[0001] The present invention relates to a fastening device for rails of the type comprising
the characteristics expressed in the preamble to Claim 1.
[0002] The rails that compose tracks are supported by sleepers, made of wood or cement,
whereto they are fastened by means of fastening devices.
[0003] Currently, many types of fastening devices are known, such as those with track bolts
or springs.
[0004] One of the most common fastening devices is constituted by a steel bar folded in
the form of an elastic clip. An example of this type of device, known as "Pandrol",
is disclosed in US Patent 5,191,838 (in particular in Figures 25 and 26).
[0005] The widespread use of the "Pandrol" device is due to its lesser cost relative to
traditional devices, such as those with track bolts.
[0006] The "Pandrol" device comprises a base element fastened in the sleeper supporting
the rail, and having in correspondence with the surface of the sleeper itself a tubular
seat in which a first end of the clip is inserted.
[0007] The "Pandrol" device, however, give rise to problems when the adjustment of a long
welded rails needs to be performed.
[0008] To carry out its adjustment, the rail must be at least partially free to slide longitudinally,
but at the same time it must be held laterally, since a certain number of trains must
be made to travel over the track in order to perform a correct adjustment operation.
[0009] Contrary to track bolt devices where this is easily achieved by slightly loosening
their grip, the "Pandrol" device does not allow to adjust its gripping action on the
rail.
[0010] For this reason, when adjusting a long welded rail on rails fastened with the "Pandrol"
device, all fastening devices must be removed to allow longitudinal expansion.
[0011] Consequently, however, trains can no longer be allowed to travel over the track,
and the adjustment needs to be performed without train passage.
[0012] This represents a considerable drawback, as it makes it difficult to perform a sufficiently
accurate adjustment of the rail.
[0013] If the adjustment is not carried out precisely, the rail, once placed back in service,
has in its interior a non uniform tension, with compressed areas alternating with
areas under traction.
[0014] In the long run this situation can lead to the warping or breakage of the rail, especially
in correspondence with weld points.
[0015] In this situation the technical task constituting the basis for the present invention
is to obtain a fastening device for rails that overcomes the aforementioned drawbacks.
[0016] In particular, a technical task of the present invention is to obtain a fastening
device for rails that can allow the longitudinal sliding of the rail and, at the same
time, guarantees lateral grip on the rail itself.
[0017] A further technical task of the present invention is to obtain a fastening device
for rails that allows the temporary substitution of the clip used in "Pandrol" devices.
[0018] The specified technical task and the indicated aims are substantially achieved by
a fastening device for rails, as described in the accompanying claims.
[0019] Further features and the advantages of the present invention shall become more readily
apparent from the detailed description of a preferred, but not exclusive, embodiment
of a fastening device for rails, illustrated in the accompanying drawings, in which:
- Figure 1 shows a lateral view of a fastening device for rails according to the present
invention applied to the flange of a rail; and
- Figure 2 shows a plan view of the fastening device of Figure 1.
[0020] With reference to the aforementioned figures, the reference number 1 globally indicates
a fastening device for rails according to the present invention.
[0021] In the illustrated embodiment, the fastening device 1 comprises a structure 2 in
which are mounted a hinging element 3, a contact element 4 and adjustment means 5.
[0022] The structure 2 has a first and a second end portions 6, 7 and an intermediate portion
8 connected between the two end portions 6, 7.
[0023] The direction that goes from the first to the second end portion 6, 7 can be defined
as a first direction of development of the structure 2.
[0024] In the illustrated embodiment, the structure 2 comprises a main plate 9 presenting
an upper surface 10 and a lower surface 11 and two shoulders 12, substantially specular
relative to each other and positioned facing each other and mutually distanced.
[0025] Each shoulder 12 is laterally fastened to the plate 9 and develops mainly in a plane
parallel to the first direction of development and perpendicular to the lower surface
11 of the plate 9.
[0026] In correspondence with the intermediate portion 8, the structure 2 has at least two
through holes 13, mutually coaxial according to a direction of development that is
substantially perpendicular to the first direction of development of the structure
2.
[0027] In the embodiment illustrated in the accompanying drawing, the through holes are
obtained through the two shoulders 12 and develop according to a direction parallel
to the lower face of the plate 9.
[0028] In accordance with the illustrated embodiment, the structure 2 further presents,
in correspondence with the second end portion 7, a threaded through hole 14 developing
perpendicularly to the plate 9.
[0029] The hinging element 3 can be pivotally engaged to a hitching element 15 mounted in
proximity to a rail, and is mounted on the structure 2 in correspondence with the
intermediate portion 8.
[0030] The hinging element 3 develops substantially transversely to the direction of development
of the structure 2 to allow, once associated to the hitching element 15, the oscillation
of the structure 2 in a vertical plane passing through the first direction of development.
[0031] In particular, the hinging element 3 is constituted by a first pivot pin 16 removably
inserted in the two through holes 13 obtained in the shoulders 12.
[0032] The first pivot pin 16 has, in correspondence with its own first end 17, an obstruction
head 18 whose diameter is greater than that of the through holes 13.
[0033] The second end 19 of the first pivot pin 16 is further provided with removable obstruction
means 20 to prevent the passage of the second end 19 through the holes 13.
[0034] Advantageously said removable obstruction means 20 are constituted by a removable
pin 21, passing through the second end 19 of the first pivot pin 16.
[0035] Further provided are both embodiments in which the first pivot pin 16, once it has
been inserted through the holes 13, can rotate about its own axis relative to the
structure 2, and other embodiments in which it is instead integral with the structure
2.
[0036] As stated, said first pivot pin 16 can be pivotally inserted in a housing 22 which
is obtained inside the hitching element 15 mounted in proximity to the rail, and which
is constituted by a substantially rectilinear through hole.
[0037] The contact element 4 is pivotally mounted on the structure 2 in correspondence with
the first end portion 6 of the structure 2, and presents an operative face 23 able
to be pressed against the surface of the flange 24 of the rail 25.
[0038] In particular the operative face 23 can be associated in abutting contact against
the upper surface 10 of the flange 24 of the rail 25, either directly or through a
bearing element 26 which may or may not already be associated to the rail 25.
[0039] The operative face 23 of the contact element 4 can further present a knurled surface,
in order to exert a greater friction against the surface of the rail 5.
[0040] Embodiments are provided in which the contact element 4 is rigidly fastened to the
structure 2 (as in the accompanying figures), and other alternative embodiments in
which the contact element 4 is instead pivotally fastened to the structure 2 itself.
[0041] The adjustment means 5 are mounted on the structure 2 in correspondence with the
first end portion 6 and serve to adjust the pressure of the contact element 4 against
the rail 25.
[0042] In the preferred embodiment (one of the simplest ones), the adjusting means 5 comprise
a second threaded pivot pin 27 able to be screwed through the structure 2 according
to a direction of development that is perpendicular both to the first direction of
development, and to the main direction of development of the first pivot pin 16.
[0043] In the illustrated embodiment said second pivot pin 27 is screwed in threaded through
hole 14 obtained through the first end portion 6 of the structure 2.
[0044] Depending on the use whereto the fastening device 1 is destined, it may or may not
also comprise the hitching element 15 able to be fastened to the sleeper of a rail
25.
[0045] If the fastening means 1 of the present invention is constructed to constitute a
wholly autonomous fastening device 1, usable instead of traditional ones, it also
comprises the hitching element 15.
[0046] Vice versa, if the fastening device 1 is constructed to be used to replace temporarily
the elastic clips of "Pandrol" fastening devices, it lacks the hitching element 15.
[0047] From the functional point of view, the fastening device 1 is used in the following
way.
[0048] It the fastening device is to be used as an autonomous fastening device 1, the first
step is to fasten the hitching element 15 to the sleeper of the rail 25.
[0049] If, on the contrary, the clip of a "Pandrol" device is just to be replaced temporarily,
the hitching element 15 of said device is used.
[0050] To mount the fastening element 1, the first step is to extract the first pivot pin
16 from the through holes 13, after removing the removable obstruction means 20.
[0051] The structure 2 is then positioned on the upper portion of the hitching element 15
in such a way as to align the through holes 13 with the housing obtained on the hitching
element itself, and in such a way that the contact element 4 is in correspondence
with the flange 24 of the rail 25.
[0052] The first pivot pin 16 is then inserted through the holes 13 and the housing, and
the removable obstruction means 20 are positioned.
[0053] At this point the structure 2 is in the condition to be able to rotate about the
first pivot pin 16, relative to the hitching element 15 in a substantially vertical
plane.
[0054] Acting now on the second pivot pin 27, the pressure exerted by the contact element
4 on the flange 24 of the rail 25 can be adjusted. By screwing the second pivot pin
27 in the structure 2 in such a way as to increase its projection from the lower face
of the plate 9, thereby increasing the distance between the first end portion 6 and
the sleeper supporting the rail 25, a rotation is caused of the structure 2 about
the first pivot pin 16 and hence a crushing of the contact element 4 against the flange
24 of the rail 25.
[0055] The present invention achieves important advantages.
[0056] In the first place, the fastening device for rails of the present invention allows,
by adjusting the pressure of the contact element against the flange of the rail through
the adjustment means, the longitudinal sliding of the rail, whilst guaranteeing the
lateral immobility of the rail itself.
[0057] The fastening device for rails of the present invention can therefore be used to
replace temporarily the clips of "Pandrol" devices during the adjustment operations
of long welded rails.
[0058] After removing all operative clips on the rail segment of interest, one can position,
instead of a part thereof, fastening devices according to the present invention, in
order to conduct the adjustment operation letting trains travel over the rail.
[0059] This allows to achieve a better adjustment of the long welded rails held by the "Pandrol"
fastening devices, and hence assuring its longer working life.
[0060] On the other hand, the fastening device of the present invention can be used in a
wholly autonomous fashion instead of the fastening devices in use today, also because
it is relatively easy to produce and its cost is not very high.
[0061] The invention thus conceived can be subject to numerous modifications and variations,
without thereby departing from the scope of the inventive concept that characterises
it.
[0062] All components can be replaced by technically equivalent elements and in practice
all materials employed, as well as the shapes and dimensions of the various components,
may be any, as dictated by n requirements.
1. A fastening device for rails characterised in that it comprises
a rigid structure (2) having a first and a second end portion (6), (7) and an intermediate
portion (8) connected between said end portions, a first direction of development
of said structure (2) extending from said first end portion (6) to said second end
portion (7);
a hinging element (3) mounted on said structure (2) in correspondence with said intermediate
portion (8), developing substantially transversely to said first direction of development
and able to be pivotally associated to a hitching element (15) mounted in proximity
to a rail (25);
a contact element (4) fastened to said structure (2) in correspondence with said first
end portion (6), and presenting an operative face (23) able to be associated in abutting
contact to said rail (25) and
adjustment means (5) mounted on said structure (2) in correspondence with said first
end portion (6), to adjust the pressure of said contact element (4) against said rail
(25).
2. A device as claimed in claim 1 characterised in that, in correspondence with said intermediate portion (8), said structure (2) presents
at least two through holes, said through holes (13) developing in mutually coaxial
fashion and substantially perpendicularly to said first direction of development,
and in that said hinging element (3) comprises a first pivot pin (16) removably inserted in said
through holes (13) and having a first end (17) and a second end (19), at least one
of said ends (17), (19) being provided with removable obstruction means (20) to prevent
the passage of said end through said through holes (13).
3. A device as claimed in claim 2 characterised in that said structure (2) further comprises due shoulders (12) mutually distanced and developing,
at least in correspondence with said intermediate portion (8), substantially parallel
to said prima direction of development, said through holes (13) being obtained through
said shoulders (12).
4. A device as claimed in claims 1, 2, or 3 characterised in that said adjustment means (5) comprise at least a second, threaded, pivot pin (27) screwed
in a threaded through holes (14) obtained in said first end portion (6) according
to a direction that is substantially perpendicular to said first direction of development
of the structure (2) and a said first pivot pin (16).
5. A device as claimed in any of the previous claims from 1 to 4 characterised in that said operative face (23) of said contact element (4) has a knurled surface.
6. A fastening device for rails comprising a hitching element (15) having an upper portion
provided with a housing and able to be fastened to a sleeper supporting a rail (25)
in proximity to the rail (25) itself,
characterised in that it comprises:
a rigid structure (2) having a first and a second end portion (6), (7) and an intermediate
portion (8) connected between said end portions, a prima direction of development
of said structure (2) extending from said first end portion (6) to said second end
portion (7);
a hinging element (3) mounted on said structure (2) in correspondence with said intermediate
portion (8), developing substantially transversely to said first direction of development
and pivotally and removably associated to said hitching element (15);
a contact element (4) fastened to said structure (2) in correspondence with said first
end portion (6), and presenting an operative face (23) able to be associated in contact
to said rail (25) and
adjustment means (5) mounted on said structure (2) in correspondence with said first
end portion (6), to adjust the pressure of said contact element (4) against said rail
(25).
7. A device as claimed in claim 6 characterised in that, in correspondence with said intermediate portion (8), said structure (2) presents
at least due through holes (13), said through holes (13) developing in mutually coaxial
fashion and substantially perpendicularly to said first direction of development,
and in that said hinging element (3) comprises a first pivot pin (16) removably inserted in said
through holes (13) and having a first end (17) and a second end (19), at least one
of said ends (17), (19) being provided with removable obstruction means (20) to prevent
the passage of said end through said through holes (13).
8. A device as claimed in claim 7 characterised in that said structure (2) further comprises due shoulders (12) mutually distanced and developing,
at least in correspondence with said intermediate portion (8), substantially parallel
to said first direction of development, said through holes (13) being obtained through
said shoulders (12).
9. A device as claimed in claim 6, 7, or 8 characterised in that said adjustment means (5) comprise at least a second, threaded, pivot pin (27) screwed
in a threaded through hole (14) obtained in said first end portion (6) according to
a direction that is substantially perpendicular to said first direction of development
of the structure (2) and to said first pivot pin (16).
10. A device as claimed in any of the previous claims from 6 to 9 characterised in that said operative face (23) of said contact element (4) has a knurled surface.