GB2117816A

GB2117816A - Improved railway track

Info

Publication number: GB2117816A
Application number: GB08305496A
Authority: GB
Inventors: Robert Pouget
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-03-12
Filing date: 1983-02-28
Publication date: 1983-10-19
Also published as: DE3308309A1; GB8305496D0; BR8301209A; LU84675A1; FR2523165B1; ES278864U; PT76364A; IT1201041B; FR2523165A1; PT76364B; IT8367278A0

Abstract

The invention relates to a railway track of the type comprising concrete sleepers, two rails, resilient plates and rigid and insulating collars cooperating with locking sleeper- screws. According to the invention, the lower face of each rail-flange and the conjugated bearing surface of each sleeper have cooperating shapes defined by directrices bent over most of the width of each rail-flange concerned, as well as the upper face of each rail-flange and the conjugated bearing surfaces of the corresponding collars. <IMAGE>

Description

SPECIFICATION Improved railway track The present invention relates to improvements in railway tracks of the type comprising concrete sleepers, two rails supported by the sleepers, resilient plates interposed between the inner face of the rail-flanges and the conjugated bearing surfaces of said sleepers, as well as rigid and insulating collars resting on the upper face of said flanges and cooperating with sleeper-screws tightly screwed into said sleepers.

The rails of these known rail tracks have flat flanges by which they rest on equally flat bearing surfaces of the sleepers.

It is the object of the present invention to control the forces applied on to the rail track by the travelling load so that they are distributed over the components of the track in the normal conditions for which they have been designed and laid. And it is thus the object of the invention to arrange for most of the forces to be transmitted from the rails to the sleepers and for the rail-clips and sleeper-screws to be bent in only by stresses reduced to a minimum. It is also the object of the invention to ensure that the means used to this effect give an increased and reliably stabilized geometrical accuracy of the track-width.

This object is reached according to the invention with a rail of which the lower face of each rail-flange and the conjugated bearing surface of each sleeper have cooperating shapes defined by directrices bent over most of the width of each rail-flange concerned and by parallel generating lines, whereas the upper face of the rail-flange and the conjugated bearing surfaces of the corresponding collars have, from the edges up to the web of the rail concered, cooperating shapes defined by directrices bent over most of the free width of the rail-flange concerned and by parallel generating lines.

These means are novel in view of the known prior art relating to railway track with wooden sleepers supporting rails of the "Vignole" type.

Indeed, French Patent No. 1198 376 and Belgian Patent No. 570 045 describe sections of rails designed with a view to reducing their volume. When their inner face is concave-shaped, said face is set apart from the sleepers and the surface part of their flange which bears against said sleepers is limited to the marginal parts of said face, which are narrow and coplanar.

As to French Patent No. 2 050 876, this provides in its middle longitudinal zone, a hollow part or a projecting part, designed to cooperate with conjugated elements of the tie-plate in order to center the rail with respect to the sleepers. But the bearing surface of the rail is flat over most of the width of its rail-flange, so that the forces cannot be transmitted and distributed as in the present invention.

The same applies to German Patent No.

608 323 which provides as centring means two longitudinal ribs cooperating with ribs provided in the sleepers, the bearing surface of the rail-flange being flat between said ribs.

According to a particularly advantageous embodiment of the present invention, the lower face of the rail flange is convex and its directrices are preferably trapezoidal pointed arch-shaped. In addition, the upper face of the rail-flange is made up of two lateral strips situated on both sides respectively of the web of the rail and extending substantially in parallel to the lower face: preferably, each one of the insulating rigid collars resting against the upper face of the rail-flange is in opposite abutment against the conjugated external side wall of the housing provided in the corresponding sleeper for each rail.

The invention will be more readily understood on reading the following description with reference to the accompanying drawings, in which: - Figures 1 to 4 are half-sections showing four possible embodiments of a rail section.

- Figure 5 is a cross-section illustrating the fitting of one rail according to Figure 1 on a sleeper.

As illustrated in Figure 5, each rail comprises a rail-flange 1 joined to a rail-head 2 by a web 3.

The present invention actually relates to the rail-flange 1 and to the means with which it cooperates. Its inner face 20 rests, by way of a sectional resilient plate 4, on a conjugated bearing surface 6 of a concrete sleeper 7. It is secured in position by sleeper screws 8 screwed into a fitting 9 integral with the concrete sleeper and immobilized by a sleeve of adhesive material 10; the sleeper screws are extended by threaded pins 11 traversing rigid insulating collars 12, elastic washers 13 and rigid washers 14, and cooperating with a lock-nut 1 5.

Each collar 12 is fitted inside a housing 1 6 of the sleeper 7, rests on the upper face 21 of the rail-flange 1, as well as on the upper face of said sleeper, and abuts on the external side wall 17 of the said housing.

According to a first embodiment illustrated in Figure 1 , the lower face 20a of the rail-flange is concave and defined by trapiezoidal directrices; the bearing surface 6a of the sleepers 7 is complementarily shaped, to take into account the thickness of the plate 4. The side strips 21 a of the upper face of the rail-flange 1, situated on either side of the web 3 of the rail, are substantially parallel to the inclined parts of the lower face 20a, but the side strips Z 1 a could just as well be converging with the said parts inclined towards the edges. In any case, said strips 21 a or 21 b are shaped complementarily to the collars 12.

According to a second embodiment illustrated in Figure 2, the lower face 20a of the rail-flange still has a trapezoidal section, but the side strips 21 c of the upper face are divergent relatively to said lower face; but mainly, said side strips, whether they are parallel (21a), convergent (21b) or divergent (21 c), all are provided with an edging 21 d which is substantially perpendicular to the web 3 of the rail, to obtain a symmetrical support of the collars on the rail-flange and on the sleeper.

According to a third embodiment illustrated in Figure 3, the lower face 20b of the rail flange 1 is convex and thereagain defined by trapezoidal directrices; the bearing surface 6b of the sleepers 7 is also complementarily shaped, to take into account the thickness of the plate 4. The side strips of the upper face of the rail-flange 1 are substantially parallel in 21 e (Figure 3) to the inclined parts of the lower face 20b, or convergent with respect thereof by forming an acute angle with the web 3 tor the strips 21 f (Figure 3) or an obtuse angle for the strips 21g (Figure 4).

According to a fourth embodiment illustrated in Figure 4, the strips 21e, 21 f or 21 g comprise as precedingly an edging 21 b perpendicular to the web.

Whatever the embodiment selected, it is important to note that the bent shapes 20a or 20b of the lower face of the rail-flange extend over practically the entire width thereof. Moreover, this arched shape of the directrices of said face can be any type, namely, as in the aforesaid embodiments, any type of polygonal arch: pointed, lobed, gothic... or curvilinear: circular, oval, elliptical, parabolical. . .

Considering for example the force R applied in A by a rail-coach wheel on the rail-head 2 of a rail forming a bend, Figure 2 shows the decomposition of that force being applied, via the rail-flange 1, through the resilient plate 4 on the sleeper 7.

In these conditions, the rail-flange 1 receives all the vertical and transversal forces applied to the rail-head 2 by the train wheels, in a straight line and in a curved path, and transmits them integrally via the resilient plate 4 to the concrete sleepers 7.

In addition, the pulling forces exerted on the sleeper-screws 8 when a train passes over a curving track, this generating a rail tipping moment, are much weaker in the case of a rail according to Figure 5 than in the case of a Vignole-type rail with flat flange; indeed the instantaneous center of rotation is situated on the edge of the flat rail-flange in a Vignole-type rail, whereas according to the invention (Figure 5) said center is still situated on the edge but lower down on account of the arched shape of the rail-flange.

The invention is in no way limited to the description given hereinabove and on the contrary covers any modifications that can be brought thereto without departing from its scope.

Claims

1. Improved railway track of the type comprising concrete sleepers, two rails supported by said sleepers, resilient plates interposed between the inner face of the rail-flanges and the conjugated bearing surface of said sleepers, as well as rigid and insulating collars resting on the upper face of said flanges and cooperating with sleeper-screws tightly screwed into said sleepers, wherein the lower face of each rail-flange and the conjugated bearing surface of each sleeper have cooperating shapes defined by directrices bent over most of the width of each rail-flange concerned and by parallel generating lines, whereas the upper face of the rail-flange and the conjugated bearing surfaces of the corresponding collars have, from the edges up to the web of the rail concerned, cooperating shapes defined by directrices bent over most of the free width of the rail-flange concerned and by parallel generating lines.

2. Railway track according to claim 1 , wherein the lower face of each rail-flange is convex.

3. Railway track according to claim 1 , wherein the lower face of each rail-flange is concave.

4. Railway track according to claim 1, wherein the directrices of the lower face of the rail-flange are trapezoidal pointed arch-shaped.

5. Railway track according to claim 1, wherein the upper face of the rail-flange is made up of two side strips situated on both sides respectively of the web of the rail and extending substantially in parallel to said lower face.

6. Railway track according to claim 2, wherein the upper face of the rail-flange is made up of two side strips situated on both sides respectively of the web of the rail and converging towards the edges with said lower face.

7. Railway track according to claim 3, wherein said upper face of the rail-flange is made up of two side strips situated on both sides respectively of the web of the rail and diverging towards the edges relatively to said lower face.

8. Railway track according to claim 5, wherein each strip comprises and edging which is substantially perpendicuiar to the web of the rail.

9. Railway track according to claim 1, wherein each insulating rigid collar resting on the upper face of the rail-flange is in opposite abutment against the conjugated external side wall of the housing provided in the corresponding sleeper for each rail.

1 0. Railway track substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.