U.S. patent application number 13/604072 was filed with the patent office on 2013-03-28 for rail sleeper.
This patent application is currently assigned to MSB-MANAGEMENT GMBH. The applicant listed for this patent is Jurgen Frenzel, Tim Frenzel. Invention is credited to Jurgen Frenzel, Tim Frenzel.
Application Number | 20130075486 13/604072 |
Document ID | / |
Family ID | 39474816 |
Filed Date | 2013-03-28 |
United States Patent
Application |
20130075486 |
Kind Code |
A1 |
Frenzel; Jurgen ; et
al. |
March 28, 2013 |
RAIL SLEEPER
Abstract
The rail sleeper (10) is provided with a sleeper body (12)
comprising one rail contact area (16) on each of the opposing ends
thereof, within which the sleeper body (12) is widened. A rail (24)
may be fixed in each rail contact area (16) by means of a hold-down
element (28) able to grip a rail foot. Each rail contact area (16)
comprises three rail contact surfaces (18) adjacent to one another
in the extension of the rail (24). At least one hold-down element
(28) is disposed between and above at least one partial region of
respective adjacent rail contact surfaces (18) of each rail contact
area (16). The sleeper body (12) is free of reinforcement elements
within each rail contact area (16) on both sides of the
intermediate spaces between adjacent rail contact surfaces
(18).
Inventors: |
Frenzel; Jurgen; (Freden
(Leine), DE) ; Frenzel; Tim; (Freden (Leine),
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Frenzel; Jurgen
Frenzel; Tim |
Freden (Leine)
Freden (Leine) |
|
DE
DE |
|
|
Assignee: |
MSB-MANAGEMENT GMBH
Freden (Leine)
DE
|
Family ID: |
39474816 |
Appl. No.: |
13/604072 |
Filed: |
September 5, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12677697 |
Apr 27, 2010 |
|
|
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PCT/EP2007/060140 |
Sep 25, 2007 |
|
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13604072 |
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Current U.S.
Class: |
238/42 |
Current CPC
Class: |
E01B 3/32 20130101; E01B
3/44 20130101; E01B 3/40 20130101; E01B 3/00 20130101; E01B 3/28
20130101 |
Class at
Publication: |
238/42 |
International
Class: |
E01B 3/44 20060101
E01B003/44; E01B 3/28 20060101 E01B003/28; E01B 3/00 20060101
E01B003/00 |
Claims
1-10. (canceled)
11. A rail sleeper comprising a sleeper body comprising
respectively a rail contact area on each of its opposing ends and
having an enlarged width within said rail contact areas, each rail
contact area being adapted for fixation of a rail therein by means
of a hold-down element able to engage a rail foot, wherein each
rail contact area comprises three rail contact surfaces arranged
adjacent to one another in the extension of the rail, at least one
hold-down element is arranged between and above at least one
partial region of respective adjacent rail contact surfaces of each
rail contact area, and the sleeper body is free of reinforcement
elements within each rail contact area on both sides of the
intermediate spaces between adjacent rail contact surfaces.
12. The rail sleeper according to claim 11, wherein respectively at
least one first reinforcement profile element, extending in the
direction of the rail, is arranged below the rail contact areas
within the sleeper body.
13. The rail sleeper according to claim 12, wherein said
reinforcement profile is arranged centrally relative to the rail
contact area or, in case of two or more reinforcement profiles,
these are arranged symmetrically and/or centrically relative to the
rail contact area.
14. The rail sleeper according to claim 12, wherein said
reinforcement profile or each reinforcement profile comprises at
least one leg extending substantially at a right angle relative to
the rail contact area and, in case of a reinforcement profile
comprising a plurality of such legs, these legs are arranged
symmetrically to the rail contact area.
15. The rail sleeper according to claim 12, wherein the sleeper
body is traversed by at least one second reinforcement profile
element which in each of the rail contact areas extends below a
middle rail contact surface and which is connected to said first
reinforcement profile elements.
16. The rail sleeper according to claim 12, wherein the sleeper
body is configured a bi-block sleeper body comprising two blocks
each including one rail contact area, and said first reinforcement
profile elements are connected to each other by a second
reinforcement profile element, said second reinforcement profile
element interconnecting said two blocks and being arranged in each
of the rail contact areas below the middle rail contact
surfaces.
17. The rail sleeper according to claim 11, wherein the region of
said second reinforcement profile element that is located between
said two blocks is protected against corrosion by an enclosure of
plastic material.
18. The rail sleeper according to claim 17, wherein said enclosure
of plastic material is formed with a receiving recess for receiving
a conductor rail.
19. The rail sleeper according to claim 11, wherein the sleeper
body comprises concrete or polymer concrete.
20. The rail sleeper according to claim 16, wherein said blocks
comprise plastic and/or said second reinforcement profile element
and optionally also said first reinforcement profile elements
comprises a substantially plane surface.
Description
[0001] The present invention relates to a rail sleeper as used in
the laying of rails and tracks.
[0002] In the field of railroad construction, rail sleepers made of
wood, concrete, steel and plastic material are known. Further, rail
sleepers are known in the most various forms, such as e.g.
monoblock sleepers, bi-block sleepers and Y-sleepers. Further known
are various fastening systems, these being e.g. rib-plate
fasteners, Pandrol fasteners or fasteners with angled guide
plates.
[0003] Rail sleepers normally comprise, on their ends, rail contact
areas where the rails are fixed on their rail feet with the aid of
hold-down elements. To allow for an increased amount of horizontal
forces to be taken up in the horizontal direction along the
extension of the rail sleepers (i.e. transversely to the extension
of the rails), it is known to broaden the width of the rail contact
areas. Examples of such rail sleepers are found in DE-A-100 23 389,
DE-A-27 35 797, DE-A-21 55 479, US-A-1 555 662 and US-A-1 406
454.
[0004] It is an object of the invention to improve the support and
fixation of rails on rail sleepers having widened rail contact
areas.
[0005] According to the invention, to achieve the above object,
there is proposed a rail sleeper provided with [0006] a sleeper
body comprising respectively a rail contact area on each of the
opposing ends thereof and having an enlarged width within said rail
contact areas, [0007] each rail contact area being adapted for
fixation of a rail therein by means of a hold-down element able to
grip a rail foot.
[0008] In this rail sleeper, it is according to the invention
provided [0009] that each rail contact area comprises three rail
contact surfaces arranged adjacent to one another in the extension
of the rail, [0010] that at least one hold-down element is arranged
between and above at least one partial region of respective
adjacent rail contact surfaces of each rail contact area, and
[0011] that the sleeper body is free of reinforcement elements
within each rail contact area on both sides of the intermediate
spaces between adjacent rail contact surfaces.
[0012] Thus, according to the invention, each widened rail contact
area comprises three rail contacts surfaces arranged adjacent to
each other in the extension of the rail. Said three rail contacts
surfaces are formed e.g. as plane surfaces arranged in a common
plane and being raised relative to their environment. The rail
supported on said rail contact surfaces is arranged to bridge the
intermediate spaces between adjacent rail contact surfaces.
According to the invention, it is further provided that the
hold-down elements are arranged to the effect that they are
positioned above the region between respectively two adjacent rail
contact surfaces and extend beyond these rail contact surfaces. In
this manner, on the respective end of the sleeper body, the rail
feet are reliably held down onto the respective three rail contact
surfaces, the rail foot resting with plane and areal contact on all
of said rail contact surfaces. This in turn is advantageous for
taking up horizontal forces acting transversely to the rail.
Further, according to the invention, the hold-down elements can be
arranged and fixed in "staggered" positions relative to the rail
contact surfaces because, in these regions, no reinforcement
(armoring) elements are arranged in the sleeper body on both sides
of the intermediate spaces between adjacent rail contact surfaces.
Such reinforcement elements are employed for clamping or
reinforcing the sleeper body, especially when concrete is used.
[0013] Alternatively, two or more hold-down elements can be
provided per group of rail contact surfaces. If the hold-down
elements are realized in the form of per se known spring clamps,
their fastening screws can be positioned laterally of the
intermediate space between respectively two adjacent rail contact
surfaces. However, at these sites, also other hold-down elements
attachable by screws can be connected to the sleeper body by means
of the screws. In case that four hold-down elements are used for
each group of three rail contact surfaces, respectively two
hold-down elements will be arranged opposite to each other. If only
two hold-down elements are used, these will be arranged diagonally
opposite to each other.
[0014] Within its widened rail contact areas, the sleeper body has
a relatively larger extension transversely to its longitudinal
extension. To make it possible to stabilize the resultant laterally
projecting areas of the sleeper body, it is suitable to provide
respectively at least one first reinforcement profile element below
the rail contact areas within the sleeper body. This reinforcement
profile element is suitably arranged substantially centrally
relative to the rail axis; in case that, for each rail contact
area, use is made of a plural number of reinforcement profile
elements, which then will preferably extend parallel to each other,
these plural reinforcement profile elements are arranged
symmetrically and centrally relative to the rail axis.
[0015] A quite good reinforcement of the widened rail contact areas
can be realized by forming the reinforcement profile element as a
profile comprising a leg extending substantially at a right angle
to the rail contact surface. Thus, for instance, the reinforcement
profile element can be realized as an angular profile, T-profile or
U-profile. These types of profiles will lend a high stability and
reinforcement to the rail contact areas and respectively to the
sleeper body within its rail contact areas.
[0016] It is particularly useful to configure the sleeper body as a
bi-block sleeper body. Thereby, the entire rail sleeper will take
up horizontal forces to a higher degree and will dissipate them
into the ballast bed. In a bi-block sleeper, it is provided by the
invention or an advantageous embodiment of the invention that the
two blocks are connected to each other by a second reinforcement
profile element. Said second reinforcement profile element in turn
is connected to the first reinforcement profile elements. Thus, the
bi-block sleeper comprises a reinforcement framework consisting of
the second reinforcement profile element and the two first
reinforcement profile elements extending transversely thereto at
the ends of the first reinforcement profile element, wherein the
intersecting/connecting points of the reinforcement profile
elements are arranged below the middle rail contact surfaces. This
applies also if the sleeper body is formed as a monoblock and
comprises the at least one second reinforcement profile
element.
[0017] Suitable materials for the sleeper body are e.g. concrete
and polymer concrete. Due to the use of reinforcement profile
elements below the widened rail contact areas and the second
reinforcement profile element between the two blocks of a rail
sleeper of the bi-block sleeper type, it is suitable to produce the
two blocks from plastic. Generally, in this regard, any type of
plastic and particularly also recycled plastic, is useful. The
plastic blocks should be able to move relative to said
reinforcement framework consisting of the second reinforcement
profile element and the first reinforcement profile elements since
plastic has a higher temperature coefficient than metal, which is
used for the reinforcements. In so far, it is of advantage if the
reinforcement profiles (longitudinal and/or reinforcement profile
elements) have smooth surfaces which allow the plastic to "slide"
thereon during its expansion or its contraction after expansion.
The first reinforcement profile elements, since they are arranged
centrically relative to the rails, will effect a centering of the
rail contact areas so that these cannot be displaced transversely
to the rails. The reinforcement profile elements, having legs
preferably extending at right angles to the rail contact areas,
provide for a fixation of the rail contact areas, which in a
plastic sleeper are made of plastic, at sites below the rail
feet.
[0018] According to an advantageous embodiment of the invention, it
is further provided that, in a bi-block sleeper, the second
reinforcement profile element between the two blocks is protected
from corrosion. For this purpose, an embodiment of the invention
provides that the region of the second reinforcement profile
element that is located between the two blocks is surrounded and
respectively filled with a plastic foam, preferably a PU foam. This
foam has the advantage that, in case of an expansion of the blocks
if these are made of plastic, it will yield and respectively follow
the temperature-induced movement of the blocks. Further, a
receiving groove or recess can be formed in the foam above the
rails sleeper so as to accommodate a conductor rail which for
safety reasons is prescribed for train control on routes admitted
for higher speeds.
[0019] The invention will be explained in greater detail hereunder
by way of several embodiments and with reference to the drawing. In
the various Figures of the drawing, the following is shown:
[0020] FIG. 1 is a plan view of an embodiment of a rail sleeper
according to the invention in bi-block design,
[0021] FIGS. 2 and 3 illustrate alternative options for rail
attachment either by use of two pairs of hold-down elements or by
use of only two hold-down elements per rail,
[0022] FIGS. 4 to 7 are perspective partial views of the
reinforcement framework of the rail sleeper,
[0023] FIG. 8 is a plan view of the rail sleeper provided with
plastic foam arranged between the blocks and surrounding the
reinforcement structure, and
[0024] FIG. 9 is a cross-sectional view taken along the line IX-IX
in FIG. 8.
[0025] The rail sleeper according to the invention will be
described hereunder in the context of its realization as a bi-block
sleeper made of plastic. As a material, preferred use is made of
recycled plastic. Recycled plastic is available in very larger
quantities and is best suited for this use. Further, such plastic
can be optimally integrated into a material cycle, which is highly
environmentally friendly.
[0026] This cycle will take the following development:
[0027] Plastic waste.fwdarw.sleeper production from the waste
materials.fwdarw.separation of materials at the end of the useful
life of the sleeper.fwdarw.new production of sleepers from the same
materials.fwdarw.plastic waste.fwdarw.sleeper production from the
waste materials.fwdarw.separation of materials at the end of the
useful life of the sleeper.fwdarw.new production of sleepers from
the same materials.fwdarw.etc. Of course, the recycled plastic
recovered from the old sleeper can also be used for other
applications.
[0028] The bi-block connection is realized e.g. by an angle iron, a
T-profile, a tube profile or a double-I profile. However, also
other materials can be used for the connection, such as e.g.
Carbon, GFK, Keflar etc. The rail sleepers can be produced with an
individual total length of e.g. 2.25 m, 2.40 m, 2.60 m or with
other desired lengths for a wide variety of rail tracks.
[0029] For a safe and long-lived operation of the rail tracks, it
is the shape of the sleeper, the load transmission surface to the
ballast, the head surface for the horizontal forces and the
material for the reduction of the dynamic vibration which are of
eminent relevance.
[0030] As a further important point, consideration has to given to
the form of the rail support on the rail sleeper. For the economic
usefulness of a track bed system, also the number of the rail
sleepers per track kilometer and the number of fastening members
per track kilometer are of relevance. When building a new
construction, all of the above mentioned assessment criteria should
be considered.
[0031] The bi-block form has been selected in order to achieve a
load-free zone in the intermediate region of the tracks so that no
"riding" of the rail sleepers will occur in the middle of the
tracks. The connection element for the two blocks, made of steel
selected from a large variety or of other materials, is each time
provided to extend to a site laterally outside the contact area of
the tracks and the fastening means. From this construction, it
results that there exists no central fastening on the rail
sleepers. This is intended to be the case. The sleeper width is
derived from the opening dimension of the tamping machine.
Preferably, this will result in a width of about 350 mm. The
sleeper thickness should preferably be 160 mm. This is a matter of
an adaptation to the large number of existing rails provided with
wooden sleepers. In this manner, it is accomplished that, in case
of a reconstruction of an existing rail with wooden sleepers, no
lowering of the subgrade has to be performed, as would be required
in case of a conversion from wooden sleepers to concrete sleepers.
[0032] Wood=160 mm [0033] Concrete.apprxeq.210 mm.
[0034] In this manner, considerable costs are saved.
[0035] For optimizing the contact surfaces for the rails and the
surfaces for horizontal load dissipation on the ballast, the
invention provides a widening of the rail sleeper under the rail.
From this, there results the basic form of the rail sleeper 10 as
shown in FIG. 1 of the embodiment comprising a bi-block sleeper
body 12. Each of the two blocks 14 comprises a rail contact area 16
comprising the successive rail contact surfaces 18 separated from
each other by interspaces 20. The widened rail contact areas 16
extend laterally beyond the blocks 14 and are reinforced by
reinforcement profiles 22. These reinforcement profiles 22 are
arranged centrally relative to the rails 24 (see also FIGS. 2 to 7)
and are rigidly connected to the ends of a longitudinal profile 26.
The longitudinal profile 26 connects the two blocks 14 of the
bi-block sleeper body 12 to each other.
[0036] By said enlargement of the sleeper width under the rails,
there is achieved the largest possible surface area offering
resistance to the horizontal forces. A further effect of the
enlargement of the sleeper width consists in a nearly continuous
support of the rails. As a further advantage, this construction
allows for a very favorable dual support of the rail on the sleeper
as known e.g. in the Y-type steel sleeper. Said enlargement also
allows for a triple support of the rail.
[0037] The arrangement of the reinforcement profiles 22 under the
rails 24 offers a manifold possibility for rail attachment, as
shown in FIGS. 2 and 3. FIG. 2 illustrates the situation wherein,
per rail 24 and sleeper block 14, respectively two pairs of
hold-down elements 28 are provided (formed as spring clamps in the
present embodiment). Said hold-down elements 28 grip around the
rails 24 on the feet of the latter, notably above the interspaces
20 between the rail contact surfaces 18. In the configuration
according to FIG. 3, there are provided, for each rail 24, two
hold-down elements 28 arranged on both sides of a rail 24 and
connecting different rail contact surfaces 18 to each other and,
respectively, being arranged above the interspaces 20 between
respective different adjacent rail contact surfaces 18. One of the
essential aspects of the invention is to be seen in said two
variants of the rail attachment by hold-down elements 28 gripping
around respective adjacent rail contact surfaces 18, as depicted in
FIGS. 2 and 3, in combination with said widened rail contact area
16 comprising three rail contact surfaces 18 serially arranged in
the direction of the rail.
[0038] The creep resistance of the rails is largely determined by
the amount of the clamping forces in the rail attachment structures
because these clamping forces will result in the frictional forces
between rail and sleeper. This creep resistance is of particular
relevance for [0039] mountain routes with narrow radii, [0040] for
taking up braking forces (such as e.g. of an eddy-current brake)
[0041] for the continuous welding of radii, and [0042] for the
securing of fracture gaps in case of rail fracture.
[0043] By this type of rail sleeper construction, a very large
contact area is accomplished. This makes it possible to provide
[0044] a dual attachment in offset configuration per sleeper head
(FIG. 3) or [0045] a quadruple attachment per sleeper head (FIG.
2).
[0046] These different attachment types can be combined with [0047]
a continuous support on the sleeper head, [0048] a dual support on
the sleeper head, [0049] a triple support on the sleeper head.
[0050] In the present embodiment of the invention, the preferred
distance between the cross-sleeper axes is 60 cm to 90 cm. Thus,
the sleepers have dimensions which make it possible to use the
sleepers also in narrow curves and to obtain optimum dissipation of
the stresses caused by the running of the vehicle onto the subgrade
and in the horizontal extension.
[0051] The type of the sleeper construction allows for an
enlargement of the sleeper distance such as e.g. [0052] classical
sleeper distance: 600 mm to [0053] new attachment distance between
the attachment parts: 600 mm+200 mm.
[0054] Obtained thereby is, for instance [0055] at a sleeper
distance of 600 mm=1,000.00 m:0.600 m=1,667 sleeper units/km [0056]
at 600 mm+200 mm=1,000.00 m:0.80 m=1,250 sleeper units/km.
[0057] The widening of the sleeper under the rail does not cause a
reduction of the contact surface as compared to the presently used
track construction.
[0058] The widening of the sleeper under the rail is
constructionally optimized with respect to its stability. Herein,
for instance, the existing longitudinal connection profile 26 of
the bi-block sleeper body 12 is reinforced by an additional steel
profile formed as a T-profile or L-profile for use as a
reinforcement profile 22 which is oriented at 90.degree. relative
to said longitudinal connection profile 26 and is welded thereto.
Examples are shown in FIGS. 4 to 7. In the embodiments according to
FIGS. 4, 5 and 7, said longitudinal profile 26 is realized as an
"upturned" angular profile whereas it is realized as a tube in FIG.
6. As reinforcement profiles, use is made preferably of T-, U- or
L-profiles, as illustrated in FIGS. 4 to 7. In this regard, it is
essential that these profiles are configured to comprise legs 30
extending at right angles to the rail contact surfaces 18. Said
legs 30 either extend in a centered arrangement relative to the
rails 24, or (as in the case of the U-profiles of the embodiments
according to FIGS. 5 and 6) they extend symmetrically to the
central axis of rail 24. In all of these cases, but particularly
when using the U-profile arranged with centric orientation relative
to the rail in the manner shown in FIGS. 5 and 6, it is achieved
that thermally induced expansion/shrinkage of the material below
the rail contact surfaces, i.e. below the rails, are substantially
prevented because, in this region, the material of the sleeper body
is "trapped" or "captured" by the profile element. This is of
interest particularly e.g. when using recycled plastic as a
material for the sleeper body, or when using other materials having
a comparatively high thermal expansion coefficient or a thermal
expansion coefficient clearly different from the thermal expansion
coefficient of the material of the reinforcement profile
elements.
[0059] By insertion of iron profiles into free regions in various
configurations within the contact area, there is achieved an
optimal construction whose statics can be calculated. For this
reason, a long useful life can be expected. However, also other
materials can be used for this purpose, such as e.g. plastic (GFK,
carbon, Keflar). For protection against corrosion in the exposed
central area of the longitudinal (connection) profile 26, use can
be made of a PU foam 32, which is illustrated in FIGS. 8 and 9.
Said PU foam 32 will adapt to possible thermal expansion movements
of the two blocks 14 which may occur if these blocks consist of
plastic material. However, the blocks 14 made of e.g. plastic
material are held in centered positions by the special
reinforcement profiles 22 under the rails 24 so that, in case of a
possible thermal expansion of the blocks 14, the rail contact area
16 will not be displaced relative to the rails 24 and will not
displace these rails.
[0060] A further advantage of the plastic foam 32 is to be seen in
that they can be provided with a receiving recess 34 as depicted in
FIGS. 8 and 9. Said receiving recess 34 serves for receiving e.g. a
conductor rail (not shown).
[0061] The material for the blocks 14 consists, on both sides, of
recycled plastic. This material is available in large quantities
and is important for the further material cycle. By this material,
the desired strength is obtained. The material has the following
properties which can be used with the aid of controlled
processes:
TABLE-US-00001 unbreakable temperature-resistant rot-resistant
environmentally friendly damping structure-borne noise can be
reinforced by glass fibers/textile fibers or carbon fibers
frost-proof UV-stabilized non-ageing dimensionally stable can be
armed by steel profiles electrically insulating all of the
materials used are reusable
[0062] As a result of the decision to use recycled plastic, a wide
spectrum for optimizing the material becomes available.
[0063] By admixture of granulate from used rubber tires, the
vibration is further reduced.
[0064] By admixture of steel sinter material, the weight of the
rail dampers can be optimized for reduction of lift-off forces.
[0065] The coloring of the rail damper can be optimized e.g. for
influencing the temperature or for marking.
[0066] Fire-protection can be optimized.
[0067] In case of installation within a tunnel, no odor nuisance
will occur as caused by impregnated wooden sleepers.
[0068] The material is absolutely humidity-resistant.
[0069] Long useful life.
[0070] Rail-support constructions can be molded into the
material.
[0071] The material can be sawn, drilled or milled without special
tools.
[0072] For the first screw connection, no additional dowels need be
inserted.
[0073] During the period of use of the rail sleepers, no rotting
process can occur in the formed screw holes.
[0074] The special characteristics of the novel type of rail
sleeper are: [0075] The selection of materials for the sleeper
body, including recyclable plastics. [0076] The optimization of
plastic as the principle material by admixture of materials [0077]
against fire/chemical influences, [0078] of granulate from used
rubber tires for vibration damping, [0079] of steel sinter material
for weight optimization, [0080] GFK for stabilization etc. [0081]
The constructional design of the rail contact area by different
welded steel profile inserts and/or plastic inserts. [0082] The
widened rail sleeper under the rail area, allowing to provide
different rail support structures and different rail attachment
constructions. [0083] The constructional design [0084] of the
double support structure of the rail, [0085] of the triple support
structure of the rail, [0086] of the offset clamping attachment of
the rail, [0087] of the dual clamping in a sleeper head.
[0088] By the present selection of materials, bores for attachment
of additional components can be generated in a very simple manner
at the most different sites on the sleeper without affecting the
statics and the strength of the sleeper. Thus, preferably, the
respective inner side of the rails can be provided with a
respective derailment-protection angle piece 36 of a suitable
dimensioning (see FIG. 8). Said derailment-protection angle pieces
36 have to be provided if the rail sleeper is to be used in
derailment-prone sites such as e.g. humps or switchyards.
[0089] Since recycled plastic as the material for use herein has
properties similar to those of a wooden sleeper and this wooden
sleeper is even nowadays still occasionally used on humps and,
further, the wooden sleeper is--to a certain extent--prone to cause
derailment, the use of the novel rail sleeper in these fields is of
particular interest.
[0090] Due to the convenient options for shaping the rail sleeper,
it is possible to realize special constructions as support
structures for [0091] railroad crossing systems, [0092] current
rails, [0093] green track systems, [0094] rail cleaning systems and
other rail construction systems.
[0095] The above described features of the novel type of sleeper
can also be achieved by use of concrete as a material. In this
case, the concrete should be reinforced--in addition to using said
steel profile members--by fibers (glass fibers, steel fibers or
plastic fibers). Herein, a further reinforcement is to be realized
by insertion of a non-prestressed reinforcement. In this
construction, the rail attachment screws are to be provided in
known plastic dowels which are to be embedded in concrete.
[0096] The novel rail sleeper construction makes it possible, in a
given load dissipation surface [0097] to reduce the number of
sleepers per rail kilometer, [0098] due to the design of the rail
contact construction, to reduce the dynamics caused by the running
of the vehicle, [0099] to considerably increase the horizontal
stiffness of the rail, [0100] due to a constructional height equal
to that of the wooden sleeper, to save the costs for lowering the
subbase, [0101] due to the reduced constructional width in
combination with the horizontal stiffness of the track, to save
ballast volume--ballasting covering only about 30 cm outside the
lateral end of the sleeper. [0102] to reduce the emission of
structure-borne and air-borne noise, [0103] to perform a continuous
welding attachment in narrow radii, [0104] to take up large braking
forces.
* * * * *