Freight coupler and rail vehicle

Abstract

A freight coupler (100) is arranged on a first rail vehicle to interconnect the first rail vehicle with a second rail vehicle. The freight coupler (100) has outer and inner portions (110; 120). The outer portion (110) includes a first locking mechanism (115) of a coupler 5 head, which first locking mechanism (115) is configured to be connected to a second locking mechanism (1115) of a counter-coupler head of the second rail vehicle. The inner portion (120) includes a mounting structure for mounting on the first rail vehicle. At least one shear member (131) interconnects the outer and inner portions (110; 120) mechanically. The at least one shear member (131) is configured to break in response to a draft force (FD) exceeding a first threshold level, which draft force (FD) pulls the outer and inner portions (110; 120) away from one another so as to disconnect the outer and inner portions (110; 120) mechanically from one another and allow the outer portion (110) to be physically separated from the inner portion (120). The at least one shear member (131) is integrated in a mechanical interface (200) that is configured to absorb buff forces (FB) between the inner and outer portions (110; 120), which buff forces (FB) are absorbed without the at least one shear member (131) being broken, and which buff forces (FB) exceed the first threshold level.

Description

[0001] Freight Coupler and Rail Vehicle

[0002] TECHNICAL FIELD

[0003] The present invention relates generally to coupler arrangements for rail vehicles. Especially, the invention relates to a freight coupler according to the preamble of claim 1 and a rail vehicle comprising such a freight coupler.

[0004] BACKGROUND

[0005] For obvious reasons, rail traffic is surrounded by rigorous safety regulations. Inter alia, today’s freight couplers are obliged to have a release function which triggers at a particular force level to save a connected rail vehicle from excessive draft forces. For example, the release level may be at 1500 kN. However, of course, depending on the regulatory framework, any other higher or lower level may also be applied. Further, the freight coupler should preferably have a design that renders it straightforward to repair a released coupler in the field. In practice, this means that no components besides the release interface should be broken if the release function is triggered.

[0006] Below follow examples of coupler designs, some of which have a release functionality.

[0007] KR 1999 0005633 U relates to a buffer structure for a railway vehicle coupler, and a pair of donut-shaped buffer members made of rubber are installed between the rear of the body of the coupler and the fixed bracket attached to the frame to relieve tensile and compressive forces generated when a railway vehicle starts or stops, thereby reducing noise and vibration of the vehicle and absorbing shock generated when connecting vehicles. In addition, elastic vertical supports are installed on both sides of the body of the coupler to ensure that the coupler is in the correct position, and are supported by the frame, thereby helping to maintain the correct position of the coupler and facilitating the connection work between vehicles.

[0008] SE 545 564 C2 shows a coupler for a railway vehicle, where the coupler comprises a front portion with a coupler head, a rear portion with a mounting structure for mounting on a railway vehicle and a coupler shank containing a through hole having a first width. The coupler shank is arranged on a pin extending through the through hole and the pin has a second width that Is smaller than the first width of the through hole. One of the coupler shank and the pin is connected to the coupler head of the front portion and the other of the coupler shank and the pin is connected to the mounting structure of the rear portion. The coupler further includes a biasing device arranged in the through hole of the coupler shank. The biasing device is configured to bias the pin to one side of the through hole.

[0009] WO 2004 / 103790 reveals a muff coupling intended for vehicle couplers of the type that comprises two components formed with ring-shaped flanges, as well as a muff consisting of at least two arch parts tightenable against each other, each of which separately has an inner flute formed between two inwardly turned bulges. The flute is delimited by obliquely inclined side surfaces in order to, upon radial tightening of the arch parts against each other, be pressed against analogously obliquely inclined shoulder surfaces on said flanges and thereby, by wedge action, transfer axial component forces to the same with the purpose of pressing the ends of the components in close contact against each other. The arch parts are formed with double sets of bulges for cooperation with double flanges on the respective component, whereby forces that are transferred between the components via the muff are distributed to a plurality of axially spaced-apart pairs of contact surfaces in an axial train of forces near the outside of the components.

[0010] WO 2022 / 207274 discloses an automatic central buffer coupler for rail vehicles, comprising a Scharfenberg-type coupler head having a coupler head housing and having a coupling lock mechanism disposed in the coupler head housing. The coupling lock mechanism includes a main pin, a coupling hoop, a coupling hoop pin and a disk. For the safety release of a coupling connection when a response force is exceed in the tension direction, the coupling hoop pin of the coupling lock mechanism is in the form of a shear pin. The automatic central buffer coupler can be applied to all designs of couplers having a parallelogram lock mechanism of the Scharfenberg type.

[0011] US 6,499,613 describes a vehicular coupler that comprises a head for coupling to an opposed, generally identical coupling head of a vehicle for mechanically connecting two vehicles together. Such coupler includes a beam member for connecting to the underside of one of such vehicles. A housing is slidably connected to the beam member and a cushioning device is connected to the coupling head. The coupling head has a rearward extension located in the housing. Primary shear bolts or pins extend through walls of the housing and into the rearward extension of the cushioning device. Secondary shear bolts or pins extend through the beam member and into the housing. Retaining bolts are secured to the housing and have upper portions located above an upper surface of the housing. A longitudinal relief area is provided in the beam member, with the upper portions of the retaining bolts being located in the relief area. The relief area terminates at a predetermined location in the beam member to provide a ledge for engagement with and retention of the upper portions of the retaining bolts when the primary and secondary shear bolts or pins are sheared in two and the coupling head and housing are moved forwardly relative to the beam member.

[0012] Although the latter two of the above coupler designs provide a release functionality, there is room for improvements. For instance, the automatic central buffer coupler of WO 2022 / 207274 is designed such that when the link pin breaks, the hook plate will rotate, which, in turn causes the break pipe to be closed. As a result, the brakes will no longer work on both the respective parts of the rail set that is separated due to the link pin being broken. Naturally, this is unacceptable from a safety point of view.

[0013] The coupler head of US 6,499,613 includes primary and secondary collision release mechanisms in the form shear bolts. However, there is no additional mechanism, which is specifically adapted to absorb buff forces. Thus, the release mechanisms will be released at buff and draft forces being equally large. Clearly, this is an undesired limitation.

[0014] SUMMARY

[0015] The object of the present invention is therefore to offer an improved solution that solves the above problems.

[0016] According to one aspect of the invention, the object is achieved by a freight coupler that is adapted to be arranged on a first rail vehicle to interconnect the first rail vehicle with a second rail vehicle. The freight coupler includes outer and inner portions and at least one shear member, which interconnects the outer and inner portions mechanically. The outer portion contains a first locking mechanism of a coupler head, which first locking mechanism is configured to be connected to a second locking mechanism of a counter-coupler head of the second rail vehicle. The inner portion contains a mounting structure for mounting on the first rail vehicle. The at least one shear member is configured to break in response to a draft force pulling the outer and inner portions away from one another so as to disconnect the outer and inner portions mechanically from one another and allow the outer portion to be physically separated from the inner portion. The draft force here exceeds a first threshold level. Specifically, the at least one shear member is integrated in a mechanical interface that is configured to absorb buff forces between the inner and outer portions. The buff forces are absorbed without the at least one shear member being broken even if the buff forces exceed the first threshold level. In other words, the freight coupler may absorb larger buff forces that the draft forces required to break the at least one shear member.

[0017] The above freight coupler is advantageous because it enables setting the draft force break level independent from the buff force resistance. Moreover, it is straightforward to arrange a set of shear members, such that it is ensured that exclusively these components break in response to any excessive draft forces.

[0018] Moreover, in particular compared to the design of WO 2022 / 207274, the freight coupler according to the invention is more easy to repair in the event that the freight coupler has been subject to draft forces above the first threshold level. Namely, replacing parts of the locking mechanism may be problematic, especially parts inside a coupling housing.

[0019] Preferably, the first threshold level at which the shear members are designed to break is in the range of 1300 kN to 1700 kN. Namely, thereby, the release requirements of many of today’s standards may be met.

[0020] It is further advantageous if the mechanical interface is configured to absorb the buff forces at a magnitude being at least 25 % above the first threshold level, i.e. at least in the order of 1625 kN to 2125 kN.

[0021] According to one embodiment of this aspect of the invention, the at least one shear member extends into at least one wall of at least one of the outer and inner portions. For example, one or more of the shear members may extend through one of the outer and inner portions and into the other of said portions. Optionally, at least one shear member may extend through both the outer and inner portions. As another option, the mechanical interface may include at least one bridging member that is arranged to connect the outer portion mechanically to the inner portion, wherein at least a first one of the at least one shear member extends through the at least one bridging member and into the outer portion and at least a second one of the at least one shear member extends through the at least one bridging member and into the inner por- tion . Thus, there is a large degree of design freedom with respect to the exact interconnection of the outer and inner portions in the proposed mechanical interface.

[0022] According to another embodiment of this aspect of the invention, the mechanical interface divides an overall length of the freight coupler into first and second lengths. Here, the first length represents an extension of the outer portion between a coupling contact face of the first locking mechanism and the at least one shear member. The coupling contact face is arranged to be connected to the counter-coupler head. The second length represents an extension of the inner portion between the at least one shear member and an innermost part of the mounting structure facing the first rail vehicle when the freight coupler is mounted thereon. The first length is shorter than or equal to the second length.

[0023] Thereby, the overall length of the unreleased coupler half of the coupler pair becomes relatively short. As a result, the risk of so- called “pole vaulting” is reduced, i.e. the risk that the unreleased coupler half makes contact with the sleepers and / or the ballast there between in front of the vehicle causing the entire vehicle to raise and possibly derail.

[0024] According to yet another embodiment of this aspect of the invention, the mechanical interface includes at least one first contact surface that forms part of the outer portion and at least one second contact surface that forms part of the inner portion. One of the at least one first and second contact surfaces is comprised in a male connection member, and the other one is comprised in a female connection member. Further, the at least one first and second contact surfaces are configured to contact one another mechanically when the freight coupler is subjected to the buff forces. Consequently, the mechanical interface may be designed to absorb large buff forces without being deformed or damaging the at least one shear member.

[0025] According to still another embodiment of this aspect of the inven- tion , the at least one shear member connects the male and female connection members mechanically to one another.

[0026] According to yet another embodiment of this aspect of the invention, the at least one shear member includes a break section that is configured to be torn off if the draft force exceeds the first threshold level, or a predefined fraction thereof depending on the number of shear members. For example, each shear member may be represented by a bolt, where the break section is a portion with a somewhat lower material thickness and / or segment made of a material with a lower strength than the rest of the bolt.

[0027] According to another embodiment of this aspect of the invention, the mechanical interface is included in a coupler shank between the outer and inner portions. According to embodiments of the invention, the coupler shank, in turn, may either have a rectangular shaped cross-section profile, or include a cross-section profile of an overall rounded shape. Thus, the design may be integrated into a wide range of freight couplers on the market.

[0028] According to yet another embodiment of this aspect of the invention, the at least one shear member includes a pin that has a symmetry axis arranged orthogonal to a longitudinal direction of the freight coupler, and the break section contains a first waist section adapted to shear off the pin into two pieces if the pin is subjected to a predetermined shear force parallel to the longitudinal direction. Alternatively, or in addition thereto, at least one of the at least one shear member may include a bolt that has a symmetry axis arranged parallel to a longitudinal direction of the freight coupler, and the break section contains a second waist section adapted to tension break if the bolt is subjected to a predetermined tension force parallel to the longitudinal direction. In other words, the mechanical interface may contain shear members being oriented parallel with the draft forces exerted on the freight coupler as well as shear members being oriented perpendicular thereto. According to embodiments of this aspect of the invention, the mechanical interface includes at least one visual indicator configured to indicate that at least one of the at least one shear member has been subjected to an excessive tension force, which has caused said at least one shear member to be deformed to an extent that has allowed the outer and inner portions to be shifted relative to one another in a longitudinal direction of the freight coupler. Thus, by studying the at least one visual indicator it may readily be noted if the freight coupler has experienced such a draft force that at least one of the at least one shear member has been severely damaged and needs to be replaced even though the outer and inner portions may not have been disconnected from one another. Of course, this is highly desired from a safety point-of-view.

[0029] For example, the at least one visual indicator may contain a surface coating that covers at least one segment of a surface zone between the inner and outer portions, where the surface zone bridges over first and second contact surfaces that are arranged to be separated by a distance from one another if the at least one shear member is subjected to the excessive tension force thus causing the surface coating to break. Hence, a broken surface coating indicates that at least one of the shear members or the entire freight coupler must be replaced.

[0030] Alternatively, the at least one visual indicator may contain an attachment device that is inserted and clamped in a spacing between first and second contact surfaces, where the first contact surface forms part of the outer portion and the second contact surface forms part of the inner portion. The first and second contact surfaces are here arranged to be separated by a distance from one another if the at least one shear member is subjected to the excessive tension so that the attachment device is allowed to leave the spacing between the first and second contact surfaces. The attachment device is advantageous because it is useful as a visual indicator also if the freight coupler is heavily soiled. According to one embodiment of this aspect of the invention, the first locking mechanism includes a pneumatic interface configured to be in fluid contact with a pneumatically operated brake system external to the first rail vehicle via the second locking mechanism of the counter-coupler head. Thus, for example, parking, service and / or emergency braking functionality may be transferred between the first and second rail vehicles.

[0031] Moreover, via the counter-coupler head, the freight coupler may include an electric interface configured to be in galvanic contact with an electrical system external to the first rail vehicle. As a result, for example electric power and / or electric signals may be transferred between the first and second rail vehicles.

[0032] As will be discussed below, the pneumatic interface is typically linked to the emergency braking functionality, such that if the pneumatic pressure level falls below a threshold value, this automatically results in emergency braking. Therefore, should the at least one shear member break and cause the outer and inner portions of the freight coupler to be disconnected from one another, this would also lead to that the pneumatic conduits in the coupler head are torn off and emergency braking being activated.

[0033] According to still another embodiment of this aspect of the invention, the mounting structure comprises a first pivot joint member configured to form a pivot joint connection with a second pivot joint member of a vehicle-carried mounting structure on the first rail vehicle. Consequently, the freight coupler is pivotable in relation to the first rail vehicle, preferably at least in a horizontal plane.

[0034] According to another aspect of the invention, the object is achieved by a rail vehicle including the proposed freight coupler. The advantages of this rail vehicle are apparent from the discussion above with reference to the proposed freight coupler.

[0035] Further advantages, beneficial features and applications of the present invention will be apparent from the following description and the dependent claims.

[0036] BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The invention is now to be explained more closely by means of preferred embodiments, which are disclosed as examples, and with reference to the attached drawings.

[0038] Figures 1 - 2 show a freight coupler according to one embodiment of the invention in respective states, wherein outer and inner portions of the freight coupler are connected to and disconnected from one another;

[0039] Figure 3 illustrates in a mechanical interface according to one embodiment of the invention, which mechanical interface interconnects the inner and outer portions of the freight coupler;

[0040] Figure 4 illustrates a shear member according to one embodiment of the invention;

[0041] Figures 5 - 9 illustrate how the mechanical interface may be implemented according to embodiments of the invention;

[0042] Figure 10 shows a mounting structure according to one embodiment of the invention;

[0043] Figure 1 1 illustrates how the outer portion may be disconnected from the inner portion of the proposed freight coupler according to one embodiment of the invention; and

[0044] Figures 12-13 illustrate how a visual indicator according to embodiments of the invention.

[0045] DETAILED DESCRIPTION

[0046] Figure 1 shows a freight coupler 100 according to one embodiment of the invention, which freight coupler 100 is adapted to be arranged on a first rail vehicle to interconnect the first rail vehicle with a second rail vehicle. The freight coupler 100 includes an outer portion 110 and an inner portion 120, which are mechanically interconnected via at least one shear member, exemplified by 131 and 132 in Figure 1. Figure 2 shows the freight coupler 100 of Figure 1 in a state where the outer and inner portions 1 10 and 120 respectively are disconnected from one another.

[0047] The freight coupler 100 comprises a coupler head. The outer portion 1 10 contains a first locking mechanism 115 of the coupler head, which first locking mechanism 115 is configured to be connected to a second locking mechanism of a counter-coupler head of the second rail vehicle, such that the first and second rail vehicles form part of a common multi-membered rail vehicle, e.g. a train set. The inner portion 120 has a mounting structure 125 for mounting on the first rail vehicle, for instance via a pivot joint, here exemplified by a first pivot joint member 123 in the form of a roller, which is adapted to connect to a second pivot joint member in the form of a pin.

[0048] According to embodiments of the invention, the shear members 131 and 132 may connect the outer portion 110 mechanically to the inner portion 120 as illustrated in Figures 1 and 2, i.e. by a portion of each shear member 131 and 132 extending through at least one wall of the inner portion 120 and further into at least one wall of the outer portion 110. Each of the shear members 131 and 132 is configured to break in response to a predefined draft force. Especially, a combined strength of the shear members that interconnect the outer and inner portions 1 10 and 120 is such that if a draft force FD that exceeds a first threshold level pulls the outer and inner portions 110 and 120 away from one another will cause the shear members to break, so as to disconnect the outer and inner portions 110 and 120 mechanically from one another and thus allow the outer portion 110 to be physically separated from the inner portion 120 as illustrated in Figure 2. The first threshold level is preferably in the range of 1300 kN to 1700 kN, and more preferably around 1500 kN. However, of course, technically it is possible to design the shear members 131 and 132 to break in response to a draft force F D at any alternative magnitude above 1700 kN or below 1300 kN.

[0049] According to the invention, the shear members 131 and 132 are integrated in a mechanical interface 200, the design of which is exemplified in Figures 3 and 5 to 7. The mechanical interface 200 is configured to absorb buff forces F B between the inner and outer portions 110 and 120, such that the buff forces F B exceeding the first threshold level are absorbed without the shear member 131 or 132 being broken. Preferably, the mechanical interface 200 is configured to absorb the buff forces FB at a magnitude being at least 25 % above the first threshold level. Hence, if the first threshold level is around 1500 kN, the mechanical interface 200 is capable of absorbing buff forces F B of at least 1875 kN. Analogously, if the first threshold level is around 1300 kN, the mechanical interface 200 is capable of absorbing buff forces F B up to at least 1625 kN; and if the first threshold level is around 1700 kN, the mechanical interface 200 is capable of absorbing buff forces F B up to at least 2125 kN.

[0050] The coupler head may be of Scharfenberg™ type, for example as defined in the European Standard EN 16019 for so-called Type 10 automatic couplers for railway applications. In such a case, the first locking mechanism 1 15 contains at least one coupling link, one coupling link pin, one main pin, a hook plate and a coupler face, which, in turn, includes a male cone, a female cone and preferably a pneumatic interface.

[0051] According to embodiments of the invention, also other types of coupler heads are envisioned, such as a SA3 (Soviet Auto-latch 3), which are also known as CA3, CA-3 or Willison coupler heads. The Janney coupler head is yet another option. This coupler head is also known under the names knuckle or tightlock coupler head and is typically used on North American mainline passenger rail cars. In case of an SA3 type of coupler head, the locking mechanism includes at least one pulling jaw, one buffing jaw, a recess and a movable lock, for example as shown in US 2,825,473. In case of a Janney type of coupler head, the locking mechanism comprises at least one knuckle, one knuckle pin, a thrower, a lock and a locklift, for example as disclosed in US 201 1 / 168655.

[0052] For coupler heads of Sharfenberg™ type as well as those of SA3- or Janney-types, the expression locking mechanism should be understood as the parts or components of the coupler which mechanically locks the coupler with a counter-coupler and components which are in contact with a counter-coupler in a locked state.

[0053] Figure 3 illustrates in the mechanical interface 200 according to one embodiment of the invention. The mechanical interface 200 here contains two bridging members 311 and 312 respectively, which are arranged to connect the outer portion 110 mechanically to the inner portion 120. Of course, any number of bridging members from one and up are equally well conceivable.

[0054] A first shear member 301 extends through the bridging member

[0055] 311 and into the outer portion 110. A second shear member 302 extends through the bridging member 31 1 and into the inner portion 120. Analogously, a third shear member 303 extends through the bridging member 312 and into the inner portion 120, and a fourth shear member 304 extends through the bridging member

[0056] 312 and into the outer portion 110. In response to the draft force FD, exceeding the first threshold level and pulling the outer and inner portions 110 and 120 away from one another the shear members 301 , 302, 303 and 304 will break. As a result, the outer and inner portions 110 and 120 will be mechanically disconnected from one another, and the outer portionl 10 is allowed to be physically separated from the inner portion 120.

[0057] Figure 4 illustrates the details of a shear member according to one embodiment of the invention, for instance 131 depicted in Figures 1 and 2. However, the shear members 301 , 302, 303 and 304 may also be designed as shown in Figure 4.

[0058] The shear member 131 either extends into a wall of one of the outer and inner portions 110 and 120 respectively, for example as illustrated in Figure 3; or into a respective wall of each of the outer and inner portions 110 and 120 respectively, for example as illustrated in Figures 1 , 2 and 4.

[0059] The shear member 131 may be embodied as a bolt with a head portion 131 h and have a symmetry axis A1 arranged orthogonal to a longitudinal direction A of the freight coupler 100 (c.f. Figure 5). The shear member 131 may include a central pin 131 p extending along the symmetry axis A1 . The pin 131 p, in turn, may contain first and second sections 401 and 402 respectively that are divided by a break section 421w, e.g. embodied as a waist, where the pin 131 p is configured to be torn off into two pieces 401 and 402, if the draft force exceeds a predefined threshold level that represents a fraction of the first threshold level, where said fraction equals the total number of shear members. The central portion 131 p may be arranged with the break section 421w positioned in level with a division between the outer and inner portions 1 10 and 120, as illustrated in Figure 4. Alternatively, the central portion 131 p may be arranged with the break section 421 w positioned in level with a respective division between one of the outer and inner portions 110 and 120 and the bridging members 311 and 312, as illustrated in Figure 3.

[0060] Moreover, the shear member 131 preferably has a threaded portion 1311 adapted to be screw fastened in at least one of said walls, e.g. 420 of the inner portion 120.

[0061] Returning now to Figure 2, according to embodiments of the invention, the mechanical interface 200 is comprised in a coupler shank 420 between the outer and inner portions 1 10 and 120.

[0062] Additionally, the mechanical interface 200 may include at least one first contact surface 210 that forms part of the outer portion 110 and at least one second contact surface 220 that forms part of the inner portion 120. One of these contact surfaces, e.g. 210, is comprised in a male connection member, and the other one, e.g. 220, is comprised in a female connection member. When the freight coupler 100 is subjected to the buff forces FB, the at least one first and second contact surfaces 210 and 220 are configured to contact one another mechanically in such a manner that essentially no mechanical stress is exerted on the shear members 131 and 132 respectively. Hence, provided that the at least one first and second contact surfaces 210 and 220 and the male and female connection members including these surfaces are sufficiently resistant to mechanical compression, the freight coupler 100 may withstand buff forces FB at magnitudes being substantially higher than the first threshold level, and preferably at least 25 % above this level.

[0063] Figures 5 to 7 illustrate different examples of how the mechanical interface 200 may be designed according to embodiments of the invention. Here, Figures 5 and 6 show a design equivalent to the design of Figures 1 and 2. In addition to the latter, Figure 5 shows another shear member in the form of 134 located opposite to the shear member 132. As apparent from the figures, the above-mentioned male connection member is included in the outer portion 110 in Figures 1 , 2, 5 and 6.

[0064] Here, a coupling contact face of the first locking mechanism 1 15 is arranged to be connected to the counter-coupler head 1115 (c.f. Figure 11 ). The mechanical interface 200 divides an overall length L of the freight coupler 100 into first and second lengths L1 and L2 respectively, where the first length L1 represents an extension of the outer portion 1 10 between the coupling contact face and the shear members 132 and 134. The second length L2 represents an extension of the inner portion 120 between the shear members 132 and 134 and an innermost part of the mounting structure 125 that faces the first rail vehicle when the freight coupler 100 is mounted thereon. Preferably, the first length L1 is shorter than or equal to the second length L2. Namely, in such a case, if the outer portion and inner portions 1 10 and 120 are torn apart by an excessive draft force FD, the overall length of the unreleased coupler half of the coupler pair becomes relatively short. As a result, the risk of so-called “pole vaulting” is reduced, i.e. the risk that the unreleased coupler half makes contact within the sleepers and / or the ballast there between in front of the vehicle causing the entire vehicle to raise and possibly derail.

[0065] Figure 7 illustrates one embodiment of the invention where the female connection member is included in the outer portion 110. This renders it possible to make the outer portion 1 10 even shorter, which, further reduces the risk of “pole vaulting” discussed above.

[0066] Figures 8 and 9 illustrate how the mechanical interface may be designed according to another embodiment of the invention. Here, the coupler shank 820 in which the mechanical interface 200 is comprised, has a cross-section profile of an overall rounded shape, such a circular cross-section profile.

[0067] As is apparent from the previous figures, the coupler shank 420 may also have a rectangular shaped cross-section profile. Naturally, according to the invention, any other shape of the crosssection profile is likewise conceivable, e.g. various kinds of polygonal shapes.

[0068] Preferably, the mechanical interface 200 comprised in the coupler shank 420 has a cross-section profile, which is non-circular because thereby, the coupler may resist torsion forces to a higher degree.

[0069] The coupler shank 820 shown in Figures 8 and 9 has a mechanical interface 200 with shear members, 831 , 832, 833, 834, 835 and 836 respectively, e.g. in the form of bolts, which each includes a break section 831w configured to be torn off if the draft force FD exceeds a predefined threshold level. In contrast to the above-described embodiments, the break section 831w is adapted to be torn off through tensile force, i.e. a force directed parallel with a symmetry axis A2 of the bolt. Thus, the symmetry axis A2 of each bolt is parallel with the longitudinal direction A of the freight coupler 100. For instance if the shear member 831 is embodied as a bolt, in addition to a threaded section, the bolt may include a break section 831w in the form of a second waist section, which is adapted to tension break if the bolt is subjected to a predetermined tension force parallel to the longitudinal direction A of the freight coupler 100.

[0070] According to the invention, regardless of the shape of the crosssection profile of the coupler shank, the shear members may be arranged with their symmetry axes parallel with the longitudinal direction A of the freight coupler 100 or orthogonal thereto.

[0071] Further, it is generally advantageous if the freight coupler 100 has such an overall outline that the mechanical interface 200 and the mounting structure 125 are at least partially arranged in a common horizontal plane, which extends along the longitudinal direction A of the freight coupler 100 and is parallel to the ground when the freight coupler 100 is mounted on the first vehicle and coupled to a counter-coupler.

[0072] Similar to the above embodiments, the mechanical interface 200 may include at least one first contact surface 811 that forms part of the outer portion 810 and at least one second contact surface 821 and 822 that forms part of the inner portion 820 of the freight coupler 100. One of the at least one first and second contact surfaces is comprised in a male connection member, and the other one of the at least one first and second contact surfaces is comprised in a female connection member. In the example illustrated in Figures 8 and 9, the first contact surfaces 811 is included in the male connection member and the second contact surfaces 821 and 822 are included in the female connection member. Of course, the reverse relationship is also possible, and, in fact, a more preferable alternative considering the “pole vaulting” aspect.

[0073] In any case, analogous to the above, the at least one first and second contact surfaces are configured to contact one another mechanically when the freight coupler 100 is subjected to the buff forces FB, such that the buff forces FB have no more than an insignificant influence on the shear members, 831 , 832, 833, 834, 835 and 836.

[0074] Figures 12 and 13 illustrate examples of a visual indicator according to two embodiments of the invention. Here, at least one visual indicator is included in the mechanical interface 200, which visual indicator is configured to indicate that at least one of the shear members has been subjected to an excessive tension force. The excessive tension force is presumed to be of such magnitude that it has caused the shear member in question to be deformed to an extent that it has allowed the outer and inner portions 110 and 120 respectively to be shifted relative to one another in the longitudinal direction A of the freight coupler 100.

[0075] Specifically, in the embodiment of Figure 12, the visual indicator is configured to indicate that for example the shear member 835 has been subjected to the excessive tension force. The visual indicator here includes an attachment device 1210 that is inserted and clamped in a spacing between first and second contact surfaces, say 811 and 822, where the first contact surface 811 forms part of the outer portion 810 of the freight coupler 100 and the second contact surface 822 forms part of the inner portion 820 of the freight coupler 100. The first and second contact surfaces 811 and 822 respectively are arranged to be separated by a distance from one another if the shear member 835 is subjected to the excessive tension force. As a result, the attachment device 1210 is allowed to leave the spacing between the first and second contact surfaces 811 and 822, for instance under the influence of gravity, and / or due to vibrations. Hence, preferably, at least one attachment device 1210 is arranged to point downwards as shown in Figure 12. For enhanced visibility, it is further advantageous if the attachment device 1210 is secured to the freight coupler 100 via a wire 1215 or similar connection means.

[0076] In the embodiment shown in Figure 13, the visual indicator inclu- des a surface coating 1310, for instance in the form of an adhesive film or paint that covers at least one segment of a surface zone Z between the inner and outer portions 820 and 810 of the freight coupler 100. The surface zone Z bridges over first and second contact surfaces, say 81 1 and 822, that are arranged to be separated by a distance from one another if at least one of the shear member 831 , 832, 833, 834 and / or 836 is subjected to the excessive tension force, and, as a result, causes the surface coating 1310 to break. Consequently, the fact that the surface coating 1310 is broken signals that the freight coupler 100 is damaged and should either be replaced or repaired prior to use.

[0077] Referring now to Figures 9 and 10, the inner portion 810 of the freight coupler 100 preferably also contains a mounting structure 925 with a first pivot joint member 923 configured to form a pivot joint connection with a second pivot joint member 1023 of a vehicle-carried mounting structure 1000 on the first rail vehicle.

[0078] According to embodiments of the invention, the inner portion 110 of the freight coupler 100 illustrated in Figures 1 , 2 and 5 to 7 may likewise include the mounting structure 125 with a first pivot joint member 123 configured to form a pivot joint connection with the second pivot joint member 1023 of the vehicle-carried mounting structure 1000 on the first rail vehicle

[0079] Figure 1 1 illustrates how the outer portion 110 may be disconnected from the inner portion 120 of the freight coupler 100 according to one embodiment of the invention.

[0080] As mentioned initially, the first rail vehicle that carries the proposed freight coupler 100 is typically equipped with a pneumatically operated brake system, which is common for all the rail vehicles that are included in same multi-membered rail vehicle. To enable this, the first locking mechanism 115 may include a pneumatic interface 1140, which is configured to be in fluid contact with an external pneumatic system via the second locking mechanism 11 15 of the counter-coupler head, i.e. the pneumatically operated brake system being common for the entire multi-membered rail vehicle.

[0081] Typically, the multi-membered rail vehicle also has common electricity and signalling systems. To this end, the freight coupler 100 may include an electric interface 1150, which is configured to be in galvanic contact with an electrical system external to the first rail vehicle via the counter-coupler head. Further, an additional interface (not shown) may be included in the freight coupler 100, which additional interface is implemented via one or more optical fibers configured to communicate data on an optical format.

[0082] Should, for some reason, an excessive draft force F D pull the outer and inner portions 110 and 120 apart, such that the at least one shear member breaks and the outer and inner portions 110 and 120 are physically separated from one another, this will also result in that the communication between the pneumatic and electrical interfaces 1140 and 1150 over the first and second locking mechanisms 1 15 and 1115 are broken. For example at least one pneumatic cable 1141 may be torn off and a plug 1151 c of an electrical cable 1151 may be pulled out. This, in turn, will cause a disruption of the electrical system in the multi-membered rail vehicle; and more important, lead to a pressure drop in the pneumatically operated brake system. The latter will trigger emergency braking in all the rail vehicles of the multi-membered rail vehicle, i.e. also any parts thereof that have been separated due to the fact that the mechanical interface 200 was released. Naturally, for general safety reasons, this is a highly desired effect.

[0083] For all above described embodiments, contact between the first contact surfaces 210 and 811 and the second contact surfaces 220, 821 and 821 are at least partly at the outer periphery of the respective inner and outer portions 120, 110, respectively. Thereby the mechanical interface 200 may be designed to withstand higher buff forces, due to relatively larger contact area. For all above described embodiments, the first contact surfaces 210 and 811 and the second contact surfaces 220, 821 and 821 are preferably arranged in a plane perpendicular to or substantially perpendicular to the longitudinal direction A of the freight coupler 100.

[0084] For all above described embodiments, the mechanical interface 200 further is arranged such that the male and female connection member of the respective inner and outer portion 120, 110 each comprises one or more guiding surfaces. Said guiding surfaces extend along or parallel to the longitudinal direction A of the freight coupler 100, as shown in Figure 3 and Figures 5 to 8. Such guide surfaces increase the stiffness of the coupler in case of side forces. Moreover, the shear member or members 132, 134 may extend through such guide surfaces, as can be seen in Figures 5 to 7.

[0085] For all above described embodiments, the guiding surface or surfaces provided on the male connection member is facing away from the longitudinal direction A or axis of the freight coupler 100, and the guiding surface or surfaces provided on the female connection member is facing towards the longitudinal direction A or axis of the freight coupler 100. Since the one of the at least one first and second contact surfaces being comprised in a male connection member, and the other one of the at least one first and second contact surfaces being comprised in a female connection member, the inner and outer portions 120, 1 10 partly overlaps longitudinally, i.e. along the longitudinal direction A or axis of the freight coupler 100. Said longitudinal overlap is preferably at least 50 mm, even more preferably at least 100 mm. Preferably, the guiding surfaces extend completely or along at least 50 % of said longitudinal overlap. Thereby, the stiffness of the coupler 100 can be increased.

[0086] The guiding surfaces provided on the inner and outer portions 120, 110 may be in contact, as shown in Figures 5 to 8. Alternatively, as shown In Figure 3, a relatively small gap may be provided between these guiding surfaces. Such a gap is preferably less than 1 mm, even more preferably less than 0.5 mm. Said guiding surfaces are shown by horizontal lines in Figure 3 and Figures 5 to 8.

[0087] 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.

[0088] Moreover, in the disclosure the term “shear member” should be understood to cover any kind of “break member,” especially those types of break members that are configured to break if they are subjected to a predetermined shear or tensile force.

[0089] The term “comprises / comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components. The term does not preclude the presence or addition of one or more additional elements, features, integers, steps or components or groups thereof. The indefinite article "a" or "an" does not exclude a plurality. In the claims, the word “or” is not to be interpreted as an exclusive or (sometimes referred to as “XOR”). On the contrary, expressions such as “A or B” covers all the cases “A and not B”, “B and not A” and “A and B”, unless otherwise indicated. 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.

[0090] It is also to be noted that features from the various embodiments described herein may freely be combined, unless it is explicitly stated that such a combination would be unsuitable.

[0091] The invention is not restricted to the described embodiments in the figures, but may be varied freely within the scope of the claims.

Claims

Claims1 . A freight coupler (100) adapted to be arranged on a first rail vehicle to interconnect the first rail vehicle with a second rail vehicle, the freight coupler comprising: an outer portion (110) comprising a first locking mechanism (115) of a coupler head, which first locking mechanism (1 15) is configured to be connected to a second locking mechanism (1115) of a counter-coupler head of the second rail vehicle, an inner portion (120) comprising a mounting structure (125) for mounting on the first rail vehicle, and at least one shear member (131 , 132, 133, 134; 301 , 302, 303, 304; 831 , 832, 833, 834, 835, 836) mechanically interconnecting the outer and inner portions (110; 120), which at least one shear member is configured to break in response to a draft force (FD) pulling the outer and inner portions (110; 120) away from one another so as to disconnect the outer and inner portions (110; 120) mechanically from one another and allow the outer portion (110) to be physically separated from the inner portion (120), which draft force (FD) exceeds a first threshold level, characterized in that the at least one shear member (131 , 132, 133, 134; 301 , 302, 303, 304; 831 , 832, 833, 834, 835, 836) is integrated in a mechanical interface (200) that is configured to absorb buff forces (FB) between the inner and outer portions (110; 120), which buff forces (FB) are absorbed without the at least one shear member (131 , 132, 133, 134; 831 , 832, 833, 834, 835, 836) being broken, and which buff forces (FB) exceed the first threshold level.

2. The freight coupler (100) according to claim 1 , wherein the first threshold level is in the range 1300 kN to 1700 kN.

3. The freight coupler (100) according to any one of claims 1 or 2, wherein the at least one shear member (131 , 132, 133, 134; 301 , 302, 303, 304; 831 , 832, 833, 834, 835, 836) extends into at least one wall (410, 420) of at least one of the outer and inner portions (110; 120).

4. The freight coupler (100) according to any of the preceding claims, wherein the mechanical interface (200) comprises at least one bridging member (311 , 312) arranged to connect the outer portion (110) mechanically to the inner portion (120), wherein at least a first one of the at least one shear member (301 , 304) extends through the at least one bridging member (31 1 , 312) and into the outer portion (1 10), and at least a second one of the at least one shear member (302, 303) extends through the at least one bridging member (311 , 312) and into the inner portion (120).

5. The freight coupler (100) according to any one of the preceding claims, wherein the mechanical interface (200) is configured to absorb the buff forces (FB) at a magnitude being at least 25 % above the first threshold level.

6. The freight coupler (100) according to any one of the preceding claims, wherein the mechanical interface (200) divides an overall length (L) of the freight coupler into first and second lengths (L1 , L2), wherein: the first length (L1 ) represents an extension of the outer portion (1 10) between a coupling contact face of the first locking mechanism (115) and the at least one shear member (131 , 132, 133, 134; 301 , 302, 303, 304; 831 , 832, 833, 834, 835, 836), which coupling contact face is arranged to be connected to the counter-coupler head, and the second length (L2) represents an extension of the inner portion (120) between the at least one shear member (131 , 132, 133, 134; 301 , 302, 303, 304; 831 , 832, 833, 834, 835, 836) and an innermost part of the mounting structure (125), which innermost part faces the first rail vehicle when the freight coupler is mounted thereon, and the first length (L1 ) is shorter than or equal to the second length (L2).

7. The freight coupler (100) according to any one of the preceding claims, wherein the mechanical interface (200) comprises at least one first contact surface (210; 811 ) forming part of the outerportion (1 10; 810) and at least one second contact surface (220; 821 , 822) forming part of the inner portion (120; 820), one of the at least one first and second contact surfaces being comprised in a male connection member, the other one of the at least one first and second contact surfaces being comprised in a female connection member, and the at least one first and second contact surfaces being configured to contact one another mechanically when the freight coupler is subjected to the buff forces (FB).

8. The freight coupler (100) according to claim 7, wherein the at least one shear member (131 , 132, 133, 134; 301 , 302, 303, 304; 831 , 832, 833, 834, 835, 836) connects the male and female connection members mechanically to one another.

9. The freight coupler (100) according to any one of the preceding claims, wherein the at least one shear member (131 , 132, 133, 134; 301 , 302, 303, 304; 831 , 832, 833, 834, 835, 836) comprises a break section (421w, 831w) configured to be torn off if the draft force (FD) exceeds the first threshold level.

10. The freight coupler (100) according to any one of the preceding claims, wherein the mechanical interface (200) is comprised in a coupler shank (420) between the outer and inner portions (110, 120).11 . The freight coupler (100) according to claim 10, wherein the coupler shank (420) has a rectangular shaped cross-section profile.

12. The freight coupler (100) according to claim 10, wherein the coupler shank has a cross-section profile of an overall rounded shape.

13. The freight coupler (100) according to any one of the preceding claims, wherein the at least one shear member (131 ) comprises a pin (131 p) that has a symmetry axis (A1 ) arranged ortho-gonal to a longitudinal direction (A) of the freight coupler, and the break section (421w) comprises a first waist section adapted to shear off the pin (131 p) into two pieces (401 , 402) if the pin (131 p) is subjected to a predetermined shear force parallel to the longitudinal direction (A).

14. The freight coupler (100) to any one of the preceding claims, wherein at least one of the at least one shear member (831 ) comprises a bolt that has a symmetry axis (A2) arranged parallel to a longitudinal direction (A) of the freight coupler, and the break section (831w) comprises a second waist section adapted to tension break if the bolt is subjected to a predetermined tension force parallel to the longitudinal direction (A).

15. The freight coupler (100) according to claim 14, wherein the mechanical interface (200) comprises at least one visual indicator (1210, 1310) configured to indicate that at least one of the at least one shear member (835) has been subjected to an excessive tension force having caused said at least one shear member (835) to be deformed to an extent that has allowed the outer and inner portions (110; 120) to be shifted relative to one another in a longitudinal direction (A) of the freight coupler (100).

16. The freight coupler (100) according to claim 15, wherein the at least one visual indicator comprises an attachment device (1210) inserted and clamped in a spacing between first and second contact surfaces (81 1 ; 821 , 822), which first contact surface (811 ) forms part of the outer portion (810), which second contact surface (821 , 822) forms part of the inner portion (820) and which first and second contact surfaces (81 1 ; 821 , 822) are arranged to be separated by a distance from one another if said at least one shear member (831 ) is subjected to the excessive tension force thus allowing the attachment device (1210) to leave the spacing between the first and second contact surfaces (811 ; 821 , 822).

17. The freight coupler (100) according to claim 15, wherein theat least one visual indicator comprises a surface coating (1310) covering at least one segment of a surface zone (Z) between the inner and outer portions (820; 810), which surface zone (Z) bridges over first and second contact surfaces (811 ; 821 , 822) that are arranged to be separated by a distance from one another if said at least one shear member (831 , 832, 833, 834, 836) is subjected to the excessive tension force thus causing the surface coating (1310) to break.

18. The freight coupler (100) according to any one of the preceding claims, wherein the first locking mechanism (115) comprises a pneumatic interface (1 140) configured to be in fluid contact with a pneumatically operated brake system external to the first rail vehicle via the second locking mechanism (1 115) of the countercoupler head.

19. The freight coupler (100) according to any one of the preceding claims, comprising an electric interface (1 150) configured to be in galvanic contact with an electrical system external to the first rail vehicle the counter-coupler head.

20. The freight coupler (100) according to any one of the preceding claims, wherein the mounting structure (125; 925) comprises a first pivot joint member (123; 923) configured to form a pivot joint connection with a second pivot joint member (1023) of a vehicle-carried mounting structure (1000) on the first rail vehicle.21 . A rail vehicle (1 100) comprising the freight coupler (100) according to any one of the preceding claims.

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