GB2239035A

GB2239035A - Baseplate for receiving railway rail

Info

Publication number: GB2239035A
Application number: GB9025652A
Authority: GB
Inventors: David Ronald Seeley
Original assignee: Pandrol Ltd
Current assignee: Pandrol Ltd
Priority date: 1989-12-13
Filing date: 1990-11-26
Publication date: 1991-06-19
Anticipated expiration: 2010-11-26
Also published as: GB9025652D0; GB2239035B

Abstract

A moulded plastics plate 10 lies on a flat and horizontal surface of a railway sleeper 15 and comprises a web 1 of uniform thickness throughout and ribs 2 and 3 projecting upwardly from the web 1 and reducing in height, proceeding along the plate, so that the thickness of the plate smoothly decreases, proceeding along the plate. A flat steel plate 17 lies on the plate 10 and the flange 18 of a rail lies on the plate 17. Two substantially e-shaped clips 30 with an additional vertical leg 31 passing into the sleeper hold the rail down with the aid of a screw-bolt having a shank 40 passing between the centre and upper limbs 32 and 33 of the e, through holes in the plates 10 and 17 and into the sleeper. The screw-bolt has a head 41 bearing downwardly on the limbs 32 and 33. Instead of having the plate 17, there could be steel inserts in the plate 10.

Description

A plate for use in an assemblv on a railway track and an assembly including the plate The present invention relates to a plate for use in an assembly on a railway track and an assembly including the plate.

United Kingdom Patent No. 2199875 discloses a clip made by bending a steel bar of circular cross-section so that it has a first straight portion which is inserted in a vertical hole in a wooden railway sleeper, a second straight portion which lies alongside the edge of the flange at the bottom of the rail and locates the rail, a third straight portion which is press downwardly against the top of the sleeper and a fourth portion which is pressed against the upper face of the flange, the second and third portions being held down by the head of a screw-bolt which passes between them and downwardly into the sleeper. Such an assembly is not suitable for the case where the sleeper is of soft wood.

According to a first aspect of the invention, there is provided a plate which is suitable for positioning under the flange at the bottom of a railway rail, the plate having an area which is to be vertically below the rail flange and the thickness of which reduces smoothly from one side to the other of said area and also having two regions between which said area lies and in each of which regions a first hole and a wider second hole pass through the plate.

United Kingdom Patent No. 1227182 (see in particular Figure 2) discloses an installation, for use on a curved portion of a railway track, in which a tapered insert is sandwiched between a railway tie (sleeper) and a tie plate on which the rail stands, so as to achieve a desired canting of the outer-curve rails. The insert increases uniformly in thickness across its entire width and has three rectangular holes to either side of the centre-line of the insert, which holes are of identical size and are in register with corresponding holes in the tie plate. Spikes, passing through the holes in the tie plate and insert and penetrating the tie, serve to secure the tie plate to the tie and to secure the rail flange to the tie plate. However, this prior art installation is not suitable for use with a clip of the afore-mentioned type.

In an embodiment of the present invention, the first holes are preferably of circular cross-section and preferably diagonally opposite one another. The second holes are also preferably of circular cross-section and preferably diagonally opposite one another and preferably the distance between each second hole and the centre-line of said area, which centre-line, in use of the plate, is to be parallel to the length of the rail, is greater than the distance between the first hole, which is on the same side of said area, and the centre-line of said area.

Preferably the thickness of the entire plate reduces smoothly from one extremity to the opposite extremity.

Preferably there are cavities in the upper side of the plate. It is advantageous for'the plate to consist of a lower web, of the same thickness throughout, with ribs projecting upwardly from it the ribs having differing heights so that the reducing thickness of the plate is achieved. The ribs may form a grid. There are preferably formed on at least two edges of the plate upward projections with portions projecting inwardly from their tips, for holding on to the plate a further plate made of steel.Preferably the plate according to the first aspect of the present invention has respective rail centralising lugs formed, at respective locations to the said one side of the said area, on the two edges of the plate that extend transversely to the length of the rail, each lug having an upwardly-projecting portion defining a locating surface for abutting against a lateral edge of the rail flange when the plate is in use, thereby to facilitate centralising of the rail with respect to the plate.

The plate is preferably made by moulding a plastics material, for example an injection mouldable rigid material, preferably a homopolymer or copolymer of an olefinically unsaturated material, of which vinyl homopolymer or copolymer and polyvinyl acetal are examples.

According to a second aspect of the invention, there is provided an installation on a railway track comprising a foundation for a railway rail, a first plate, according to the first aspect of the invention, laid on the foundation, a second plate made of steel of uniform thickness throughout lying on the first plate, a rail standing on the second plate with the rail flange vertically above said area of the first plate, two clips holding down opposite sides of the rail and locating the rail, each of the clips having a portion passing through a hole in the second plate and the first hole in the first plate, and a screw-bolt which holds the clip down and has a shank which passes through a hole in the second plate and the second hole in the first plate and into the foundation.

An example in accordance with the invention is described below with reference to the accompanying drawings, in which: Figure 1 shows a plan view of a plate, Figure 2 shows a sectional view of the plate, taken as indicated by the arrows II in Figure 1, Figure 3 shows an end view of an assembly on a railway track including the plate of Figures 1 and 2, the plate being shown in section, Figure 4 shows a plan view of the assembly, Figure 5 shows a plan view of another plate, and Figure 6 shows a sectional view of the plate shown in Figure 5, taken as indicated by the arrows VI-VI in Figure 5.

Figures 1 and 2 show a plate 10 which has been injection-moulded in one piece and consists of Hostaform C902l acetal copolymer. The plate is substantially rectangular and includes a web 1 at the bottom, which is of uniform thickness throughout, with parallel ribs 2 projecting upwardly from it forming a grid with parallel ribs 3 which project upwardly from it, some of the ribs being at the edges of the web 1. The ribs are such that when the web 1 is placed on a flat and horizontal surface and a flat plate, with parallel planar major faces, is laid on the plate 10, the flat plate will touch the tips of substantially all of the ribs and will be inclined to the horizontal, with a gradient of about 1 in 30 or whatever gradient is required in order to give the rail the desired inclination when the plate is used in an assembly as described below.Thus the ribs on the left side of the plate are taller than those on the right side and the tips of the ribs themselves are not horizontal but inclined downwardly from left to right. Thus it is achieved that the thickness of the plate reduces smoothly from the left-hand end to the right-hand end of the plate, over the entire length of the plate.

The plate is formed with two vertical throughgoing holes 4 of circular cross-section on opposite sides of a centre-line 5 of the plate, these holes being equidistant from the centre-line 5, diagonally opposite one another and of 16 mm. diameter or whatever diameter is required having regard to the dimensions of the clip mentioned below. The plate also has two wider holes 6 passing vertically through it, these holes being equidistant from the centre-line 5, further from it than are the holes 4, diagonally opposite one another and of 27 mm. diameter or whatever diameter is required to suit the screw-bolt mentioned below. Each of the holes 4 and 6 is surrounded or partly surrounded by curved ribs 7 the tips of which would touch the flat plate mentioned above when the flat plate is laid on the plate 10.

It is to be noted that the ribs 2 are closer together in the vicinity of the holes 4 and 6 than elsewhere and the same applies to the ribs 3.

There are dotted lines 8 in the drawing which represent the left-hand and right-hand limits of the part of the plate which, when the plate is used in an assembly as described below, is vertically below the flange at the bottom of the rail. It is to be noted that the innermost sides of the holes 4 lie very close to the lines 8.

Each of the ribs 2 and 3 which extends along one of the edges of the plate 10 is formed with a number of approximately semi-circular recesses 9 to allow run-off of rainwater. There are also two upward projections 11 or, as illustrated, one such projection, on each of the longer edges of the plate 10 and one upward projection 11 on each shorter edge of the plate, each projection 11 on the shorter edges having at its tip a portion 12 projecting inwardly with its lower surface horizontal and its upper surface inclined to the horizontal.

Alternatively, the portion 12 can be continuous across its width and can consist of a rounded horizontal tab projecting inwardly.

Figures 3 and 4 show a rail foundation consisting of a sleeper 15 made of soft wood and having a flat and horizontal upper surface 16 on which lies the web 1 of the plate 10 according to Figures 1 and 2. A flat plate 17, made of sheet steel without bending it, is laid on the plate 10 so that its lower surface is in engagement with the tips of substantially all of the ribs on the plate 10, and the flange 18 of a rail having a web 19 is placed on the upper surface of the plate 17, the plate 17 having holes 20 and 21 through it which register with the holes 4 and 6 through the plate 10. The portions 12 on the projections 11 snap-over the plate 17 to hold the two plates together.

A clip 30, as shown in United Kingdom Patent Specification No. 2199875, is provided on each side of the rail to hold the rail down on the plate 17. Each clip has a first straight portion 31 which passes through one of the holes 20 in the plate 17 and one of the holes 4 in the plate 10 and is inserted in a vertical hole in the sleeper 15, a second straight portion 32 which lies alongside the edge of the flange 18 at the bottom of the rail and locates the rail, a third straight portion 33 which is pressed downwardly against the top of the plate 17 and a fourth portion 34 which is pressed against the upper face of the rail flange 18. A screw-bolt having a shank 40 and a head 41 has its shank passing between the portions 32 and 33 of the clip, through one of the holes 21 in the plate 17 and one of the holes 6 in the plate 10 and is screwed into the sleeper 15.Its head 41 eventually engages the upper sides of the portions 32 and 33 and holds the lower side of these portions of the clip in contact with the plate 17. This involves movement of the portion 32 of the clip downwardly, as indicated by the dotted lines.

It is in principle possible to dispense with the steel plate 17, which in the example shown in Figures 3 and 4 spreads the load over all the ribs 2 and 3 and prevents wear enlarging the holes through the plate 10.

Instead of having a plate 17 on the plate 10, the latter could be provided with four steel inserts, two on each side of the centre-line 5, to receive, in through-going holes, the straight portion 31 of the clip and the shank 40 of the screw-bolt, respectively. The inserts could be inserted in the plate 10 after production of the latter or the material of the plate could be moulded around the inserts.

Figures 5 and 6 show another plate embodying the present invention. This plate is similar to the pad of Figures 1 and 2 except that the single central projection 11 on each longer edge of the plate of Figures 1 and 2 has been shifted to a position to the right (in Figures 5 and 6) of the centre-line 5, and a lug 50 is present to the left of the centre-line 5 on each longer edge of the plate. Each lug 50 has an upwardly-projecting portion in the shape of a fin having a substantially vertical face opposed to the centre-line 5 and an inclined face that slopes downwards away from the centre-line 5. The vertical faces of the lugs 50 abut against one edge of the rail flange, when the plate is in use, so as to centralise the rail with respect to the plate.

Claims

1. A plate which is suitable for positioning under the flange at the bottom of a railway rail, the plate having an area which is to be vertically below the rail flange and the thickness of which reduces smoothly from one side to the other of said area and also having two regions between which said area lies and in each of which regions a first hole and a wider second hole pass through the plate.

2. A plate according to claim 1 in which the first holes are of circular cross-section.

3. A plate according to claim 1 or 2 in which the first holes are diagonally opposite one another.

4. A plate according to any preceding claim in which the second holes are of circular cross-section.

5. A plate according to any preceding claim in which the second holes are diagonally opposite one another.

6. A plate according to any preceding claim in which the distance between each second hole and the centre-line of said area, which centre-line, in use of the plate, is to be parallel to the length of the rail, is greater than the distance between the first hole, which is on the same side of said area, and the centreline of said area.

7. A plate according to any preceding claim in which the thickness of the entire plate reduces smoothly from one extremity to the opposite extremity.

8. A plate according to any preceding claim in which there are cavities in the upper side of the plate.

9. A plate according to any preceding claim which consists of a web, of the same thickness throughout, with ribs projecting from it, the ribs having differing heights so that the reducing thickness of the plate is achieved.

10. A plate according to claim 9 in which the ribs form a grid.

11. A plate according to any preceding claim in which there are formed on at least two edges of the plate upward projections with portions projecting inwardly from their tips, for holding on to the plate a further plate made of steel.

12. A plate according to any preceding claim, further comprising respective rail centralising lugs formed, at respective locations to the said one side of the said area, on the two edges of the plate that extend transversely to the length of the rail, each lug having an upwardly-projecting porticn defining a locating surface for abutting against a lateral edge of the rail flange when the plate is in use, thereby to facilitate centralising of the rail with respect to the plate.

13. A plate according to any preceding claim in which each of the said regions includes respective steel inserts through which the said first and second holes pass respectively.

14. A plate according to any preceding claim made by moulding a plastics material, i.e. an injection mouldable rigid material which is a homopolymer or copolymer of an olefinically unsaturated material.

15. A plate according to any preceding claim made by moulding vinyl homopolymer or copolymer or polyvinyl acetal.

16. A plate according to claim 14 or 15 when read as appended to claim 13 which has been made by moulding the material of the plate around the said inserts.

17. A plate which is suitable for positioning under the flange at the bottom of the railway rail, the plate being substantially as hereinbefore described with reference to Figures 1 and 2 or to Figures 5 and 6 of the accompanying drawings.

18. An installation on a railway track comprising a foundation for a railway rail, a first plate, according to any preceding claim, laid on the foundation, a second plate made of steel of uniform thickness throughout lying on the first plate, a rail standing on the second plate with the rail flange vertically above said area of the first plate, two clips holding down opposite sides of the rail and locating the rail, each of the clips having a portion passing through a hole in the second plate and the first hole in the first plate, and a screw-bolt which holds the clip down and has a shank which passes through a hole in the second plate and the second hole in the first plate and into the foundation.

19. An installation according to claim 18 in which the first plate is in accordance with claim 9 or 10 and the second plate rests on the tips of its ribs.

20. An installation according to claim 18 or 19 in which the first plate is in accordance with claim 11 and the lower sides of said projections engage the upper face of the second plate.

21. An installation according to any one of claims 18 to 20 in which the first plate is in accordance with claim 12 and the said locating surface of each rail centralising lug abuts against a lateral edge of the rail flange.

22. An installation according to any one of claims 18 to 21 in which each clip has, in addition to the portion which passes through the hole in the first plate, second, third and fourth portions and bent portions joining them to form an e-shaped structure and the shank of the screw-bolt passes between the second and third portions, i.e. between the centre arm and the upper arm of the e, and the screw-bolt has a head which presses downwardly on the second and third portions of the clip.

23. An installation on a railway track substantially as hereinbefore described with reference to Figures 3 and 4 of the accompanying drawings.