Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
Expansion insert for a rail spike
TECHNICAL FIELD
The invention relates to an expansion or expansion
insert for rail spikes according to the preamble of
patent claim 1.
PRIOR ART
As a result of stressing of railroad tracks, the
crosstie screws and rail spikes loosen. The track gauge
and guiding distance and also the rail height are
changed. During rehabilitation of the tracks, the firm
screw fit is re-established in that the old crosstie
screws are removed and the hole is drilled out and
cleaned. Subsequently, an expansion inert is introduced
into this hole. The hole is filled with grouting
compound and subsequently a new crosstie screw is
screwed in, wherein the expansion insert provides the
new crosstie screw with a firm hold. In order to
correct the track height, a base plate, preferably a
Lupolen base, is laid on the crosstie, usually before
the hole is grouted.
This method and the use of the expansion insert have
now proven successful for many years. The method is
known under the name Traversan crosstie rehabilitation.
The method and the associated expansion insert are
likewise described in CH 514 734.
For crosstie screws having blunt screws, CH 514 734
proposes using an expansion insert as per figure 5,
said expansion insert having the form of a helical
spring. For pointed screws, an expansion insert as per
figure 3 is used. This expansion insert has three
axially parallel legs, which are bent from a one-piece
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bar material. A free end which is at the top in the
installed state of the expansion insert is bent
substantially horizontally. This bend or catch is
intended to be caught by the screw and to serve as an
additional screw guide.
In some countries, rail spikes are usually used instead
of crosstie screws. However, both of the expansion
inserts described in CH 514 734 have the drawback that
when used in combination with a rail spike, the pull-
out resistance is too low. The pull-out resistance is
understood to mean the resistance to a force with which
the rail spike is intended to be pulled out of the
crosstie. In addition, it was found that the
introduction of a rail spike into a hole provided with
such an expansion insert is problematic, because the
expansion insert has often pushed the spike out of the
center axis of the hole.
EP 1 449 961 also discloses an expansion insert, which
is advantageous in connection with screws having blunt
screw ends. However, similar drawbacks arise from the
technical teaching of EP 1 449 961 and the use for rail
spikes has proven difficult.
DESCRIPTION OF THE INVENTION
It is an object of the invention to increase the
tensile strength of the arrangement and to allow use of
rail spikes, in particular having a pointed end.
Such an object is achieved by an expansion insert or
expanding insert according to claim 1. Accordingly, an
expansion insert for rail spikes has two, first and
second legs that are connected together via a first
bend and extend at least approximately parallel to one
another, and also has a third leg connected to the
second leg via a second bend. The first leg and the
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second leg are located in a common first plane and the
third leg is located in a second plane which is
substantially perpendicular to the first plane.
As a result, it is possible to create an expansion
insert in the case of which all three legs come to lie
in the region of the surface of the hole in the
crosstie, wherein consequently the cross section of the
hole is only minimally reduced with the expansion
insert inserted, thereby making it easy to drive in the
rail spike.
Preferably, the second plane extends through the second
leg, as a result of which the expanding insert can be
designed to be even more compact.
Preferably, the first leg has a free end which forms an
at least approximately rectilinear extension of the
first leg. Particularly preferably, the free end forms
exactly a rectilinear extension.
Preferably, the third leg has a free end which forms at
least approximately, preferably exactly, a rectilinear
extension of the third leg.
Preferably, the first leg and/or the third leg have at
their free end(s) a hooking section which extends at an
angle, preferably perpendicularly, to the respective
leg.
Preferably, the expansion insert is produced in one
piece from a bar material and is manufactured from a
special steel.
Preferably, the first bend is located in the first
plane and the second bend in the second plane.
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Preferably, the first and second legs extend at least
approximately parallel to one another and/or wherein
the first leg and the second leg are at least
approximately the same length.
Preferably, the third leg extends at an acute angle or
at least approximately parallel to the second leg.
Preferably, the first bend and the second bend have the
same bending radius. The first and the second bend can
in this case be formed in a semicircular or quadrant-
shaped manner, wherein two quadrant-shaped bends are
then connected via a straight leg. In the latter
embodiment, it is also possible to refer to a web.
Further embodiments are specified in the dependent
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described in
the following text with reference to the drawings,
which serve merely for explanatory purposes and should
not be interpreted as being restrictive. In the
drawings:
figure 1 shows a cross section through a railroad
crosstie having expansion inserts according
to the invention;
figure 2 shows a side view of a rail spike for use in
combination with the expansion inserts
according to figure 1;
figure 3 shows a view from the front of the rail spike
from figure 2;
figure 4 shows a view from below of the rail spike
from figure 2;
figure 5 shows a side view of an expansion insert from
the right;
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figure 6 shows a front view of the expansion insert
according to figure 5;
figure 7 shows a side view of the expansion insert
according to figure 5 from the left;
figure 8 shows a top view of the expansion insert
according to figure 5; and
figure 9 shows a perspective view of the expansion
insert.
DESCRIPTION OF PREFERRED EMBODIMENTS
Figure 1 illustrates a cross section through a track
section of a railroad crosstie. On a crosstie 1, a rail
2 is fastened to a rib plate 5 by means of rail spikes
7. The rail spikes 7 project through openings 50 in the
rib plate and extend into holes 3 which are produced in
the crosstie 1, wherein the rail spikes 7 are fixed in
the holes 3. When the firm spike fit is renewed, in
order to fix the rail spikes 7, in each case an
expansion insert 4 is lowered into the holes 3 and
optionally grouted in a watertight manner therein by
means of a grouting compound 6. The rail spikes 7 in
the process clamp the rail 2 to the crosstie 1 or rib
plate 5.
Figures 2 to 4 show an embodiment of a rail spike 7 for
use in the track structure according to figure 1. The
rail spike 7 comprises a head section 70, a shank
section 71 adjoining the latter, and a spike tip
section 72 which adjoins the shank section 71. The
spike tip section 72 ends with a spike tip 73. As seen
from the head section 70, the shank section 71 and the
spike tip 72 extend along a center axis M. The head
section 70 comes into contact with the rail 2 and
clamps the latter against the rib plate 5. The shank
section 71 projects through the receiving opening 50 in
the rib plate 5 and extends into the hole 3 in the
crosstie.
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Preferably, the shank section 71 has a square or
rectangular cross section. Alternatively, the shank
section 71 can also have a circular cross section.
The spike tip section 72 is in this case designed such
that the cross section of the spike tip section 72, as
seen from the shank section 71, is reduced
continuously. Preferably, the degree of reduction is
constant over the spike tip section 72 from the shank
section 71 to the spike tip 73.
The spike tip 73 can have a multiplicity of different
shapes. In the present embodiment, it is provided with
a convex edge.
Such a rail spike 7 typically has a diameter in the
range of 14 to 19 mm, in particular 16 mm, and a length
in the range of 130 to 180 mm, in particular 165 mm.
Figures 5 to 9 illustrate the expansion insert 4
according to the invention. It is bent from a one-piece
bar material, preferably composed of special steel, as
can also be used for reinforcing iron.
The expansion insert 4 has three legs 40, 41, 42, which
are formed in a slightly resilient manner with respect
to one another. A first and a second leg 40, 41 extend
at least approximately, here exactly, parallel to one
another. The first and second legs 40, 41 are connected
together via a first bend 43. The first leg 40 and the
second leg 41 are located in a common first plane El.
That is to say that for example the center axes along
which the legs 40, 41 are part of this first plane El
and define this first plane El. This first plane El
extends in the plane of the drawing sheet in figure 6
and is indicated by a line El in figure S. The first
bend 43 is formed in a manner bent in the first plane
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El of the two legs 40, 41, as can be seen best from
figure 9.
Opposite the first bend 43, the second leg 41 is
adjoined by a second bend 44 which is then followed by
the third leg 42. The third leg 42 is located in a
second plane E2 which is perpendicular to the first
plane El. Preferably, the second plane E2 is located
such that it extends through the second leg 41 such
that the third leg 42 comes to lie over the second leg
41. The second plane E2 is illustrated correspondingly
in figure 5. On account of this arrangement, the
expansion insert 4 according to the invention can be
used for rail spikes, since the expansion insert is
inserted into the hole 3 such that all three legs 40,
41, 42 are in contact with the wall of the hole 3 and
none of them reduces the cross section of the hole more
than necessary. Consequently, the rail spike can be
driven in well without excessive deformation of the
expansion insert being necessary, as occurs for example
in embodiments of the prior art. In addition, the rail
spike is not deflected from its axis during the driving
in operation. While the rail spike is being driven in,
the legs are pressed into the side wall of the hole.
Consequently, the rail spike 7 and the expansion insert
4 are clamped together in the hole.
The first leg 40 has a first free end 46 which forms at
least approximately, preferably exactly, a rectilinear
extension of this leg 40.
The third leg 42 has a second free end 45, which forms
at least approximately, preferably exactly, a
rectilinear extension of this leg 42. Preferably, the
third leg 42 is adjoined by a hooking section 47, which
extends away from the third leg 42 at an angle,
preferably perpendicularly, and extends preferably in
the second plane E2. The hooking section 47 is pushed
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into the wood of the crosstie by the hammering down of
the rail spike, it being possible in this way to
further increase the resistance to pulling out.
Optionally, the first leg 40 can comprise a hooking
section (not illustrated here), which is designed in an
analogous manner to the hooking section 47.
The second leg 41 is preferably designed to be longer
than the first leg 40, as can be seen in figure 2. The
third leg is preferably designed to be shorter than the
two other legs 40, 41. However, it extends preferably
along at least two thirds of the length of the
expansion insert 4.
Preferably, all three legs 40, 41, 42 extend parallel
to one another. Alternatively, the third leg 42 can
extend at an acute angle to the second leg 41, as can
be seen best in figure 3. Both embodiments are
advantageous, since both provide a very compact
structure.
Preferably, the first bend 43 and the second bend 44
have the same bending radius, this being advantageous
with regard to the compact structure. On account of the
arrangement of the first bend 43 and the second bend
44, the expansion insert can be designed to be very
compact, this allowing insertion into holes 3 which
have a comparatively small diameter, as is usual for
holes for rail spikes.
The first leg 40 typically has a length from the free
end 46 to the first bend 43 of 75 to 105 mm.
Particularly preferred is a length range between 78 and
98 mm, in particular 93 mm.
The second leg 41 typically has a length from the first
bend 43 to the second bend 44 of 90 to 120 mm.
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Particularly preferred is a length range between 95 and
110 mm, in particular 100 mm.
The third leg 42 typically has a length from the free
end 45 to the second bend 44 of 65 to 100 mm.
Particularly preferred is a length range between 83 and
93 mm, in particular 88 mm.
Both bends 43, 44 have preferably a radius of 6 to
12 mm, particularly preferably of 8 to 10 mm, in
particular 9 mm.
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LIST OF REFERENCE SIGNS
1 Crosstie
2 Rail
3 Hole
4 Expansion insert
40 First leg
41 Second leg
42 Third leg
43 First bend
44 Second bend
45 Free end
46 Free end
47 Hooking section
Rib plate
50 Receiving opening
6 Grouting compound
7 Rail spike
70 Head section
71 Shank section
72 Spike tip section
73 Spike tip
Center axis
