 measured in parallel to the symmetrical axis S on the one side and the point of intersection SG on the other side corresponds to around 1.7 times the distance AG of the punctiform supporting zones 120, 121 from the centers Z110, Z111 of the supporting zones 110, 111 of the torsional sections 108, 109 that is also measured in parallel to the symmetrical axis S. In practice, the distance AG can for example be approximately 100 mm and the distance AS approximately 150 mm, wherein the distance AS can also be varied in a range from for example 130 mm to 170 mm if this is expedient with respect to the setting of the natural frequencies or on the basis of structural circumstances.

(25) Practical tests have shown that the tension clamp 101 has a 50% higher natural frequency than a conventionally shaped tension clamp 101 designated Skl15 and described in the above-mentioned brochure “System 300 highly elastic rail fastening for conventional and high speed—the proven solution for slab tracks”.

(26) The force-path characteristic curves of the second loading and unloading determined in the tests are shown in FIG. 8, wherein the characteristic curve of the conventional tension clamp Skl15 is shown as a solid line and the characteristic curve of the tension clamp 101 according to the invention is shown as a dashed line.

(27) It is demonstrated that the characteristic curve of the tension clamp 101 according to the invention has a flatter gradient, which has a favorable effect on the durability of the tension clamp 101. As a result of this, the tension clamp 101 not only has improved natural frequency behavior compared to the conventional Skl15, but also has improved durability. In other words, the tension clamp 101 according to the invention can tolerate significantly greater levels of deformation than the conventional tension clamp Skl15.

(28) The characteristic values “natural frequency”, vertical durability and the gradient of the characteristic curve of the tension clamps determined in the tests on the conventional tension clamp Skl15 and the tension clamp 101 according to the invention can be found in Table 1.

(29) In order to determine the natural frequency, modal analyses were initially carried out using the Finite Element Method “FEM” and the results obtained were then verified by means of measurements carried out on the test stand and on the platform.

(30) The vertical durability was determined using the DBS918127 standard by Deutsche Bahn AG of June 2010 (DB Standard), chapter 5.3 “Vertical durability”.

(31) The natural frequency determined for the tension clamp 101 is so high that even under unfavorable conditions of use, for example in tunnels or on bridges, there will not be any stimulation of the tension clamp 101 in the range of its natural frequencies.

(32) TABLE-US-00001 TABLE 1 SKL15 Tension clamp 101 First natural frequency 500-600 Hz 900-1000 Hz Vertical durability 3 mm at least 5 mm Gradient of the 0.7-0.8 mm/kN 0.3-0.4 mm/kN characteristic curve