WO2018083455A1

WO2018083455A1 - Fastening railway rails

Info

Publication number: WO2018083455A1
Application number: PCT/GB2017/053267
Authority: WO
Inventors: Stephen John Cox; John Phillip Porrill; Daniel Mark HALL
Original assignee: Pandrol Limited
Priority date: 2016-11-01
Filing date: 2017-10-31
Publication date: 2018-05-11
Also published as: GB201900671D0; GB201618426D0; GB2570219A; GB2570219B

Abstract

A railway rail fastening assembly (100), for fastening a railway rail (200) at a rail seat region (301) of an underlying rail foundation (300), having a resilient fastening device (4) for generating a substantially vertical clamping force (P) for use in damping a foot (201) of the rail (200). The assembly further comprises a shoulder (3) configured to retain the resilient fastening device (4) at one side of the fait seat region (301) of the rail foundation (300) in a configuration in which the resilient fastening device (4) does not bear on the rail foot (201), and force trensmission means (10) configured to at least partially convert the clamping force (P) generated by the resilient fastening device (4) into a substantially horizontal force (L) and apply the substantially horizontal force to the rail foot (201) on opposite sides of rail web.

Description

FASTENING RAILWAY RAILS

The present invention relates to fastening railway rails to an underlying rail foundation. Conventionally railway rails are fastened to an underlying rail foundation, such as a concrete sleeper or slab track, using two resilient rail fastening clips per fastening site, one of the clips bearing against the foot of the rail at a first location on one side of the raii web and the other of the clips bearing against the rail foot at a second location opposite to the first location on the other side of the rail web. Together the two clips apply a clamping force to the raii foot which is sufficient to secure the rail.

According to an embodiment of the present invention there is provided a railway rail fastening assembly for fastening a railway rail at a rail seat region of an underlying raii foundation, wherein the assembly consists of a resilient fastening device configured to generate a substantially vertical clamping force for use in clamping a foot of the rail, a shoulder configured to retain the resilient fastening device at one side of the rail seat region of the raii foundation in a configuration in which the resilient fastening device does not bear on the raii foot, and force transmission means configured to convert at least some of the clamping force generated by the resilient fastening device into a substantially horizontal force, apply the substantially horizontal force to a vertical edge of the raii foot at a first rail foot region thereon, and cause the substantially horizontal force to be reacted at a vertical edge of the rail foot at a second raii foot region thereon, where the second raii foot region is on the opposite side of a web of the rail to the first rail foot region.

Contrary to the prior art therefore, an assembly embodying the present invention uses only one resilient fastening device to apply to the rail foot the same amount of clamping force required to secure the rail which would be achieved using two resilient fastening devices in a conventional rail fastening assembly. The present assembly achieves this by applying a lateral force (derived from the vertical clamping force generated by one resilient fastening device) to one side of the rail foot and reacting it from the opposite side of the rail foot, in accordance with Newton's Third Law. The applicant has found that the proposed assembly meets the minimum rail industry requirement for longitudinal restraint (creep) of the rail. By using only one resilient fastening device, an assembly embodying the present invention may be cheaper overall than a conventional assembly using two resilient fastening devices. In addition, the assembly may provide a good level of resilience, in which case it will be particularly suitable for use in areas where a higher level of vibration attenuation is a requirement.

The resilient fastening device is preferably a resilient rail fastening clip, which may for example be a longitudinally-driven or laterally-driven clip of a conventional shape (for example, shaped like a PANDROL e-clip™ fastener as shown in GB1510224B, a

PANDROL FASTCUP FC™ fastener as shown in EP0619852B1. or a PANDROL

FASTCUP FE™ fastener as shown in EP1987199B1), providing a conventional level of clamping force (i.e. no greater than that which would typically be provided in a conventional rail fastening assembly employing two clips of the same design)

A preferred embodiment of the force transmission means comprises: first and second rail retaining devices each adapted to bear on the rail foot and to extend upwardly at first and second regions respectively on the railway rail foundation adjacent to the rail seat region, where the first region is on the opposite side of the rail seat region to the second region; and wedge means comprising a wedge member configured for location between the shoulder and the second rail retaining device. The shoulder is located on the railway rail foundation at a third region which is outside the rail seat region and is adjacent to but spaced from the second region, such that the resilient fastening device, when retained by the shoulder, is arranged to apply the clamping force to the wedge member. Application of the clamping force to the wedge member brings about application of the substantially horizontal force to the rail foot via the first and second rail retaining devices. The first and second rail retaining devices are not adapted to retain resilient fastening devices. The second rail retaining device may be wholly or partly laterally displaceable (i.e. movable in a direction perpendicular to the longitudinal axis of the rail). in this embodiment the vertical force exerted by the resilient fastening device on the wedge member is converted by the wedge member into a lateral force which is transferred into the rail foot via the first and second rail retaining devices, in particular, as the wedge member is driven vertically downwards under the load of the resilient fastening device It is caused by the shoulder to move laterally and therefore pushes against the second rail retaining device. This causes the second rail retaining device to apply a lateral force to the adjacent rail edge, which in turn causes the opposite rati edge to be pushed into contact with the first rail retaining device. In accordance with Newton's Third Law, the first rail retaining device reacts the lateral force and prevents the rail from moving vertically. The applicant has found that this embodiment can provide a vertical to lateral conversion factor of 1.5 times the input load produced by the single clip, however the conversion factor in other embodiments may be tuned to suit the application and so may be more or less than 1.5 times. The second rail retaining device may be provided on either the gauge side or the field side of the rail, but providing it on the gauge side is preferable as this will ensure that a more constant track gauge is maintained. An advantage of this particular embodiment is that any dynamic vertical movement of the rail is not transferred directly to the resilient rail fastening device, thereby ensuring that the resilient rail fastening device is not affected by any vertical movements which would cause it to go beyond its fatigue limit. In one assembly embodying the present invention, each of the first and second rail retaining devices has a first, upright abutment face. The first abutment face is configured to bear on an upright edge of a foot of the rail to be fastened. The second rail retaining device has a second, upright abutment face on an opposite side of the second rail retaining device to the first abutment face. The first rail retaining device may have a second abutment face which extends transversely with respect to the first abutment face, the second abutment face being configured to overhang an upper surface of the rail foot.

At least one of the first and second rail retaining devices may be configured so as to be removable from the railway rail foundation.

In a preferred embodiment of the present invention, a face of the shoulder which faces the second region has the form of a downwardly-sloping ramp. In this case the wedge member has a sloping face which is configured to abut the face of the shoulder, an upright face which is located on an opposite side of the wedge member to the sloping face and is configured to bear against the second rail retaining device, and an upper face. The wedge member may for example be made of a hard plastics material, such as Nylon™, or cast metal (in the latter case, the second rail retaining device will need to be electrically insulated). Blocking members may be provided for inhibiting movement of the second rail retaining device and/or wedge member in a direction parallel to the longitudinal axis of the rail

An assembly embodying the present invention may further comprise an intermediate member configured for location between the first rail retaining device and the adjacent upright edge of the rail foot. Where, as aforementioned, the first rail retaining device has first and second abutment faces, the intermediate member may have an upright first portion configured for location between the first abutment face of the rati retaining device and an adjacent edge of the rail foot, and a second portion which extends transversely from the first portion and is configured for location between the second abutment face of the rail retaining device and the upper surface of the rail foot. The intermediate member may be formed of plastics or rubber material. The intermediate member is desirably fitted to the first and second abutment faces of the first rail retaining device.

Reference will now be made, by way of example, to the accompanying drawings, in which:

Figure 1A shows a plan view of a first assembly embodying the present invention; Figure 1B shows an end view of the assembly shown in Figure 1A;

Figures 2A. 28 and 2C show respective plan, cross-sectional and end views of a second assembly embodying the present invention, the cross-sectional view of Figure 2B being taken on line X-X in Figure 2A: and

Figures 3A, 3B and 3C show respective plan, cross-sectional and end views of a modification of the second assembly, the cross-sectional view of Figure 3B being taken on line X-X in Figure 3A. As shown in Figures 1A and 18. a railway baseplate 300 is provided with a first railway rail fastening assembly 100 for fastening a railway rail 200 at a rail seat region 301 of the baseplate 300. The assembly 100 consists of a removable resilient fastening device 4, a shoulder 3 secured to the baseplate 300, and force transmission means 10. The resilient rail fastening device 4 is configured to generate a substantially vertical clamping force P for use in clamping a foot 201 of the rail 200. The shoulder 3 is configured to retain the resilient fastening device 4 at one side of the rail seat region 301 of the rail foundation 300 in a configuration in which the resilient fastening device 4 does not bear on the rail foot 201. The force transmission means 10 are configured to convert the clamping force P generated by the resilient fastening device 4 into a substantially horizontal force L and apply forces L, of equal magnitude and opposite direction, respectively to the vertical sides of the rail foot 201 at first and second rail foot regions thereon on opposite sides of a web 202 of the rail 200.

In this embodiment, the force transmission means 10 comprise a first rail retaining device 1 , made of metal for example, and a second rail retaining device 2, each of which retaining devices 1 , 2 is adapted to bear on respective sides of the rail foot 201 and to extend upwardly at first and second regions A, 8 respectively on the baseplate 300 adjacent to, and on opposite respective sides of, the rail seat region 301. The force transmission means 10 further comprise wedge means 5 comprising a wedge member 50 {for example, of plastics material) configured for location between the shoulder 3 and the second rail retaining device 2. The shoulder 3 is located on the railway rail foundation 300 at a third region C which is outside the rail seat region 301 and is adjacent to but spaced from the second region B. The shoulder 3 is configured such that the resilient fastening device 4, when retained by the shoulder 3, is arranged to apply the clamping force P to the wedge member 50. Application of the clamping force P to the wedge member 50 brings about application of the substantially horizontal force L to the rail foot 201 via the first and second rail retaining devices 1 , 2. In the present embodiment the second rail retaining device 2 is laterally disptaceable (i.e. movable towards the rail foot) from the region B such that the force L applied to the second rail retaining device 2 is transferred into the rail foot 201.

The first rail retaining device 1 has a first, upright abutment face 11 , configured to bear on an adjacent upright edge 201a of the rail foot 201. and a second abutment face 12, which extends transversely with respect to the first abutment face 11 and is configured to overhang an upper surface 201c of the rail foot 201. The second rail retaining device 2 comprises a first part 20 and a second part 21. The first part 20, which may for example be made of cast metal, has a first, upright abutment face 20a and a second, upright abutment face 20b on an opposite side of the first part 20 to the first abutment face 20a. The second part 21 , which may for example be made of a semi-resilient material, has a first, upright abutment face 21a affixed to the second face 20b of the first part 20, and a second, upright abutment face 21 b, on an opposite side of the second part 21 to the first abutment face 21a, which is configured to bear on an adjacent upright edge 201 b of the rail foot 201.

A face 3a of the shoulder 3 which faces the second region B has the form of a downwardly-sloping ramp. The wedge member 50 has a sloping face 50a which is configured to abut the ramp face 3a of the shoulder 3. The wedge member 50 also has an upper face 50c, and an upright face 50b which is located on an opposite side of the wedge member 50 to the sloping face 50a and is configured to bear against the abutment face 20a of the second rail retaining device 2. When {as shown in Figure 1A) the foot 201 of a railway rail 200 to be retained is located in the rail seat region 301 between the abutment faces 11 , 21 b of the first and second rail retaining devices 1 , 2, application of the downwards force P to the upper face 50c of the wedge member 50 by part of the resilient fastening device 4 retained in the shoulder 3 causes a lateral force L acting in the direction of the line A-B-C to be applied to the abutment face 20a of the second rail retaining device 2 and thence io the side of the rail foot 201 adjacent to the second rail retaining device 2. In accordance with Newton's Third Law, this causes a force equal and opposite to lateral force L to be applied to the opposite side of the rail foot 201 through the first rail retaining device 1. In the embodiment of Figures 1A and 1B the first rail retaining device 1 is fixed to the baseplate 300 at the first region A alongside the rail seat region 301, but could instead be removable (for example, it could be a hook-in component). The second rail retaining device 2 is attached to the baseplate 300 at the second region B alongside the rail seat region 301 in such a way that it can be moved away from the second region B so as to allow the rail to be threaded into the first rail retaining device 1. For example, the second rail retaining device 2 may have a base portion (not shown) whereby it is permanently or temporarily retained in a slot in the baseplate 300 within which it can be moved towards and away from the rail seat region 301 , The assembly 100 of Figures 1A and 1B includes an intermediate member 60, made of stiffened plastics or rubber material, which has an upright first portion 61 fitted to the first abutment face 11 of the first rail retaining device 1 so as to be located adjacent to the edge 201a of the rail foot 201, and a second portion 62 which extends transversely from the first portion 61 and is fitted to the second abutment face 12 of the first rail retaining device 1 so as to be located adjacent to the upper surface 201c of the rail foot 201. End walls 60a of the intermediate member 60, which abut respective end surfaces of the first rail retaining device 1, serve to inhibit migration of the intermediate member 60 aiong the rail 200.

A resilient rail pad 6 is provided on the rail seat region 301 of the baseplate 300. The stiffness of the material {for example, rubber, EVA or poiyurethane) from which the pad 6 is formed is less than that of the materials} from which the intermediate member 60 is formed.

The intermediate member 60 is separate to the pad 6, but in some embodiments (not shown) the intermediate member 60 may be joined to. or be integrally formed with, the pad 6.

Migration of the second retaining device 2 and wedge member 50 along the rail 200 is inhibited by blocking members 70, comprising L-shaped upstands 71, 72 located on the baseplate 300 so as to be positioned at respective ends of those components 2. 60. The wedge means 5 may in addition further comprise a post {not shown), secured to the baseplate 300, on which the wedge member 50 is mounted, whereby the wedge member 50 is movable vertically but not horizontally. Figures 2A, 28 and 2C show railway baseplate 300 provided with a second railway rail fastening assembly 1000 for fastening a railway rail 200 at a rail seat region 301 of the baseplate 300. Second railway rail fastening assembly 1000 is the same as first railway rail fastening assembly 100 (as exemplified by the use in Figures 2A to 2C of the same reference numerals as those of Figures 1 A and 1B, where appropriate) except that the second rail retaining device 2 is replaced by a modified second rail retaining device 2X which comprises a first part 20X and a second part 21X. Like the first part 20 of the second rail retaining device 2, the first part 20X (which may for example be made of cast metal) of the modified second rail retaining device 2X has a first, upright abutment face 20Xa and a second, upright abutment face 20Xb on an opposite side of the first part 20X to the first abutment face 20Xa, but the part 20X differs from the part 20 in that it is substantially L-shaped in cross-section such that it has a portion 20Xc which extends transversely with respect to the abutment faces 20Xa, 20Xb so as to overlie the top of the rail foot 201. Like the second part 21 of the second rail retaining device 2, the second part 21 X (which may for example be made of a semi-resilient material) of the modified second rail retaining device 2X has a first, upright abutment face 21Xa affixed to the second face 20Xb of the first part 20X, and a second, upright abutment face 21 Xb, on an opposite side of the second part 21X to the first abutment face 2lXa, which is configured to bear on an adjacent upright edge 201b of the rail foot 201. but the part 21 X differs from the part 21 in that it is substantially L-shaped in cross-section such that it has a portion 21XC which is affixed to the portion 20Xc of the first part 20X and extends transversely with respect to the abutment faces 2lXa, 21 Xb so as to bear on the top of the rail foot 201. in the embodiments of Figures 1 A and 18 and 2A to 2C, centre lines CL1. CL2, CL3 of the first rail retaining device 1, the second rail retaining device 2 and the shouider 3 He in a straight line (and are coincident with the lateral centre line CLB of the baseplate 300 in this case). However, in other embodiments the centre line CL1 of the first rail retaining device 1 may be offset along the longitudinal axis of the rail (for example by approximately 90mm, i.e. +/- 45mm centre to centre about the lateral centre line CLB of the baseplate 300) from the centre line CL2 of the second rail retaining device 2, provided that a rectilinear extension of the centre line CL1 of the first rail retaining device 1 intersects a portion of the second rail retaining device 2. An example of such an embodiment is shown in Figures 3A, 38 and 3C, which show a reconfiguration 1000' of the second assembly 1000 of Figures 2A to 2C on a modified baseplate 300'. Figure 3A shows a total offset of 2x mm {+/- x mm with respect to the centre line CIS of the baseplate 300) between the centre line CL1 of the first rail retaining device 1 and the centre line CL2 of the second rail retaining device 2.

Claims

1. A railway rail fastening assembly for fastening a railway rail at a rail seat region of an underlying rail foundation, wherein the assembly consists of a resilient fastening device configured to generate a substantially vertical clamping force for use in clamping a foot of the rail, a shoulder configured to retain the resilient fastening device at one side of the rail seat region of the rail foundation in a configuration in which the resilient fastening device does not bear on the rail foot, and force transmission means configured to convert at least some of the clamping force generated by the resilient fastening device into a substantially horizontal force, apply the substantially horizontal force to a vertical edge of the rail foot at a first rail foot region thereon, and cause the substantially horizontal force to be reacted at a vertical edge of the rail foot at a second rail foot region thereon, where the second rail foot region is on the opposite side of a web of the rail to the first rail foot region.

2. An assembly as claimed in claim 1. wherein:

the force transmission means comprise;

first and second rail retaining devices each adapted to bear on the rail foot and to extend upwardly at first and second regions respectively on the railway rail foundation adjacent to the rail seat region, where the first region is on the opposite side of the rail seat region to the second region; and

wedge means comprising a wedge member configured for location between the shoulder and the second rail retaining device; and

the shoulder is located on the railway rail foundation in a ihird region which is outside the rail seat region and is adjacent to but spaced from the second region, such that the resiiient fastening device, when retained by the shoulder, is arranged to apply the clamping force to the wedge member,

whereby application of the clamping force to the wedge member brings about application of the substantially horizontal force to the rail foot via the first and second rail retaining devices.

3. An assembly as claimed in claim 2_: wherein:

each of the first and second rail retaining devices has a first, upright abutment face, the first abutment face being configured to bear on an upright edge of a foot of the rail to be fastened, and the second rail retaining device has a second, upright abutment face on an opposite side of the second rail retaining device to the first abutment face.

4. An assembly as claimed in claim 2 or 3, wherein the first rail retaining device has a second abutment face which extends transversely with respect to the first abutment face, the second abutment face being configured to overhang an upper surface of the rail foot.

5. An assembly as claimed in claim 2, 3 or 4, wherein the second rail retaining device has a portion which extends transversely with respect tb the first and second upright abutment faces, the transversely-extending portion being configured to overlie an upper surface of the rail foot.

6. An assembly as claimed in claim 2, 3, 4 or 5, wherein:

a face of the shoulder which faces the second region has the form of a downwardly-sloping ramp; and

the wedge member has.

a sloping face which is configured to abut the face of the shoulder, an upright face which is located on an opposite side of the wedge member to the sloping face and is configured to bear against the second rail retaining device, and

an upper face.

7. An assembly as claimed in any one of claims 2 to 6, wherein the force transmission means further comprise blocking members for inhibiting movement of the second rail retaining device in a direction parallel to the longitudinal axis of the rail.

8. An assembly as claimed in any one of claims 2 to 7, wherein the force transmission means further comprise an intermediate member configured for location between the first rail retaining device and the adjacent upright edge of the rail foot.

9. An assembly as claimed in claim 8, when read as appended to claim 3. wherein the intermediate member has an upright first portion configured for location between the first abutment face of the rail retaining device and an adjacent edge of the rail foot, and a second portion which extends transversely from the first portion and is configured for location between the second abutment face of the rail retaining device and the upper surface of the rail foot.

10. An assembly as claimed in claim 8 or 9. wherein the intermediate member is formed of plastics or rubber material.

11. An assembly as claimed in claim 8, 9 or 10. wherein the intermediate member is fitted to the first rail retaining device.