TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a modular rail fastening system, integrated by bonded
components, which is applicable in the railroad industry as a fastening system for
a ballastless track or on ties and more specifically, in relation to the track apparatuses
that require highly elastic fastening systems to improve their performance.
[0002] The benefits arising from an increase in the elasticity of the track lead to a reduction
in the dynamic overloads on it, an increase in passenger comfort and a significant
reduction in the noise levels and vibrations generated by railroad traffic.
[0003] These improvements make the development and use of the elastic components for rail
fasteners especially interesting for the purpose of using them in metropolitan railroad
operations and, in general, in all operations that seek to improve the performance
of infrastructure when faced with problems arising from a rigid track.
BACKGROUND OF THE INVENTION
[0004] Currently, the elastic fasteners used on railroad tracks are based on one of the
following two models:
- a) A model that uses sheets or pads placed under the running rail or under the bearing
plate in order to obtain the elasticity required.
- b) A model that uses elastic bearing plates manufactured for a bonding or vulcanizing
method that joins, integrates and compacts the main parts of these plates by injecting
an elastic component such as rubber.
[0005] Fastener is taken to mean that which is formed by the rail bearing plate with its
elastic clips and its pre-installable sheets or pads under the running rail and under
the bearing plate. Anchors on the ties or on the concrete slab also form part of fasteners.
The elastic characteristics of the fastener depend on the geometry, dimensions and
composition of the elastomer used.
[0006] Both systems a) and b) are to be applied to tracks on ties (ballast track) and tracks
on concrete slab, the latter being assembled with the 'Top-Down' or 'Bottom-Up' system.
[0007] The type and method of anchoring the fasteners to the concrete slab or to the ties
and the components such as eccentric bushings or toothed regulators of the plate position
complete the materials of the fastening system, although, on occasion, they do not
form part of the development of the elastic system itself.
[0008] Among track apparatuses, there is combined use of two types of plates: standard and
special. There are various types of special plates, object of this invention, within
the same apparatus, and they adapt geometrically and functionally to the different
areas of the track apparatus, which are mainly switches and crossings.
[0009] The current state of the art, in terms of highly elastic fasteners for track, is
summarized below.
[0010] The standard elastic fastener of type a) which is used on ties or concrete slab achieves
elasticity using an elastic sheet (6) under the bearing plate (9). The assembly is
completed by elastic clips (1) and their screws, the pre-installable elastic sheet
under the rail (2), the insulation and adjustment sheet under the plate (3) and the
anchors (4) to the tie or concrete slab. Figure 1 shows an example of this type.
[0011] The special elastic fastener for track apparatuses of type a) which is used on ties
or concrete slab, achieves elasticity using an elastic sheet (6) under the bearing
plate (9). The assembly is completed by elastic clips (1) and their screws, the pre-installable
elastic sheet under the rail (2), the insulation and adjustment sheet under the plate
(3) and the anchors (4) to the tie or concrete slab. Figure 2 shows an example of
this type.
[0012] The standard elastic fastener of type b) represented in figure 3 is used with ties
or concrete slab, and elasticity is achieved by using a compact bonded plate system
(5 = 5a + 5b + 5c), where (5a) is the upper plate, (5b) is the elastic plate and (5c)
is the lower plate. The assembly is completed by elastic clips (1) and their screws,
the pre-installable elastic sheet under the rail (2), the insulation and adjustment
sheet under the plate (3) and the anchors (4) to the tie or concrete slab.
[0013] The special elastic fastener of type b) represented in figure 4 specifically for
track apparatuses is used with ties or concrete slab, and elasticity is achieved by
using a compact bonded plate system (7 = 7a + 7b + 7c), where (7a) is the upper plate,
(7b) is the elastic plate and (7c) is the lower plate. The assembly is completed by
elastic clips (1) and their screws, the pre-installable elastic sheet under the rail
(2), the insulation and adjustment sheet under the plate (3) and the anchors (4) to
the tie or concrete slab.
DESCRIPTION OF THE INVENTION
[0014] The present invention relates to the development of the special bonded fasteners
with application to the track and to the special bearing plates of the track apparatuses.
This invention is an alternative to some of the current technical proposals, such
as the ones represented in figures 2 or 4.
[0015] The special bearing plates of a track apparatus are all of those that are not standard,
for example: slide bars, plates composed of the heel of the switch, plates composed
of embedded switches, guard-rail supports, plates composed of the crossing entrance
and exit or the crossing bearing plates.
[0016] The bonded fastener of the invention is based on a concept of modularity, for which
reason each special bearing plate of the bonded fastener has been divided into different
and independent main parts that offer the possibility of remaining joined together,
forming an assembly adapted to the dimensions required by the track apparatus, or
being separated to facilitate maintenance and replacement tasks.
[0017] This modular fastening system object of the invention can be described from bottom
to top in the following way:
The first level has the insulation and adjustment/levelling sheet of the assembly,
manufactured, for example, with HDPE material, which insulates the rest of the components
that make up the fastener with respect to the concrete slab or tie. Preferably, the
insulation sheet is adjustable in length based on the total length of the fastener,
and is also adjustable in thickness, for the proper levelling of the track.
The second level has two bonded shoulders or side pieces which are the same and joined
by a central support upon which a plate with the same elasticity as the pieces is
placed in line with a bonding of the shoulders. The shoulders and the central support
comprise the joining means that allow for the coupling of each shoulder to the central
support. The shoulders have a geometry that is adapted to integrate the attachment
anchors into the concrete slab. There is also the possibility that they comprise a
system for adjusting the position of the modular fastening system within the track
apparatus.
The third level has the upper plate of the track apparatus, relative to a special
bearing plate and generally manufactured with ribbed plates or steel sheets. It is
placed under the rails and contains elastic clips and the necessary pre-installable
sheets. This plate is surrounded on its ends, preferably around the perimeter, by
the bonding of the shoulders and is attached to them by threaded bolts. The perimeter
bonding limits the longitudinal and lateral movements of the plate.
[0018] Preferably, the fourth level has stop ends, nails or latches that are attached to
the shoulders which limit the vertical upward movements of the upper plate.
[0019] The invention of this fastening system, in addition to having the same capabilities
as any other similar system, has certain advantages with respect to the current state
of the art, such as:
- A conceptual design that is simpler than that of the current systems on the market
and which facilitates the manufacturing process and effectively limits the lateral
and vertical movements of the track under the effect of loads.
- Greater flexibility to use any type of plate or track apparatus project, since the
system modularity allows the bonded plate to have any length since it is adjustable
by default. Designs that are completely free from limitations can be developed. In
this case, the invention is adapted to the design of each apparatus. On the other
hand, to date, the projects of bonded plates for track apparatuses are conditioned
designs because they must adapt to the existing lengths of the bonded models (generally
between three and five different types).
- Since the system is entirely modular, the partial and mass manufacture of the elements
that comprise the assembly is possible, independent of the type of upper plate that
is used. This way, the manufacture of a single special plate or a spare part is very
streamlined, with a minimal delivery period.
- Optimization of the design and manufacturing periods. The design and manufacture of
the components of the track apparatus would not be sequential, but they could be taken
on in parallel since the bonded components of each one of the special plates are the
same. Therefore, the manufacture of those bonded components is not conditioned by
the existence or the lack thereof of the manufacturing project nor by the type of
track apparatus to be developed. With the current state of the art it is necessary
to first have the complete project of the track apparatus available and afterwards
each bonded plate of the switch or crossing can be manufactured individually.
- With this invention the bonded plates can be attached to the slab with four anchoring
points, which reduces the amount of stress per unit of anchoring. The bonded shoulders
increase the surface of support and improve load distribution and transmission to
the slab.
- Unlike other systems, this invention contains a system that neutralizes the vertical
upward stress of the plates, materialized in stop ends, nails or latches that vertically
fix the position of the upper plate within the bonded assembly, limiting the tensile
stress on the plates.
- With this invention the manufacturing process of the bonded plates is simplified because
there is no need for a casting model or a rubber injection mold for each desired length,
which therefore reduces the investment in tools.
- There is no need to have stock of each one of the complete bonded plates for new installations
and maintenance, meaning that stock and storage costs are reduced.
- The modular system facilitates the assembly and disassembly of all of its components,
allowing for the complete or partial substitution of any of the integrated fastening
parts that are worn-out or deteriorated, meaning that maintenance tasks are streamlined.
- This modular system can be applied to the existing track apparatuses of the Rail Network
which require a change in elasticity for reasons of exploitation, thus taking advantage
of both the iron of the apparatus as well as the ties placed on the track. With the
currently existing monoblock plates, the ties could not be reused.
DESCRIPTION OF THE DRAWINGS
[0020] As a complement to the description provided herein, and for the purpose of helping
to make the characteristics of the invention more readily understandable, in accordance
with a preferred practical embodiment thereof, said description is accompanied by
a set of figures constituting an integral part of the same, which by way of illustration
and not limitation represent the following:
Figure 1 is a schematic view, with a transverse cross section, of a standard fastener
based on the elasticity of the sheet under the bearing plate according to the state
of the art.
Figure 2 is a schematic view, with a transverse cross section, of a special fastener
of the track apparatus also based on the elasticity of the sheet under the bearing
plate according to the state of the art.
Figure 3 is a view of a standard bonded fastener according to the state of the art.
Figure 4 is an upper view of a special bonded fastener of the track apparatus according
to the state of the art.
Figure 5 is an example of a complete modular bonded plate according to the invention,
where side bonded shoulders or pieces, the central support, the special bearing plate,
latches and the insulation and adjustment plate are seen.
Figure 6 shows in detail one of the bonded shoulders according to the invention, with
its latch, inserted for the attachment of the special bearing plate and the guide
bushings for the rods of the central support.
Figure 7 shows in detail one of the bonded shoulders according to the invention, in
which one of the lightening blocks that simplify the bonding process and the castings
of the elastic bonded component that improve the absorption of vibrations and noise
can be seen.
Figure 8 is an example of a complete modular bonded fastener according to the invention
in working position, where the bonded shoulders or side pieces, the central support,
the special bearing plate, latches, the insulation and adjustment plate, anchors to
the concrete slab, elastic clips for the rail and the pre-installable elastic sheets
can be seen.
Figure 9 is an example of a complete modular bonded fastener according to the invention
in working position, adapted to a standard solution, where the bonded shoulders or
side pieces, the special bearing plate, latches, the insulation and adjustment plate,
anchors to the concrete slab, elastic clips for the rail and the pre-installable elastic
sheets can be seen.
Figure 10 is a schematic perspective view of the central support with an elastic plate.
PREFERRED EMBODIMENT OF THE INVENTION
[0021] With reference to the figures discussed above, it can be observed how in one of the
possible embodiments of the modular rail fastening system proposed by the invention,
that it comprises, according to figure 5, two side bonded pieces (10), also called
shoulders, that are joined (with the appropriate assembly or disassembly means) by
a piece whose length is adjustable to the needs of the track called the central support
(11), which are integrated together to make up a compact and mechanically resistant
assembly called a bonded body (12).
[0022] As observed in figures 6 and 10, each shoulder (10) and central support (11) preferably
comprise joining means that allow for the coupling of each shoulder (10) to the central
support (11), which restrict movement between the side pieces (10) and the central
support (11), except in the longitudinal direction of the attachment, which is transversal
to the fixed rail, such as rods (8) that emerge from the central support (11) and
are inserted into the guide bushings (19) located on the side pieces (10).
[0023] An elastic plate is placed on the central support (11) which, together with the bonded
shoulders (10), make up the elastic base of the bonded body (12), upon which the special
bearing plate (9) is placed. This bearing plate contains the elastic clips (1) and
the pre-installable elastic sheets under the rail (2), such that the special bearing
plate (9) covers the entirety of the elastic plate (6) and partially covers each one
of the bonded shoulders (10).
[0024] The elastic plate (6) is fitted upon the retaining central support (11) to prevent
longitudinal and transversal movements that can be produced during assembly and to
define a central area between the two side pieces (10).
[0025] Preferably, the elastic plate (6) comprises a plurality of castings (23) distributed
strategically such that they allow for the adjustment of the elasticity of the existing
central area between the two side pieces (10).
[0026] Lastly, the entire assembly is mounted on an insulation and adjustment sheet (3)
under an adjustable-length plate based on the total length of the fastener and on
the thickness, which is also adjustable, to achieve proper levelling of the track.
This prevents the rest of the pieces from coming into direct contact with the concrete,
permitting easier maintenance when having to change the components of the special
fastener.
[0027] The bonded shoulder (10) is one of the modules of this invention and it is seen in
detail in figures 6 and 7. It has the hollows and recesses necessary to achieve the
range of elasticity desired and it is made up of the following parts:
[0028] A cast base (14) that contains the housings (15) on the two sides of the cast base
(14), defining an anchor point on each side of each side piece (10) for the attachments
to the concrete, and it comprises the elastic bonded component (16), which is generally
rubber-based. The cast base (14) with the elastic bonded component (16) partially
surrounds the area of the special bearing plate (9) through elevated areas (21), remaining
fitted to the ends of the special bearing plate (9) and acting as a perimeter stop
end that limits its longitudinal and lateral movements.
[0029] The housings (15) comprise a toothed regulator (22) to withstand the transversal
forces to the rail and adjust the position of the modular fastening system.
[0030] The cast base (14) comprises a plurality of lightening blocks (20) which makes filling
with the elastic bonded component (16) easier, simplifying the bonding process.
[0031] The elastic bonded component (16) comprises a plurality of castings (20') that favor
its deformation, improving the absorption of vibrations and noise.
[0032] An insert (17) forming a compact block is embedded in the elastic bonded component
(16) and contains threaded bolts (18) to attach the special bearing plate (9) to the
bonded body (12).
[0033] A nail or latch (13) that attaches the special bearing plate (9) to the side pieces
(10) is screwed onto the cast base (14) in order to limit the vertical stress on the
plates, and it preferably comprises an elastomer bonded to the latch (13) itself that
supports the special bearing plate (9) through said bonded elastomer (16'), on the
one hand avoiding metal-to-metal contact and on the other, elastically absorbing the
vertical movements on the special bearing plate (9).
[0034] The fastener system of the invention limits deflection and vertical and lateral movements
by having the special bearing plate (9), preferably metal, fitted or surrounded by
elastic material in the areas previously indicated, such that the stress and vibrations
coming from the track are absorbed and minimized.
[0035] Figure 8 shows an example of a complete modular plate in a working position on a
track apparatus.
[0036] On the other hand, it is envisaged to arrange the corresponding pre-installable elastic
sheets under the rail (2) in order to avoid direct metal-to-metal contact between
the rail and the special bearing plate (9). Finally, each rail is securely attached
to the special bearing plate (9) with two clips (1) that exert a load on each one
of the rails. Each clip (1) is screwed to the special bearing plate (9) assembly with
a screw set comprising a hook, nut and bolt.
[0037] The central support (11) and the elastic plate (6) are adaptable and adjustable in
length to any measurement required by the track apparatus. Likewise, the side pieces
(10) are common and the same for any of the plates of the track apparatus.
[0038] The modular fastening system can be used to transform the elasticity of apparatuses
in service with the maximum use of the components installed on the track.
[0039] Therefore, as can be seen from the foregoing, the concept of the bonded monoblock
plate described in the background section has been changed for the concept of a modular
fastening system, which can be assembled/dissembled and adjusted, creating the opportunity
to place it on existing track apparatuses, while using most of the components of those
apparatuses.
[0040] Figure 9 shows an alternative use, relative to an example of a complete modular bonded
fastener according to the invention in working position, adapted to a standard solution,
where the bonded shoulders or side pieces (10), the standard bearing plate, latches
(13), the insulation and adjustment plate (3), anchors (4) to the concrete slab, elastic
clips for the rail (1) and the pre-installable elastic sheets (2) can be seen.
[0041] This alternative use is applied to those cases that require the fastening of a single
rail, without having to do anything more than disassemble the central support (11)
and directly join both side pieces (10) together through the joining means and adjusting
the insulation and adjustment sheet (3) to the new length, according to the dimensions,
in order to fasten a single rail.
[0042] The side pieces (10) on both sides, equipped with the respective latches (13) and
anchors (4), are the same ones used in fastening the special bearing plate (9), according
to a modular design shared by both types of fasteners.
[0043] In this case, elasticity is exclusively defined as the elastic bonded component (16)
of the side pieces (10), since there is no elastic plate (6).
[0044] The characteristics offered by the modularity of the fastener in this case are the
following:
- By being a shared design, there is a smaller number of different components and units
of storage and therefore, of casting models and bonding molds, which reduces the initial
investment.
- A total of four anchors are required to prevent the side pieces from rotating when
faced with loads in the longitudinal direction of the rail caused by the acceleration
and braking of the rolling stock.
[0045] In view of this description and the set of figures, a person skilled in the art will
understand that the embodiments of the invention that have been described can be combined
in multiple ways within the object of the invention. The invention has been described
according to preferred embodiments thereof, but for the person skilled in the art,
it will be evident that multiple variations can be introduced in said preferred embodiments
without departing from the object of the invention as has been claimed.
1. A modular rail fastening system characterized in that it comprises two side pieces (10) joined to both sides of a central support (11),
where each side piece (10) comprises a cast base (14) and an elastic component (16)
bonded to said cast base (14), forming a compact bonded body (12), the system comprising
a special bearing plate (9) that covers the entirety of an elastic plate (6) placed
on the central support (11) and partially covering each one of the side pieces (10),
and also comprising an insulation and adjustment sheet (3) under the plate for separating
it from the concrete and levelling the track.
2. The modular fastening system according to claim 1, wherein each side piece (10) comprises
an insert (17) that is embedded into the elastic bonded component (16) forming a compact
block, wherein said insert (17) houses at least one threaded bolt (18) upon which
the special bearing plate (9) is mounted.
3. The modular fastening system according to any of the previous claims, wherein each
side piece (10) and central support (11) comprise joining means that allow the coupling
of each side piece (10) to the central support (11) and that restrict movement between
the side pieces (10) and the central support (11) except in the longitudinal direction
of the attachment.
4. The modular fastening system according to claim 3, wherein said joining means comprise
rods (8) housed in the central support (11) and inserted in the guide bushings (19)
located on the side pieces (10).
5. The modular fastening system according to any of the previous claims, wherein the
elastic bonded component (16) comprises a plurality of castings (20') that favor its
deformation, improving the absorption of vibrations and noise.
6. The modular fastening system according to any of the previous claims, wherein each
side piece (10) has elevated areas (21) coated with the elastic bonded component (16)
that act as perimeter stop ends, and in which the ends of the special bearing plate
(9) fit, limiting the longitudinal and sideways movements of the track.
7. The modular fastening system according to any of the previous claims, wherein the
cast base (14) comprises a plurality of lightening boxes (20) that simplify and facilitate
the bonding process.
8. The modular fastening system according to any of the previous claims, wherein each
side piece (10) comprises at least one housing (15) suited for anchoring to a concrete
slab.
9. The modular fastening system according to claim 8, wherein each housing (15) is located
at one end of the cast base (14), defining an anchor point on the side piece (10).
10. The modular fastening system according to claim 9, wherein, on each anchor point,
the housing (15) comprises a toothed regulator (22) to withstand the transversal forces
to the rail and adjust the position of the fastening system.
11. The modular fastening system according to any of the previous claims, wherein the
elastic plate (6) is fitted on the retaining central support (11), defining a central
area between the two side pieces (10).
12. The modular fastening system according to claim 11, wherein the elastic plate (6)
comprises a plurality of castings (23) that allow the elasticity of the existing central
area between the two side pieces (10) to be adjusted.
13. The modular fastening system according to any of the previous claims, which comprises
at least one latch (13) that attaches the special bearing plate (9) to the side pieces
(10) in order to limit the vertical stress on the plates.
14. The modular fastening system according to claim 13, wherein said latch (13) comprises
an elastomer (16') bonded to said latch (13) and which supports the special bearing
plate (9) through said bonded elastomer (16'), on one side preventing metal-to-metal
contact and on the other, elastically absorbing the vertical movements of the special
bearing plate (9).
15. The modular fastening system according to claim 11, wherein the central support (11)
and the elastic plate (6) are adaptable and adjustable in length to any measurement
required by the track apparatus, while at the same time, the side pieces (10) are
common and the same for any of the plates of the track apparatus.
16. The modular fastening system according to any of the previous claims, which can be
used to transform the elasticity of the apparatuses in service with the maximum use
of the components installed on the track.