Object of the Invention
[0001] The present invention belongs to the field of points for trams and particularly to
railway crossings.
[0002] 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
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
Description of the Invention
[0010] 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 crossing is characterized
in that 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.
[0011] 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.
[0012] 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
[0013] 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
[0014] 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.
[0015] 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).
[0016] The three parts (140, 150 and 160) can be 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.
[0017] 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.
[0018] 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.
1. Tram crossing (100) comprising a fixed part (110) embedded in concrete comprising
a hollowed-out central surface (130) suitable for receiving a composite central part
(140, 150 160) and a bolting system (135, 145, 175) for fixing the composite central
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, the crossing being
characterized in that 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).
2. 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).
3. Tram crossing (100) according to claim 1, comprising 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.
4. Tram crossing (100) according to claim 3, 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).