WO1989010450A1

WO1989010450A1 - An arrangement for use in the fastening of rails to steel railroad sleepers

Info

Publication number: WO1989010450A1
Application number: PCT/FI1989/000078
Authority: WO
Inventors: Olavi MÄNTYSAARI
Original assignee: Maentysaari Olavi
Priority date: 1988-04-26
Filing date: 1989-04-26
Publication date: 1989-11-02
Also published as: AU3427889A; FI89291C; FI881958A; FI89291B; FI881958A0

Abstract

The invention relates to an arrangement for use in fastening rails to steel railroad sleepers. The rail (3), possibly together with a spacing plate (7), is placed on top of the sleeper (1), and a separate lug (4) is fastened to the sleeper, at a point next to the rail (3). A spring element (5) fastened to the lug is tensioned against the foot of the rail (3). In order to achieve sufficient lateral restraint for the railroad sleeper (1), a separate laterally restraining element (2) with downwardly oriented branches is fastened under the sleeper so that the lug (4) will serve as a fastening element. The laterally restraining stop (2) preferably is over its entire distance against the lower surface of the sleeper (1), thus supporting the sleeper at its most stressed point.

Description

An arrangement for use in the fastening of rails to steel railroad sleepers

The present invention relates to an arrangement for use in fastening rails to steel railroad sleepers, wherein the rail, possibly together with a spacing plate, is disposed on top of the sleeper, a separate lug is fastened to the sleeper, and a spring element is tenεioned against the rail by means of the lug.

The purpose of railroad sleepers and the rail fastening devices belonging to them is to keep the rails at the cor¬ rect distance from each other and in the correct position, to lead into the railroad bed the vertical forces caused by train loads as well as the horizontal forces caused by traffic and thermal stresses.

Timber, steel and concrete are known as materials for rail¬ road sleepers. The advantages of steel sleepers as compared with timber sleepers and concrete sleepers include their long and equal life, their light weight as compared with concrete sleepers, their good resistance to tropical and freezing temperatures, their good bearing on the track in the direction of the rails, the ease of making railroad points, their suitability for mass production, their being economical when appropriately designed, their suitability for high axle loads, and furthermore, significant advan¬ tages in terms of environmental protection.

According to studies, the use of steel sleepers saves ballast in the railroad bed approximately 600 m³/km, the sleepers are so light in weight that they can be handled manually, and they can be recycled as a valuable raw mate¬ rial for steel production. Steel railroad sleepers are usually U-shaped profiles made either by hot-rolling or from metal plate by hot- or cold- working, the bottom of the U constituting the top of the sleeper. Prior known sleeper forms include UIC 28, Thussen AG's S 82, Australian BHP's M- and -series, and the sleepers manufactured by Japanese Nippon Steel and the American company Omark Industries. In all of the said sleepers the lateral restraint in relation to the railroad bed has been provided for by bending the ends of the sleepers downwardly. This work step is cumbersome and re¬ quires an additional sleeper length of 20-30 cm.

Railroad rails are currently fastened to a steel sleeper either by welding a separate spacing plate to the top of the sleeper (Thussen AG) , by means of a bolt joint (Nippon Steel) or by shaping elevations and openings in the top of the sleeper in order to pass fastening springs through them (Omark) . Welded structures are disadvantageous in terms of fatigue resistance, a bolt joint is an expensive alterna¬ tive, and the hot-shaping of the top of the sleeper is also an expensive work step.

The object of the present invention is to provide an ar¬ rangement which enables the lateral restraint to be imple¬ mented in a relatively simple manner, without bending the ends of the sleeper.

In order to achieve this the invention is characterized in that the lug is fitted to extend through at least one open¬ ing in the sleeper and that below the sleeper there is fitted an element provided with a downwardly oriented pro¬ trusion, the element being held in place by the lug and serving as the element which restrains the sleeper laterally.

By using separately manufactured laterally restraining stops it is possible to eliminate the bending of the sleeper ends, which is a procedure inconvenient and expen¬ sive in terms of manufacture and increases the consumption of material. Also, the lateral restraint of the sleeper is in this case better than when using conventional systems, since the stop bears on compacted ballast under the sleeper and, when necessary, there may be several stops in one and the same sleeper.

Furthermore, since the laterally restraining stop can be fitted in such a manner that it will support the sleeper at its most stressed point, it is possible further to reduce the material thickness of the sleeper somewhat. The method according to the invention is suitable for use in conjunc¬ tion with steel sleepers of different shapes, irrespective of their manufacturing method and the rail gauge. Likewise, by shaping the lug to suit the spring type, the method can be used with various fastening spring types already on the market. Since the structure has no welded joints or screw joints, the assembling can be carried out, when necessary, without special tools on the railroad worksite, and the end result is advantageous in terms of resistance to fatigue- causing loads.

According to one preferred embodiment of the invention, the laterally restraining element is held by at least two lugs on different sides of the rail. In addition, the laterally restraining element has preferably against the lower side of the sleeper a portion which has openings through which the branches of the lug extend.

The invention and its other characteristics and advantages are described below in greater detail in the form of exam¬ ples and with reference to the accompanying drawings, in which Figures la-d depict schematically various implementations of the laterally restraining elements according to the invention,

Figure 2 depicts a cross section, transverse to the rail, of an arrangement according to the invention, and

Figure 3 depicts an enlarged section through A-A in Figure

2.

Figure 1 shows a steel railroad sleeper 1 which has a cross sectional shape of an inverted U and which is provided with laterally restraining stops 2 of different shapes. In Fig¬ ure la, each of the laterally restraining stops of the railroad sleeper has two downwardly oriented branches. In Figures lb and lc the stop has in each case only one branch. In Figure Id the laterally restraining stop 2 has one branch, which is located in the middle of the element 2, i.'e. at the point under the rail.

Referring to Figures 2 and 3, a lug 4 made of flat steel is fastened at a point next to the rail 3 to the railroad sleeper 1, and by means of the lug the spring 5 is ten- sioned so that it presses the rail 3 downwardly with the aid of a sealing member 6 placed in between. There is, furthermore, a spacing plate 7 placed between the railroad sleeper 1 and the rail.

According to the invention, an element 2 is fastened under the railroad sleeper 1, the element having a downwardly ex¬ tending branch and thus serving as the laterally restrain¬ ing stop for the sleeper.

The upper surface of the laterally restraining stop 2 is against the inner surface of the sleeper 1 and supports the sleeper at the point under the rail 3, i.e. at the most stressed point of the sleeper. The lug 4 works to fasten the laterally restraining stop 2 so that one branch of the lug, bent double, extends through an opening in the sleeper and a corresponding opening in the laterally restraining stop, while the other branch extends through an opening in the sleeper and an opening in the laterally restraining stop. The latter lug branch 12 is, in the manner indicated in Figure 2, bent sidewardly so that it is against the lower side of the laterally restraining stop 2 and presses against the stop when the lug 4 is tensioned upwardly under the effect of the spring 5.

There is, of course, a lug 4 with a spring 5 installed symmetrically on each side of the rail. The openings for the lug are so large that the lug 4 can be passed into place when the rail is not yet in place.

The laterally restraining stop and its downwardly oriented branches are preferably formed from the same piece, for example, by means of a press. Alternatively, branch pieces, which may be one or more, are fastened by welding to the body of the laterally restraining stop.

Figures 2 and 3 show an embodiment example of a laterally restraining stop 2, in which the sturdiness of the struc¬ ture is increased by stiffening grooves 8 pressed into the stop plate. By forming a pressed depression 9 in the stop plate, the stop plate 2 can be locked in place for security by means of lugs 4. By designing the lugs 4 so that they lock themselves to the sleeper 3 and to the stop plate 2, the assembling of the components - body 3, stop plates 2 and lugs 4 - can be carried out in advance without using springs 5.

Claims

1. An arrangement for use in the fastening of rails to steel railroad sleepers, in which case the rail (3), pos¬ sibly together with a spacing plate (7), is placed on top of the sleeper (1), a separate lug (4) is fastened to the sleeper, and a spring element (5) is tensioned against the rail (3) with the aid of the lug, characterized in that the lug (4) is fitted to extend through at least one opening in the sleeper (1), and that below the sleeper there is fitted an element (2) provided with a downwardly oriented branch, the element (2) being held in place by the lug (4) and serving as a laterally restraining element for the sleeper.

2. An arrangement according to Claim 1, characterized in that the laterally restraining element (2) is held by at least two lugs (4) on different sides of the rail (3) .

3. An arrangement according to Claim 1, characterized in that the laterally restraining element (2) has, substan¬ tially against the lower side of the sleeper (1), a portion which has openings through which the branches of the lug extend.

4. An arrangement according to Claim 3, characterized in that at least one lug portion (12), which near the edge of the rail (3) extends through an opening in the laterally restraining element (2), is bent to come against the lower side of the laterally restraining element, whereupon the force produced by the rail fastening spring (5) will press the said part (12) of the lug (4) against the laterally restraining element (2) .

5. An arrangement according to Claim 1, characterized in that under the sleeper (1) there are in each case two late¬ rally restraining elements (2), one at each rail (3).

6. An arrangement according to Claim 1, characterized in that the laterally restraining element (2) is a U-profile which fits inside the profile of the sleeper (1) and from which there is bent, or to which there is fastened by weld¬ ing, at least one downwardly extending branch 8.