WO2003054303A1

WO2003054303A1 - Steel sleeper assembly

Info

Publication number: WO2003054303A1
Application number: PCT/GB2002/005552
Authority: WO
Inventors: David Farrington
Original assignee: Corus Uk Limited
Priority date: 2001-12-11
Filing date: 2002-12-09
Publication date: 2003-07-03
Also published as: GB0129512D0; AU2002350914A1; GB2383066A

Abstract

A steel sleeper assembly comprises a sleeper (1) of inverted 'U' cross-section having an elongate upper wall (2) bordered by downwardly extending side walls (3) which terminate in longitudinally extending ground engaging surfaces. A slot (5) is formed in the upper wall towards one end thereof for receiving a complementary shaped spade (10) whose height is greater than that of each side wall of the sleeper. In a preferred embodiment, two slots are formed in the sleeper upper wall, one towards each end thereof. The side walls of the sleeper may be inclined outwardly away from the centre line thereof.

Description

STEEL SLEEPER ASSEMBLY

This invention relates to steel sleeper assemblies.

Steel sleepers for supporting railway lines are well known. Conventionally, these are generally of inverted "U" cross-section with the sleeper interior filled with ballast. Clearly, sleepers need to be firmly anchored to the ground and/or ballast and one problem is to find an efficient anchorage for a sleeper which is to be inserted under existing rails.

One object of this invention is to provide an assembly which meets these criteria.

In one aspect the invention provides an assembly comprising a steel sleeper of inverted "U" cross-section having an elongate upper wall bordered by downwardly extending side walls which terminate in longitudinally extending ground engaging surfaces, and a slot formed in the upper wall towards one end thereof for receiving a complementary shaped spade whose height is greater than that of each side wall of the sleeper.

In a preferred embodiment, two slots are formed in the sleeper upper wall, one towards each end thereof. The side walls of the sleeper may be inclined outwardly away from the centre line thereof.

The or each spade may be produced from steel and its height may be such that, in use, its lower end lies below ground or ballast surface and its upper end stands proud of the upper wall surface of the sleeper.

The shape of the or each spade in cross-section and that of the respective slot into which it is received may be generally linear, arcuate or angled. In a preferred arrangement, that part of the or each spade which protrudes above the upper wall surface of the sleeper departs from the line of the respective slot such that the protruding spade section at least partially overlies a solid part of the sleeper surface. This provides added resistance to forces imposed on the system in a lateral direction.

In another aspect the invention provides an assembly comprising a steel sleeper generally of inverted "U" cross-section having an elongate upper wall bordered by downwardly extending side walls which terminate in longitudinally extending ground engaging surfaces, an end plate secured to and extending from one end of the sleeper upper wall, a spade formed with an aperture through which the sleeper end plate protrudes and means for releasably attaching the spade to the end plate, the height of the end plate being greater than that of each sleeper side wall.

In one arrangement, the end plate is formed with an opening for receiving a fixing dimensioned to urge the inner face of the spade into firm engagement with the respective end face of the sleeper. The fixing may comprise a tapered wedge which may seat against a closure plate.

In a preferred embodiment an end plate is secured to and extends from each end of the sleeper upper wall.

The invention will now be described by way of example only with reference to the accompanying diagrammatic drawings in which :-

Figure 1 is plan view from above of one end of a sleeper assembly in accordance with the invention;

Figure 2 is a section taken along line II-II of Figure 1;

Figure 3 is a section taken along line III-III of Figure 1; Figure 4 is a first view of a spade which forms part of the assembly illustrated in Figures 1 and 2;

Figures 5 and 6 are side sectional and plan views from above of the spade illustrated in Figure 4;

Figure 7 is a plan view from above of an alternative sleeper assembly in accordance with the invention;

Figure 8 is a section taken along VIII-VIII of Figure 7;

Figure 9 is a section taken line IX-IX of Figure 8;

Figure 10 is a plan view from above of a further sleeper assembly in accordance with the invention;

Figure 11 is a section taken along line XI-XI of Figure 10; and

Figure 12 is an end view of the assembly illustrated in Figure 10.

The assembly illustrated in Figures 1 to 6 comprises a steel sleeper 1 (only one end of which is illustrated) of inverted ^,U" cross-section having an upper wall 2 bordered by downwardly and outwardly extending side walls 3 which terminate in ground or ballast engaging surfaces 4. Set in the upper wall of the sleeper are a series of ballast holes 5 and apertures 6 for receiving removable clips 7 (see Figure 2) which co-operate to retain a rail 8 in place on the sleeper.

Towards each end of the upper wall of the sleeper are formed slots 9 (only one of which is shown) into each of which is received a steel spade 10 which extends downwardly through the sleeper to a position below ground or ballast level to secure the sleeper in its required position. Thus, the height of the spade is less than the height of the sleeper side walls. As will be seen from Figure 2 and Figures 4 to 6, the spade 10 has an upper section 12 whose shape is misaligned with that the of slot 9 whereby the upper section 12 on assembly stands proud of the upper wall surface of the sleeper. The lower section 14 of the spade complements that of the slot thereby enabling the major length of the spade to pass through the slot with the lower rim of the upper spade sectionl2 in engagement with the sleeper upper wall.

The shape of the spade is designed to apply pressure to the slot walls at selected locations effectively to lock the spade in position without requiring an interface fit. In one arrangement, the spade is designed to spring out after it has reached a set position so that it cannot be pushed upwards by the action of traffic.

As shown in Figure 1 to 6, the cross-section of the spade is of generally arrow-head shape with the apex of the arrow-head facing the end face of the sleeper. Other spade cross-sections can be employed; the spade in cross-section may, for example, be linear, angled or curvilinear. Any cross-section which provides the required anchorage of the sleeper is acceptable.

The lower boundary of the spade may be tapered to assist driving of the spade into the ground.

The assembly illustrated in Figures 7 to 9 is similar to that illustrated in Figures 1 to 3 excepting that only one side of the protruding upper end 12 of the spade 10 is misaligned relative to the slot 9 formed in the sleeper upper wall 1.

Typically, each slot is positioned between 75mm and 85mm for the nearest sleeper end measured along the upper wall 2. Typically the spade thickness is of the order of lOmm with the minimum slot width being typically of the order of 11mm and around 15mm on the slot centre line and, possibly, at one or each slot end.

A small shearing deformation may be provided in one or each side of the spade which will spring out to prevent the spade from being withdrawn upwardly after it is driven downwardly into the ballast and/or ground.

In the embodiment illustrated in Figures 10 to 12, an end plate 15 is secured and protrudes from to each end of the steel sleeper. Only one end plate 15 is illustrated in figures 10 to 12. In this embodiment, each spade comprises a plate 19 formed with an opening 20 through which the respective end plate 15 protrudes. Each spade 19 is retained in abutting relationship with the respective end face of the sleeper by means of a wedge shaped fixing 22 which bears against one rim 23 of the respective end plate 15 and a steel closure plate 24 positioned between the end plate and the fixing 22. The closure plates 24 effectively close the openings 20 of the spades 19. The height of the openings 20 enable the spades to be driven downwardly into the ground to provide a firm anchorage for the sleeper.

In use, the sleepers are sited as required and the spades 10, 19 simply driven downwardly into the ground. In the embodiments of Figures 1 to 9, the respective spades pass through the slots 9, and in the embodiment of Figures 10 to 12, the spades 19 slide relatively to the end faces of the sleeper.

It will be appreciated that the foregoing is merely exemplary of sleeper assemblies in accordance with the invention and that various modifications can readily be made thereto without departing from the true scope of the invention.

Claims

1. An assembly comprising a steel sleeper of inverted "U" cross-section having an elongate upper wall bordered by downwardly extending side walls which terminate in longitudinally extending ground engaging surfaces, and a slot formed in the upper wall towards one end thereof for receiving a complementary shaped spade whose height is greater than that of each side wall of the sleeper.

2. An assembly as claimed in claim 1 wherein two slots are formed in the sleeper upper wall, one towards each end thereof.

3. An assembly as claimed in claim 1 or claim 2 wherein the side walls of the sleeper are inclined outwardly away from the centre line thereof.

4. An assembly as claimed in any one of the preceding claims wherein the or each spade is produced from steel and its height is such that, in use, its lower end lies below ground or ballast surface and its upper end stands proud of the upper wall surface of the sleeper.

5. An assembly as claimed in any one of the preceding claims wherein the shape of the or each spade in cross-section and that of the respective slot into which it is received is generally linear.

6. An assembly as claimed in any one of the preceding claims wherein the shape of the or each spade in cross-section and that of the respective slot into which it is received is generally arcuate.

7. An assembly as claimed in any one of the preceding claims wherein the shape of the or each spade in cross-section and that of the respective slot into which it is received is generally angled.

8. An assembly as claimed in any one of the preceding claims wherein that part of the or each spade which protrudes above the upper wall surface of the sleeper departs from the line of the respective slot such that the protruding spade section at least partially overlies a solid part of the sleeper surface.

9. An assembly comprising a steel sleeper generally of inverted "U" cross-section having an elongate upper wall bordered by downwardly extending side walls which terminate in longitudinally extending ground engaging surfaces, an end plate secured to and extending from one end of the sleeper upper wall, a spade formed with an aperture through which the sleeper end plate protrudes and means for releasably attaching the spade to the end plate, the height of the end plate being greater than that of each sleeper side wall.

10. An assembly as claimed in claim 9 wherein the end plate is formed with an opening for receiving a fixing dimensioned to urge the inner face of the spade into firm engagement with the respective end face of the sleeper.

11. An assembly as claimed in claim 10 wherein the fixing comprises a tapered wedge which seats against a closure plate.