GB2513565A

GB2513565A - A Railway Rail Fastening Clip

Info

Publication number: GB2513565A
Application number: GB1307658.3A
Authority: GB
Inventors: Stephen John Cox; David Christopher Herron
Original assignee: Pandrol Ltd
Current assignee: Pandrol Ltd
Priority date: 2013-04-29
Filing date: 2013-04-29
Publication date: 2014-11-05
Anticipated expiration: 2033-04-29
Also published as: TWI621753B; WO2014177835A1; HK1198187A1; GB2513565B; JP2016514776A; TW201508131A; GB201307658D0; JP6143400B2

Abstract

A railway rail fastening clip 10 comprising a rod (20, fig. 6) of resilient metal which, progressing from one end (A) of the rod to the other end (B), comprises: a first portion 11, which starts at one end of the rod, a second portion 12, a third portion 13, a fourth portion 14, and a fifth portion 15 which ends at the opposite of the rod. The second and fourth portions comprise reverse bends which are configured such that when the clip is viewed from above in an installed configuration, the third and fifth portions appear to be on opposite sides of an axis of the first portion. The fourth portion comprises first and second sub portions 14a, 14b and midlines 24a, 24b of the first and second sub portions have a first and second radii of curvature 14a', 14b' respectively in a plane P substantially defined by the fourth portion, the first radius of curvature being greater than the second radius of curvature.

Description

A RAILWAY RAIL FASTENING CLIP

The present disclosure relates to a railway rail fastening clip, in particular, but not exclusively, a railway rail fastening olin comprising a portion with a changing radius of curvature.

Background

Various forms of resilient rail clips are known, for example as shown and described in GBl5lO224A. Fipurest2 and 3 of the accompanying drawings shows the prior art rail fastening assembly disclosed in GB1510224A.

In GB1510224A the applicant proposed a railway rail fastening clip of the type having a first portion I, a bent second portion 2, a third portion 3, a bent fourth portion 4, and a fifth portion 5. When the clip is in use, the fifth portion 5 bears on the foot of a rail and extends in a direction substantially parallel to the longitudinal axis of that rail. The first portion 1 engages a passageway in a clip anchoring device and the third portion 3 bears on another part of the anchoring device.

In use, the railway rail fastening clip is in a stressed state so as to bear on the foot of the rail and hold the rail in place. In particular, the fastening clip is subject to vertical loads, which act on the first, third and fifth portions and result in stresses in the fastening clip. In addition, the fastening clip may be subject to lateral loads in a direction perpendicular to the longitudinal axis of the rail, for example when a train passes over a portion of the rail that the fastening clip bears dawn on. Such lateral loads may result in further stresses in the fastening clip.

It is desirable that the fastening clip withstands the stresses induced by the vertical and lateral. loads in a reliable manner.

In this regard, the present disclosure seeks to provide a railway rail fastening clip that may withstand the stresses induced by the vertical and lateral loads in a more reliable manner.

Statements of Invention

According to an aspect of the present invention there is provided a railway rail, fastening clip comprising a rod of resilient metal which, progressing from one end of the rod to the other end, comprises: a first portion, which starts at one end of the rod; a second portion; a third portion; a fourth portion; and a fifth portion which ends at said other end of the rod, wherein the second and fourth portions comprise reverse bends which are configured such that when the clip is viewed from above in an installed configuraticn, the third and fifth portions appear to be on opposite sides of an axis of the first portion, wherein the fourth portion comprises first and second subportions, midlines of the first and second subportions having first and second radii of curvature respectively In a plane substantially defined by the fourth portion, the first radius of curvature being greater than the second radius of curvature.

The first subportion of the fourth portion may he positioned between the third portion and the second subportion of the fourth portion.

The second subportion of the fourth portion may be at or near the geometric apex of the fourth portion. The second subpcrtion of the fourth portion may be spaced apart from a midpoint of-the fourth portion. The midpoint may be half way between the third and fifth portions. The second subportior1 of the fourth portion may be closer to the fifth portion than the third portion.

The fourth portion may further comprise a third subportion.

The third subportion may have a third radius of curvature.

The third subportion of the fourth portion may be positioned between the fifth portion and the second subportion of the fourth portion. The third radius of curvature may be greater than the second radius of curvature.

The first subportion of the fourth portion may be adjacent to the third portion. The second subportion of the fourth portion may be adjacent to the fifth portion.

Pdternatively, the third subportion of the fourth portion may be adjacent to the fifth portion, e.g. with the third subportion between the second subportion and the fifth portion.

The first radius of curvature may be greater than half of the distance between rnidlines of the third and fifth portions. The first radius of curvature may be greater than or equal to 55% of the distance between midlines of the third and fifth portions. The first radius of curvature may be greater than or equal to 60% of the distance between midlines of the third and fifth portions.

The second radius of curvature may be less than haif of the distance between midlines of the third and fifth por.ions.

rJ-r second radius of curvature may be less than or equal to 45% of the distance between midlines of the third and fifth portions. The second radius of curvature may be less than or equal to 40% of the distance between midlines of the third arid fifth portions.

The distance between midlines of the third and fifth portions may be measured at ends of the third and the fifth portions adjacent to the fourth portion.

The fourth portion may be shaped so as to substantially lie in a plane. The fourth portion plane may be angled with respect to a horizontal plane when the rail fastening clip is in an installed configutation.

The rod may have a length less than 20 times its thickness.

in particular, the rod may have a length less than 18 times its thickness.

The above-mentioned radii of curvature may apply to a midline of the rod.

The subportions of the fourth portion may have different centres of rotation.

A transition between the first and second subportions of the fourth portion nay be at a point away from either end of the fourth portion.

A railway rail fastening assembly may comprise the above-mentioned railway rail fastening clip.

Brief Description of the Drawings

Reference will now be made to the accompanying drawings in which: Figure 1 shows a side view of a previously-proposed railway rail fastening clip taken in the direction of arrow I in Figure 2; Figure 2 shows an end view of the same clip, taken in the direction of arrow II in Figure 1; Figure 3 shows a plan view of the same clip; Figure 4 shows a side view of a railway rail fastening clip according to an embodiment of the present invention taken in the direction of arrow V in Figure 5; Figure 5 shows an end view of the clip according to the embodiment of the present invention, taken in the direction of arrow IV in Figure 4; Figure 6 shows a plan view of the clip according to the embodiment of the present invention; Figure 7 shows a view of the cup according to the embodiment of the present invention normal to a plane defined by the fourth portion (the first portion has been omitted for clarity) ; arid Figure 8 shows stress contour lines for the previously-proposed clip (Figure 8 (a) ) and the clip according to the embodiment of the present invention (Figure 8 (h)

Detailed Description

With reference to Figures 4, 5, 6 and 7, a railway rail fastening clip 10 according to an embodiment of the present invention comprises a rod 20 which, progressing from a first end of the rod to a second end B, comprises: a first portion 11, which starts at the first end of the rod A; a second portion 12; a third portion 13; a fourth portion 14; and a fifth portion 15, which ends at the second end B of the rod. As shown in Figure 6, the points where these portions meet is marked approximately by the lines 11-12, 12-13, 13-14, 14-15.

The first and fifth portions 11, 15 are substantially straight. By contrast, the second and fourth portions 12, 14 comprise reverse bends, which are configured such that when the clip is viewed from above in an installed configuration (e.g. as depicted in Figure 6), the third and fifth portions 13, 15 appear to be on opposite sides of a midline 21 of the first portion 11. In other words, the average radius of curvature for the fourth portion 14 is greater than that for the second portion 12.

As depicted in Figure 4, a midline 24 of the fourth portion 14 substantially lies in a plane P which is angled with respect to a horizontal plane H when in the installed configuration. (Figure 7 is a view of the fourth portion 14 normal to the plane P of the fourth portion.) Accordingly, the third portion 13 may comprise a subportion 13a adjacent to the second portion 12, and a subportion 13b adjacent to the fourth portion 14. The subporti.ons 13a, 13b may bend, e.g. in different planes, so as to provide a transition from the second portion 12 to the fourth portion 14. For example, the suhportion l3b may bend from the plane of the secord portion 12 ho the plane P in which the fourth portion substantially lies.

In use, the fifth portion 15 is configured to bear down on a rail (not shown), either directly or via an insulator.

The fifth portion 15 may comprise a flattened face iSa for contacting the rail. The third portion 13 may bear down on an anchoring device (not shown) and the first portion 11 may reside in a receiving portion, e.g. bore, of the anchor.ing device. Alternatively, the clip 10 may he orientated the other way round, with the third and fifth portions 13, 15 bearing down on the rail and the anchoring device respectively.

The rod 20 may deform when installed so as to provide a force bearing down on the rail. Accordingly, the rod 20 may be made of metal, e.g. a resilient metal. The cup 10 may be formed by bending the rod 20 about one or more formers. In terms of its dimensions, the rod 20 may have a length approximately 17.9 times its thickness.

As best depicted in Figure 7, the fourth portion 14 comprises first and second subpornions 14a, i4h. The first subportion 14a of the fourth portion 14 may be positioned between the third portion 13 and the seoond subportion 14h of the fourth portion 14. Aooordingly, the first subportion i4a of the fourth portion 14 may be adjacent to the third portion 13. The second subportion 14b of the fourth portion 14 may be at or near a geometric apex of the fourth portion, e.g. the point furthest from the third and/or fifth portions 13, 1.5.

It will be appreciated that a transition 14a-14b between the first and second subportions 14a, 14b of the fourth portion is at a point away from either end of the fourth portion 14. The transition 14a-14b may be at or near the geometric apex of the fourth portion 14.

Midlines 24a, 24b of the first and second suhportions Na, 14b have first and second radii of ourvature l4a', 14b' respectively in a plane substantially defined by the fourth portion, e.g. as depicted in Tigure 7. (NB, the midlines 21, 22, 23, 24, 23 of respective portions 11, 12, 13, 14, of the rod 20 corresponds to a line substantially through the centre of the rod.) The first radius of curvature i4a' is greater than the second radius of curvature Nb' As depicted, the fourth portion 14 may further comprise a third subportion 14c, however in an alternative arrangement (not shown) , the third subportion may be omitted. The third subportion 14c of the fourth portion may be positioned between the fifth portion 15 and the second subportion 14b of the fourth portion 14. The third subportion 14c of the fourth portion 14 may be adjacent to the fifth portion 15. Alternatively, in the case of the third subportion 14c being omitted, the second subportion 14b of the fourth portion 14 may be adjacent to the fifth portion 15.

It will be appreciated that a transition 14b-14c between the second and third subportions 14b, 14c of the fourth portion is at a point away from either end of the fourth portion 14.

The midline 24c of the third subportion may have a third radius of curvature 14c'. The third radius of curvature 14c' may be greater than the second radius of curvature 14b'. The first and third radii of curvature 14a', 14c' may be substantially equal.

The first radius of curvature 14a' may be greater than half of the distance 0 between the midlines 23, 25 of the third and fifth portions 13, 15 where the third and fifth portions meet the fourth portion 14. The first radius of curvature 14a' may be greater than or equal to 55% of the distance D between the midlines 23, 25 of the third and fifth portions.

The secor.d radius of curvature 14b' may be less than half of the distance D between midlines 23, 25 of the third and fifth portions. The second radius of curvature 14b' may be less than or equal to 45% of the distance D between midlines 23, 25 of the third and fifth portions.

With reference to Figure 7, a first angle 14&' subtended by the first subportion 14a may be greater than a second angle 14b'' subtended by the second subportion 14b.

Similarly, a third angle l4c'' subtended by the third subpcrtion 14c may be greater than the second angle l4b'' subtended by the second suhportion 14b. The first angle l4a'' subtended by the first subporticn Na may he greater than the third angle 14c'' subtended by the third subporrton 14c.

Again with reference to Figure 7, the length of the arc along the midline 24a forming the first subportion l4a may be greater than the length of the arc forming the second subportion l4b. Similarly, the length of the arc along the midline 24c forming the third subportion 14c may be greater than the length of the arc forming the second subportion 14b. The length of the arc along the midline 2a forming the first subportion Na may be greater than the length of the arc forming the third suhportion 14c.

Tn a particular example, the first, second and third subportions Na, l4h, 14c of the fourth portion 14 have inner radii of curvature of approximately 40 mm, 20 mm and mm respectively, that is the radius of curvature from the centre of rotation to the inner edge of the rod 20.

(In other words, these are the radii of the formers around which the rod is bent to form the subportions l4a, l4b, l4c.) In the particular example, the rod 20 has a diameter of 19 rrrn. As such, the first, second and third radii of curvature Na', l4b', l4c', which are measured from the respective centre of rotation to the respective midline 24a, 24b, 24c of the rod 20, are approximately 49.5 mm, 29.5 mm, and 49.5 mm respectively. The distance D between the midline 23 of the third pornion 13 to the midline 25 of the fifth portion 15, where they meet the fourth portion 14, is approximately 80 mm.

In the particular example shown, the first subportion l4a may be subtended by first angle 14a'' of approximately 70±10 degrees, the second subportion lAb may be subtended by second angle 14b' of approximately 55±10 degrees and the third subportion 14c may be subtended by a third angle 14c'' of approximately 55±10 degrees. However, it will be appreciated that other angles may be selected for the first, second and third subportions.

Figure 8 (a) shows stress contours for third and fourth portions 3, 4 of a previously-proposed railway clip subjected to a given deflection. The deflection includes a vertical component, which includes the static deflection applied to the clip upon installation, and a dynamic lateral, component, which occurs when a train passes over a portion of the rail that the fastening clip bears down on.

As depicted, there are low, medium and high stress regions LS, MS, HS in the fourth portion 4. In particular, the high stress region HS is in a region of the fourth portion towards the third portion 3.

By contrast, Figure 8(b) shows equivalent stress contours for the third and fourth portions 13, 14 of a railway clip according to the embodiment of the present invention subjected to the sane deflection as for Figure 8 (a) . As depicted, there are low and medium stress regions LS, MS in the fourth portion 14, but no high stress region with the embodiment of the present invention. The clip of the present invention better distributes the dynamic stresses around the third and fourth portions and the maximum dynanic stress experienced by the clip is lower.

The present invention therefore advantageously reduces the stresses in the fourth portion 14. This in turn enables a more reliable railway clip and/or a reduction in the diameter of the clip, thereby saving material.

Claims

Cia ins 1. A railway rail fastening clip comprising a rod of resilient metal which, progressing from one end of the rod to the other end, comprises: a first portion, which starts at one end of the rod; a second portion; a third portion; a fourth portion; and a fifth portion which ends at said other end of the rod, wherein the second and fourth portions comprise reverse bends which are configured such that when the clip is viewed from above in an installed configuration, the third and fifth portions appear to be on opposite sides of an axis of the first portion, wherein the fourth portion comprises first and second suhportions, midlines ofthe first and second subportions having first and second radii of curvature respectively in a plane substantially defined by the fourth portion, the first radius of curvature being greater than the second radius of curvature.
2. The railway rail fastening clip of claim 1, wherein the first suhportion of the fourth portion is positioned between the third portion and the second suhportion of the fourth portion.
3. The railway rail fastening clip of claim i or 2, wherein the second subportion of the fourth portion is at or near the geometric apex cf the fourth portion.
4. The railway rail fastening clip of any of the preceding claims, wherein the second subportion of the fourth portion is spaced apart from a midpoint of the fourth portion.
5. The railway rail fastening clip of any of the preceding claims, wherein the second subportion of the fourth portion is closer to the fifth portion than the third portion.
6. The railway rail fastening clip of any of the preceding claims, wherein the fourth portion further comprises a third subportion, a midline of the Third subportion having a third radius of ourvature.
7. The railway rail fastening clip of claim 6, wherein the third subportion of the fourth portion is postioned between the fifth portion and the second subportion of the fourth portion.
8. The railway rail fastening clip of claim 6 or 7, wherein the third radius of curvature is greater than the second radius of curvature.
9. The railway rail fastening clip of any of the preceding claims, wherein the first radius of curvature is greater than half of the distance between midlines of the third and fifth portions.
10. The railway rail fastening clip of claim 9, wherein the first radius of curvature is greater than or egual to 55% of the distance between midlines of the third and fifth portions.
ii. The railway rail fastening clip of any of the preceding claims, wherein the second radius of curvature is less than half of the distance between midlines of the third and fifth portions.
12. The railway rail fastening clip of claim 11, wherein the second radius of curvature is less than or equal to 45% of the distance between midlines of the third and fifth portions.
13. The railway rail fastening clip of any of the preceding claims, wherein the fourth portion is shaped so as to substantially lie in a plane.
14. The railway rail fastening clip of claim 13, wherein the fourth portion plane is angled with respect to a horizontal plane when the rail fastening clip is in an installed configuration.
15. A railway rail fastening assembly comprising the railway rail fastening clip of any of the preceding claims.
16. A railway rail fastening clip or railway rail fastening assembly substantially as described herein with reference to and as shown in Figures 4 to 8.