GB2075578A

GB2075578A - Railway points

Info

Publication number: GB2075578A
Application number: GB8109351A
Authority: GB
Original assignee: Elektro Thermit GmbH
Current assignee: Goldschmidt ETB GmbH
Priority date: 1980-05-08
Filing date: 1981-03-25
Publication date: 1981-11-18
Also published as: IT1142657B; GB2075578B; AT371515B; ATA38881A; FR2482148A1; JPS6134521B2; JPS573901A; IT8147946A0; DE3017533C2; FR2482148B1; DE3017533A1

Abstract

Railway points have first rail sections (1,2) the end portions of which are transversely movable for alignment with fixed rail sections (3,5 and 4,6) comprising main and branch tracks respectively. A pair of connecting rails (11,12 and 13,14) are located on either side of each movable rail section portion and are connected (at 16,17) to the movable rail section portion only in the region at the entry to the points near where the movable rail section connects with the fixed rail section and (as 25,26,27) to the ends of the fixed rail sections (3,4,5,6) comprising the continuation of the main track and the branch track. The connecting rail portions serve to transmit tensile and thrust forces between the various fixed rail sections and portions thereof. <IMAGE>

Description

SPECIFICATION Railway points The invention relates to railway points, wherein a movable portion of a main track is transversely movable horizontally for alternative alignment with the main and branch tracks.

The closed distribution of forces which exists in continuously welded track is interrupted in the region of discontinuities in the track, these discontinuities being due to design reasons, such as, for example, at points, in the region of the transition from the transversely movable rail sections to the rail ends of the main track and of the branch track. Relative movements between the two rail ends thereby occur at these discontinuities, that is to say, a gap is set up between the rail ends, which is larger or smaller depending on the temperature. To prevent the wheel from hammering at the joint-gap, it is necessary to design the joint-gap to be as small as possible and to keep the joint-gap constant. It has already been proposed to solve this problem by means of expansion-joints, or with the aid of articulated designs.However, these designs are extremely expensive to build and to maintain, and they are extremely susceptible to wear.

The object underlying the invention is accordingly to maintain the longitudinal connection between the transversely movable rail sections and the rails of the main track and of the branch track, respectively, by means of an inexpensive and simple design which is as maintenane-free as possible, without requiring too large a gap.

According to the invention there are provided railway points comprising first rail sections each comprising a fixed portion forming part of a main track and a movable end portion: fixed rail sections forming a continuation of the main track and a branch track, the end portions of the first rail sections being transversely movable for alternative alignment with the ends of the fixed rail sections comprising the main and branch tracks; and two pairs of connecting rails associated with respective movable end portions of the first rail sections, said connecting rails of each pair being located inside and outside the track and being securely connected by force-transmitting means to the ends of respective ones of the fixed rail sections of the main and branch tracks and to the transversely movable end portion of the respective first rail sections, the connection to the movable end portion being at a location adjacent the point of connection of such movable end portion with the fixed portion of the respective first rail section.

The connecting rails, arranged in this manner, conduct the temperature-dependent longitudinal forces parallel to the joint-gap between the fixed rail ends of the main track and of the branch track, conduction occurring in the onward direction, so that relative movements no longer occur in the region of the joint-gap.

The profile and length of the connecting rails, and the force-transmitting attachment, in each case, of their ends to the transversely movable running rails and to the fixed ends of the rails of the main track and of the branch track, respectively, are set, on the one hand, by the local conditions and by the forces expected to occur, and, on the other hand, according to the type and profile of the rails which are to be relieved of load.

A rail having a tongue-like profile has proved particularly advantageous as a connecting rail. These tongue-profile rails are lower than the normal profiles, so that the railbases of the running rails can be moved without obstruction. At the same time, it is further advantageous that, using these tongue-profile rails, it is possible to have recourse to a rolled profile which is already available and is already used in the construction of points for the manufacture of point blades. The expense of manufacture of a specific single-purpose profile or special profile is thereby dispensed with.

It is significant that the connecting rails are not secured over a defined length between their force-transmitting attachment points, and that they can accordingly move freely in the horizontal direction, in a resilient manner, in order to be able to follow the transverse movements of the running rails in the deviation region.

The length of the connecting rails must be designed so that their bending, caused by the transverse movement in the deviation region, is borne elastically, that is to say, the connecting rails cannot be secured by force-transmitting means at a point where there is still the danger that they will not withstand these forces and that they will accordingly break, or deform plastically. The length consequently depends on the shape of the profile and on the material of the connecting rails.

The attachment, by force-transmitting means, of the connecting rails to the transversely movable rail sections and to the rail ends, respectively, is expediently effected by means of high-strength bolts, which are guided through bores in distance pieces, which are matched to the rail web and are located between the connecting rails and the transversely movable rail sections and the rail ends respectively. With this arrangement, the force flux propagates from the stressed running rails, via the distance pieces, to the connecting rails.

The region of the joint-gap is thereby kept free of tensile forces and compressive forces, which result from the temperature-dependent length changes in the track. The connecting rails are easy to install, require no additional maintenance and do not wear.

The invention is explained in greater detail by way of example with reference to an illustrative embodiment shown in the accornpany- ing drawings in which: Figure 1 shows the plan view of a set of points embodying the invention; Fig tire 2 is a detail cross-section taken along line il-ll of Fig. 1; and Figure 3 5 a detail cross-section taken along line Ill-Ill of Fig. 1.

In Fig. 1, the operating region of a set of points is illustrated from the positions A-B, this region being formed by the running rails (1,2) of the main track having end portions which are mounted to be transversely movable alternatively to align with the fixed running rail ends (3,5) of the main track and of the branch track (4,6). The joint-gaps (7, 8, 9, 10) are located at the position c. With the points positioned as illustrated in Fig. 1 the rails are aligned for travel to take place in the direction of the main track. The running rails (1 ,2) which are mounted to be transversely movable, are positioned at the joint-gaps (7,8), opposite to and in alignment with the fixed main track rail ends (3,5).If the point were to be reset, the transversely movable running rails (1,2) wouid be moved to come into aligned opposition, at the joint-gaps (9,10), to the fixed running rail ends (4,6) of the branch track, it being possible to effect the resetting as convenient by devices, not illustrated, driven pneumatically, hydraulically or electrically.

In order to avoid relative movements in the longitudinal direction of the running rails (1,2), at the joint-gaps t7,8,9,10), here represented at position c, there is provided uninterrupted path for the transmission of force through the connecting rails (11,12,13 and 14), which are located in pairs beside the running rails (1,2), inside and outside the track.

These connecting rails of each pair are connected together, over the longitudinal extent of the rails between c and d behind the joint-gaps (7,8,9,10), as well as between a and b at the beginning of the point, by highstrength bolts, in a force-transmitting manner.

Distance pieces or spacers (16, 17, 25 and 26) hold the connecting rails at a distance from the running rails. In a specific region, here represented between b and c, the connecting rails remain unsecured. Starting from the beginning of the point, the transmission of force thus takes the path from the running rail (1), which is mounted to be transversely movabie, via the force-transmitting high-strength bolted connections in the attachment region between a and b, onto the connecting rails (11,12), and is conducted back onto the running rail ends (3,4) of the main track and of the branch track, respectively, these rail ends being located at fixed positions, via the attachment bolts, also force-transmitting, in the region from c to d.The joint-gaps (7,8,9,10) are thereby kept free, at the position c, of tensile forces and compressive forces resulting from the length changes of the rails due to changes in ambient temperature. The connecting rails (1 1 ,1 2,1 3 and 1 4) are rnanufacturesd from the same rail profile as the running rail ends !3,4,5 and 6) of the main track and of the branch track, that is to say, they have the profile of a tongue-profile rail. In the unsecured region, in this case between b and c, the connecting rails !11 to 1 4) can move in the horizontal direction in a resilient manner and can also move transversely in conjunction with the transverse movement of the movable end portions of the running rails (1 ,2) when the points are reset.

Fig. 2 shows the force-transmitting highstrength bolting of the running rail (1), which is mounted to be transversely movable, to the connecting rails (11,12). Tongue-proTile rails are employed for the connecting rails (11.12) these being lower than the running rails. The connecting rails accordingly do not rest on the sleepers (15) of the running rails. Distance pieces or spacers (16,17) are located between the running rail (1) and the connecting rails (11.12), these distance pieces being matched both to the rail web of the running rail and to the rail web of the connecting rail. The distance piece (16) holds the connecting rail (11) at an appropriate distance from the running rail (1), so that no misplaced wheel flange can run onto it.The distance piece (1 7) holds the connecting rail (1 2) at a distance relative to the running rail (1), so that the wheel flanges of the vehicle wheels can roll through without hindrance. The force-transmission from the connecting rails to the running rails takes place through the high-strength bolt (18), which is guided through the bores (19,20,21) in the webs of the connecting rails and in the webs of the running rails, and through the washers (22) and the high-strength nut (23).

The common force-transmitting connection of the connecting rails (11,1 2), both with the running rail (3) and with the running rail (4), by means of a high-strength bolt (24), is shown in Fig. 3.

The connecting rails (11,12) are held at a distance relative to the fixed ends (3,4) of the running rails, by means of the distance pieces (25,26). A further distance piece (27) pro- - duces the distance between the rail ends (3,4), this distance being necessitated by the geometry of the point at this position. The rail ends (3,4) and the connecting rails !11,12)- are connected together, in a force-transmitting manner, by means of the straight-through fixed bolt (24), which passes through the bores (28 to 31), the washers (32) and the high-strength nut (33).

Claims

1. Railway points comprising first rail sections each comprising a fixed portion forming part of a main track and a movable end portion; fixed rail sections forming a continuation of the main track and a branch track, the end portions of the first rail sections being transversely movable for alternative alignment with the ends of the fixed rail sections comprising the main and branch tracks; and two pairs of connecting rails associated with respective movable end portions of the first rail sections, said connecting rails of each pair being located inside and outside the track and being securely connected by force-transmitting means to the ends of respective ones of the fixed rail sections of the main and branch tracks and to the transversely movable end portion of the respective first rail sections, the connection to the movable end portion being only at a location adjacent the point of connection of such movable end portion with the fixed portion of the respective first rail section.

2. Railway points according to Claim 1, wherein the connecting rails have a tongueprofile-rail-like profile.

3. Railway points constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.