CA2017855C - Ribbed elastomeric rail pad - Google Patents
Ribbed elastomeric rail pad Download PDFInfo
- Publication number
- CA2017855C CA2017855C CA002017855A CA2017855A CA2017855C CA 2017855 C CA2017855 C CA 2017855C CA 002017855 A CA002017855 A CA 002017855A CA 2017855 A CA2017855 A CA 2017855A CA 2017855 C CA2017855 C CA 2017855C
- Authority
- CA
- Canada
- Prior art keywords
- rail
- pad
- rib
- tie
- edge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
- E01B9/00—Fastening rails on sleepers, or the like
- E01B9/68—Pads or the like, e.g. of wood, rubber, placed under the rail, tie-plate, or chair
- E01B9/685—Pads or the like, e.g. of wood, rubber, placed under the rail, tie-plate, or chair characterised by their shape
- E01B9/686—Pads or the like, e.g. of wood, rubber, placed under the rail, tie-plate, or chair characterised by their shape with textured surface
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
- E01B9/00—Fastening rails on sleepers, or the like
- E01B9/68—Pads or the like, e.g. of wood, rubber, placed under the rail, tie-plate, or chair
- E01B9/685—Pads or the like, e.g. of wood, rubber, placed under the rail, tie-plate, or chair characterised by their shape
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Railway Tracks (AREA)
Abstract
This invention relates to improvements in rail insulating pads which are used to electrically and dynamically insulate the rail from the rail tie.
More particularly it relates to a rail fastening of the kind in which a rail, having a field edge and a gauge edge is fastened to a rail tie by a rail seat consisting of a rail tie, a rail pad between the tie and the rail; a pair of rail clamp supports secured to said tie on either side of said rail and abutting said rail pad; rail clamp associated with each rail clamp support each clamp having a portion secured in said clamp support and a portion bearing down on said rail flange, the improvement comprising the provision of a said rail pad to electrically and dynamically insulate said rail tie from said rail wherein there is a rib provided on the field edge portion of the rail pad.
More particularly it relates to a rail fastening of the kind in which a rail, having a field edge and a gauge edge is fastened to a rail tie by a rail seat consisting of a rail tie, a rail pad between the tie and the rail; a pair of rail clamp supports secured to said tie on either side of said rail and abutting said rail pad; rail clamp associated with each rail clamp support each clamp having a portion secured in said clamp support and a portion bearing down on said rail flange, the improvement comprising the provision of a said rail pad to electrically and dynamically insulate said rail tie from said rail wherein there is a rib provided on the field edge portion of the rail pad.
Description
a~~~.'~~°~~
m s~~D sz~ASTOMSRxc ~AZL PAD
This invention relates to improvements in rail insulating pads which are used to electrically and dynamically insulate the rail from the rail tie.
Many rail pad constructions have been proposed to provide the necessary insulation and to protect the rail ties from damage and the rail seal from instability. U.K.
Patents 2154635 and 2152119-provide pads of relatively hard material which provide, by way of selective removal of material from the pads, good attenuation and rail stability.
~iowever, improved durability of rail pads is a long sought after advantage.
Tn curved track the rail head is subject to the vertically down gravity forces from the rolling stock and in 1,5 addition, horizontal centrifugal forces. These combine to impart a rolling tendency to the rail which is resisted by the rail fasteners. and the pad beneath the rail.
These forces cause a pressure on the rail pad which is greatest under the field edge of the rail which often causes this edge to cut into the soft rail pad and in some extreme cases, to cut it right through.
The field edge is the outside edge of the rail in a track formed by a pair of rails. The inside edge is referred to as the gauge side of gauge edge of the rail.
- It. is an object of this invention to provide a rail pad having improved durability. ~' To this end the present invention provides a rail pad to- electrically and dynamically insulate a rail from the rail tie in which the rail pad incorporates an upstanding rib.on either or, both the upper and lower. surface of-said pad on the field edge 'side of said pad., This invention is a way to reduce the intensity of the pressure under the field edge. of the rail thereby prolonging the life of the elastomeric rail pad. This is done. by providing a ridge on the field edge of the pad which runs parallel to the length of the' rail and is located with-the edge a'short distance away from the rail edge towards ~~31.'~~~~
the rail centre. Preferably the ridge may be about lOmm wide with the edge approximately l0mm from the field edge of the rail. The rib. is preferably about 1 or l.5mm high and is preferably of a material which is compressed flat by the load of the rail and in so doing, creates a higher than normal pressure in the region of the rib which then subtracts some of the load from the region of the pad directly underneath the rail edge thereby causing~a reduced pressure in this region with the consequent reduction in the tendency for the rail edge to cut the pad. Of course the increased pressure in the proximity of the pad does not create a cutting tendency since there is no edge in this area.
The rib should have a low height, preferably 1 to 1~5mm so that under the load of the installed rail fastening clips it compresses down to the general level of the remainder of the pad thereby ensuring that the rib does not carry the total load and also to ensure that the pad peripheral edges are in contact with the concrete rail seat and rail to ensure a.n adequate seal to prevent the ingress of damaging abrasive grit particles.
The rib can be placed either on the top side of the pad or on the bottom or alternatively, distributed between both top and bottom. However, the preferred position is. on top to minimise the risk of dust entering between.the pad and concrete rail face.
- Although most situations call for the rib to be on~
'the field edge of the pad where the function is normally required, in some:unusual situations where the track is canted and. the. traffic. travelling around the curve, is moving slower than the designed speed for the cant, the rail head can receive a lateral force by the gravity component which exceeds the centrifugal component giving a net force towards the centre of the curve. Por this reason the rib is ~5 preferably applied to both the field and gauge sides which has t-he additional benefit of making the pad less susceptible bo being installed the incorrect way around.
A preferred embodiment of this invention will now be described with respect to the drawings in which figure 1 is a general schematic view of a rail seat illustrating the position of the rail pad; figure 2 is a plan view of a preferred form of the invention and figure 3 is an edge view of the pad.
figures 4A and 4B provide a comparison of the standard prior art pads and the pads of this invention.
In figure 1 the rail seat comprises a rail 7, a rail tie 8 and the rail pad 9 interposed between them. The rail is fastened by the rail clips 11 seated in the clip holders 10 embedded in rail tie 0. An insulator 12 lies between the rail 7 and the fastener 11.
In figures 2 and 3 the rail pad 9 comprises field side 21 and gauge side 22' with the edge recesses 23 to fit about the clip holders 10. Grooves 2~! are provided in the surface of the pad to improve attenuation. The low ribs 25 are each about.lrnm in height and are designed to lie under the rail within l0mm of the field and gauge edges of the rail.
~- In figure 4A a standard rail pad 30 is shown under a rail 7. The arrows on the rail head indicate the direction of forces imposed on the rail by the passing rail ' trucks. The arrow 28 on the field side 21 of the rail pad shows deep indentation underload which leads to Butting of the pad along the field edge of 'the -rail. In figure 4B a pad 9 of this invention shows reduced indentation 29 on the field edge 'due to the provision of~ribs 25. There is also less roll by the ra~,l with consequent improved stability.
From the abave de-scr,iption, it can be seen that the , present invention provides an improved rail pad with enhanced durability.
m s~~D sz~ASTOMSRxc ~AZL PAD
This invention relates to improvements in rail insulating pads which are used to electrically and dynamically insulate the rail from the rail tie.
Many rail pad constructions have been proposed to provide the necessary insulation and to protect the rail ties from damage and the rail seal from instability. U.K.
Patents 2154635 and 2152119-provide pads of relatively hard material which provide, by way of selective removal of material from the pads, good attenuation and rail stability.
~iowever, improved durability of rail pads is a long sought after advantage.
Tn curved track the rail head is subject to the vertically down gravity forces from the rolling stock and in 1,5 addition, horizontal centrifugal forces. These combine to impart a rolling tendency to the rail which is resisted by the rail fasteners. and the pad beneath the rail.
These forces cause a pressure on the rail pad which is greatest under the field edge of the rail which often causes this edge to cut into the soft rail pad and in some extreme cases, to cut it right through.
The field edge is the outside edge of the rail in a track formed by a pair of rails. The inside edge is referred to as the gauge side of gauge edge of the rail.
- It. is an object of this invention to provide a rail pad having improved durability. ~' To this end the present invention provides a rail pad to- electrically and dynamically insulate a rail from the rail tie in which the rail pad incorporates an upstanding rib.on either or, both the upper and lower. surface of-said pad on the field edge 'side of said pad., This invention is a way to reduce the intensity of the pressure under the field edge. of the rail thereby prolonging the life of the elastomeric rail pad. This is done. by providing a ridge on the field edge of the pad which runs parallel to the length of the' rail and is located with-the edge a'short distance away from the rail edge towards ~~31.'~~~~
the rail centre. Preferably the ridge may be about lOmm wide with the edge approximately l0mm from the field edge of the rail. The rib. is preferably about 1 or l.5mm high and is preferably of a material which is compressed flat by the load of the rail and in so doing, creates a higher than normal pressure in the region of the rib which then subtracts some of the load from the region of the pad directly underneath the rail edge thereby causing~a reduced pressure in this region with the consequent reduction in the tendency for the rail edge to cut the pad. Of course the increased pressure in the proximity of the pad does not create a cutting tendency since there is no edge in this area.
The rib should have a low height, preferably 1 to 1~5mm so that under the load of the installed rail fastening clips it compresses down to the general level of the remainder of the pad thereby ensuring that the rib does not carry the total load and also to ensure that the pad peripheral edges are in contact with the concrete rail seat and rail to ensure a.n adequate seal to prevent the ingress of damaging abrasive grit particles.
The rib can be placed either on the top side of the pad or on the bottom or alternatively, distributed between both top and bottom. However, the preferred position is. on top to minimise the risk of dust entering between.the pad and concrete rail face.
- Although most situations call for the rib to be on~
'the field edge of the pad where the function is normally required, in some:unusual situations where the track is canted and. the. traffic. travelling around the curve, is moving slower than the designed speed for the cant, the rail head can receive a lateral force by the gravity component which exceeds the centrifugal component giving a net force towards the centre of the curve. Por this reason the rib is ~5 preferably applied to both the field and gauge sides which has t-he additional benefit of making the pad less susceptible bo being installed the incorrect way around.
A preferred embodiment of this invention will now be described with respect to the drawings in which figure 1 is a general schematic view of a rail seat illustrating the position of the rail pad; figure 2 is a plan view of a preferred form of the invention and figure 3 is an edge view of the pad.
figures 4A and 4B provide a comparison of the standard prior art pads and the pads of this invention.
In figure 1 the rail seat comprises a rail 7, a rail tie 8 and the rail pad 9 interposed between them. The rail is fastened by the rail clips 11 seated in the clip holders 10 embedded in rail tie 0. An insulator 12 lies between the rail 7 and the fastener 11.
In figures 2 and 3 the rail pad 9 comprises field side 21 and gauge side 22' with the edge recesses 23 to fit about the clip holders 10. Grooves 2~! are provided in the surface of the pad to improve attenuation. The low ribs 25 are each about.lrnm in height and are designed to lie under the rail within l0mm of the field and gauge edges of the rail.
~- In figure 4A a standard rail pad 30 is shown under a rail 7. The arrows on the rail head indicate the direction of forces imposed on the rail by the passing rail ' trucks. The arrow 28 on the field side 21 of the rail pad shows deep indentation underload which leads to Butting of the pad along the field edge of 'the -rail. In figure 4B a pad 9 of this invention shows reduced indentation 29 on the field edge 'due to the provision of~ribs 25. There is also less roll by the ra~,l with consequent improved stability.
From the abave de-scr,iption, it can be seen that the , present invention provides an improved rail pad with enhanced durability.
Claims (11)
1. In a rail seat in which a rail having a flange, a field edge and a gauge edge is fastened to a rail tie by a pair of rail clamps which bear down on the flange of said rail and on rail clamp supports secured to said rail tie on either side of said rail such that a portion of said rail clamp seats in said rail clamp support, and wherein a wear resistant pad lies between the rail tie and the rail and said pad abuts said rail to electrically and dynamically insulate said rail tie from said rail, wherein the said wear resistant rail pad incorporates a rib extending longitudinally of said rail, said rib comprising a long raised structure upstanding from said rail pad surface and having a width relatively narrow in relation to the length thereof and said rib being provided portion of the rail pad to reduce intensity on a surface of a field edge of pressure on the pad under the region of the field edge of the rail to reduce the tendency of the rail to cut into the rail pad.
2. The rail seat of claim 1 wherein said rib is of sufficient height to effect reduction of a force transmitted to said pad at said field edge of the rail.
3. The rail seat of claim 1 or 2 wherein said rib is on the upper surface of said rail pad.
4. The rail seat of any one of claims 1 to 3 wherein an additional rib is provided on a gauge edge portion of the pad.
5. The rail seat of claim 1 wherein said rib is of a size and of a material such that, when said rib is compressed by a load, a higher than normal pressure is created in the region of the rib which subtracts a portion of the load from the region of the pad directly underneath the rail edge.
6. The rail seat of claim 1 or 2 wherein said rib is on the lower surface of said rail pad.
7. The rail seat of claim 1 or 2 wherein said rib is on the upper surface of said rail pad and wherein another rib is provided on the lower surface of said rail pad.
8. A rail pad for electrically and dynamically insulating a rail tie from a rail wherein said rail has a field edge and a gauge edge and said rail is fastened to said tie by means including a rail seat consisting of said rail, said rail tie and said rail pad between said tie and said rail and abutting said rail, and wherein there is a rib provided on a surface of a field edge portion of the rail pad, said rib comprising a long raised structure upstanding from said rail pad surface and having a width relatively narrow in relation to the length thereof and said rib extending lengthwise of the rail pad to reduce the intensity of the pressure on the pad under the region of the field edge of the rail to reduce the tendency of the rail to cut into the rail pad.
9. The rail pad as defined in claim 8 wherein the rib is parallel to said rail.
10. The rail pad as defined in claim 8 or claim 9 wherein an additional rib is provided on a gauge edge portion of the pad.
11. The rail pad of claim 8 wherein said rib is of a size and of a material such that, when said rib is compressed by a load, a higher than normal pressure is created in the region of the rib which subtracts a portion of the load from the region of the pad directly underneath the rail edge.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AUPJ4636 | 1989-06-09 | ||
| AUPJ463689 | 1990-05-28 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2017855A1 CA2017855A1 (en) | 1990-12-09 |
| CA2017855C true CA2017855C (en) | 2000-08-01 |
Family
ID=3773975
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002017855A Expired - Lifetime CA2017855C (en) | 1989-06-09 | 1990-05-30 | Ribbed elastomeric rail pad |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0402093A3 (en) |
| AU (1) | AU627314B2 (en) |
| CA (1) | CA2017855C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4234007A1 (en) * | 1992-07-08 | 1994-01-13 | Schwihag Gmbh | Footrest modification for railroad tracks |
| DE102016108097B3 (en) * | 2016-05-02 | 2017-07-13 | Semperit Ag Holding | Rail pad |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2377942A (en) * | 1942-09-05 | 1945-06-12 | Hubbard & Company | Cushioned tie plate |
-
1990
- 1990-05-28 AU AU55999/90A patent/AU627314B2/en not_active Expired
- 1990-05-30 CA CA002017855A patent/CA2017855C/en not_active Expired - Lifetime
- 1990-06-05 EP EP19900306089 patent/EP0402093A3/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| AU5599990A (en) | 1990-12-13 |
| CA2017855A1 (en) | 1990-12-09 |
| EP0402093A3 (en) | 1991-02-06 |
| EP0402093A2 (en) | 1990-12-12 |
| AU627314B2 (en) | 1992-08-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 20100530 |