Note: Descriptions are shown in the official language in which they were submitted.
' CA 02004173 1999-04-O1
Strap For The Quick Fastening Of A Railroad Rail
The subject of the present invention is a strap for the
quick fastening of a railroad rail to ties or stringers
made of concrete, wood, plastic or metal, the said strap
being composed of a steel or reinforced plastic rod
having a vertical rectilinear part terminating in an
eccentric heel intended for interacting with a catching
means associated with the tie or with a metal sole plate
fastened to the tie, and a curved part which forms a
spring and the end of which is intended to press onto the
flange of the rail after the rotation of the rod about
its vertical part, during which rotation the said end
moves on a ramp intended for tensioning that part of the
strap forming a spring and for leading it onto the flange
of the rail.
A strap of this type is described in the Patent Applica-
tion FR 2, 608,182 . For fastening a rail to a concrete tie
without a metal pad, the strap is used together with a
plastic abutment pierced with a hole which the rod of the
strap passes through. For fastening a rail to a metal
pad, this strap is used without an abutment. In both
cases, once the bearing end of the strap has been brought
onto the flange of the rail, the tension on the strap
tends to cause the latter to tilt, so that its rectili-
near rod comes to bear against the edge of the hole in
the abutment or in the metal pad. Although this torsion
is not particularly troublesome where a metal pad is
concerned, in contrast it has disadvantages with regard
to a strap used with a plastic abutment. To overcome this
disadvantage, the upper edge of the hole in the abutment
has been reinforced by means of a collar. The abutment
nevertheless tends to lift as a result of tilting about
its outer edge and, on the other hand, instead of
exerting a vertical pressure on the concrete of the tie,
it exerts a transverse pressure against the side wall of
its receptacle in the concrete. Such a stress on the
- 2 -
CA 02004173 1999-04-O1
concrete can cause the concrete to crack. Moreover, the
abutment has to withstand compressive and torsional
forces which are difficult to control.
An object of the present invention is to provide a
fastening strap overcoming the abovementioned disad-
vantages, whilst at the same time preserving the simplic-
ity of the prior strap. More specifically, the object of
the invention is to provide a fastening strap which
exerts a vertical pressure on the abutment or on the
metal pad at all times and the rod of which does not tilt
and does not come to bear against the edge of the hole in
the abutment or in the metal sole plate.
The strap according to the invention is characterized in
that the curved part of the rod of the strap has a form
both undulated vertically and wound about the vertical
part of the rod, in such a way that it has an inter-
mediate bearing point formed by the bottom of the first
undulation and a main bearing point located near the end
of the rod, these two bearing points being mutually
opposite in relation to the vertical part, but at
different distances from this vertical part, the radius
of revolution of the intermediate bearing point being
substantially smaller than the radius of revolution of
the main bearing point.
Since the strap always bears at two mutually opposite
points in relation to the rectilinear part of the strap,
this part maintains a vertical position. When the strap
is used with an abutment, the intermediate bearing of the
strap exerts on the abutment a vertical force which
results in a favorable compression of the concrete of the
tie in the zone absorbing the lateral forces of the rail.
The strap according to the invention can be supplied
together with its abutment, to form a device for
fastening a rail to a concrete tie. Another subject of
the invention is such a fastening device, characterized
- 3
CA 02004173 1999-04-O1
in that the perimeter of the upper face of the abutment is
contained between the circle of revolution of the
intermediate bearing point and the circle of revolution of
the main bearing point.
A railroad tie equipped with such fastening devices has,
for each rail, a recess intended for receiving the rail and
two receptacles which are laterally adjacent to this recess
and in which the abutments of the fastening devices are
1o seated. The tie has a ramp extending at least between that
edge of the said receptacles opposite the recess intended
for the rail and the edge of this recess, these ramps
forming the ramps intended for tensioning the straps, and
means embedded in the tie for the retention of the rods of
the straps.
Therefore, the invention provides a fastening strap for the
quick fastening of a railroad rail to ties, the strap being
a rod having a vertical rectilinear part terminating in an
eccentric heel intended for interacting with a catching
means associated with the tie, and a curved part which
forms a spring and the end of which is intended to press
onto a flange of the rail after rotation of the strap about
its vertical part to an installed position, during which
rotation the end moves on a ramp intended for tensioning
that part of the strap forming a spring and for leading it
onto the flange of the rail. The curved part of the strap
has a shape both undulated vertically and wound
- 4 -
- CA 02004173 1999-04-O1
about the vertical part of the rod so as to form an
intermediate bearing point formed by a bottom of a first
undulation and a main bearing point located near the end of
the strap formed by a second undulation. These two bearing
points are disposed on mutually opposite sides of the
vertical part and at different distances from this vertical
part, a radius of revolution of the intermediate bearing
point being substantially smaller than a radius of
revolution of the main bearing point.
Another aspect of the invention is a sole plate for a
railroad tie equipped with straps according to the
invention, the rods of which pass through holes provided in
the pad and catch on countersinks into which the holes
open, the sole plate having a receptacle intended for
receiving the rail and, on each side of this receptacle,
ramps the extension of which coincides with the flange of
the rail, characterized in that the ramps have the form of
a path in an arc of a circle, the mean radius of which is
2o equal to the radius of revolution of the main bearing point
of the straps. The start of the ramp can correspond to the
point of temporary fastening of the strap to the sole
plate.
Furthermore, the fastening strap is advantageously equipped
with a profiled piece made of synthetic
- 9a -
CA 02004173 1999-04-O1
material, serving for plugging that part of the hole used
for the passage of the eccentric catching heel of the
strap and for guiding its vertical rectilinear part
during its rotation.
An exemplary embodiment of the strap and examples of the
use of this strap will now be described, with reference to
the accompanying drawings:
Figure 1 is a first elevation view of the fastening
strap.
Figure 2 is a plan view of this same fastening strap.
Figure 3 is a side view of this strap in the direction A
of Figure 1, that is to say in a position rotated through
90° in relation to Figure 1.
Figure 4 is an elevation view of a metal sole plate
equipped with a fastening strap according to the inven
tion.
Figure 5 is a plan view of this same metal sole plate.
Figure 6 is a partial sectional view of a concrete tie
equipped with a fastening strap according to the inven-
tion, according to a first embodiment.
Figure 7 is a partial plan view of this same concrete
tie.
Figure 8 is a perspective view of the anchoring socket
embedded in the concrete.
Figure 9 shows a complete tie with the rails fastened.
Figure 10 is a partial view of Figure 3, showing the
strap equipped with an auxiliary closing and guiding
piece.
_ 5 _
CA 02004173 1999-04-O1
Figure 11 is a top view of this same strap part.
Figure 12 is a view in vertical section of the auxiliary
piece shown in Figures 10 and 11.
Figure 13 is a partial view, in section according to
XIII-XIII of Figure 15, of a concrete stringer equipped
with a fastening strap and with a rail, according to a
second embodiment.
Figure 14 is a side view in section according to XIV-XIV
of Figure 15.
Figure 15 is a plan view of the stringer of Figure 13.
Figure 16 is an exploded view of the metal support
equipping the stringer of Figures 13 to 15 and of the
abutment.
Figure 17 shows the same stringer equipped with an
abutment of a different form.
The strap illustrated in Figures 1 to 3 is composed of a
steel rod of circular cross-section, having a vertical
rectilinear part 1 equipped, at its base, with a heel 2
directed perpendicularly relative to the axis 3 of this
rectilinear part. The steel rod has a form both undulated
vertically and wound about the axis 3 of the vertical
part. The undulated part is composed of a short rising
part 4, rectilinear as seen in horizontal projection
{Figure 2), followed by a falling part 5 extending over
a little more than a semicircle, as seen in horizontal
projection, a first low point 6 constituting an
intermediate bearing point and followed by a rising part
7, first rectilinear, as seen in horizontal projection,
and then rounded, at the same time passing via a high
point, to fall again in a longer undulation 8 of low
curvature, terminating at the bottom of the undulation in
a bent part 9 parallel to the part 7, as seen in
- 6 -
' CA 02004173 1999-04-O1
horizontal projection, and constituting a main bearing
point 10. The bearing points 6 and 10 have flats intended
for reducing the wear of both the strap at its bearing
points and the parts on which it bears: The bearing
points 6 andl0, as seen in plan view, that is to say in
the direction of the axis 3 (Figure 2), are mutually
opposite diametrically in relation to the middle 11 of
the catching heel 2. In this same view, the axis 3 of the
rectilinear part is located substantially at the center
of the triangle formed by the parts 7 and 8 of the rod
and by the straight line connecting the bearing points 6
and 10. It will be seen later that this arrangement
directs the forces in a suitable way and ensures that the
strap has a high stability. The vertical rectilinear part
1 can be of greater or lesser length, depending on the
type of tie on which it is to be used. It will be seen
that the main bearing point 10 and the intermediate
bearing point 6 are not at the same level, the bearing
point 10 being approximately 1 cm lower than the bearing
point 6.
The use of the fastening strap illustrated in Figures 1
to 3 for the fastening of a rail by means of a metal sole
plate will now be described with reference to Figures 4
and 5.
These figures show a metal sole plate 12 having a recess
13 intended for receiving a rail 14, with an elastic pad
15 made of rubber and two lateral abutments 16 and 17
made of plastic being interposed. The lower face 18 of
the metal sole plate 12 is inclined slightly, since it is
intended to be fastened to a concrete tie having an
inclined plane. For this purpose, the metal sole plate 12
has two oblong holes 18 and 19 intended for receiving tie
screws which are preferably screwed into PLASTIRAIL
(registered trade mark) anchoring sockets embedded in the
concrete. On each side of the recess 9, the sole plate 12
has two plane bearing surfaces 20 and 21 intended for
receiving the fastening straps. Only the bearing surface
_ 7 _
20 need be described in detail, the bearing surface 21
being identical to the bearing surface 20, but arranged
upside down in relation to the rail. The bearing surface
20 is plane and horizontal. It has a part of circular
contour 22 and a rectilinear part 23 extending along the
recess 13. Round the plane part 20 there extends, over a
quarter circle, a ramp 24 in the form of a path rising
progressively in the direction of the rail 1~. The top of
this ramp 20 is level with the edge of the flange 25 of
the rail. The middle of the plane part 20 is pierced with
a hole 26, the form of which matches the forrn of the
profile of the rectilinear part 1 of the strap and of the
heel 2, as seen in the plan view of Figure 2, there being
the play necessary for the free insertion of the rec-
tilinear part 1 of the strap into this hole 26. The hole
26 opens into a countersink 27 made in the lower face of
the sole plate 12.
The fastening strap is installed in the position repre-
sented by dot-and-dash lines, that is to say in a posi-
Lion rotated through 180° about the axis 3 in relation to
the posi~ion represented by unbroken lines. In this
position, the catching heel 2 can be introduced freely
into the hole 26. The main bearing point 10 is in a
pasition 10' outside the ramp 24, and the catching heel
2 is very slightly below the countersink 27. As a result
of a slight rotation of the strap, simultaneously the
main bearing point 10 of the strap is brought onto the
raattp 24 and the heel 2 of the strap is brought up against
the countersink 27. As a result of an. additional slight
rotation of the strap, the latter is given a slight
tension sufficient to fasten the strap temporarily to the
metal sole plate 12. This position is designated by 10".
The metal sole plate can thus be supplied equipped with
the fastening straps, the straps being held sufficiently
for transport and placing on the track. Once the metal
sole plate is fastened to the tie and the rail 14 placed
in its receptacle, each of the fastening straps is driven
in rotation, in such a way that its main bearing point 30
- 8~
~~~.'~e~
moves along the ramp 24, the mean .radius of which is
equal to the radius of revolution of the bearing point 10
about the axis 3. As regards the intermediate bearing
point 6, this moves on the horizontal plane surface 20.
The bearing point 10 finally comes to bear on the flange
25 of the rail, at the same time exerting a pressure of
the order of 10 to 12 kN. Furthermore, the strap bears on
the bearing surface 20 of the sole plate by means of its
intermediate bearing point 6, thereby exerting a vertical
pull on the catching heel 2 via the rectilinear part 1 of
the strap. The countersink 27 extends approximately over
a semicircle, in such a way that the heel comes ug
against the end of this countersink, thus limiting the
rotation of the fastening strap. It is possible to
provide a notch in the countersink 27, so that the
catching heel 22 is locked in this countersink, thereby
preventing the removal of the strap, once the rail has
been fastened. In the right-hand portion of Figure 5,
some parts corresponding to the left-hand portion have
been designated by the same references accompanied by the
sign
The arc of rotation of the strap between the installation
position and the rail-fastening position need not necess-
arily be 180°, but can be less than or more than 180°.
The use of a fastening strap according to the invention
for fastening a rail to a concrete tie 28 without a metal
sole plate will now be described by means of Figures 6
and ?. This concrete tie can be made completely of
concrete or be composed of two concrete blocks connected
by means of a metal rod, as illustrated in Figure 9.
Figures 6 and ? show only part of the tie, that is to say
the part corresponding to a rail. For each of the rails,
the tie 28 has a recess 29 intended for receiving the
rail. nn each side of this recess 29, the tie 28 has two
ramps 30 and 31 descending avaay from the recess 29. On
each side of the recess 29, the tie 28 also possesses two
rectangular receptacles 32 and 33, the bottom of which is
g
~~)'~~'
,at the Same level as the bottom of the recess 29 and
which communicate with this recess. Two profiled sockets
34 made of synthetic material and surrounded by metal are
embedded in the concrete. These sockets have the same
composition and the same external form as the PIaASTIRATL
(registered trade mark) sockets serving for the fastening
of the tie screws and described in the French Patent
Application No. 88.12,185. These sockets 34, at their
base, have a widening 35 forming a countersink 3b
intended for performing the same function as the counter-
sink 27 of the metal sole plate. The socket 34 is shown
in perspective in Figure 8. Above the widening 35, the
socket has a profile 37 matching the profile of the
catching heel 2 of the fastening strap. In this
35 embodiment, the fastening strap has a rectilinear part 1
substantially longer than the strap illustrated in
Figures 1 to 3, so as to be capable of catching at the
bottom of the socket 34. Of course, the sockets 34 open
out into the.bottom of the receptacles 32 and 33. The
fastening strap is mounted together with an abutment 38,
made of synthetic material, inserted between the curved
Bart of the strap and the concrete. This abutment 38 has
the form of a rectangular parallelepiped extended later-
ally by a bearing surface 39 which is in the form of an
arc of a circle and which extends the plane upper face of
the abutment and engages on the bottom of the receptacle
32 in a stepped manner. The general form of the abutment
38 corresponds to the form of the receptacle 32 in which
this abutment is seated. The abutment 38 has a profiled
hole 40 allowing the passage of the catching heel 2 of
the strap. The perimeter of the abutment 38 as contained
between the circle of revolution of the intermediate
bearing point 6 and the circle of revolution of the main
bearing point 10, ~.~r such a way that this main bearing
point ZO is always~utside th~ abutment.
The fastening strap equipped with its abutanent 38 is
first introduced into the socket 34 in the position
represented by dot-and-dash lines 6', 10', that is to say
-1:0-
1
,in a position rotated through 180° in relation to the
position represented by unbroken lines. In this position,
the main bearing point 10' is 1 or 2 mm from the surface
of the concrete on the ramp 30. As a result of a slight
rotation of the strap in the clockwise direction, the
heel 2 of the strap enrages under the countersink 36. As
a result of an additional slight rotation, the main
bearing point 10' rises slightly on the ramp 30, the
effect of which is to exert some tension on the strap,
this tension ensuring the temporary fastening of the
strap to the concrete tie. This temporary fastening
position is, for example, the position 10". The tie can
therefore be equipped with the fastening straps at the
factory. To fasten the rail 14, it is sufficient to
continue rotating the strap. During this rotation, the
main bearing point 10 rises progressively on the ramp 30
of the concrete, the end of which is level with the
flange 25 of the rail. The main bearing point 10 comes to
bear under tension on the flange 25 with a pressure of
the order of 10 to 12 kN. The rotation of the abutment is
limited by the form of the widening 35 of the socket 34
which forms a stop limiting 'the rotation of the catching
heel 2. During the rotation of the strap, the inter-
mediate bearing point 6 slides on the horizontal surface
of the abutment 3s, at the same time keeping the rec-
tilinear Bart 1 of the strap in a vertical position. The
strap exerts no lateral pres$ure on the hole 40 in the
abutment 3s. In the final position, the intermediate
bearing point 6 grips the bearing surface 39 of the
abutment against the corxcrete. The compression of the
concr~te in this zone is expedient because the concrete
can thus better withstand the transverse forcss attribut-
able to the lateral pressure exerted by the rail via the
abutment 3s.
The socket 34 can, of course, also be provided with a
locking notch for the heel 2 of the strap, if it is
desirable that the latter be unremnovable.
.. 11 _
~~~~~a~
The complete tie ~8 is illustrated in Figure 9. A com-
posite concrete/steel tie has been represented by dot-
and-dash lines. The tie is equipped with four straps 1.
It is supplied equipped with these straps, the temporary
fastening of which is sufficient to keep the assembly in
place during transport and putting on the track.
The hole 26 in the metal sale plate and the hale 40 in
the abutment 3~ allows sand and dirt to penetrate.
Figures 10 to 12 show a means of plugging this hale,
whilst at the same time ensuring a better guidance of the
vertical part 1 of the strap during its rotation. Figures
10 and 11 illustrate a part of the strap shown in Figures
1 to 3. Fastened to the vertical part 1 between the heel
2 and the first curved part 4 of the strap is a plastic
plug 41 which fills the vertical space between the heel
2 and the part 4 and the profile of which fills the
profile of the hole 26. This plug 41 is equipped with two
curved arms 42 and 43, by means of which the plug 41 is
fastened by gripping to the cylindrical part 1 of the
strap. The plug 4~. is preferably slightly larger than the
hale 26 and hollava, as shovrn by the cross-section il-
lus~trated in Figure 12, so as to have a transverse
elasticity in order to plug the hale 26 more effectively.
xn Figure 10, dot-and-dash lines also represent the level
of the surface 20 of the metal sole plate. When the strap
is being intraduced inter the hole 26, the plug 41 is
engaged into this hole 26 together with the rectilinear
part of the strap, the assembly as a whale accupying the
entire cross-section of the hole 26. During the rotation
of the strap, the plug 41 remains in place, serving as a
. guide for the part 1 of the strap. Figure 11 shows the
strap after sorate rotation of the latter in relation to
the p7.ug 41 retained xn the hole 26.
The strap illustrated in Figures 6 and 7 and in Figures
13 to 17 can, of course, be equipped with a plug similar
to the plug 41 and differing from this only in its
length.
_ 12_
The form of the undulations of the strap and the form of
its heel and of the holes for the passage of this heel
can, of course, differ from the forms shown.
The abutment 38 could be larger and have a ramp similar
to the ramp 24 for the main bearing point 10 of the
strap.
The rails are sometimes laid on stringers or ties roads of
prestressed concrete. The manufacture of stringers or
ties made of prestressed concrete does not allow the
presence of recesses, such as the recesses provided in
the ties illustrated in Figures 6 and 7. In this case, it
is expedient to resort to another solution for fastening
the abutments made of synthetic material. Figures 13 to
16 illustrate such a solution. Anchored in the prestres-
sed-concrete stringer or tie 50, the surface of which is
smooth, are metal supports 51 in the form of a bow of
rectangular profile, the lower ends of which are bent to
ensure an anchorage in the concrete. An abutment 52 made
of synthetic material is mounted on each of the bows 51.
In parallel with the profile of the bow 51, this abutment
52 likewise has a bow-shaped profile, as shown in Figure
16. More specifically, the abutment has a plane upper
face 53, a relatively thick side 54 serving as a center-
ing abutment for the rail 14, and two thinner lateral
sides 55 to 56 serving for retaining the abutment on the
bow 51, the side 56 being equipped with a heel 57, the
upper face of which is in the form of a ramp 58 rising
towards the part 54. A horizontal wall 59 starting from
the part 54 extends between the walls 55 anal 56. The
distance between the wall 59 and the part 53 of the
abutment corresponds to the thickness of the bar forming
the bow 51. The stop 52 is slipped laterally onto the bow
51 in the direction of the arrow of Figure 16, the bow
engaging between the part 53 and the wall 59 and between
the walls 55 and 56. The abutment 52 is provided with a
profiled hole 60 coinciding with a hole 61 of the same
profile in the bow 51, for the passag$ of the strap. The
_ 13 _
v~~~~~~.~'~
upper portion of the part 54 of the abutment has~a
chamfer 62. When the abutment 52 is mounted on its
support 51, the sides 55 and 56 and the heel 57 are in
cantact with the stringer 50. mhe abutment 52 is first
equipped with a strap identical to the straps of the
preceding figures. As before, the main bearing point 10
of the strap is brought onto the start of the ramp 58 in
order to fasten the strap temporarily. After the rail 14
has been installed between these abutments, this being
made easier by the chamfers 62, the strap is driven in
rotation in such a way that the main bearing point 10
rises on the ramp 58 to the height of the flange and the
rail 14. As in the preceding embodiments, the perimeter
of the upper face 53 of the abutment is contained between
the circle of revolution of the intermediate bearing
point 6 and the circle of revolution of the main bearing
point 10.
By providing abutments having different thicknesses in
the region of the part 54, it is possible, if the ap-
propriate thickness is selected, to wedge the rail
perfectly in the lateral direction.
Moreover, the thin wall 5~ leas the effect of insulating
the strap electrically from the metal support 51.
The abutment described above need not necessarily be
mounted upon its metal support 51 before the laying of
the rail. Figure 17 illustrates an alternative embodiment
allowing the insulating abutment to be fastened after the
laying of the rail. Since the abutment is a wearing part,
its replacement can thus be carried out without moving
the rail. The abutment 63 differs from the abutment 52 in
that the wall 59 is replaced by a ra.m 64 parallel to the
part 54° corresponding to the part 54, this rim 64
terminating in a hookashaped eactra thickness 65 having a
chamfer 66. The wall 64 is not connected to the side
walls corresponding to the walls 55 and 56 of Figure 16.
The abutment 63 is installed vertically on the metal
14 -
1 '
support 51, a simple pressure on the abutment moving
apart elastically the Tall 6~ which is fastened to the
support 51 by snapping.
The abutment 63 is advantageously equipped with a flex-
ible tongue 66 extending laterally from the part 54'. d3s
emerges from the drawing, this tongue 66 is intended to
rest on the flange of the rail 14. Tt is attached to the
abutment somewhat high up, in such a way that it can
follow the flange of the rail in its descending movement
when it is being fastened by means of the strap. The
tongue 66 is finally gripped between the flange of the
rail and the main bearing point 10 of the strap. The
tongue 66 protects the flange of the rail against a
punching effect as a result of the friction of the strap
and insulates the metal strap electrically from the rail.
The part 54' of the abutment possesses, in its lower
part, a chamfer 67 intended to make it easier to intro-
duce this part 54' between the support 51 and the flange
of the rail.
Tn a simplified embodiment, the support 51 and the
abutment 52 could be produced in one piece from a ductile
material, such as cast .iron, graphite cast iron, alloy or
composite material. The abutment so obtained takes the
form of a piece anchored in the concrete and leaving a
bowpshaped part located above the concrete and intended
for the fastening of a strap, such as the strap desc-
ribed.
15-
