GB2582332A

GB2582332A - Protecting rail clip anchoring devices

Info

Publication number: GB2582332A
Application number: GB1903753.0A
Authority: GB
Inventors: George Allen Kenneth
Original assignee: Pandrol Ltd
Current assignee: Pandrol Ltd
Priority date: 2019-03-19
Filing date: 2019-03-19
Publication date: 2020-09-23
Anticipated expiration: 2039-03-19
Also published as: GB2582332B; FR3094019A1; GB201903753D0

Abstract

A protective cover 1 the prevents impact damage to a clip-retaining head of a rail clip anchoring device 2 secured to a railway sleeper 8 adjacent to a rail 5. The protective cover 1 comprises side shielding 11a that extends alongside at least one upright exterior side portion of the head of a rail clip anchoring device 2 so as to cover at least part of the head of the rail clip anchoring device when a rail clip 3 is in its operative position, and attachment means for securing the protective cover 1 in position; the attachment means comprising at least one securing element which secures the protective cover to a section of the rail clip 3 and is retained by the rail clip anchoring device wherein the clip can be installed/removed from the rail clip anchoring device, and to be attached to the rail while the protective cover is attached to the rail clip. The protective cover is configured such that whilst attached to the clip, a portion of the rail clip is accessible during installation/removal wherein the rail clip protrudes from an edge of the protective cover.

Description

PROTECTING RAIL CLIP ANCHORING DEVICES

The present invention relates to protecting rail clip anchoring devices.

On high-speed railway track, loose ballast stones or other relatively heavy debris may be picked up by trains travelling along the track and thrown along the track with great force. Such debris may damage track equipment and rail fastening elements. Damage to anchoring devices which are used to retain clips for fastening railway rails in the track is of concern because these are typically embedded into concrete sleepers, so if an anchoring device is damaged the sleeper has to be repaired and this involves a significant amount of cost and disruption.

It is therefore desirable to find a way to avoid or limit damage to rail clip anchoring devices.

According to an embodiment of a first aspect of the present invention there is provided an anchoring device protective cover (hereafter referred to as a "protective cover") configured to inhibit infliction of impact damage to a clip-retaining head of a rail clip anchoring device secured to a railway sleeper adjacent to a railway rail, wherein the protective cover comprises: side shielding means configured to extend in a desired position alongside at least one upright exterior side portion of the head of the rail clip anchoring device so as to mask at least part of the head of the rail clip anchoring device as seen in side elevation when a rail clip is in its operative position in the rail clip anchoring device; and attachment means for securing the protective cover in the desired position, the attachment means comprising at least one securing element configured to secure the protective cover to a portion of the rail clip to be retained by the rail clip anchoring device in such a manner as to allow the rail clip to be installed in and removed from the rail clip anchoring device, and to be driven onto and off the railway rail, while the protective cover is still attached to the rail clip; the protective cover being configured such that, whilst the protective cover is attached to the rail clip, a portion of the rail clip to which access is required during installation and removal of the rail clip protrudes from an edge of the protective cover. That is, the shape of the protective cover is such that, when the clip is in its operative position (i.e. bearing on the rail foot), the protective cover shields at least the most vulnerable part of the side portion of the anchoring device. A side portion of the head is a portion of the anchoring device which extends transversely with respect to the rail foot when the anchoring device is in use.

Since a portion of the rail clip protrudes from the protective cover, the rail clip may be driven into place in the anchoring device and extracted, without the need to remove the cover, using standard installation and extraction techniques and equipment.

The side shielding means may be dimensioned such that there is a gap between a lowermost edge of the side shielding means and an upper surface of the railway sleeper when the protective cover is in use. This avoids the possibility of contact between the protective cover and the sleeper when the rail clip carrying the protective cover is moved into and out of position on the rail.

The at least one portion of the rail clip may be (i) a portion of the clip to which force is applied when installing the clip into the anchoring device, which portion protrudes from a first edge of the protective cover, (ii) a rail bearing portion of the rail clip, which portion protrudes from a second edge of the protective cover different from the first edge; or (ii) both a portion of the clip to which force is applied when installing the clip into the anchoring device and a rail bearing portion of the rail clip, which portions protrude from respective first and second opposite edges of the protective cover.

The protective cover may be configured for use with a laterally-drivable rail clip. In this case, the attachment means may comprise first and second securing projections; there being at least two first securing projections which are supported by the protective cover at respective locations which are spaced apart in a direction substantially perpendicular to the lateral driving direction of the rail clip; and there being at least one second securing projection which is supported by the protective cover at a location spaced from the first securing projections in a direction substantially parallel to the lateral driving direction of the rail clip. The or each second securing projection may be shorter than the first securing projections. There may be two second securing projections.

The protective cover may be configured for use with an M-shaped rail clip, wherein the or each second securing projection is arranged to extend between inner legs of the M-shaped rail clip, and/or each first securing projection is arranged to extend between an inner leg and an outer leg of the M-shaped rail clip.

The side shielding means may comprise a single side shield wall, for positioning against the side portion of the head which, because of the direction of train travel, is more likely than the other side portion to suffer impact damage. More preferably, for practical reasons, the side shielding means comprise two side shield walls which are configured to extend alongside respective upright exterior side portions of the head, the two side shield walls being spaced apart for receiving the head of the anchoring device between them.

A protective cover embodying the present invention is desirably made of a low cost yet robust plastics material, for example high density polyethylene (HDPE). The shape and/or material of the protective cover may in some cases be chosen such that the cover is expected to be "single use", i.e. the cover is sufficiently strong as to protect the anchoring device from damage which would otherwise be caused by an impact, but is itself broken by the impact and must then be replaced.

The shape and/or material of the protective cover may be chosen primarily to protect an anchoring device from damage of the kind which can be caused by average-sized ballast stones flying along the track and striking the side of the anchoring device, but not intended to provide much if any protection from generalised impact damage caused by greater force, for example by derailed trains or loose equipment dragging along underneath trains.

A protective cover embodying the present invention may further comprise a top shielding portion configured to overlie the at least one upright exterior side portion of the head of the anchoring device. In a particularly advantageous arrangement the top shielding portion may be connected to and between two spaced-apart side shield walls, so as to overlie the rail clip and both upright side portions of the anchoring device.

Embodiments of the protective cover of the present invention may be designed to protect any kind of rail clip anchoring device having upright exterior side portions which are susceptible to damage, but it is considered to be particularly desirable to provide a protective cover for protecting anchoring devices intended for retaining laterally-drivable resilient railway rail fastening clips, for example rail clips which are substantially M-shaped in plan.

The attachment means may be configured to secure the cover in a detachable manner. For example, the attachment means may comprise a snap-fit mechanism.

A protective cover embodying the present invention may be attached to the clip prior to installation of the clip into the shoulder, or afterwards.

Embodiments of the protective cover of the present invention may be designed for use with any form of rail clip which is retained in an anchoring device having upright exterior side portions, for example laterally-driven M-shaped clips as mentioned above.

According to an embodiment of a second aspect of the present invention there is provided an assembly for use in rail fastening apparatus, the assembly comprising: an anchoring device protective cover embodying the first aspect of the present invention; and a rail clip; the anchoring device protective cover being configured for use with the rail clip. Preferably the rail clip is a laterally-drivable resilient rail clip which is substantially M-shaped in plan.

According to an embodiment of a third aspect of the present invention there is provided a rail fastening apparatus comprising: an assembly embodying the second aspect of the present invention; and a rail clip anchoring device configured for use with the assembly.

Reference will now be made, by way of example only, to the accompanying drawings, in which: Figures 1A to 1G show respective views of an anchoring device protective cover embodying the present invention, Figure 1A being an isometric top view, Figure 1B being a top plan view, Figure 1C being an isometric bottom view, Figure 1D being a front view, Figure 1E being a side view, Figure 1F being a rear view, and Figure 1G being a bottom plan view; Figures 2A and 2B are front and rear views of an assembly comprising the anchoring device protective cover of Figures 1A to 1G attached to a rail clip; Figure 3A and 3B are plan views of the rail clip shown in Figures 2A and 2B, with and without a toe insulator; Figures 4A, 4B and 4C are side, rear and plan views of a rail clip anchoring device with which the anchoring device protective cover and clip of Figure 2 are intended to be used; Figures 5A and 5B are first and second perspective views of a rail fastening apparatus comprising the anchoring device protective cover and rail clip of Figure 2 and a rail clip anchoring device in an arrangement where the rail clip is retained by the anchoring device; Figure 5C is a cross-sectional view of the anchoring device protective cover taken on the line X-X in the arrangement shown in Figures 5A and 5B; and Figure 6 is another cross-sectional view of the anchoring device protective cover with rail clip and anchoring device.

Figures 1A to 1G show an anchoring device protective cover 1 embodying the present invention which comprises side shielding means 11 for protecting the sides of a rail clip anchoring device (2 in Figures 4A, 4B and 4C), top shielding means 12 for protecting the top of the anchoring device, and attachment means for securing the protective cover in the desired position.

The side shielding means 11 comprise a first side shield wall 11A configured to extend alongside a first upright exterior side portion of a head (21 in Figures 4A, 4B and 4C) of the anchoring device and a second side shield wall 11B configured to extend alongside a second upright exterior side portion of the head, the two side shield walls 11A, 11B being spaced apart for receiving the head of the anchoring device between them. A front edge of each side shield wall 11A, 11B is formed with a cut-out 111A, 111B to accommodate a sidepost insulator (7 in Figures 5A and 5B) located between the head of the anchoring device and a rail foot (5 in Figures 5A and 5B). Projecting inwardly from respective inner surfaces 112A, 1128 of the side shield walls 11A, 11B there are clip engagement portions 113A, 113B having recesses shaped to receive outer leg portions of the rail clip (31, 37 in Figures 3A and 3B) retained by the anchoring device.

The protective cover 1 further comprises a top shielding member 12 joined to respective curved upper portions of the two side shield walls 11A, 11B such that the top shielding member 12 overlies the two upright exterior side portions of the head of the anchoring device.

The top shielding member 12 is formed of first, second and third planar segments 12A, 12B and 12C, the first and second segments 12A, 12B inclining upwardly from respective upper edges of the side shield walls 11A, 11B and being connected by the third segment 12C such that the top shielding member 12 is shaped so as to have a substantially convex outer surface 121 and a complementary substantially concave inner surface 122. A section of each of the first, second and third segments slopes downwardly towards the rear edge of the top shielding member 12. A front edge of the top shielding member 12 is formed with a cut-out 123 to accommodate a toe insulator carried by the rail clip (see Figure 3A).

The attachment means 13 comprise a snap-fit mechanism whereby the protective cover may be attached to the rail clip which is to be retained by the anchoring device.

The snap-fit mechanism is formed of a pair of first shaped flexible members 131A, 131B projecting from the inner surface 122 at the first and second segments 12A, 12B respectively and a pair of second shaped flexible members 132A, 132B projecting from the inner surface 122 at spaced-apart locations on the third segment 12C. The second shaped flexible members 132A, 132B are longer and less rigid than the first shaped flexible members 131A, 131B. The second shaped flexible members 132A, 132B are spaced apart from the first shaped flexible members 131A, 131B so that the second shaped flexible members 132A, 132B are positioned close to the cut-out 123 at the front edge of the top shielding member and the first shaped flexible members 131A, 131B are positioned further back towards the rear of the top shielding member 12. Together the flexible members 131A and 132A form a first structure configured for snap-fitting attachment onto one inner leg portion of the rail clip, and the flexible members 131A and 132A form a second structure configured for snap-fitting attachment onto another inner leg portion of the rail clip, as shown in Figures 2A and 2B.

In this example the protective cover 1 is made of 3mm thick HDPE (dimension (a) in Figure 1D), but other materials and/or material thicknesses may be used. By way of example only, using the dimensions shown in Figures 1E and 1F, the overall depth (c) of the protective cover 1 is 82mm, the depth (b) of the top of the protective cover 1 from the recess 123 to the rear edge is 70mm, the overall height (d) of the protective cover 1 is 42.5mm and the overall width (e) of the protective cover 1 is 128mm.

This embodiment of the protective cover is intended for use with a resilient rail fastening clip as shown in Figures 2A and 2B. This clip is shown in more detail in Figures 3A and 3B and is of the type disclosed by the present applicant in W093/12294, W093/12295 and W093/12296, but this protective cover embodiment could, with only minor modifications (e.g. the size of the cover and the positioning and shape of the attachment means), be adapted for use with a similar rail clip which was disclosed by the applicant in W02007/096620. Both of those clips are substantially M-shaped in plan view and are used in a railway rail fastening system in which the rail clip is driven laterally onto the rail and can be held in a rail clip anchoring device in a "pre-assembly" or "parked" position in which the toe portion of the clip does not bear on the rail. This enables railway sleepers to be preloaded at the factory with clips which are held in the pre-assembly position such that when the sleepers are delivered to site the clips can simply be driven home once the rail is in place. In addition, when maintenance of the rail or sidepost insulators (which lie between the rail and the shoulder) is subsequently required, the clip can be driven off the rail back into the pre-assembly position, or further into an "insulator-change position" in which the clip does not overlie the sidepost insulator, so complete withdrawal of the clip from the shoulder is not necessary. Such clips are sometimes known as "switch-on/switch-off" clips.

Although for simplicity Figures 3A and 3B show a clip 3 which is of the type disclosed in W093/12294, W093/12295 and W093/12296, the clip of W02007/096620 is of a similar shape. That is, referring to Figures 3A and 3B, each of the above-mentioned switch-on/switch-off clips are made from a rod of resilient material shaped so as to have, proceeding from one end A of the rod to the other end B of the rod, firstly a substantially straight first portion 31, then a substantially bent second portion 32, then a third portion 33, then a fourth portion 34 which is substantially U-shaped and forms the toe portion of the clip 3, then a fifth portion 35, then a substantially bent sixth portion 36, and finally a substantially straight seventh portion 37. The first and seventh portions 31, 37 of the clip 3 form outer leg portions. The third and fifth portions 33, 35 of the clip 3 form inner leg portions, the third and fifth portions 33, 35 lying between the first and seventh portions 31, 37. As shown in Figure 3A on its toe portion (fourth portion) 34 the clip 3 carries a toe insulator 4. The protective cover 1 may be considered to be an additional (optional) part of a rail fastening sub-assembly together with the clip 3 and toe insulator 4.

As shown in Figures 2A and 2B, when attached to the rail clip 3, each first flexible member 131A, 131B of the protective cover 3 is positioned between a respective inner leg 33, 35 and a respective outer leg 31, 37 of the rail clip 3 so as to exert an inwardly-directed force at respective first positions on the inner leg 33, 35, whereas each second flexible member 132A, 132B of the protective cover 3 is positioned between the inner legs 33, 35 of the rail clip 3 so as to exert an outwardly-directed force on respective second positions on the inner leg 33, 35. The second flexible members 132A, 132B are separated from the first flexible members 131A, 131B and are shorter so as not to snag on part of the anchoring device 2 (connection portion 230, described below) as the rail clip 3 is driven, whilst still securely attaching the protective cover 1 to the clip 3.

Figures 4A, 4B and 4C show the anchoring device 2 with which the embodiment of protective cover shown in Figures 1A to 1G is designed to be used. The anchoring device 2 has a head 21 configured to retain a rail clip 3 of the type shown in Figures 3A and 3B, and a stem 22 which, when the anchoring device 2 is in use, is embedded in a concrete sleeper (8 in Figures 5A and 5B). The head 21 comprises two interconnected spaced-apart walls 210, between which the inner legs 33, 35 of the rail clip 3 to be retained are held when the anchoring device 2 is in use. The exterior face of each wall 210 has a channel 221 for receiving respective outer leg portions 31, 37 of the rail clip 3, the roof of each channel 221 being provided with clip-engaging projections 220 for engaging cooperating recesses formed in upper surfaces of the outer leg portions 31, 37. The walls 210 are interconnected at the front end of the anchoring device by a connection portion 230. The top surface of the connection portion 230 provides a ledge on which the toe portion of the rail clip rests when in its "parked" position.

Figures 5A to 5C illustrate the protective cover 1 of Figures 1A to 1G in use with the rail clip anchoring device 2 shown in Figures 4A to 4C and the rail clip 3 shown in Figures 3A and 3B. The anchoring device 2 has a stem 22 which is embedded in a concrete sleeper 8 adjacent to the foot 5 of a railway rail. The rail foot 5 sits on a cushioning pad 6, and a sidepost insulator 7 is seated on the front of the anchoring device 2 adjacent to the rail foot 5. The protective cover 1 is attached to the rail clip 3, as described above and shown with reference to Figures 2A and 2B. In the cross-sectional view of Figure 6 the cushioning pad 6, sidepost insulator 7 and sleeper 8 are omitted for clarity.

The protective cover 1 does not prohibit the rail clip 3 from being driven into and out of the anchoring device 2, or from being driven onto or off the rail foot 5, because the attachment means 13 connecting the protective cover 1 to the rail clip 3 are such that the protective cover 1 moves with the rail clip 3, and they are positioned so that, as the rail clip 3 moves, they do not interfere with any portion of the anchoring device 2. As the rail clip 3 is driven forward into its operative position bearing on the rail foot 5, its position relative to the anchoring device 2 changes such that in this configuration the protective cover 1 masks the head of the anchoring device 2 as seen in side elevation.

In this embodiment the portion 34 at the front of the clip 3 carrying the toe insulator 4 and the portions 32, 36 at the rear of the clip are not covered by the protective cover 1, so it is still possible to carry out key operations, such as driving the clip into place and extracting it, using standard existing machines without modification. The fact that the toe portion 34 and the rear portions 32, 36 of the clip, and the sidepost insulator 7, remain exposed will not generally be a problem, because (as discussed above) the rail clip 3, the toe insulator 4 and the sidepost insulator 7 may be replaced relatively easily and at comparatively low cost. The very bottom of the head 21 of the anchoring device 2 adjacent to the surface of the concrete sleeper 8 is also left exposed by the protective cover 1 in this embodiment, because impacts on the anchoring device at this point are unlikely to result in damage and clearance is needed above the sleeper surface.

Claims

Claims 1. An anchoring device protective cover configured to inhibit infliction of impact damage to a clip-retaining head of a rail clip anchoring device secured to a railway sleeper adjacent to a railway rail, wherein the protective cover comprises: side shielding means configured to extend in a desired position alongside at least one upright exterior side portion of the head of the rail clip anchoring device so as to mask at least part of the head of the rail clip anchoring device as seen in side elevation when a rail clip is in its operative position in the rail clip anchoring device; and attachment means for securing the protective cover in the desired position, the attachment means comprising at least one securing element configured to secure the protective cover to a portion of the rail clip to be retained by the rail clip anchoring device in such a manner as to allow the rail clip to be installed in and removed from the rail clip anchoring device, and to be driven onto and off the railway rail, while the protective cover is still attached to the rail clip; the protective cover being configured such that, whilst the protective cover is attached to the rail clip, at least one portion of the rail clip to which access is required during installation and removal of the rail clip protrudes from an edge of the protective cover.
2. An anchoring device protective cover as claimed in claim 1, wherein the side shielding means are dimensioned such that there is a gap between a lowermost edge of the side shielding means and an upper surface of the railway sleeper when the protective cover is in use.
3. An anchoring device protective cover as claimed in claim 1 or 2, wherein the at least one portion of the rail clip is (i) a portion of the clip to which force is applied when installing the clip into the anchoring device, which portion protrudes from a first edge of the protective cover, (ii) a rail bearing portion of the rail clip, which portion protrudes from a second edge of the protective cover different from the first edge; or (ii) both a portion of the clip to which force is applied when installing the clip into the anchoring device and a rail bearing portion of the rail clip, which portions protrude from respective first and second opposite edges of the protective cover.
4. An anchoring device protective cover as claimed in claim 1, 2 or 3, configured for use with a laterally-drivable rail clip.
5. An anchoring device protective cover as claimed in claim 4, wherein the attachment means comprise first and second securing projections; there being at least two first securing projections which are supported by the protective cover at respective locations which are spaced apart in a direction substantially perpendicular to the lateral driving direction of the rail clip; and there being at least one second securing projection which is supported by the protective cover at a location spaced from the first securing projections in a direction substantially parallel to the lateral driving direction of the rail clip.
6. An anchoring device protective cover as claimed in claim 5, wherein the or each second securing projection is shorter than the first securing projections.
7. An anchoring device protective cover as claimed in claim 5 or 6, wherein there are two second securing projections.
8. An anchoring device protective cover as claimed in claim 5, 6 or 7, configured for use with an M-shaped rail clip, wherein the or each second securing projection is arranged to extend between inner legs of the M-shaped rail clip.
9. An anchoring device protective cover as claimed in claim 8, wherein each first securing projection is arranged to extend between an inner leg and an outer leg of the M-shaped rail clip.
10. An anchoring device protective cover as claimed in any preceding claim, wherein the side shielding means comprise a side shield wall.
11. An anchoring device protective cover as claimed in any one of claims 1 to 9, wherein the side shielding means comprise two side shield walls which are configured to extend alongside respective upright exterior side portions of the head.
12. An anchoring device protective cover as claimed in claim 11, wherein the two side shield walls are spaced apart for receiving the head of the anchoring device between them.
13. An anchoring device protective cover as claimed in any preceding claim, further comprising a top shielding member configured to overlie the at least one upright exterior side portion of the head of the anchoring device.
14. An anchoring device protective cover as claimed in claim 13, when read as appended to claim 11 or 12, wherein the top shielding member is connected to and between the two side shield walls.
15. An anchoring device protective cover as claimed in claim 13 or 14, when read as appended to any one of claims 5 to 8, wherein each of the first and second securing projections extend from the top shielding member.
16. An anchoring device protective cover as claimed in any preceding claim, wherein the attachment means are configured to secure the cover in a detachable manner.
17. An anchoring device protective cover as claimed in claim 16, wherein the attachment means comprise a snap-fit mechanism.
18. An assembly for use in rail fastening apparatus, the assembly comprising: an anchoring device protective cover as claimed in any preceding claim; and a rail clip; the anchoring device protective cover being configured for use with the rail clip.
19. An assembly as claimed in claim 18, wherein the rail clip is a laterally-drivable resilient rail clip which is substantially M-shaped in plan.
20. Rail fastening apparatus comprising: an assembly as claimed in claim 18 or 19; and a rail clip anchoring device configured for use with the assembly.