EP3623529B1

EP3623529B1 - Tram crossing with composite parts

Info

Publication number: EP3623529B1
Application number: EP18382668.4A
Authority: EP
Inventors: Vicente Albisua Aspiazu
Original assignee: Amurrio Ferrocarril y Equipos SA
Current assignee: Amurrio Ferrocarril y Equipos SA
Priority date: 2018-09-17
Filing date: 2018-09-17
Publication date: 2021-06-02
Anticipated expiration: 2038-09-17
Also published as: PT3623529T; EP3623529A1; ES2882711T3

Description

Object of the Invention

The present invention belongs to the field of points for trams and particularly to railway crossings.
The object of the present invention is a tram crossing comprising an embedded fixed part and another composite central part comprising three disconnected elements fixed to said embedded fixed part.

Background of the Invention

Railway crossings or movable point crossings are the elements that are placed at tram points that allow the passage of wheels at the location where two rails cross. Said crossings are made up of an outer part which is embedded in concrete of the railway track, and a central part which can be removable.
Conventionally, tram crossings are manufactured using a thick sheet metal in which the grooves enabling the passage of tram wheel flanges are machined. In other manufacturing processes, the crossings can be assembled using manganese steel rails or castings.
Wheel-to-crossing weight transfer changes, which may cause flattening and wear, usually occur in said crossings, and particularly in the central part of the crossing.
Common solutions for repairing crossings consist of replacing the central part of the crossing with a completely new one, which is a costly process since it requires specialized skilled labor and the complete replacement of the crossing. However, not all of the central part of the crossing is worn equally, meaning that part of the crossing is wasted during said replacement. In most points, circulation is only in one direction, which is usually the main track for tram circulation, with there being little circulation on the other track, which is defined as the diverted track. This causes wear in some areas of the crossing but not in others, and therefore when the central part is replaced in its entirety, materials from the areas of the central part with remaining service life are wasted.
Mechanically speaking, the contact areas between the outer part of the crossing that is embedded in concrete and the removable central part must have a 0 mm rail-joint gauge in the areas of the crossing where the tram wheel rolls and goes from the embedded fixed part of said crossing to the removable central part and vice versa, i.e., there must be continuity between the rolling of the parts of the crossing to prevent impacts, mechanical deformations, and maladjustments. However, in conventional crossings in which a single element including the entire central part to be replaced is used, it is virtually impossible to achieve 0 mm rail-joint gauges, since this can only be achieved by manufacturing the crossing in assembly workshops. So on site, when the central part must be replaced in its entirety, there will be flattening of material and wear that will make it very difficult or almost impossible to remove and insert a new central part to replace the worn central part if generous rail-joint gauges are not left, which will in turn cause blows and heavy wear for the passage of trams during use.
Other track crossing repair methods consist of resurfacing the damaged areas by means of typical welding and grinding requiring skilled labor, increasing the maintenance cost.
Therefore there is a need to obtain new crossings in which repairing the central part of the crossing does not require the complete replacement of said central part to thereby enable prolonging the service life of areas of the crossing that have not deteriorated and at the same time prevents maintaining said crossings by means of weld filling and grinding, which require skilled labor.
AT505047A1 relates to a horizontally divided switch heart with a switch body and individually exchangeable plug-in parts in the form of wing rails and heart tip, the plug-in parts being insertable into fitting slots in the switch body, the plug-in parts being wider in cross section in the area of the wheel running surface than in the area of the fitting slots.

Description of the Invention

The present invention relates to a tram crossing comprising a fixed part embedded in concrete, and comprising a hollowed-out central surface, where said hollowed-out central surface is suitable for receiving a composite central part and a bolting system for fixing the composite central part to the hollowed-out central surface. Once the embedded fixed part and the composite central part are fixed, they form rolling area comprising rolling grooves for the passage of tram wheels. The composite central part comprises three disconnected elements. The three disconnected elements comprise a right wing rail, a left wing rail, and a frog. The composite central part therefore comprises three elements not connected to one another. The bolting system allows fixing each of the three elements forming the composite central part.
The crossing according to the present invention therefore allows a perfect fit of the rail-joint gauges between the three disconnected parts forming the central part, in contrast with conventional crossings where the fitting of a single central part in different rail-joint gauges constitutes a major complication. The three disconnected parts can be mounted at a 0 mm rail-joint gauge in the joints of the rolling grooves for the passage of the tram wheel flanges, by means of fixing wedge plates in non-rolling areas of the tram wheels. The wedge plates can have different sizes in order to obtain the desired 0 mm rail-joint gauge. The wedge plates are fixed by the bolting system.
The crossing of the present invention allows removing only the parts of the composite central part that experience more wear. The wing rails are the parts of the composite central part that experience frequent circulation of the tram and are therefore the parts that experience the most wear, whereas the frog of the crossing is the part that experiences the least wear and can therefore remain intact for a longer time, thereby prolonging the use thereof and lowering crossing maintenance costs.

Description of the Drawings

To complement the description that is being made and for the purpose of helping to better understand the features of the invention according to a preferred practical embodiment thereof, a set of drawings is attached as an integral part of said description in which the following has been depicted with an illustrative and non-limiting character:

Figure 1 shows part of a tram crossing according to the present invention.
Figure 2 shows an exploded view of the tram crossing according to the present invention.
Figure 3 shows a detailed view of part of the tram crossing according to the present invention.
Figure 4 shows the tram crossing according to the present invention.

Preferred Embodiment of the Invention

Figure 1 shows part of a tram crossing (100) according to the present invention. The tram crossing (100) comprises a fixed part (110) embedded in concrete. The embedded fixed part (110) comprises a hollowed-out central surface (130) comprising threaded boreholes (135). A composite central part of the tram crossing is placed on said hollowed-out central surface (130), which is shown in Figure 2. The threaded boreholes (135) allow fixing the composite central part to the hollowed-out central surface (130) as shown in Figure 2. The embedded fixed part (110) comprises a first segment (120a) of the rolling grooves for the passage of a tram.
Figure 2 shows an exploded view of the tram crossing (100) comprising the embedded fixed part (110) with the hollowed-out central surface (130) and the composite central part. The composite central part comprises three elements not connected to one another, as can be seen in Figure 2. The composite central part therefore comprises a right wing rail (160), a left wing rail (140), and a frog (150) as well as threaded boreholes (145) that allow fixing the composite central part to the hollowed-out central surface (130) of the embedded fixed part (110) by means of a screw and nut assembly (175). The detail of a screw and nut (175) is shown in Figure 3. The frog (150) comprises a second segment (120b) of the rolling grooves which, when connected to the first segment (120a) of the embedded fixed part (110), form the rolling grooves for the passage of the tram over the crossing (100).
The three parts (140, 150 and 160) are assembled at a 0 mm rail-joint gauge in the contact joints between the frog (150) and the wing rails (140) and (160). The fixing of the three parts (140, 150 and 160) allows completing the attachment of the segments of the rolling grooves for the passage of the tram over the crossing. The fixing of said parts therefore allows the first segment (120a) of the rolling grooves established in the embedded fixed part (110) and the second segment (120b) of the rolling grooves established in the frog (150) to be attached to one another. The crossing (100) likewise comprises non-rolling areas of the tram comprising a clearance (165) at the end of the three parts (140, 150 and 160) in contact with the edges of the hollowed-out central surface (130). Wedge plates (170) that allow fitting the three parts (140, 150 and 160) fixed by means of screws and nuts (175) are inserted in the clearance (165) of the non-rolling areas. The wedge plates (170) are therefore inserted in the non-rolling areas of the tram wheel on the crossing (100), as seen in Figure 2. The wedge plates (170) can have different sizes to obtain the 0 mm rail-joint gauge. Figure 2 shows, for each wing rail (140) and (160), a wedge plate in the longitudinal direction of the crossing and a wedge plate in the transverse direction, thereby obtaining the desired 0 mm rail-joint gauge in the rolling area of the tram wheel.
Figure 3 shows a detailed view of the clearance (165) of the non-rolling area of the tram and the fixing between the left wing rail (140) and the embedded fixed part (110) by means of the screw and nut (175). It can be seen how the nut is introduced through the threaded borehole (145) of the left wing rail (140) and through the threaded borehole (135) of the hollowed-out central surface (130), fixing the left wing rail (140) to the embedded fixed part (110) of the tram crossing (100). The clearance (165) allows fitting the wing rail by means of the wedge plate (170) fixed to said wing rail by means of the same screw and nut (175) to obtain the 0 mm rail-joint gauge in the rolling area.
Figure 4 shows the tram crossing (100) comprising the embedded fixed part (110) and the composite central part comprising the right wing rail (160), the left wing rail (140), and the frog (150) fixed to said embedded fixed part (110) by means of screws and nuts (175). The wedge plates (170) inserted in the clearance (165) of the non-rolling areas and fixed by means of screws and nuts (175), which allow fitting the composite central part to the hollowed-out central surface (130) of the embedded fixed part (110), can also be seen.

Claims

Tram crossing (100) comprising a fixed part (110) comprising a hollowed-out central surface (130), a composite central part (140, 150 160), wherein the hollowed-out central surface (130) is adapted to receive the composite central part (140, 150 160) , and a bolting system (135, 145, 175) for fixing the composite centra part (140, 150 , 160) to the hollowed-out central surface (130), wherein the embedded fixed part and the composite central part form rolling grooves (120a, 120b) for the passage of a tram, wherein the composite central part (140, 150 , 160) comprises three disconnected elements:
a right wing rail (160);

a left wing rail (140); and

a frog (150), and
wherein the bolting system (135, 145, 175) allows fixing each of the disconnected elements (140, 150 , 160) to the hollowed-out central surface (130), the tram crossing (100) characterized in that the fixed part (110) is embedded in concrete, wherein the tram crossing (100) further comprises:
a set of wedge plates (170) fixed in non-rolling areas of the tram by means of the bolting system (135, 145, 175) to obtain a 0 mm rail-joint gauge in rolling areas of the tram, the set of wedge plates (170) being inserted in a clearance of the non-rolling areas, said clearance being at the end of the three disconnected elements (140, 150 160) in contact with the edges of the hollowed-out central surface (130), and

wherein the set of wedge plates (170) comprises, for each wing rail (160, 140), a wedge plate (170) fixed in the longitudinal direction of the tram crossing (100) and a wedge plate (170) fixed in the transverse direction of the tram crossing (100).
Tram crossing (100) according to claim 1, wherein the bolting system comprises a set of threaded openings (135) established on the hollowed-out central surface (130), a set of threaded openings (145) in the right wing rail (160), a set of threaded openings (145) in the left wing rail (140), a set of threaded openings (145) in the frog (150), and a set of screws and nuts (175).