Patent Description:
Within the field of couplers for railway vehicles, it is generally desirable to protect an end of the coupler when not in a coupled position. The purpose of this is to prevent intrusion of moisture and dirt during both operation and standstill of the rail vehicle, and also to protect the end of the coupler from objects accidentally present on railway tracks such as animals that may collide with the railway vehicle. By using a sturdy front cover, malfunction due to animal collision and similar is thus avoided.

However, railway couplers form an important part of the crash management system for railway vehicles, and in order to function as intended and absorb collision forces it is very important that such forces are guided along the coupler to allow energy absorption devices such as dampers and deformation tubes to be activated. When a collision occurs, there is a risk that bending forces cause the coupler to buckle, thereby preventing the energy absorption devices from operating as intended. The result is often significant damage to the railway vehicle and to any goods or passengers present inside.

<CIT> discloses a protective shroud for the coupler head of a train coupler, comprising a deformable sheet of elastic material forming a cover element which is mounted at its periphery in a frame and together with the frame pivotally supported and controlled to be pivoted about an axis transverse to a longitudinal axis of the train coupler between a relaxed noncovering position displaced from the coupler longitudinal axis and a stretched covering position intersecting the coupler longitudinal axis at the front of the coupler head.

<CIT> discloses a device adapted to at least partially cover a couplerhead of a multi-car vehicle, wherein the device comprises a front window and a front face cover, wherein a top cover section and side cover sections are connected to the front window, and the front face cover is adapted to be (a) selectively attached to or detached from the front window and/or the cover sections and/or (b) rotatable such that the front face cover can be swung towards a side cover section.

There is therefore a need for improvements within the area of front covers for couplers, so that the front end may be protected but at the same time maintaining desired operation of the crash management system in the event of a collision.

The object of the present invention is to eliminate or at least to minimize the problems discussed above. This is achieved by a front cover, a coupler having a front cover, a method for mounting a front cover, and a method for deforming a front cover according to the appended independent claims.

The front cover according to the invention comprises a cover body for covering a front end of the coupler, wherein the cover body comprises at least one deformation zone. Said deformation zone has a cover portion that is configured to break or deform when subjected to a collision force for providing access through the cover body at the at least one deformation zone during a collision. Thereby, a collision with another rail vehicle will allow the couplers of the rail vehicles to couple or mate due to the deformation or breakage of the deformation zones so that the mechanical coupler becomes accessible. By enabling coupling or mating (where couplers are held with their front ends facing each other) to take place during the collision, it is ensured that collision forces propagate through the coupler so that they may be absorbed as intended. The front cover is thus able to serve the main purpose of protecting the end of the coupler while at the same time giving access to the coupler when subjected to the collision force.

Suitably, the cover body comprises a first cover body section for covering a mechanical coupler on the front end of the coupler and a second cover body section for covering an electrical coupler on the front end of the coupler, wherein the first cover body section comprises the at least one deformation zone. Thereby, the electrical coupler is protected by the second cover body section that does not comprise a deformation zone. This serves to protect the electrical coupler and to prevent access to it as long as the front cover remains in place.

Also, the second cover body section is suitably offset from the first cover body section in a first direction, said first direction being a direction that is horizontal when the front cover is mounted on a coupler. This further protects the electrical coupler since a collision force will in most cases hit the first cover body section on the mechanical coupler first. Since the mechanical coupler is stronger and less easily damaged, this means that the electrical coupler is further protected from damage by any collision force being first applied to the mechanical coupler through the first cover body section.

Suitably, the front cover comprises at least one holder for mounting the front cover on a coupler. Thereby, the front coupler is held in place in a convenient and reliable way. In some embodiments, said at least one holder comprises a breakable part that is configured to break when subjected to a collision force. Thereby, as soon as the holder breaks, the collision force is distributed through the front cover and onto the end of the coupler so that energy absorbing components of the coupler may act as intended.

Said collision force is suitably a force of at least <NUM> kN. This is a force that causes activation of at least one damper and it is advantageous that the collision force causes deformation or breakage of the cover portion so that a coupling connection of a damper is able to penetrate the front cover and enter an opening in the front end of the coupler on which the front cover is mounted. Thereby, the front end of the coupler and also the front end of a second, colliding coupler are held adjacent to each other so that buckling of the coupler is avoided. Alternatively, said collision force is suitably a force of at least <NUM> kN. This is a force that causes irreversible deformation to energy absorption devices in the coupler, and for any forces at this level or larger it is advantageous that the deformation of the deformation zones occurs so that access to the end of the coupler is provided to allow for front ends of the coupler and a colliding coupler being held adjacent to each other in situations where the coupler collides with a railway vehicle. This has the benefit that buckling of the coupler is avoided so that energy absorption may take place as desired.

In some embodiments, the at least one cover portion is made from an elastomer, preferably comprising rubber. This is beneficial in allowing for a deformation in the event of a collision force, and the elastomer may also provide breakage when it is stretched by an object that pushes against the deformation zones. When the coupler collides with a railway vehicle having a similar coupler, that object will be a protruding part of a mechanical coupler, i.e. a coupling connection, and by the object pushing into or through the deformation zone the object will penetrate the front cover and extend into an opening of the coupler on which the front cover is mounted. This in turn causes the front ends of the couplers to meet and contact each other via the front cover or optionally to be held at a distance from each other in situations where the coupling connection is not able to enter the opening fully. This prevents buckling at the front ends of the couplers so that the collision force may be absorbed by the energy absorption devices in the couplers.

In some embodiments, the at least one cover portion is made from a brittle material. Thereby, the cover portion is able to break into a plurality of pieces when subjected to the collision force and this allows access to the coupler on which the front cover is mounted. Suitably, the at least one cover portion comprises metal or reinforced polymer. If comprising metal, the cover portion is suitably formed as a sheet. A reinforced polymer is suitably fiberglass or carbon fiber reinforced polymer.

Suitably, a cover portion may protrude from the cover body to form a protruding portion for covering a protruding coupling connection of a coupler in a mounted state on a front end of a coupler. Thereby, a protective cover is achieved for a coupling connection that extends from the end of the coupler.

Also, the cover portion of the at least one deformation zone may be mounted on the cover body. Thereby, the cover body may be provided with an opening at the deformation zone and the opening may be covered by the cover portion and be attached to form the front cover.

In another embodiment, the cover portion of the at least one deformation zone is integrated with the cover body. Thereby, the deformation zone may be formed by the same material as the cover body, and the feature of deforming or breaking may be achieved by the cover portion being thinner than the cover body, or alternatively in any other suitable way.

The present invention also comprises a coupler for a rail vehicle, wherein the coupler comprises a mechanical coupler that has at least one coupling connection for forming a mechanical coupling with a similar coupler. The coupler further comprises a front cover according to the invention, wherein the front cover is mounted on a front end of the coupler such that a cover portion of a deformation zone of the front cover covers a coupling connection. Thereby, protection for the mechanical coupler and optionally also for an electrical coupler is achieved, while at the same time allowing access to the front end of the coupler through the cover body in the event of a collision force being applied to the front cover.

The present invention also comprises the method for mounting the front cover on a coupler of a rail vehicle. The inventive method comprises providing a front cover according to the invention and also providing a coupler that has at least one coupling connection for mechanically coupling the coupler to a similar coupler, wherein the coupling connection is arranged at a front end of the coupler. The invention also comprises applying the front cover to the front end of the coupler such that a deformation zone of the cover body of the front cover covers the coupling connection of the coupler. Thereby, the front end of the coupler is protected by the cover body and the deformation zone is arranged so that access to the coupling connection is possible when a collision force is applied to the deformation zone. In this way, both main advantages of the invention are achieved by on the one hand protecting the coupler end and on the other hand allowing access to the coupling connection so that collision forces may be handled in the event of a crash.

The invention may suitably also comprise mounting a holder of the front cover on the coupler for fixating the front cover in relation to the coupler. Thereby, the front cover is held in place by the holder in a stable and convenient way.

Also, the front cover is suitably placed on the front end of the coupler such that a first cover body section covers the mechanical coupler with the coupling connection and a second cover body section covers an electrical coupler of the coupler. The first cover body section and the second cover body section are suitably formed as sheets or panels that are configured to be attached to each other and to extend across the front end of the coupler when mounted. Thereby, the mechanical coupler may be protected by the first cover body section that comprises the deformation zone whereas the second cover body section serves to protect the electrical coupler. By not providing a deformation zone in connection with the electrical coupler, damage to the electrical coupler is minimized.

The invention suitably also includes a method for deforming a front cover. This method comprises hitting a front cover mounted on a front end of a first coupler by a front end of a second coupler such that a collision force is applied in a first direction, and deforming or breaking a cover portion of at least one deformation zone on the front cover such that a coupling connection arranged in the front end of the second coupler enters an opening arranged in the front end of the first coupler. The coupling connection suitably protrudes from the coupler end and the opening is suitably provided in the coupler end for providing access to the coupler so that the protruding coupling connection may be received into said coupler end and a mechanical coupling between the couplers may occur or the coupling connection may be held at least partially in the opening in order for the front ends of the couplers to mate. The front cover provides the advantage of enabling the mechanical coupling to occur even though the front cover itself is not removed before the collision force is applied.

Many additional benefits and advantages of the present invention will be readily understood by the skilled person in view of the detailed description below.

The invention will now be described in more detail with reference to the appended drawings, wherein.

All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary in order to elucidate the respective embodiments, whereas other parts may be omitted or merely suggested. Any reference number appearing in multiple drawings refers to the same object or feature throughout the drawings, unless otherwise indicated.

<FIG> discloses a front cover <NUM> according to a first embodiment of the present invention. The front cover <NUM> is mounted on a front end of a coupler <NUM> that will be descried below with reference to <FIG>. When in the following terms such as upper, lower, horizontal and vertical are used in connection with the front cover <NUM>, this is to be understood as directions and relations that refer to orientation of the front cover <NUM> in a mounted state on a coupler such as shown in <FIG>.

In the following, the term "provide access" is to be understood as allowing one object to approach another without being hindered by another object placed between them. Thus, when access is provided to a coupler this means that a cover portion that is held in front of a coupling connection breaks or deforms so that a protruding coupling connection is able to enter an opening of the coupler. A collision force as defined herein is a force that causes an energy absorption device such as a damper of the coupler to be activated. A first collision threshold is defined as the smallest force that causes reversible energy absorption of a component in the coupler. The first collision threshold is for the present invention <NUM> kN and this corresponds to a smaller collision such as might occur when a rail vehicle impacts another at low speed, and may also be caused by a hard coupling between two rail vehicles when a speed of one vehicle brought into contact with the other for a coupling procedure is higher than suitable.

Alternatively, the collision force may be defined as a force that causes non-reversible deformation to at least one energy absorption device in a coupler, typically a deformation tube. Non-reversible deformation is in turn defined as a deformation of a component by which the component is unable to elastically resume its original shape after the force has been absorbed. A second collision threshold is defined as the smallest force that causes non-reversible deformation to an energy absorption device, and the second collision threshold is for the present invention <NUM> kN. This corresponds to a collision such as may typically occur during operation of railway vehicles, i.e. not at low speeds and not where a coupling procedure takes place.

In a coupler, energy absorption devices are generally provided in the form of elastically deformable elements, suitably buffers and dampers, along with energy absorption devices in the form of non-elastically deformable elements such as deformation tubes. A collision force is thus a force that is large enough so that buffers that are typically elastic rubber elements are not able to absorb it. The first collision threshold given above corresponds to a situation where at least one damper is activated, and the second collision threshold corresponds to a situation where the damper or dampers is/are not able to handle the collision force so that irreparable deformation occurs.

The threshold mentioned herein may be compared with a force needed to cause coupling between two similar couplers. This force is generally in the range of <NUM> - <NUM> kN but depends on properties and design of the couplers themselves.

When couplers meet at speed, their collision or impact often cause transverse forces that result in pivoting or buckling at their meeting front faces. In order to avoid pivoting, the impact would need to be very small (typically at only <NUM> kN or below) and also without significant transversal component. In reality, this is very rarely the case so that most impacts at speed would result in buckling of the railway vehicles unless measures were in place to prevent it.

In the following, various embodiments of a front cover will be described and it will be mentioned how the front cover may interact with a front end of a coupler. When thus referring to a coupler this may be understood as the coupler shown in <FIG> but it is to be noted that the front cover may also be used with other kinds of couplers that are designed differently. Thus, when it is said that the front cover is mounted on or interacts in some way with "the coupler", this is to be understood as a railway coupler in general and not to be limited to the coupler shown in <FIG> and described in more detail herein.

Starting with <FIG>, some elements of a front end <NUM> of a coupler <NUM> is shown. The coupler comprises a mechanical coupler <NUM> for mechanically coupling to a similar coupler, as is well known in the art. In the coupler <NUM> shown herein, the mechanical coupler <NUM> comprises a protruding coupling connection <NUM> and an opening <NUM> for allowing access to a receiving coupling connection (not shown). The coupler <NUM> also comprises draft gear <NUM> that is fixedly mounted on a railway car as is well known to the skilled person.

This is a general depiction of an automatic coupler that is well known within the art and that functions by a protruding coupling connection of one coupler being inserted into a receiving coupling connection of another similar coupler. By the coupling connections mating automatically with each other a secure mechanical coupling is achieved. One type of such automatic coupling is shown by the Scharfenberg coupler. Also provided in the coupler <NUM> of <FIG> is an electrical coupler <NUM> that is configured to mate with an electrical coupler of a similar coupler by the electrical coupler <NUM> extending and connecting to the other coupler.

Since couplers and their coupling to each other are well known within the art they will not be described in detail herein; suffice it to say that couplers may have different designs and operation as long as they are able to establish a mechanical connection and preferably also an electrical or electronic connection such that mechanical force and preferably also electrical or electronic signals may be transmitted from one coupler to the other. The mechanical coupler may comprise two coupling connections <NUM> side by side or may alternatively comprise two coupling connections <NUM> that are arranged differently in relation to each other (one above the other, or one at a distance from the other in any suitable direction). Alternatively, only one coupling connection <NUM> or more than two coupling connections <NUM> may be provided.

Apart from a mechanical and suitably also electrical coupler, the coupler <NUM> may also comprise other kinds of connections that may be formed between the coupler <NUM> and a similar coupler.

The term "mating" as used herein is to be understood as two couplers facing each other with at least one protruding coupling connection of one of them being at least partially inserted into an opening of the other. This means that the mating couplers are held adjacent to each other with their front ends facing each other.

In a coupled position when the coupler <NUM> is connected to the similar coupler, the mechanical coupler with the at least one coupling connections <NUM> is engaged and so is the electrical coupler <NUM>. During operation and during standstill, the front end <NUM> of the coupler <NUM> is protected from damage by its connections and closeness to the other coupler, so that intrusion of dirt and damage caused by objects hitting the front end <NUM> is largely prevented. In an uncoupled state, however, and especially in situations where the railway car on which the coupler <NUM> is arranged is in operation (i.e. being conveyed along a railway track), damage caused by snow, dirt and small objects such as sand hitting the front end <NUM> and possibly entering openings provided for the coupling connections <NUM> and the electrical coupler <NUM> may cause malfunction and lower the future performance of the coupler <NUM>. For this purpose, the front cover <NUM> of the present invention is provided.

The front cover <NUM> comprises a cover body <NUM> that in this embodiment is in the form of a first cover body section <NUM> and a second cover body section <NUM>. In the first cover body section <NUM>, at least one deformation zone <NUM> is provided and in turn comprises a cover portion <NUM> that extends across the deformation zone <NUM> so that the front cover <NUM> is provided without openings through the cover body <NUM>. The cover body <NUM> itself, i.e. those parts of the cover body <NUM> that do not belong to the cover portion(s) <NUM> on the deformation zone(s) <NUM> are not designed to deform or break. Thus, when the term cover body <NUM> is used herein, this is to be understood as a rigid body that is not configured to deform or break but instead remain in place during a collision. When in the following embodiments are described in which the cover portion(s) <NUM> is/are formed by a portion of the cover body <NUM> being weakened (see e.g. <FIG>), that weakened portion is to be understood as a cover portion <NUM> although it is integrated with the cover body <NUM>.

In the first embodiment, a protruding cover portion <NUM> is provided on one deformation zone <NUM> and a non-protruding cover portion <NUM> is provided on another deformation zone <NUM>, but it is to be noted that the number of deformation zones <NUM> may vary and that the cover portions <NUM>, <NUM> may have different shapes depending on design of the coupler <NUM> on which it is to be mounted. Where a protruding coupling connection <NUM> is provided, this suitably corresponds to a protruding cover portion <NUM> in a deformation zone <NUM> of the front cover <NUM>. On the other hand, where a coupling connection <NUM> that does not protrude significantly from the front end <NUM> is provided, this suitably corresponds to a non-protruding cover portion <NUM>. The protruding cover portion <NUM> is typically conical or frustoconical but may alternatively have another shape.

As also shown in <FIG>, the deformation zones <NUM> are provided in the first cover body section whereas the second cover body section <NUM> does not comprise any deformation zones <NUM>. The purpose of this is to arrange the deformation zones <NUM> aligned with the coupling connections <NUM> of the mechanical coupler <NUM> while at the same time providing the second cover body section <NUM> without deformation zones to cover the electrical coupler <NUM>.

The deformation zones <NUM> are designed to be deformable so that coupling connections of a second coupler will be able to access coupling connection <NUM> of the coupler <NUM> in the event of a collision between railway vehicles in a situation when the front cover <NUM> is in place on the front end <NUM>. Although collision with objects present along or on railway tracks may damage the coupling connections, damage caused by two railway vehicles colliding is especially serious since it generally contains a very large collision force. The coupler <NUM> is generally designed to be able to absorb such forces, but typically rely on the forces to be transmitted through the coupler in a suitable way in order for the energy absorption devices to function as intended. For this reason, pivoting or buckling of the coupler <NUM> must be avoided.

By thus enabling an establishing of a mechanical coupling or a mating in the event of a collision between two railway vehicles, significant advantages are achieved since collision forces that are applied to the coupler <NUM> may be distributed in elastically deformable and non-elastically deformable elements of the coupler <NUM> so that the forces are absorbed and damage to other parts of the coupler <NUM> and to the railway vehicle to which it is connected may thereby be decreased or even minimized. Collision of the coupler <NUM> with a similar coupler will be described in more detail further below.

The cover portions <NUM> suitably comprise a deformable material that is able to be stretched or broken when subjected to a collision force that is at the first collision threshold or larger. Such a deformable material suitably has a shore A hardness of <NUM> or less, and one suitable material is a polymer material such as polyurethane or silicone rubber. Even more suitably, the deformable material could have a shore A hardness of <NUM> or less, and one material that is particularly advantageous in this regard is natural rubber. Other materials that are also suitable include EPDM rubber and neoprene. When referring to shore A values herein, this is to be understood as being according to ASTM D2240-<NUM>.

In some embodiments, the cover portions <NUM> could instead comprise a material that is brittle so that a collision force of the first collision threshold or larger causes the cover portion to break away and provide access to the coupling connections <NUM> of the coupler <NUM>. A brittle material as used herein is defined as a material that breaks into at least two pieces without undergoing significant deformation when subjected to a force. The brittle material would then have an elongation at break of <NUM>% or less, suitably <NUM>% or less and even more suitably <NUM>% or less. For the purpose of this invention, a suitable brittle material for the cover portions <NUM> would then be a material that breaks into at least two pieces when subjected to a force of the first collision threshold. Such materials include polymers, suitably reinforced polymers such as fiberglass (glass fibre reinforced polymer) or carbon fiber reinforced polymer. One particularly suitable material is epoxy reinforced with a filler such as glass bubbles. When using polymers, the material is advantageously rendered brittle by addition of hard fillers (suitable materials include glass and carbon, but other materials such as talc, kaolin and wollastonite may also be used, or alternatively nanoclay or graphene may also be suitable. Round and cubic filling materials like calcium carbonate, silica or glass beads are especially suitable since they are able to reinforce the material without significantly increasing tensile strength. In some embodiments, the cover portions <NUM> could alternatively be made form a polymer that is not reinforced.

It is suitable that the brittle cover portions <NUM> that are configured to break when subjected to a collision force is at the same time able to withstand forces of at least <NUM> kN, more suitably at least <NUM> kN, in order to be able to avoid breaking in the event of a collision with a small object such as an animal. This protects the coupling connections.

The cover body <NUM> may comprise only one deformation zone <NUM> that is covered by a cover portion <NUM>, or alternatively there may be a plurality of deformation zones <NUM> with cover portions <NUM>. Each cover portion <NUM> of a front cover <NUM> according to the invention may comprise the same material, or alternatively different materials may be used for the cover portions <NUM>.

In some embodiments, the cover portions <NUM> may be fastened onto the cover body <NUM> in a suitable way, such as by welding or riveting. In other embodiments, the cover portions <NUM> may be integrated with the cover body <NUM> and comprise a material that is also present in the cover body <NUM> as such. In order to achieve the deformable or breakable properties of the cover portions <NUM>, the deformation zones <NUM> may in such embodiments have a smaller thickness than the rest of the cover body <NUM>. Where a material such as polyurethane is used, the deformation zones <NUM> may have a thickness that is less than <NUM>/<NUM>, preferably less than <NUM>/<NUM> and even more preferably less than <NUM>/<NUM> of a thickness of another part of the cover body <NUM>. A suitable thickness for the deformation zone <NUM> would in one example be <NUM> - <NUM>, whereas the rest of the cover body would have a thickness of <NUM>-<NUM> for a polymer material. When a steel is used for the rest of the cover body, the steel body could have a smaller thickness such as <NUM> and the deformation zone <NUM> would then suitably be less than <NUM>. When the deformation zone <NUM> is much thinner than other parts of the cover body <NUM>, the same material may be used both for the cover portion <NUM> and for the cover body <NUM>, since rendering the material significantly thinner will in most cases also render it more easily deformable so that the cover portion <NUM> is flexible enough to deform when subjected to the collision force. The cover body <NUM> suitably comprises a material that has a hardness of at least <NUM> shore A in order to provide stability to the front cover <NUM>. Suitable materials include polymers, suitably reinforced polymers such as glass fiber reinforced polymer (fiberglass) or carbon fiber reinforced polymer. Metals such as steel are also suitable, as mentioned above.

<FIG> discloses a second embodiment of the front cover <NUM> in an unmounted state, showing the cover body <NUM> with the at least one deformation zone <NUM>. In the second embodiment, two deformation zones <NUM> are provided side by side in a horizontal direction so that they are suitable for covering a mechanical coupler such as the one shown in <FIG>. One of the deformation zones <NUM> comprises a protruding cover portion <NUM> and the other comprises a non-protruding cover portion <NUM>. Also provided are at least one holder <NUM> that serves to mount the front cover <NUM> on the front end <NUM> of the coupler <NUM>. The front cover <NUM> according to the second embodiment comprises only one section of the cover body <NUM>, whereas the first embodiment comprised one section for covering the mechanical coupler and another for covering the electrical coupler, as mentioned above. The at least one holder <NUM> suitably comprises a metal such as steel.

The protruding cover portion <NUM> may have any suitable shape for allowing it to be placed on the coupling connection <NUM> of the coupler <NUM>. In the second embodiment, the protruding cover portion <NUM> is shown with a frustoconical shape that is selected in order to follow a shape of the coupling connection <NUM> so that a distance between the protruding cover portion <NUM> and the coupling connection <NUM> is small when the front cover <NUM> is mounted on the coupler <NUM>. Suitably such distance may be less than <NUM>, even more suitably less than <NUM> or even less than <NUM>. It is generally advantageous for the distance to be as small as possible, since this allows for only a small deformation of the protruding cover portion <NUM> in order for the coupling connection <NUM> to reach and connect with the coupling connection of the other coupler. Also, since the protruding coupling connection <NUM> generally differs in width only a few millimeters or even less compared with the opening that provides access into the coupler <NUM>, it is highly advantageous for the cover portions <NUM> to be able to break or to be deformed and stretched so that they have a thickness of only one millimeter or even less in a deformed or stretched state. This is particularly advantageous since a protruding coupling connection <NUM>, generally in the shape of a cone, is in many couplers <NUM> adapted to fit into an opening of a similar coupler with the opening having a diameter that exceeds a diameter of the protruding coupling connection <NUM> by only a few millimeters or even one millimeter. In order for the cover portions to be able to deform and allow the protruding coupling connection <NUM> to fully enter the opening the cover portion <NUM> should thus in a deformed and stretched state have a thickness of less than a millimeter so that the intrusion of the coupling connection <NUM> is not hindered.

When a brittle material is used as cover portions <NUM>, it is to be noted that it may be advantageous to arrange the cover portions <NUM> at a distance from the coupling connections <NUM> so that the cover portions <NUM> are able to shatter and fall away during a collision so that material from the cover portions <NUM> is entirely removed from the coupling connections <NUM>.

<FIG> discloses the second embodiment from a rear side, showing the holders <NUM> and also showing the protruding cover portion <NUM> and the non-protruding cover portion <NUM> from the back. the protruding cover portion <NUM> and the non-protruding cover portion <NUM> may be joined separately to the cover body <NUM> but may alternatively also be joined to each other so that a larger deformation zone <NUM> is formed and includes both cover portions <NUM>.

Also provided in the second embodiment is at least one handle <NUM> that serves to facilitate handling and mounting of the front cover <NUM>. Such handle <NUM> is preferably fastened onto the cover body <NUM>.

The at least one holder <NUM> is fastened onto the coupler <NUM> in order for the front cover <NUM> to reach a mounted state. Suitably, mounting the front cover <NUM> comprises fitting the deformation zones <NUM> onto the coupling connections <NUM> of the mechanical coupler <NUM> of the coupler, so that access to the coupling connections <NUM> may be provided by deformation or breaking of the cover portions <NUM>.

Suitably, the at least one holder <NUM> is configured to break when subjected to the collision force that is of a magnitude of the first collision threshold or higher. By the holders <NUM> breaking, the transmission of forces from the front cover <NUM> to the coupler <NUM> through the holders <NUM> is avoided, thereby facilitating the distribution of forces through the coupler <NUM> in order to reach the energy absorption devices as intended. In some embodiments, the at least one holder <NUM> may instead be configured to undergo an elastic or plastic deformation when a collision occurs so that it bends when subjected to a collision force.

<FIG> discloses the front cover <NUM> according to the first embodiment in the mounted state on a coupler <NUM>. The first cover body section <NUM> is marked by a rectangle and the second cover body section <NUM> is marked by another rectangle.

In <FIG>, the front cover <NUM> of <FIG> is shown in a planar view from the side, with the first cover body section <NUM> mounted on the mechanical coupler <NUM> at a distance from the front end <NUM> of the coupler <NUM>. The second cover body section <NUM> is mounted on the electrical coupler <NUM>, and the second cover body section <NUM> is also offset from the first cover body section <NUM> in a first direction D. This is a direction that is horizontal when the front cover <NUM> is in the mounted state, and it is also a direction that is essentially perpendicular to the cover body <NUM>. <FIG> also shows the holders <NUM> that are joined to the cover body <NUM> and said holders <NUM> are in the mounted state attached to the coupler <NUM>.

The first cover body section <NUM> of the cover body <NUM> is suitably formed as a plate that extends across the front end <NUM> of the coupler in such a way that it covers the mechanical coupler <NUM>. It is advantageous during a collision that the first cover body section <NUM> is essentially planar since this aids in guiding an applied collision force in the first direction D.

As shown in <FIG>, the offset of the second cover body section <NUM> gives the cover body <NUM> a stepped profile. Further, the offset is suitably selected so that the second cover body section <NUM> is at a distance from the electrical coupler <NUM> that is larger than the distance from the first cover body section <NUM> to the mechanical coupler <NUM>.

The first cover body section <NUM> and the second cover body section <NUM> are suitably formed as sheets or panels that are configured to be attached to each other and to extend across the front end of the coupler when mounted.

<FIG> shows the front cover <NUM> and the coupler <NUM> during or immediately after the collision force is applied. In this image, the collision force is shown as a force F in the first direction D. The collision force causes the holders <NUM> to break free, either by the holders <NUM> themselves comprising a breakable part that is configured to break when subjected to the collision force, or by an attachment of the holders <NUM> that joins the holders <NUM> to the front cover <NUM> or to the coupler <NUM> being configured to break.

By the collision force F, the cover body <NUM> is pushed in the first direction D and the at least one deformation zones <NUM> deforms or breaks to provide access to the mechanical coupler <NUM>. Also, the cover body <NUM> is pushed against the mechanical coupler <NUM>, but due to the stepped profile and the offset of the second cover body section <NUM>, the second cover body section <NUM> does not contact the electrical coupler <NUM>. Thereby, the electrical coupler <NUM> is protected from the collision force and the mechanical coupler <NUM> serves to transmit the force into the coupler <NUM> where it may be decreased through the absorption devices acting to reversibly or non-reversibly absorbing the force.

Mounting of the front cover <NUM> on the coupler <NUM> may take place at any suitable time when the rail vehicle is not moving. The mounting comprises providing the front cover <NUM> and a coupler <NUM> on which it is to be mounted, and in order to fasten the front cover <NUM> onto the coupler <NUM> the at least one deformation zone <NUM> is aligned with a coupling connection <NUM> of the coupler <NUM> and the cover body <NUM> is fastened in a position where the deformation zone <NUM> is thus aligned.

Suitably, the at least one holder <NUM> is provided and the mounting comprises fastening the holders <NUM> to the coupler <NUM>. In some embodiments, the holders <NUM> may be provided on the coupler an be fastened to the front cover <NUM> during mounting, but it is advantageous to provide the holders <NUM> on or in connection with the front cover <NUM> so that they may be transported, handled and mounted together without relying on holders <NUM> being present in connection with the coupler <NUM>. Depending on dimensions of the coupler <NUM> on which the front cover <NUM> is to be mounted, a length of the holder <NUM> may be adjusted so that the cover body <NUM> may be held at a suitable distance from the mechanical coupler <NUM>.

In embodiments where a second cover body section <NUM> is provided, mounting suitably comprises aligning the second cover body section <NUM> with the electrical coupler <NUM> of the coupler <NUM>.

A collision between a coupler <NUM> having a front cover <NUM> mounted thereon and a second coupler <NUM> will now be described in more detail with reference to <FIG>. In the following, it is assumed that the second coupler <NUM> has the same function and design as the coupler <NUM> already described, and terms and reference numerals previously used in connection with the coupler <NUM> will therefore also be used when referring to similar or identical components of the second coupler <NUM>.

As already mentioned, a collision between two rail vehicles is a situation where significant damage may be done to the couplers and also to the rail vehicles and any goods or passengers present inside them. Also, especially in situations where one or more of the rail vehicles is/are derailed, significant damage may also occur to surrounding buildings and other structures in the vicinity. A coupler typically comprises energy absorption devices for absorbing collision forces so that the force transmitted to the rail vehicle is decreased, but in order for such devices to function as intended it is generally required that the collision force is applied to the front end of the coupler without the coupler twisting or pivoting at the front end. Otherwise, the coupler may buckle by the front end of the coupler acting as a pivot, and this prevents operation of the energy absorption devices of the coupler so that the resulting damage to the railway vehicle is significantly increased.

For this purpose among others, couplers are configured to automatically couple mechanically when brought into contact with a similar coupler. Since this provides a stable, non-pivotable connection between the couplers the front end of the coupler is no longer able to act as a pivot and the collision force is therefore transmitted in the horizontal direction through the coupler as intended. When one or both of the couplers have a front cover <NUM> mounted on its front end <NUM>, it is generally not possible for the automatic coupling to take place since a width of the front cover <NUM> will cause the couplers to be held with their front ends at a distance from each other. However, the couplers will still be able to reach a position where at least one coupling connection <NUM> of one of the couplers protrudes into an opening of the other coupler, and this will serve to limit pivoting of the front ends in relation to each other. This position where a coupling connection extends into an opening so that a front end of one coupler is held against a front end of another coupler with at least one front cover held between them, is referred so herein as a mating position and as the front ends mating.

In <FIG>, a first stage of a collision between the coupler <NUM> and a second coupler <NUM> is shown. The collision force F is also shown. In the first stage, the front cover <NUM> of the coupler <NUM> starts to deform by the coupling connection <NUM> of the second coupler <NUM> contacting the front cover <NUM> at the deformation zone <NUM>. In the first stage, the front end <NUM> acts as a first pivot P1. A second pivot P2 and a third pivot P3 are formed where the coupler <NUM> and the second coupler <NUM> each connect to their respective railway vehicle.

<FIG> discloses a second stage of the collision where the coupling connections <NUM> of the coupler <NUM> and the second coupler <NUM> have connected to each other or the protruding coupling connection has been inserted at least partially into the opening of the other coupler so that the front ends of the couplers <NUM>, <NUM> are mating. At this stage, the front end <NUM> of the coupler <NUM> contacts the front end of the second coupler <NUM> and the front cover <NUM> is held between them. The first pivot P1 is now eliminated, rendering the connection between the coupler <NUM> and the second coupler <NUM> stable, but the second pivot P2 and the third pivot P3 are still able to pivot.

In <FIG>, the second coupler <NUM> is shown with its energy absorption devices exposed in order to further elucidate the energy absorption. In a third stage, a damper <NUM>, <NUM> of each of the couplers <NUM>, <NUM> absorbs energy as commonly known in the art. In a fourth stage shown in <FIG> deformation units <NUM>, <NUM> are non-elastically deformed, causing irreversible deformation. Once all four stages have taken place, whatever collision force is left after energy absorption by the couplers <NUM>, <NUM> is finished is transferred to the railway vehicles that in turn generally comprise devices for absorbing energy.

The collision described above with reference to <FIG> shows a collision where the collision force is above the second collision threshold so that the deformation tubes <NUM>, <NUM> are activated. In collision where the force is smaller, or in situations where two couplers are coupled but the front cover <NUM> is accidentally not removed, the collision or coupling would instead comprise only the first, second and third stages. The collision force is in this event at or above the first collision threshold but below the second collision threshold. As a result of such a smaller collision or a hard coupling where a speed of one of the couplers is higher than intended, no absorption devices in the coupler is irreversibly damaged and operation of the coupler may continue without requiring maintenance. For a collision involving a collision force above the second threshold, however, repair or even replacing of the coupler is needed.

<FIG> discloses a third embodiment of the front cover <NUM>, having a cover body <NUM> that surrounds the deformation zones <NUM> but that in the mounted state does not extend to cover the front end of the coupler. This front cover <NUM> comprises one protruding cover portion <NUM> and one non-protruding cover portion <NUM> but it may alternatively comprise just one cover portion <NUM> or more than two, depending on the coupler where it is to be mounted.

<FIG> discloses an embodiment where the cover portions <NUM> are integrated with the cover body <NUM> and where a protruding cover portion <NUM> is used to cover one of the deformation zones <NUM>. The protruding cover portion <NUM> may be rendered deformable or breakable by material in the protruding cover portion <NUM> being thinner than material in the cover body <NUM> surrounding the deformation zones <NUM>, or alternatively the protruding shape as such may be sufficient to cause breakage when a collision takes place. The other deformation zone <NUM> shown in <FIG> is covered by a non-protruding cover portion <NUM> that is also integrated with the cover body <NUM>. The material of the non-protruding cover portion <NUM> is rendered deformable or breakable by creating at least one groove <NUM> to weaken the material. Suitably, as shown in <FIG> two grooves are made to intersect each other in order to cause a weakening at the intersection in particular. Grooves may be made by milling or cutting, or by any other suitable method. In some embodiments, a protruding cover portion <NUM> may also comprise at least one groove, or alternatively any cover portion <NUM> in the front cover <NUM> may comprise at least one groove.

<FIG> discloses a fourth embodiment of the front cover <NUM>, that differs from the embodiments described above by comprising at least one but suitably a plurality of protrusions <NUM> that extend from the cover body <NUM> and that are configured to match protrusions <NUM> on a similar front cover <NUM> that is mounted on another coupler. The protrusions <NUM> suitably comprise a material that is harder than the cover body <NUM> so that the protrusions deform less than the cover body <NUM> during a collision. By the protrusions <NUM> being placed to match protrusions <NUM> on an opposing front cover <NUM>, they will contact each other during the collision and hold the front covers <NUM> at a distance and aligned with each other. It is advantageous that the protrusions <NUM> extend a smaller distance from the cover body <NUM> than the protruding cover body <NUM>, in order to ensure that the mating of the couplers <NUM>, <NUM> may take place. In one embodiment, the protrusions <NUM> may suitably be placed on either side of the deformation zones <NUM> in a horizontal direction. In another embodiment, the protrusions <NUM> may instead be provided at four corners of the cover body <NUM>, and in yet another embodiment the protrusions <NUM> may be provided in a rectangle or circle around the deformation zones <NUM>.

Claim 1:
Front cover for a coupler for a rail vehicle, the front cover comprising a cover body (<NUM>) for covering a front end of the coupler, wherein the cover body (<NUM>) comprises at least one deformation zone (<NUM>), said deformation zone (<NUM>) having a cover portion (<NUM>) that is configured to break or deform when subjected to a collision force for providing access through the cover body (<NUM>) at the at least one deformation zone (<NUM>) during a collision, wherein the cover portion (<NUM>) of the at least one deformation zone (<NUM>) is integrated with the cover body (<NUM>), and characterized in that the cover portion (<NUM>) is configured to deform or break by the cover portion (<NUM>) comprising at least one groove (<NUM>).