GB2555387A

GB2555387A - Railway chair key

Info

Publication number: GB2555387A
Application number: GB1617832.9A
Authority: GB
Inventors: John Cox Stephen
Original assignee: Pandrol Ltd
Current assignee: Pandrol Ltd
Priority date: 2016-10-21
Filing date: 2016-10-21
Publication date: 2018-05-02
Anticipated expiration: 2036-10-21
Also published as: GB201617832D0; GB2555387B

Abstract

The railway chair key 7 has two separate components 40,70, the first component 40 has a shaped, compressible portion formed from an elastic material, preferably rubber; the railway chair key is used for securing a rail 20 in a railway chair assembly 10 having two upright portions 1,2, the first component 40 is shaped to fit between the rail head 23 and foot 21 with a first face 40A contacting the rail web 22 and a second face 40B opposing, but spaced from, the upright 1; the second component 70 locates between the second face 40B and the upright 1, having an operative configuration (fig.5) where the first component is compressed to secure the rail in the rail chair assembly. Preferably, the second component is made from steel or cast iron, having an oval cross-section, and has a spigot 72 with which a tool can be used to rotate the second component into its operative configuration. The second component may have a rigid plate 42 forming part of the second face 40B, having a curved recess to accommodate the second component 70, the plate is configured to assist in compressing the first component.

Description

(71) Applicant(s):

Pandrol Limited (Incorporated in the United Kingdom)

Station Road, ADDLESTONE, Surrey, KT15 2AR, United Kingdom (72) Inventor(s):

Stephen John Cox (74) Agent and/or Address for Service:

Haseltine Lake LLP

5th Floor Lincoln House, 300 High Holborn, LONDON, WC1V7JH, United Kingdom (51) INT CL:

E01B9/58 (2006.01) (56) Documents Cited:

GB 0477616 A US 0227896 A

GB191228256

GB191409415

GB191116253 (58) Field of Search:

INT CL E01B Other: WPI; EPODOC (54) Title of the Invention: Railway chair key

Abstract Title: A two part compressible railway chair key (57) The railway chair key 7 has two separate components 40,70, the first component 40 has a shaped, compressible portion formed from an elastic material, preferably rubber; the railway chair key is used for securing a rail 20 in a railway chair assembly 10 having two upright portions 1,2, the first component 40 is shaped to fit between the rail head 23 and foot 21 with a first face 40A contacting the rail web 22 and a second face 40B opposing, but spaced from, the upright 1; the second component 70 locates between the second face 40B and the upright 1, having an operative configuration (fig.5) where the first component is compressed to secure the rail in the rail chair assembly. Preferably, the second component is made from steel or cast iron, having an oval cross-section, and has a spigot 72 with which a tool can be used to rotate the second component into its operative configuration. The second component may have a rigid plate 42 forming part of the second face 40B, having a curved recess to accommodate the second component 70, the plate is configured to assist in compressing the first component.

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RAILWAY CHAIR KEY

The present invention relates to a railway chair key for securing a railway rail in a railway chair assembly.

As shown in Figure 1 of the accompanying drawings, a railway chair assembly 10 with which the present invention is concerned has first and second upright portions 1, 2 between which there is a space for accommodating a railway rail 20. A foot 21 of the railway rail rests on a seat portion 3 of the railway chair assembly 10 which is provided between the first and second upright portions 1, 2. One side of a web 22 of the railway rail 20 is spaced from the first upright portion 1, and the other side of the web 22 bears on the second upright portion 2. The railway rail 20 is secured by a railway chair key 30 (which in this example is a specially-shaped metal component but may be a simple wooden wedge) wedged (usually by hammering) between the first upright portion 1 and the web 22 of the rail 20. A railway chair assembly 10 of this kind is typically used to provide a seat for the type of railway rail shown in Figure 1, which has a slightlyrounded rather than a flat-faced foot 21 and is known as a bullhead rail. The shape of the foot 21 is different to the head 23 of the rail.

It is desirable to provide an improved railway chair key which can secure a rail in a railway chair assembly more effectively.

According to an embodiment of the present invention there is provided a railway chair key which comprises a first component, comprising a compressible portion formed of elastic material (preferably a type of rubber), and a second component, which is not joined to the first component and is configured for location between the first component and the first upright portion of the railway chair assembly. A railway chair key embodying the present invention does not comprise any component configured for location between the second upright portion of the railway chair assembly and the rail web, and does not suspend the rail above the seat portion of the railway chair assembly. The compressible portion of the first component is shaped for location between a head and a foot of a railway rail (which may be a bullhead rail or another type of rail) to be accommodated in the railway chair assembly. The first component has a first face configured to contact the said one side of the web of the railway rail and a second face configured to be opposite to, but spaced from, the first upright portion.

The shape of the second component is such that, in an operative configuration of the second component, the second component compresses the compressible portion of the first component by a desired amount sufficient to secure the railway rail in the railway chair assembly. A preferred embodiment of the railway chair key consists of only two components, the first component and the second component.

As a railway chair key embodying the present invention employs a first component comprising elastic material which compresses upon application of a separate second component, the rail can be secured more effectively.

In an embodiment of the present invention the second component may be made of steel or cast iron.

Preferably, a cross-section of the second component has a major dimension and a minor dimension, where the minor dimension of the cross-section is sized to allow the second component in a first orientation to fit between the first component of the railway chair key and the first upright portion of the railway chair assembly without significant compression (i.e. compression less than the desired amount of compression, and preferably close to negligible or zero) of the compressible portion of the first component, and the major dimension of the cross-section is sized to cause the second component when rotated into a second orientation, corresponding to the operative configuration of the second component, to bring about the desired amount of compression of the compressible portion of the first component. The second component may have a rectangular cross-section, but desirably has an oval, or substantially oval (for example, cam-shaped), cross-section. The second component may have a portion for engaging with a tool for achieving rotation of the second component into and out of its operative configuration.

In order to prevent unwanted loosening of the railway chair key, the railway chair key may be designed such that the second component is rotatable beyond the point where it effects maximum compression on the compressible portion (for example, by a relatively small amount) in order to counter any tendency for the second component to rotate back out of its operative configuration and release the compressible portion of the first component. Alternatively, the second component may be shaped so as to foul on a part of the railway chair assembly when in its operative configuration in order to prevent it rotating further forwards. The second component may instead be shaped so that rotation of the second component either forwards or backwards from its operative configuration represents a local minimum in the cam dimension, which would discourage back off.

The first component may further comprise a rigid (for example, steel or cast iron) plate forming part of the second face of the first component, at a region of the second face where the second component will contact the first component, which plate is configured to assist in compressing the compressible material of the first component by spreading the load applied to the plate by the second component into the compressible material. This is particularly helpful when the area of contact between the first and second components is relatively small, especially where there is only line contact. The plate is shaped so as to have a recess with a curved profile shaped so as to accommodate the second component.

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

Figure 1 (described above) is a front view of a prior art railway chair assembly accommodating a bullhead rail secured using a prior art railway chair key;

Figures 2 and 3 are front views of the prior art railway chair assembly of Figure 1 accommodating a bullhead rail secured using a first railway chair key embodying the present invention;

Figures 4 and 5 are front views of the prior art railway chair assembly of Figure 1 accommodating a bullhead rail secured using a second railway chair key embodying the present invention; and

Figure 6 is a perspective view of the second component of the railway chair key of Figures 4 and 5.

A first railway chair key 6 embodying the present invention will now be described with reference to Figures 2 and 3. The railway chair key 6 consists of two components, a first component 40 and a second component 50. The first component 40 comprises a compressible portion 41 formed of rubber. The compressible portion 41 of the first component 40 is shaped for location between the head 23 and foot 21 of the railway rail 20 to be accommodated in the railway chair assembly 10. The first component 40 has a first face 40A configured to contact one side of the web 22 of the railway rail 20 and a second face 40B configured to be opposite to, but spaced from, the first upright portion 1 of the railway chair assembly 10. The second component 50 (see Figure 3), which may for example be a steel or wooden wedge member, is configured for location between the second face 40B of the first component 40 and the first upright portion 1 of the railway chair assembly 10, and in this embodiment has an oval cross-section. A rigid (for example, steel or cast iron) plate 42 forms part of the second face 40B of the first component 40, at a region 43 of the second face 40B where the second component 50 will contact the first component 40. The region 43 forms a recess in the second face 40B, the recess having a curved floor.

Insertion of the railway rail key 6 into the railway chair assembly 10 will now be described. As shown in Figure 2, firstly the first component 40 is put into position alongside the rail web 22 (it can be slid into position either from the end or from above), the first component extending between the foot 21 and the head 23 of the rail 20. Then the second component 50 is driven into place (for example by hammering) between the first upright portion 1 of the railway chair assembly 10 and the second face 40B of the first component 40, compressing the rubber portion 41 and thereby locking the first component 40 in place.

A second railway chair key 7 embodying the present invention will now be described with reference to Figures 4, 5 and 6. Like the railway chair key 6, the railway chair key 7 consists of two components, one of which is the first component 40 as described above, and the other of which is a second component 70. The second component 70, which is configured for location between the second face 40B of the first component 40 and the first upright portion 1 of the railway chair assembly 10, comprises an elongate locking member 71 having a spigot 72 at each end for engaging with a lever tool (not shown) for achieving rotation of the locking pin 71 into and out of its operative configuration. The locking member 71 has an oval cross-section, where the minor dimension a of the oval cross-section is sized to allow the locking member 71 in a first orientation (as shown in Figure 4, where the minor dimension a is oriented substantially horizontally) to fit between the first component 40 and the first upright portion 1 of the railway chair assembly 10 with no compression of the rubber portion 41 of the first component 40, and the major dimension b of the oval cross-section is sized to cause the locking pin 71 when rotated into a second orientation (as shown in Figure 5, where the major dimension b is oriented slightly above horizontal) to bring about a desired amount of compression of the rubber portion 41 of the first component 40.

Claims

Claims

1. A railway chair key for securing a railway rail in a railway chair assembly, the railway chair assembly being of a type having first and second upright portions defining therebetween a space for accommodating a railway rail in an arrangement in which a foot of the railway rail bears on a seat portion of the railway chair assembly which is provided between the first and second upright portions, one side of a web of the railway rail is spaced from the first upright portion, and the other side of the web bears on the second upright portion, wherein the railway chair key comprises:

a first component comprising a compressible portion formed of elastic material, the compressible portion being shaped for location between a head and a foot of a railway rail to be accommodated in the railway chair assembly, the first component having a first face configured to contact the said one side of the web of the railway rail and a second face configured to be opposite to, but spaced from, the first upright portion; and a second component which is not joined to the first component and is configured for location between the second face of the first component and the first upright portion, the shape of the second component being such that, in an operative configuration of the second component, the second component compresses the compressible portion of the first component by a desired amount sufficient to secure the railway rail in the railway chair assembly; and the railway chair key does not comprise any component configured for location between the second upright portion of the rail chair assembly and the rail web.
2. A railway chair key as claimed in claim 1, wherein the elastic material of the compressible portion is rubber.
3. A railway chair key as claimed in claim 1 or 2, configured for securing a bullhead rail.
4. A railway chair key as claimed in any preceding claim, wherein a cross-section of the second component has a major dimension and a minor dimension, where the minor dimension of the cross-section is sized to allow the second component in a first orientation to fit between the first component of the railway chair key and the first upright portion of the railway chair assembly without significant compression of the compressible portion of the first component, and the major dimension of the crosssection is sized to cause the second component when rotated into a second orientation, corresponding to the operative configuration of the second component, to bring about the desired amount of compression of the compressible portion of the first component.
5. A railway chair key as claimed in claim 4, wherein the second component has an oval, or substantially oval, cross-section.

5
6. A railway chair key as claimed in claim 4 or 5, wherein the second component has a portion for engaging with a tool for achieving rotation of the second component into and out of its operative configuration.
7. A railway chair key as claimed in any preceding claim, wherein the second component is made of at least one of: steel; and cast iron.

10
8. A railway chair key as claimed in any preceding claim, wherein the railway chair key consists of only two components, the first component and the second component.
9. A railway chair key as claimed in any preceding claim, wherein the first component further comprises a rigid plate forming part of the second face of the first component, at a region of the second face where the second component will contact

15 the first component, which plate is configured to assist in compressing the compressible material of the first component.
10. A railway chair key as claimed in claim 9, wherein the plate is shaped so as to have a recess with a curved profile shaped so as to accommodate the second component.

20 11. A railway chair key as hereinbefore described with reference to Figures 2 and 3 or Figures 4 and 5 of the accompanying drawings.

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Application No: GB1617832.9