GB2351514A

GB2351514A - Check rail clamp assembly

Info

Publication number: GB2351514A
Application number: GB9915116A
Authority: GB
Inventors: Calvin Lamb
Original assignee: Balfour Beatty PLC; BICC PLC
Current assignee: Balfour Beatty PLC
Priority date: 1999-06-30
Filing date: 1999-06-30
Publication date: 2001-01-03
Anticipated expiration: 2019-06-30
Also published as: GB9915116D0; GB2351514B

Abstract

The assembly, for mounting a check rail 11, comprises a support bracket 1 having a check rail mounting face 15, a clamp member 25, and fastening means 33 for urging the clamp member 25 to clamp a check rail 11 against the check rail mounting face 15. The support bracket 1 further comprises a clamp member mounting face 19 against which, in use, the clamp member 25 is urged by the fastening means 33, the area of contact between the clamp member mounting face 19 and a corresponding face of a slider 30 associated with the clamp member 25 being inclined with respect to the plane of force, i.e. vertically, exerted by the fastening means 33 on the clamp member 25 to create a reactive force in a different plane, i.e. horizontally, on the clamp member 25 to clamp a check rail 11 against the check rail mounting face 15. A shim 35 is placed between a seat 31 for the fastening means, clip 33, and the slider 30 for an unworn check rail 11, but is transferred to between the rail and the face 15 when the rail is worn.

Description

2351514 Check Rail Clamp This invention relates to a check rail clamp for

use on a railway.

A check rail functions to align the wheels on railway vehicle axle sets to prevent damage to other track components and to ensure that the wheel set tracks a particular path where a wheel may have a tendency to derail or where a derailment would be a particular safety hazard. Check rails may be used in railway track adjacent the high side of curves, across bridges, adjacent turnout frogs and at elevated sections of track for transit systems. At turnout frogs, check rails are utilised to divert the path of one wheel of a railway vehicle axle set in such a manner as to cause the opposite wheel to be drawn away from the point of the turnout frog. If check rails are not utilised at turnout frogs, a railway vehicle wheel passing through the frog, particularly a wheel which is worn, may strike the point of frog and thereby cause undesired wear or damage to the frog point as is well known in the art. Thus, a check rail may be defined as a track work assembly which diverts or sets the path of one wheel of a railway vehicle axle set in such a manner as to cause the opposite wheel to track a desired path.

Traditionally, check rails have been non-adjustable and have required replacement when the check rail face has worn to the point that it no longer properly guides the path of the. non-guided wheel of a railway vehicle axle set.

Check rails have often been formed from lengths of track rail laid parallel to the running rail to be guided. However, installation of the heavy track rail is difficult and somewhat imprecise. In many instances the check rail assembly has been mounted on the same tie plates as that of the traffic rail, so linking the installation points of the check rail to the tie spacing. Bolt holes are then required to be drilled at suitable locations to enable the check rail to be fastened in its desired location, and close tolerances need to be observed to ensure correct positioning of the check rail. Sometimes, the check rail has been fastened to the traffic rail, requiring drilling of the running rail in the field. This has made installation of the guard rail difficult under the best of conditions and extremely difficult under adverse. conditions, such as bad weather or where electrical power is unavailable to trackwork installation crew.

2 EP 0553055 describes a check rail clamp assembly which overcomes some of these problems by use of a clamp member and a spring clip to hold the check rail in place without the need for bolt holes. Shims may be inserted behind the check rail to provide adjustment of the lateral position of the check rail and allow compensation for wear of the check rail.

However, one problem which has been found with the check rail assembly taught by EP 0553055 concerns the ergonomic design of the assembly. The clamp member and spring clip are arranged to provide a clamping force in a substantially horizontal direction to pull the check rail against a vertical face of a support bracket.

Such arrangement requires the spring clip to be arranged in a substantially vertical orientation, which does not allow for easy manipulation of the clip from above the check rail clamp assembly. Unfortunately, standard clip tooling used for fitting of rail clips is not designed for installation of clips in a vertical orientation, and as a result, fitting of clips to the clamp assembly has proven to be awkward and problematic.

One solution to this problem would be to design and use a more convenient clip fitting tool for fastening the check rail. However, this is not desirable because it would require trackwork installation crew to carry and use two separate clip fitting tools, one for use with normal horizontally orientated running rail fastening clips, and one for use with the vertically orientated check rail clamp fastening clips.

It is an object to provide a check rail clamp assembly which may be installed and adjusted by means of a clamp fastening which is easily accessible from above using standard tooling.

According to the invention there is provided a check rail clamp assembly for mounting a check rail, the assembly comprising a support bracket having a check rail mounting face, a clamp member, and fastening means for urging the clamp member to clamp a check rail against the check rail mounting face, characterised in that the support bracket further comprises a clamp member mounting face against which, in use, the clamp member is urged by the fastening means, the area of contact between the clamp member mounting face and the clamp member being inclined with respect to the plane of force exerted by the fastening means on the 3 clamp member to create a reactive force in a different plane on the clamp member to clamp a check rail against the check rail mounting face.

By making the area of contact between the clamp member mounting face and the clamp member inclined with respect to the plane of force exerted by the fastening means on the clamp member, a reactive force is induced on the clamp member which acts in a different plane and can be used to clamp the check rail against the check rail mounting face. In this way, the clamp member fastening means can be. arranged to act in a different orientation to that required to clamp the check rail against the check rail mounting face. Thus, the clamp member fastening io means can be orientated for easy manipulation from above the check rail clamp assembly.

Suitably, the clamp member mounting face is inclined at an angle of less than 500 to the plane of force exerted by the fastening means.

Preferably, the clamp member mounting face is inclined at an angle of substantially 450 to the plane of force exerted by the fastening means, the assembly further comprising at least one shim for installation either between the check rail mounting face and a check rail or between the clamp member and the fastening means.

By making the clamp member mounting face inclined at an angle of substantially 450 to the plane of force exerted by the fastening means, the lateral positioning of a check rail can be easily adjusted by transferring shims from a position between the check rail mounting face and a check rail to a position between the clamp member and the fastening means and vice versa. Preferably, the clamp member fastening means comprises a spring clip. 25 A spring clip provides for easy installation, adjustment and removal using a standard clip tooL According to another aspect of the invention, there is provided a railway comprising a check rail mounted in position by means of the check rail clamp assembly. 30 The invention will now be further described by way of example with reference to the accompanying figures in which:

4 Fig. 1 is an exploded perspective view of a check rail clamp assembly according to the invention; Fig. 2 is a perspective view of the check rail clamp assembly as adjusted for use with an unworn check rail; and Fig. 3 is a perspective view of the check rail clamp assembly as adjusted for use with a worn check rail.

As can be seen in Fig. 1, the check rail clamp assembly comprises a support bracket 1 which may be bolted down onto a sleeper or other support structure by means of bolts. The support bracket 1 forms a flat bed for a running rail 5, and to one side of the bed the support bracket is provided with two identical parallel upstanding plates 7 arranged perpendicular and of a similar height to the running rail when present. On the edge facing the running rail, each plate is adapted to support a check rail 11 by presenting a horizontal ledge 9 about half way up for receiving the bottom surface of a horizontal foot 13 of the check rail 11, and a vertical check rail mounting face 15 adapted to engage the vertical rear surface 17 of the check rail 11. The edges of plates 7 facing away from the running rail form clamp member mounting faces 19 which are inclined at an angle of substantially 450 to the vertical check rail mounting faces 15. Between the plates 7 the support bracket 1 is provided with an upstanding post 21, which forms a centre stem shoulder as described below and is provided with a horizontal bore 23 close to the top which extends through it in a direction which is parallel to the planes of the plates 7.

The check rail clamp assembly includes a clamp member 25 which serves to retain the check rail 11 against check rail mounting faces 15 and on ledges 9.

The clamp member 25 has a body designed to lie in a horizontal orientation when assembled and is formed with a central elongate hole 26 designed to allow the post 21 of the support bracket to pass through. An upturned hook 27 is formed at one end of the body having a width slightly smaller than the gap between the plates 7 and designed to engage the foot 13 of the check rail 11. At the opposite end of the body the clamp member has a back plate 28 which is as wide as the parallel plates 7. A slider 30 is designed to sit on and straddle the clamp member 25, the slider also being formed with a central elongate hole 32, skis 29 on either side which are inclined at an angle of 450 to the vertical when assembled and arranged to engage with the inclined faces 19 of the plates 7, and vertical faces 34, which engage the back plate 28 of the clamp member 25 when assembled.

To assemble the check rail clamp, the hook 27 of the clamp member 25 is engaged with the foot 13 of a check rail 11, and the clamp member 25 is placed onto the support bracket 1 such that the post 21 passes through the elongate hole 26. The slider 30 is then placed over the clamp member such that the skis 29 engage with the inclined faces 19. A clip seat 31 is placed over the post 21 to sit on the upper surface of the slider. Finally, the middle arm of a spring clip 33, such as a Pandrol clip, is installed into the bore 23 of the post 21 using an appropriate clip tool to lock the assembly together. The height of the post 21 is such that upon installation of the clip 33, the toe and heel bear down on the clip seat 31, exerting a downward force onto the slider 30 and clamp member 25. The downward force pushes the slider down, but because of the engagement of the skis 29 on the faces 19, the slider is subjected to a reactive force which urges the vertical faces 34 against the back plate 28 of the clamp member 25, so pushing the clamp member in a direction away from the running rail, and creating a clamping force which pulls the check rail 11 against the vertical check rail mounting faces 15 by means of the hook 27 acting on the foot 13.

To enable adjustment of the clamp assembly, the height of the post 21 may be designed to accommodate the insertion of shim(s) 35 between the clamp member 25 and the clip seat 31 and between the check rail mounting faces 15 and the check rail 11. When using an unworn check rail, the shim(s) 35 may be inserted between the clamp member 25 and the clip seat 31 as illustrated in Fig. 2. To adjust the lateral position of the check rail as it wears, the geometry of the interaction of the clamp member with the clamp member mounting faces 19 of the support bracket 1 enables the shim(s) 35 to be transferred to the position between the check rail mounting faces 15 and the check rail 11 as illustrated in Fig. 3 without changing the force exerted by the clip 33, the shim(s) 35 being held in place by a face plate 37.

6 The invention is described herein with reference to Figures 1 to 3 by way of example only. It will be clear that the invention extends to further modifications not described.

7

Claims

1. A check rail clamp assembly for mounting a check rail, the assembly comprising a support bracket having a check rail mounting face, a clamp member, and fastening means for urging the clamp member to clamp a check rail against the check rail mounting face, characterised in that the support bracket further comprises a clamp member mounting face against which, in use, the clamp member is urged by the fastening means, the area of contact between the clamp member mounting face and the clamp member being inclined with respect to the plane of force exerted by the fastening means on the clamp member to create a reactive force in a different plane on the clamp member to clamp a check rail against the check rail mounting face.

2. A check rail clamp assembly according to claim 1, wherein the clamp member mounting face is inclined at an angle of less than 500 to the plane of force exerted by the fastening means.

3. A check rail clamp assembly according to claim 2, wherein the clamp member mounting face is inclined at an angle of substantially 4511 to the plane of the force exerted by the fastening means, the assembly further comprising at least one shim for installation either between the check rail mounting face and a check rail or between the clamp member and the fastening means.

4. A check rail clamp assembly according to any preceding claim, wherein the clamp member fastening means comprises a spring clip.

5. A railway comprising a check rail mounted in position by means of a check rail clamp assembly according to any preceding claim.

6. A check rail clamp assembly substantially as described herein with reference to the description and drawings.