[0001] The present invention concerns a centering device for centering a front coupler of
a railway car of a railway vehicle, and a method for centering such front coupler.
[0002] The present invention also relates to a railway vehicle comprising a centering device
for centering a front coupler of a railway car of a railway vehicle.
[0003] The present invention relates in particular to a centering device which can be easily
deactivated for coupling respective couplers of railway cars in tight curves, or for
easy accessibility of components mounted near the front automatic coupler.
[0004] A coupler of a railway car comprises in a manner per se known a coupling rod which
is, at a rear end, connected to a main joint and which, at a front free end, includes
coupling members for connection with analogous coupling members placed on another
coupler road of another railway car. The coupler is laterally swingable and a centering
device is arranged to secure the coupling rod in a non-swingable neutral position
when the coupler is inactive.
[0005] Couplers of the above-related kind are found on pulled railroad cars as well as pulling
locomotives, and have frequently the form of automatic couplers, i.e. couplers that
enable automatic connection without manual handling of the proper coupling members.
In practice, such automatic couplers are centrally placed on the individual end of
a car body or chassis, and are swingable in order to enable connection of railway
cars that are placed in curves, i.e. on railway tracks that are more or less curved.
During ride, the front couplers should be swingable for the railway vehicle to be
able to alternatingly pass righthand curves as well as left-hand curves. However,
when an individual coupler is inactive, i.e. not connected to the coupler of another
railway car, the same has to be reliably retained in a neutral position, which usually
consists of an intermediate position in which the coupler points perpendicularly out
from the end of the car body, because otherwise the coupler would dangle during ride.
[0006] Furthermore, automatic couplers are subjected to constant as well as occasional vertical
loads of considerable size, namely in the form of the dead weight of the coupler.
[0007] For these reasons, some form of auxiliary support is usually required, at least for
long couplers having a large dead weight that counteracts and compensates the vertical
stresses. In this connection, it should also be mentioned that the coupling rods of
the couplers are swingable not only laterally, but to a certain extent also vertically
in order to enable ride in hilly topography.
[0008] Front automatic couplers have a specific gathering range, based on type of coupler
head selected, which is a range in which two couplers can couple automatically. A
coupler is free to rotate horizontally without resistance but if there is a curve
such that the couplers are not within gathering range, then automatic coupling is
not possible, so, in order to rescue a railway vehicle, it is necessary to manually
align the couplers and then perform the coupling. Prior art centering devices provide
resistance to manual movement for coupling.
[0009] Since the couplers usually have spring actuated centering devices it is not possible
to keep a coupler at specific angle because the centering device pushes the coupler
to make it center.
[0010] Prior art devices for centering a front coupler are known, for example from document
WO 2005/032906 (Dellner).
[0011] This known device have the disadvantages of being bulky and not allowing isolating
the centering function of the device for keeping the coupler at specific angle, thus
leading to great life cycle costs and difficulties in maintenance and operation of
the centering device.
[0012] There is therefore the need to provide an innovative device and method for centering
a front coupler of a railway car capable of isolating the centering function of the
coupler, with a reliable design and a better functionality, lower life-cycle costs
and which is easy to maintain.
[0013] These and other objects are fully achieved by virtue of device for centering a front
coupler of a railway car having the characteristics defined in independent claim 1,
by a method for centering a front coupler of a railway car having the characteristics
defined in independent claim 7, and by a railway vehicle as defined in claim 9.
[0014] Preferred embodiments of the invention are specified in the dependent claims, whose
subject-matter is to be understood as forming an integral part of the present description.
[0015] Further characteristics and advantages of the present invention will become apparent
from the following description, provided merely by way of a non-limiting example,
with reference to the enclosed drawings, in which:
- Figure 1 is a perspective view of a front automatic coupler of a railway car of the
prior art shown in its entirety;
- Figure 2 shows a prospective view of a device for centering a front automatic coupler
of a railway car according to the present invention;
- Figure 3 shows an exploded view of the device of figure 2;
- Figure 4 shows a side view of the device for centering a front automatic coupler according
to the present invention,
- Figure 5 shows a side sectional view of an enlargement of the device for centering
a front automatic coupler of figure 5;
- Figure 6 shows a sectional top view of the device for centering a front automatic
coupler in an engaged position; - Figure 7 shows a sectional top view of the device
of figure 2 in a retracted position; and
- Figure 8 shows a railway vehicle comprising a device for centering a front automatic
coupler of a railway car according to the present invention.
[0016] In figure 1, which is derived from figure 1 of document
WO 2005/032906, a front coupler is shown, preferably in the form of an automatic coupler, which
in a conventional way includes a coupling rod 1, which at a front, free end includes
coupling members 2,3 and at a rear end is connected to a main joint generally designated
4. In said main joint, on one hand, a vertical axle or axle spindle 5 is included,
which at upper and lower ends is connected to a fastening plate 6, which can be fixed
on an car body (not shown), e. g., by means of a screw or bolt joint indicated 7.
[0017] In practice, the fastening plate 6 is placed in the middle of the end of the car
body in question, with the plate on a vertical plane from which the coupling rod 1
protrudes substantially horizontally. Furthermore, the main joint 4 includes a ring
8 surrounding the axle 5, which ring is turnable backward and forward in relation
to the axle and to which the coupling rod 1 is connected. In other words, the main
joint 4 enables lateral swinging of the coupling rod 1, e.g. at a 45° angle of deflection
to each direction from the position shown in fig. 1. Furthermore, the main joint 4
includes means, not shown, to enable turning of the coupling rod 1 as well as limited
vertical swinging of the coupling rod in relation to the fastening plate 6.
[0018] In view of the above, it is clear that the coupling rod 1 in figure 1 is shown in
a neutral or starting position, in which the coupling rod 1 points straight ahead,
i.e., perpendicularly to the fastening plate 6. From this neutral position, the coupling
rod 1 may be variably swung towards the left as well as the right to a maximum angle
of deflection.
[0019] Characteristic of the front coupler according to the prior art is that there is a
bracket-like carrier 9 placed under the coupling rod 1, which is connected to a turnable
ring included in a house 10 arranged under the main joint 4, in which a device for
centering the front coupler, of known type, is integrated or built-in.
[0020] According to the present invention, an innovative device for centering the front
automatic coupler, to be placed into the house 10, is provided, and it will be disclosed
in detail the following .
[0021] Figure 2 shows a prospective view of a device 50 for centering a front coupler of
a railway car (also called in the following
"centering device") according to the present invention, said centering device 50 being arranged to be
placed into the house 10 for securing the coupling rod 1 in the neutral position thereof,
according to the disclosure of
WO 2005/032906.
[0022] Figure 3 shows an exploded view of the centering device 50.
[0023] The centering device 50 has the purpose of securing the coupling rod 1 in the neutral
position thereof.
[0024] The centering device 50 comprises a cam disk 52 and a roller device 54 arranged to
engage a grove 52a of the cam disk 52 (see figure 6).
[0025] When the coupling rod 1 is in the neutral position, it points straight ahead, and
the roller device 54 is in engagement with the grove 52a, as it is shown in fig. 6.
Thanks to the centering device 50, ride may take place without the coupling rod 1
swinging or dangling in an uncontrolled way.
[0026] When the front coupler has to be connected to an analogous front coupler on another
railway car, and the two railway cars are placed on a non-straight track, the coupling
rod 1 is swung out laterally to an angle of deflection that is determined by the curve
radius of the track, so that coupling members of the respective coupler can be brought
into engagement with each other.
[0027] The above-cited swinging out takes place against the action of a spring 64 of the
centering device 50, as described in detail here below.
[0028] Figure 4 shows a side view of the centering device 50 placed under the coupling rod
1, and figure 5 shows a side sectional view of an enlargement of the centering device
50 of figure 4.
[0029] In figure 5, the cam disk 52 is in an engaged position corresponding to the one of
figure 6, disclosed in detail herein-below.
[0030] The cam disk 52 is connected to the coupling rod 1, so that when it rotates, the
coupling rod 1 rotates as well.
[0031] Returning to figure 3, the roller device 54 is fixed to an end 56 of a screw-thread
component 58 by means of a screw 60.
[0032] The screw-thread component 58 comprises a proximal plate 62a and a distal plate 62b
arranged to be placed in contact with the respective ends of a spring 64, preferably
made of Belleville washers, which is placed between the plates 62a, 62b, wound around
a cylindrical support 66. The plates 62a, 62b can be identical each other or different
each other in shape. Advantageously, the plates 62a, 62b are circular-shaped, square-shaped
or triangle-shaped. The plates 62a, 62b can have however any other desired shape.
[0033] A cylinder 68 is advantageously provided around the spring 64 to protect it.
[0034] Bars 70 connect the two plates 62a, 62b and fix them at the end of the spring 64
so that the cylindrical support 66 protrudes out from the distal plate 62b. For example,
when plates 62a, 62b are triangle-shaped as visible on Figure 3, three bars 70 connect
the two plates 62a, 62b.
[0035] Figure 6 shows a sectional top view of the device of figure 2 in an engaged position
wherein the roller device 54 engages the grove 52a of the cam disk 52.
[0036] A nut 72 is screwed on the cylindrical support 66 so that when the nut 72 is tightened,
it compresses the spring 64 and the roller device 54 retracts out of the grove 52a
of the cam disk 52, as visible on figure 7.
[0037] When the nut 72 is unscrewed, as visible on figure 6, the spring 64 push the roller
device 54 against the lateral surface of the cam disk 52 so that, when the cam disk
52 rotates, the roller device 54 engages the grove 52a thus centering the coupling
rod 1.
[0038] Figure 7 shows a sectional top view of the centering device 50 in a retracted position
wherein the nut 72 has been tightened, so as to compress the spring 64 and the roller
device 54 has retracted out of the groove 52a.
[0039] Since now the roller device 54 is out of grove 52a, the cam disk 52 is free to rotate.
Once the nut 72 is released, the roller device 54 touches the cam disk 52 and performs
the centering function of the automatic coupler. Since the cam disk 52 is connected
to the coupling rod 1, rotation of cam disk 52 controls the rotation of the front
coupler.
[0040] The profile of the cam disk 52 can be made to suit any centering angle requirement.
[0041] The centering device 50 for centering a front automatic coupler of the present invention
has the following advantages:
- it allows to easily isolate the centering function without the need to use any special
tool because the coupler can be easily moved away for good accessibility, thus reducing
the maintenance time;
- it gives to maintenance operators the flexibility to move the automatic coupler laterally
without any effort, for maintenance activities of the coupler or of its surrounding
equipment;
- it allows to keep the coupler at a specified desired angle for coupling in tight curves;
- it improves the reliability of the coupler and decreases the life cycle cost as it
is not active when couplers are coupled during service operation; and
- it has a simple design.
[0042] Figure 8 shows a railway vehicle 100 having a coupling rod 1 and a centering device
50 as above disclosed.
[0043] Clearly, the principle of the invention remaining the same, the embodiments and the
details of production can be varied considerably from what has been described and
illustrated purely by way of non-limiting example, without departing from the scope
of protection of the present invention as defined by the attached claims.
1. Centering device (50) for centering a front coupler of a railway car comprising a
coupling rod (1), said centering device (50) comprising:
- a cam disk (52) having a lateral surface with a recess (52a), said cam disk (52)
being connected to the coupling rod (1) so that when it rotates, the coupling rod
(1) rotates;
- a roller device (54) arranged to contact the lateral surface of the cam disk (52)
when it is pushed by a spring (64) towards said lateral surface of the cam disk (52),
so that when the cam disk (52) rotates, the roller device (54) engages the recess
(52a) thus limiting pivoting of the cam disk (52) and centering the coupling rod (1),
said roller device (54) being further arranged to disengage the recess (52a) when
the spring (64) is compressed by tightening a nut (72), so as to make the coupling
rod (1) free to rotate.
2. The centering device (50) of claim 1, wherein the spring (64) and the roller device
(54) are mounted on a screw-thread component (58).
3. The centering device (50) of claims 1 or 2, wherein the spring (64) is made of Belleville
washers.
4. The centering device (50) of claim 2 or 3, wherein the screw-thread component (58)
comprises a proximal plate (62a) and a distal plate (62b) arranged to be put in contact
with the respective ends of the spring (64).
5. The centering device (50) of claim 4, wherein the spring (64) is wound around a cylindrical
support (66) which protrudes out from the distal plate (62b) and wherein the nut (72)
is screwed on said cylindrical support (66).
6. The centering device (50) of claim 5, wherein a cylinder (68) is provided around the
spring (64) to protect it.
7. Method for centering a front coupler of a railway car comprising a coupling rod (1),
the method comprising the steps of:
- providing a centering device (50) according to any of the preceding claims;
- releasing the nut (72) so that the roller device (54) touches the cam disk (52)
and engages the recess (52a), thus centering the coupling rod (1).
8. Method according to claim 7, further comprising the step of tightening the nut (72)
to compress the spring (64) so that the roller device (54) retracts out of the recess
(52a) of the cam disk (52), thus making the coupling rod (1) free to rotate.
9. Railway vehicle (100) comprising a centering device (50) for centering a front coupler
according to any of the claims 1 to 6.
10. Railway vehicle (100) according to claim 9, wherein the centering device (50) is coupled
to a coupling rod (1), thus allowing centering the coupling rod (1) by releasing the
nut (72) so that the roller device (54) touches the cam disk (52) and engages the
recess (52a)