FIELD OF THE INVENTION

The present invention relates to the field of railway wagons, and more particularly to a coupler for railway wagons.

BACKGROUND OF THE INVENTION

In this application, couplers are synonym with automatic couplers, such as Janney couplers (also known as AAR couplers), SA3 couplers, and Scharfenberg copulers. Such common couplers for railway wagons are generally rigid both longitudinally and laterally. This works well when driving along the railway and coupling wagons together and apart, because they are designed to handle for instance curves on the railway. However, in certain conditions where more extreme movements between the wagons occur, such as when laterally displacing displaceable wagons, as those shown in EP 2723619, which are coupled together, the rigid couplers cause problems.

When, for instance, laterally pivoting a wagon to displace one of its ends to the side of the railway for loading/unloading, the other end pivots as well, about a pivot axis at the boggie, causing a displacement of the coupler at that end both laterally and longitudinally of the railway to an extent exceeding that of basic use. That displacement of the coupler causes large forces on the coupler and the coupler to which it is coupled, which tend to brake the couplers.

SUMMARY OF THE INVENTION

It would be advantageous to improve the coupler to be able to absorb also the large displacements caused at, for example, laterally displacing the railway wagon as described above.

To better address this concern, in a first aspect of the invention there is presented a coupler for railway wagons, the coupler comprising an outer coupler part having a first end and a second end, and an inner coupler part having a first end and a second end, wherein the outer coupler part comprises a head arranged at the first end of the outer coupler part for automatic coupling to a head of an adjacent railway wagon, wherein the inner coupler part is arranged to be pivotally connected to a railway wagon to enable lateral pivoting of the coupler, wherein the outer coupler part is longitudinally movably connected with the inner coupler part at an

interconnection portion of the coupler, positioned at the second end of the outer coupler part and at the first end of the inner coupler part, the coupler further comprising a first resilient element arranged at the interconnection portion and attached to the outer coupling part and to the inner coupling part such as to provide a resilient longitudinal movement between the outer and inner coupling parts, and a second resilient element arranged to make the lateral pivoting resilient and to bias the head to a central position. Due to the combination of the lateral and longitudinal movability and the resilient elements, the coupler can manage excessive movements of the coupler, such as when laterally displacing a railway wagon as mentioned above, that is pivoting out one of its ends, which causes significant lateral as well as longitudinal displacements of the coupler. Additionally, by means of the second resilient element, when the displacing forces have stopped the coupler head is returned to a basic position where it is aligned with the coupler head that it is coupled to.

In accordance with an embodiment of the coupler, the second resilient element is arranged at the outer coupler part.

In accordance with an embodiment of the coupler it comprises a first support beam supporting the outer coupler part and extending laterally of the coupler. The support beam ensures that the couplers of two wagons have the same height when about to be coupled together.

In accordance with an embodiment of the coupler the second resilient element is arranged at the first support beam. In accordance with an embodiment of the coupler the second resilient element comprises a first spring arranged at one side of the outer coupler part, and a second spring arranged at the other side of the outer coupler part, a first engagement member attached to the first spring and arranged to engage with the outer coupler part, and a second engagement member attached to the second spring and arranged to engage with the outer coupler part. This is a reliable and simple construction of the second resilient element.

In accordance with an embodiment of the coupler the outer coupler part comprises first slide walls arranged at the second end of the outer coupler part, and the inner coupler part comprises second slide walls arranged at the first end of the inner coupler part. The first and second slide walls engage with each other and slide against each other when the outer and inner coupler parts move longitudinally of each other. The slide walls provide a controlled longitudinal movement of the outer coupler part relative to the inner coupler part.

The invention also includes a railway wagon comprising two couplers of the kind described above, wherein the couplers are arranged at the ends of the railway wagon. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail and with reference to the appended drawings in which:

Fig. 1 is a schematic illustration of the construction principles for an embodiment of the coupler according to the present invention:

Fig. 2 is a schematic perspective view of an embodiment of the coupler according to the present invention; and

Fig. 3 is a schematic view from above showing a railway wagon having couplers as shown in Fig. 2. DESCRIPTION OF EMBODIMENTS

In one embodiment the coupler 1 comprises a an outer coupler part 2 having a first end 3 and a second end 4, and an inner coupler part 5 having a first end 6 and a second end 7. The outer coupler part 2 comprises a head 8 arranged at the first end 3 thereof for automatic coupling to a head of an adjacent railway wagon. The head 8 can be of any known type which is designed for automatic coupling as exemplified above in the background of the invention. The inner coupler part 5 is arranged to be pivotally connected to a railway wagon at the second end 7 of the inner coupler part 5, to enable lateral pivoting of the coupler 1. The outer coupler part 2 is longitudinally movably connected with the inner coupler part 5 at an interconnection portion 9 of the coupler 1 , positioned at the second end 4 of the outer coupler part 2 and at the first end 6 of the inner coupler part 5. The coupler 1 comprises a first resilient element 10 arranged at the interconnection portion 9. The first resilient element 10 is attached to the outer coupler part 2 and to the inner coupling part 5 such as to provide a resilient longitudinal movement between the outer and inner coupler parts 2, 5. The first resilient element 10 can be an ordinary coil spring, but also any other kind of feasible resilient element. The coupler 1 further comprises a second resilient element 11 , arranged to make the lateral pivoting resilient and to bias the head 8 to a central position. The second resilient element 11 is preferably provided at the outer coupler part 2, but it can be provided at the inner coupler part 5 as well. By means of the longitudinal and lateral movability of the coupler 1 , it is possible for the coupler to accommodate the forces caused by the lateral displacement of the railway wagon without damaging the coupler 1. The resilient elements 10, 11 ensure that the coupler 1 returns to an idle position when the forces have been removed again. This is important, inter alia, for enabling smooth automatic coupling of railway wagons.

The inner coupler part 5 comprises an attachment portion 12, where an inner end of the first resilient element 10 is attached, and a guide portion 13 arranged between the attachment portion 12 and the first end 6 of the inner coupler part 5. The guide portion 13 comprises an aperture 14. The outer coupler part 2 extends through the aperture 14 and is attached to an outer end of the resilient element 10 between the guide portion 13 and the attachment portion 12 of the inner coupler part 5. The outer coupler part 2 comprises first slide wall portions 15 extending through the aperture 14, and the inner coupler part 5 comprises second slide wall portions 16 constituting inner walls of the aperture 14. Thus, the first and second slide wall portions 15, 16 engage with each other and slide against each other when the outer and inner coupler parts 2, 5 move longitudinally of each other. Primarily, the first resilient element 10 is a compression spring. However, it can be arranged as a combined compression and traction spring as well.

A first support beam 17 is arranged at the outer coupler part 2 and extends laterally of the coupler 1. The first support beam 17 supports the coupler 1 so that the coupler does not dip in height, which could make coupling more difficult. The first support beam 17 is elongated and extends beyond the coupler 1 at both sides thereof. The second resilient element 11 is arranged at the first support beam 17. More particularly, the second resilient element 11 comprises a first spring 18 arranged at one side of the outer coupler part 2, and a second spring 19 arranged at the other side of the outer coupler part 2, a first engagement member 20 attached to the first spring 18 and arranged to engage with the outer coupler part 2, and a second engagement member 21 attached to the second spring 19 and arranged to engage with the outer coupler part 2. In this embodiment the engagement members 20, 21 are realized as protrusions protruding upwards from a common bar 24 extending beneath the outer coupler part 2, and the first and second springs 18, 19 are connected with opposite ends of the bar 24. When the coupler 1 moves laterally to one side, it pushes the first engagement member 20 and thereby compresses the first spring 18, and when the coupler 1 moves laterally to the other side, it pushes the second engagement member 21 and thereby compresses the second spring 19. The first and second springs should not be too hard, for instance a spring force of below 10 kN can be used. When the lateral force ceases the coupler 1 is returned to the starting position, or idle position, by the second resilient element 10.

The coupler 1 is provided with a second support beam 22 as well, supporting the coupler 1 at the interconnection portion 9 and extending laterally of the coupler 1 , and an upper beam 23 extending above the coupler 1 laterally thereof, preventing the coupler 1 from raising when subjected to excessive forces as mentioned above.

Fig. 3 illustrates a railway wagon 25 comprising two couplers 26, 27 arranged one at each end of the railway wagon 25. At both ends the railway wagon 25 is coupled to other wagons 28, 29. The railway wagon has been laterally displaced at one end thereof in order to load/unload the railway wagon 25, which has caused the coupler 27 at the opposite end of the railway wagon 25 to both be slightly pushed together, by compressing the first resilient element of that coupler 27, and of the coupler 30 with which it is coupled as well, and laterally pivoted by an angle a, as shown in Fig. 3. It should be noted that the lateral pivoting is exaggerated in order to be readily observable and understood in Fig. 3. In practise, for a typical railway wagon based on the lateral displacement solution in EP 2723619 and with a length on the coupler of about 1.5 m a maximum angle becomes about 10-15 degrees. It should be noted that with said displacement solution, the turning part of the railway wagon, also called load carrier, is pushed a minor distance, for instance about 50 mm, along the rails towards the adjacent railway wagon. If many load carriers are displaced at the same time that longitudinal displacement adds up and causes a problem with the support devices, which are lowered to ground in order to support the load carrier during the lateral displacement. Due to the present solution, the longitudinal displacement is absorbed by the first resilient elements 10. To further exemplify the present solution, the first resilient element preferably has a non-linear characteristic where the compression force needed for compressing the first resilient element an incremental distance d increases non-linearly from low towards higher. In other words, the first resilient element is initially soft and then increasingly harder.

An additional advantage with the present solution is that the lateral displacement can be performed also when the railway wagons are standing in a curve of the railway.

It should be noted that even if the couplers are coupled together automatically, they are typically arranged to be manually uncoupled.

However, the present invention encompasses couplers with automatic decoupling too.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.