GB2475734A

GB2475734A - Suspended rail fastening assembly

Info

Publication number: GB2475734A
Application number: GB0920889A
Authority: GB
Inventors: Stephen John Cox
Original assignee: Pandrol Ltd
Current assignee: Pandrol Ltd
Priority date: 2009-11-30
Filing date: 2009-11-30
Publication date: 2011-06-01
Anticipated expiration: 2029-11-30
Also published as: GB0920889D0; GB2475734B

Abstract

The assembly, for suspending the rail 1 above a rail foundation 206, which foundation 206 has projecting therefrom first and second upstands 204 each having an aperture 214 therein, comprises a first group of components for supporting one side of the rail 1 and a second group of components for supporting the other side of the rail 1, and each group of components comprises a bracket 202, an elastic member 201 for location between the bracket 202 of that group and the rail 1 so as to suspend it by its head 100 above the rail foundation 206, a wedge member 203 for location between the bracket 202 of that group and an adjacent one of the said first and second upstands 204, and a resilient fastening clip 205 having a first part 215 for location in the aperture 214 in the said adjacent upstand 204 and a second part 216 and which is configured such that the second part 216 bears on the wedge member 203 of the same group of components when the first part 215 thereof is located in the said aperture 214.

Description

SUSPENDED RAIL FASTENING ASSEMBLY

The present invention relates to a suspended rail fastening assembly for suspending a railway rail above a rail foundation.

The applicant's patent EP0758418B relates to a railway rail fastening assembly in which the head of the rail is suspended at discrete locations along its length above the rail foundation. As shown in Figure 1 of the accompanying drawings, in one embodiment of such an assembly the rail head 100 is supported by means of a pair of elastic members 101 to which a clamping load is applied through respective brackets 102. The desired clamping load is maintained by means of respective wedges 103 inserted between each bracket 102 and an associated upstand or shoulder 104 which is fixed to an underlying rail baseplate 105 secured to a concrete sleeper 106. Such a suspended rail fastening assembly serves to reduce vibration and accordingly is advantageous in an underground railway system, for example.

In order to improve, and reduce the stiffness of, an existing underground railway system, the applicants wish to be able to retrofit such suspended rail fastening assemblies to existing sleepers, which are cast into track slab, without the need to remove or replace cast-in upstands or shoulders which are provided on each such sleeper. Each shoulder is provided with an aperture for receiving a resilient rail fastening clip of a type known as the PANDROL e-clip® (disclosed in GB1 51 0224A) which holds down a railway rail located between pairs of the shoulders. A first part of the rail fastening clip is configured for location in the shoulder aperture and a second part is configured to bear down on the foot of the rail.

According to an embodiment of the present invention there is provided a suspended rail fastening assembly for suspending a railway rail above a rail foundation, which foundation has projecting therefrom first and second upstands each having an aperture therein, the assembly comprising a first group of components for supporting one side of the railway rail and a second group of components for supporting the other side of the railway rail, and each group of components comprising a bracket, an elastic member for location between the bracket of that group and the railway rail so as to suspend the railway rail by its head above the rail foundation, a wedge member for location between the bracket of that group and an adjacent one of the said first and second upstands, and a securing member having a first part for location in the aperture in the said adjacent upstand and a second part, wherein each securing member comprises a resilient fastening clip which is configured such that the second part bears on the wedge member of the same group of components when the first part thereof is located in the said aperture.

This assembly has lower stiffness than the assembly it replaces, and has the additional advantage that no break-out or coring out of the existing shoulders in the sleepers is required in order to install it. Consequently, an assembly embodying the present invention can be installed very quickly and at minimal cost. Moreover, it still allows the assembly it replaces to be reinstalled if required.

The resilient fastening clip may have a third part configured to bear on an upper surface part of the upstand when the first part of the clip is located in the aperture.

Preferably, the resilient fastening clip comprises a rod of resilient material bent so as to have, proceeding from one end of the rod to the other end, a first substantially straight portion which constitutes the said first part, then a second portion which is bent through 1800, then a third portion which constitutes the said third part, then a fourth portion which is bent through 180°, and finally a fifth portion which constitutes the said second part, the said third and fifth portions appearing to lie on opposite sides of the said first portion when the clip is viewed from above.

Reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 (described above) shows a prior art suspended rail fastening assembly; and Figure 2 shows a suspended rail fastening assembly embodying the present invention, In order to retrofit an assembly embodying the present invention to an existing concrete sleeper 206 having cast-in upstands or shoulders 204, all the components of the previous assembly except for the cast-in shoulders 204 are removed, the railway rail 1 is lifted and the components of an assembly embodying the present invention are installed so as to suspend the rail 1 above the sleeper 206. As shown in Figure 2, the head 100 of the rai' 1 is supported by means of a pair of elastic members 201 to which a clamping load is applied through respective brackets 202. The desired clamping load is maintained by means of respective wedge members 203 inserted between each bracket 202 and an associated one of the two upstands or shoulders 204. The assembly further comprises resilient rail clips 205 having respective first parts 215 which are driven into apertures 214 of the shoulders 204, respective second parts 216 which are configured to bear down on upper surfaces 213 of the wedge members 203 in order to prevent the wedge members 203 from becoming loose, and respective third parts 217 which bear on respective upper surface portions 224 of the shoulders 204.

Most of the required locking force in the assembly comes from the wedge members 203, rather than the clips 205. The clips 205 are preferably generally similar in shape and form, but not identical, to those removed from the original assembly before an assembly embodying the present invention is installed. In particular, each clip 205 preferably comprises a rod of resilient material bent so as to have, proceeding from one end of the rod to the other end, a first substantially straight portion which constitutes the said first part 215, then a second portion which is bent through 180°, then a third portion which constitutes the said third part 217, then a fourth portion which is bent through 180°, and finally a fifth portion which constitutes the said second part 216, the said third and fifth portions appearing to lie on opposite sides of the said first portion when the clip is viewed from above.

Claims

Claims 1. A suspended rail fastening assembly for suspending a railway rail above a rail foundation, which foundation has projecting therefrom first and second upstands each having an aperture therein, the assembly comprising a first group of components for supporting one side of the railway rail and a second group of components for supporting the other side of the railway rail, and each group of components comprising a bracket, an elastic member for location between the bracket of that group and the railway rail so as to suspend the railway rail by its head above the rail foundation, a wedge member for location between the bracket of that group and an adjacent one of the said first and second upstands, and a securing member having a first part for location in the aperture in the said adjacent upstand and a second part, wherein each securing member comprises a resilient fastening clip which is configured such that the second part bears on the wedge member of the same group of components when the first part thereof is located in the said aperture.
2. An assembly as claimed in claim 1, wherein the said resilient fastening clip has a third part configured to bear on an upper surface part of the upstand when the first part of the clip is located in the said aperture.
3. An assembly as claimed in claim 2, wherein the resilient fastening clip comprises a rod of resilient material bent so as to have, proceeding from one end of the rod to the other end, a first substantially straight portion which constitutes the said first part, then a second portion which is bent through 180°, then a third portion which constitutes the said third part, then a fourth portion which is bent through 180°, and finally a fifth portion which constitutes the said second part, the said third and fifth portions appearing to lie on opposite sides of the said first portion when the clip is viewed from above.
4. A suspended rail fastening assembly substantially as shown in and hereinbefore described with reference to Figure 2 of the accompanying drawings.