CONTAINER

The present invention is directed to a freight container comprising a plurality of walls forming at least one of a side wall, a floor or a roof of said container, said container comprising an attachment point arranged for receiving an attachment element of a lifting device for lifting said container, and an impact portion in at least one of said walls proximal to said attachment point for protecting said at least one wall in use against damage by accidental impact of said attachment element.

To enable efficient supply chain systems to be implemented, freight containers are preferably of a standard size. Types of freight containers may vary according to their application, but include nominal 20 and 40 foot ISO containers and 10, 25, 30, 45, 48, and 53 foot containers and SWAP bodies and NON ISO

shipping/freight containers for conveyance of goods by road, rail and/or sea.

Freight containers must be designed to be sufficiently robust to be resistant against rough conditions, e.g. during handling and transportation. The ISO container standards provide minimum structural properties relating to the strength of the walls, roof and floor. Rigidity and weatherproofing standards are also set. The standards ensure that the containers are suitable for purpose as freight, shipping or cargo containers. The subject matter of the present document may be applied to standardized freight containers, although application is not limited thereto and also provides benefits if applied to non-standardized freight containers.

Heretofore, freight or shipping containers generally have used a metal framework with composition board (usually steel or aluminium sheathed) or other composite material panels attached to the framework by bolts, rivets or welding. As will be appreciated, nowadays freight containers may be made of any suitable material, for example materials that are not only durable, but also light weight or having outstanding thermal properties to protect the goods within. Therefore compositions of plastics, fiber, foam, resin or any other type of materials may applied for creating containers suitable for any specific purpose.

In order to allow for handling, containers are usually equipped with corner castings. The corner castings are used to secure cables and other components to the shipping containers during lifting and handling of the containers, as well as to secure the containers to one another and to the transport vehicle. As will be

appreciated, the corner castings are placed at a standardized distance relative to each other on the freight container, such as to allow a handling vehicle, such as a specially designed fork lift, to pick up the containers for handling.

Due to the tremendous loads routinely placed on the corner castings, these components sustain a significant amount of wear and tear damage. Use of damaged and/or worn ISO corner castings presents a safety risk that can have disastrous consequences. For example, in applications that require the shipping container to be lifted or hoisted in the air, a damaged and/or worn corner casting can result in the container being dropped. Handling equipment being equipped with attachment elements, such as attachment hooks, top loaders, spreaders, may also impact against areas adjacent to the corner casting, thereby damaging the roof and/or walls.

Although regular maintenance on the corner castings and the surrounding area is absolutely vital, it is also necessary to protect the surroundings of a corner casting against the impact of attachment elements, such as to improve the life span of the container. The roof of a container is frequently damaged. On average a container suffers roof damage more than once per year. As will be understood, containers that are not water tight (e.g. due to damage) are rejected since they are no longer able to protect their load against the harsh conditions during transportation. For a shipping company having a fleet of hundreds or thousands of containers, one can imagine that repairs to roofs of damaged containers is an ongoing activity in view of the frequency wherein it occurs.

Therefore, in order to resolve this problem, within the surrounding area of a corner casting the container is often equipped with an impact portion for protecting the wall of the container against impact of the attachment element. Prior art solutions exist for example in the use of impact plates, i.e. reinforcement plates (e.g. steel) that are fixed to the container near attachment points such as corner castings.

As an example of such a construction, international patent application nr. WO 2006/045077 (applicant: Alkan Shelter LLC; inventor: Myers et. al.) is directed to a lightweight container made of non-metallic laminated panels bonded together and having a same or similar coefficient of expansion. The container described in this document comprises aluminium or impact-resistant plastic plates having a thickness of about ¼ inch and placed adjacent the corner castings to provide protection against impact.

However, the use of impact resistant plates to protect the immediate wall area around the corner casting through deflecting the impact, often merely transfers the impact to an adjacent region of the impact resistant plate. Further, as the impact resistant plates may not extend more than 750 mm from either end of the container to conform to the requirements of ISO 1496-1 , protection does not extend to areas affected by deflected impacts and/or impacts from wayward crane operators.

In WO 201 1/070145 and WO 201 1/070147, impact portions are proposed that are made of flexible patches covering a cut-out portion near the corner castings or attachment points. These impact portions resolve the abovementioned issues encountered with reinforcement plates, as the flexible patches can be extended to the ends of the wall and effectively reduce the force of impact on the surrounding wall parts. However, despite the above improvements, the proposed solution has not proven to be sufficiently durable itself and requires maintenance and replacement frequently. The flexible patches are prone to being torn as a result of the impact force.

The present invention seeks to find a solution that resolves the abovementioned disadvantages. It is an object of the present invention to provide a freight container having an impact portion that can withstand frequently occurring types of impact of an attachment element, providing having a long life span.

The above mentioned objects of the invention are achieved in that there is provided a freight container in accordance with claim 1 . Advantageous embodiments of such a freight container are defined in the dependent claims.

The freight container in accordance with the invention comprises a plurality of walls forming at least one of a side wall, a floor or a roof of said container, said container comprising an attachment point arranged for receiving an attachment element of a lifting device for lifting said container, and an impact portion in at least one of said walls proximal to said attachment point for protecting said at least one wall in use against damage by accidental impact of said attachment element, said impact portion comprising a flexible element attached to said at least one wall at an interior side of said container and covering an open section of said container, said open section being formed by a cut-out portion of said wall, wherein said flexible element is fixed to said container at least at one or more fixing locations on a periphery about the circumference of said open section, and wherein said periphery extends over said flexible element such as to create a buffer area on said flexible element between an edge of said periphery and said fixing location, for preventing damage to said flexible element due to impact of said attachment element on said flexible element in said buffer area. The impact portion of the freight container according to the present invention protects the flexible element around the periphery thereof against impact of the attachment element. If the attachment element impacts on the flexible element near the edge, the location of impact is at a certain distance away from the fixing location. As a result, the buffer area on the flexible element provides sufficient resiliency to distribute the force of the impact, and to prevent the foil from tearing near the fixing location. Any impact closer to the fixing location will hit the periphery of the cut-out portion. Although this may create a dent in the periphery, this is not disastrous since the resilient flexible element underneath the periphery (the flexible element covers the cut-out portion from the interior side of the wall) will be sufficiently flexible to adapt to the new shape (with dent) of the periphery, without damage to the foil.

Moreover, as an additional advantage, since the fixing location is covered by both the periphery of the cut-out portion and the flexible element, any glue or fixing elements (bolts, rivets, clamps, etc.) providing fixing of the flexible element at the fixing location, will be well protected against harsh weather conditions. This makes the configuration more durable. Also, any dents in the periphery caused by an impact of the attachment element on the periphery (instead of the foil) will be located sufficiently away from the fixing location, which prevents the fixing of the flexible element (e.g. by means of a glue or a fixing element of any kind) to break or release upon impact.

According to a further embodiment of the present invention, a frame is attached to the at least one wall in the open section, wherein the frame comprises a strip or extending part forming at least a part of the periphery, and at least a part of the edge. As a skilled person may appreciate, the use of such a frame will prevent or reduce the risk of damage to the wall itself, and a damaged frame is easier and less expensive to replace or fix.

In a further embodiment, the flexible element is attached at the fixing location to the frame, and the frame is fixed to the wall in a removable manner, for enabling replacing of the impact portion. Creating an impact portion formed by a frame wherein the flexible element is attached to the frame as described above, provides a configuration that can be repaired easily in case of any unforeseen damage by simply replacing the frame with the flexible element. A repair of this kind can be performed fairly easy without the necessity to relocate or empty the freight container. Such a repair can be performed 'on the spot'. According to a further embodiment of the invention, at least a part of the frame structure described above is formed by a post of the construction frame of the container. As will be appreciated, such a post is usually part of a construction frame of the container wherein the side walls, the floor and the roof are attached to the construction frame. Although the post is usually not easy to replace (mostly not replaceable at all without bringing damage to the structural integrity or taking apart the whole container), the post itself provides a very rigid and strong element for attaching the impact portion.

A particular embodiment of the present invention provides an impact portion comprising two flexible layers, such as flexible foils or other types of flexible layers, having a flexible filling interposed in between the two layers (a sandwich configuration). The two flexible layers are (at least partly) attached to each other or to an attachment element around their circumference, providing a cushion configuration. The cushion configuration provides a convex shape of the impact portion on an exterior side as attached to the wall (exterior with respect to the container).

The convex shape of the impact portion on the exterior side of the wall has the advantage that any water on the impact portion will not reside there during use. Pockets of water that would reside on the impact portion could form a danger during transportation, for example in case the water would be frozen in 'below-zero' weather conditions, and would fall off the container while it is loaded on a truck being transported on the road. In addition, as may be appreciated, from the perspective of durability, it also has benefits to prevent any water (in particular sea water) to reside on the flexible element of the impact portion.

In the above mentioned embodiment, the flexible filling may comprise at least one of a group comprising a flexible foam, a gel, a granular filling substance, or a fibre based filling.

The flexible filling of the above mentioned embodiment preferably has an elongation at break (also referred to as 'elongation at rupture') within a range of 50% - 500% at a temperature of 20°C. More preferably, the elongation at break is larger than 100%, and even more preferably the elongation at break is 200% at a temperature of 20°C.

The flexible layers or flexible foils could be of any suitable material, as will be described further below. In an embodiment, the sandwich configuration consists of a first and a second flexible layer, wherein at least one of the flexible layers is made of a suitable flexible material such as rubber. The other flexible layer comprises, or is formed of, a spring type or spiral type bed. Such a bed may for example comprise a plurality of mutually interconnected spirals, for example made of metal wire. A bed may also be formed of a pattern of interconnected metal springs. In this embodiment, the spring type or spiral type bed will preferably be located on the bottom side of the impact corner, i.e. facing the interior of a container, as the springs may be shielded moist and salt water. Moreover, also the interior flexible filling of the sandwich configuration is preferably kept dry. The other flexible layer, e.g. rubber, will be the top side. The use of a spiral type or spring type flexible layer making prevents unauthorized access to the container by cutting or otherwise damaging the impact corner, thereby providing additional security.

According to a further embodiment of the invention, the flexible element of the impact portion comprises one or more (flexible) ribs extending transverse to a surface of the flexible element at an interior side relative to the container, for providing a self bearing construction, allowing for example a convex shape of the flexible element on an exterior side thereof with respect to the container (and the wall).

Instead of the above mentioned embodiment using a sandwich configuration comprised of two flexible foils and a flexible (foam) filling, the latter embodiment also provides the desired convex shape at the exterior side of the wall, but is less expensive to produce in view of the more straightforward design. As an example, the whole flexible element, foil and ribs, may be formed from a single flexible material. Such a configuration is less expensive to produce than a flexible element made of two flexible foils and a flexible filling (sandwich configuration), as described above.

According to an embodiment of the invention, the flexible element comprises at least one material of a group comprising natural rubber, polyurethane rubber, neoprene ^® (i.e. polychloroprene), or natural or polyurethane rubber comprising an additional neoprene ^® outer layer. The material forming the element may optionally be reinforced using embedded fibres. In case such fibres are randomly oriented, preferably in an curly or non-stretched fashion, the material effectively maintains its flexibility. The embedded fibres render the material to be more resistant to cutting or tearing, amongst other thereby making the impact corners more burglar proof and preventing them to become a security weak spot. Such fibres may for example comprise aramide fibres, such as Twaron ^® , e.g. in combination with rubber (but not limited thereto), or ultra high molecular weight polyethylene such as Dyneema ^® , e.g. in combination with other materials such as polychloroprene (but not limited thereto). As will be appreciated, in making a suitable choice of materials and fibres it will be necessary to consider the various processing steps and conditions during the manufacturing process. For example, Dyneema ^® fibres in combination with vulcanized rubber may not be a suitable choice in view of the vulcanization temperatures to be applied (> 120°C) that may be detrimental to the material properties of Dyneema ^® (the properties of which cannot withstand temperatures higher than 70°C); however, the combination of Dyneema ^® with neoprene ^® is a suitable combination in this respect. The skilled person is capable of making a suitable choice on the basis of these teachings.

The freight container and the impact portion at least have an operational temperature within the range of -40°C through 70°C, such as to allow use of the freight container under all weather conditions everywhere in the world.

The fixing location of the impact portion extends preferably in the direction parallel to the edge of the periphery over at least a part thereof. In such configuration, since the foil is supported across a certain distance along its perimeter, it can be fixed very securely to the wall of the container.

According to a further embodiment, the modulus of elasticity of the periphery is smaller than the modulus of elasticity of the flexible element. This is in particular advantageous in preventing damage to said flexible element due to impact of said attachment element.

Brief description of the drawings

The invention will further be elucidated by description of some specific embodiments thereof, making reference to the attached drawings, wherein:

Figure 1 illustrates a cross section of an impact corner of the present invention as attached to a freight container;

Figure 2 illustrates schematically a top view of a freight container in accordance with the present invention;

Figures 3a and 3b respectively illustrate an embodiment of an impact portion with the present invention providing a top view (Figure 3a) and a cross sectional view (Figure 3b);

Figures 4a and 4b illustrate a perspective view from the embodiment of Figures 3a and 3b from the top and bottom respectively; Figures 5a and 5b schematically illustrate a further embodiment of an impact portion of the present invention providing a top view (Figure 5a) and a cross sectional view (Figure 5b);

Figures 6a and 6b illustrate a perspective view from the top and from the bottom of the embodiment illustrated in Figures 5a and 5b;

Figures 7a and 7b schematically illustrate a further embodiment of the impact portion of the present invention, providing a bottom view (Figure 7a) and a cross sectional view (Figure 7b);

Figure 8a and 8b schematically illustrate a further embodiment of the impact portion of the present invention, providing a bottom view (Figure 8a) and a cross sectional view (Figure 8b);

Figure 9 illustrates a cross section of an impact corner of an embodiment of the present invention as attached to a freight container;

Figure 10 illustrates a cross section of an impact corner of an embodiment of the present invention as attached to a freight container;

Figure 1 1 is a close-up of a spiral type flexible layer that may be used in the embodiment of figure 10;

Figure 12 is a schematic illustration of a spring type flexible layer that may be used in the embodiment of figure 10;

Figure 13 is an exploded view of the embodiment of figure 10 showing the spiral type and spring type flexible layers of figures 1 1 and 12 as options.

In the present description, the term 'corner casting' is intended to refer generally to an attachment point on the freight container, to which an attachment element may in use be attached such as to allow for handling of the container. Such an attachment point is not necessarily location on a corner of the container, but may reside anywhere on the container (e.g. in the middle) and on any wall (roof, sides, floor). This therefore equally applies to the location of an impact portion, which is functionally located near an attachment point. The term 'corner casting' is a

professional term indicating such an attachment point on a container in transportation industry.

Moreover, wherever identical reference signs are used in more than one figure, these reference signs refer to corresponding features in the various drawings.

Figure 1 schematically illustrates a cross sectional view of an impact portion 9 as attached to a freight container 1 in accordance with the present invention. The freight container 1 consists of a plurality of walls for defining the sides, the floor and the roof of the container. In Figure 1 , side wall 2 and roof 3 are partly visible in cross section.

Figure 2 schematically illustrates a top view of the freight container 1 , illustrating how the impact portions of the present invention may be located in the roof section of the container near the corner castings or attachment points. Figure 2 schematically illustrates the roof section 3, corner castings 43, 44, 45, 46, 49, 50, 51 and 52, and impact portions 9, 55, 56, 57, 60, 61 , 62 and 63. The roof section 3 comprises open sections that form open sections 8 which are covered by a flexible element of the impact portion (such as impact portion 9) from the interior side of the freight container 1.

In Figure 1 , a cross section of the open section 8 in the roof section 3 is generally indicated by an arrow. The flexible element 9 covers the open section 8 from the interior side of the freight container 1 . A frame element 15 is attached to the roof 3 in the open section 8. Near side wall 2, on the top side thereof, a corner frame 5 is present which is part of the construction of the freight container. In the present embodiment illustrated in Figure 1 , the impact portion comprises a flexible element 9 formed by a first layer 25 of flexible foil and a second layer 26 of a flexible foil, having a foam 28 interposed between the layers 25 and 26. The flexible element 9 is on one side attached to the frame 15, and on the other side attached to the corner frame 5 of the freight container 1.

A rigid periphery 10 of the open section 8 is defined by a strip 16 of the frame 15, and near the corner frame 5 by an extending part 35 of the corner frame 5. The edge 1 1 of the open section 8 is effectively formed by the edges of the strip 16 (extending part 36) of frame 15 and the extending part 35 as illustrated in figure 1.

The flexible element 9 of the impact portion, formed by first layer 25, second layer 26 and foam filling 28, is attached to the open section by means of fixing elements 19 and 20 illustrated in figure 1 . Although in figure 1 , since it is a cross sectional view, only fixing elements 19 and 20 are visible, a skilled person may appreciate that preferably, similar fixing elements are located all around the flexible element 9 surrounding the perimeter thereof in a similar manner as fixing elements 19 and 20. For fixing the flexible element 9 to the periphery 10, the fixing elements are attached by means of rivets 21 , 22 extending all the way through, the flexible element 9 and the periphery 10. The skilled person may appreciate that other fixing means may be applied, such as screws, bolts, glue, clamps, or the like, as long as the flexible element 9 is secured sufficiently for resisting any forces of impact experienced during use. The use of for example glue has the benefit that this may also provide a water tight seal. Of course, for providing sufficient robustness, combinations of fixing means may be applied at the fixing location or fixing region (note that the term 'fixing region' may be more suitable in case a glue or the like is used for fixing the flexible element 9 - although it should be understood that the term 'fixing location' as used herein is meant to include a fixing region as is achieved with for example a glue connection).

In accordance with the invention, around the periphery 10 of the open section 8, extending parts such as extending parts 35 and 36 (extending part 36 being formed by strip 16) extend at least partly over first layer flexible foil 25 such as to define buffer areas, such as buffer areas 39 and 40, between the edges 1 1 and the fixing elements 19 and 20. The buffer areas 39 and 40 are respectively indicated by dashed lines 30, 31 , 32 and 33 in figure 1 . The extending parts 35 and 36 on the periphery 10 of the open section 8 are defined by dashed lines 30', 31 ', and 32', and 33'

respectively.

It will be appreciated by the skilled person, the extending parts 35 and 36 around the periphery 10 of the open section 8, protect the flexible element 9 of the impact portion against impacts of the attachment element (not shown) of a handling vehicle (e.g. a forklift) near the fixing elements 19 and 20. Absence of the extending parts 35 and 36, such as in prior art solutions, will cause the flexible foil 25 and 26 to tear due to the fact that the impact would take place too close to the fixing elements and the distance between the impact location and the fixing element is too small for the material to provide sufficient resiliency and flexibility to distribute the forces. As a result, such a configuration may easily lead to damage of the flexible element 9. As will be appreciated, the probability of impact of an attachment element on or near the periphery 10, in particular in the direct location of the attachment point or corner casting, is larger than anywhere else on the impact portion. The impact portion of the present invention therefore provides substantial advantages over the prior art.

The present invention protects the flexible element 9 by means of the extending parts 35 and 36. If the impact location is in proximity to the fixing elements 19 or 20, impact will take place on the extending parts 35 or 36 instead of in the buffer area 39 and 40. This will in the worst case only create a dent in the extending parts. The skilled person may appreciate that the extending parts may be designed for being able to withstand such an impact to a certain extent. Since the impact portion is mainly formed by the flexible element 9, the presence of a dent in the extending parts (35, 36) will not be a real problem as the shape of the flexible element will adapt to the dent. In accordance with the inventive concept, the periphery 10 (and thereby the extending parts 35 and 36) is 'rigid' in relation to the flexible element 9. This means that at least the modulus of elasticity of the rigid periphery 10 is preferably smaller that the modulus of elasticity of the flexible element.

If the impact location of an attachment element (not shown) takes place slightly off the edge 1 1 on the flexible foil 25, e.g. near the buffer area 40, the buffer area 40 on the flexible foils 25 and 26 of the flexible element 9 provides sufficient flexibility for the material of the flexible element to withstand the force of impact without being torn from the fixing element 19.

Although in the embodiment of figure 1 , the flexible element (25, 26, 28) is attached to frame 15 on one side, and on corner frame 5 on the other side, (corner frame 5 being part of the construction) an alternative embodiment may be provided which is easily replaceable in case of damage. Such an embodiment could for example be created by providing a frame such as frame 15 all the way around the perimeter of the flexible element (25, 26, 28) and attaching the frame in a removable manner to the walls (e.g. roof) of the freight container. During maintenance, such a frame can easily be taken off for inspection, or for replacing.

An additional advantage is achieved in the embodiment of figure 1 by the convex shape of the flexible foil 25 on the exterior part of the freight container. Any water which may land on the flexible foil 25 in use (e.g. rainwater or water during cleaning of the container) easily flows off the flexible foil 25. As a result, since water does not reside on the flexible foil 25, this prevents a dangerous situation in case the outside temperature is below freezing point. Any water that resides on the roof of the container (or on the impact portion) could freeze, and could fall off the container during transportation or handling, providing a potentially dangerous situation for any traffic around the container or persons standing nearby. In figures 3a and 3b, a flexible element 60 of an impact portion of the present invention, according to a further embodiment, is schematically illustrated. Figure 3a provides a top view of the flexible element 60. Around the perimeter 62 of the flexible foil 61 of the element 60, a plurality of holes 64 is present, for attaching the flexible element to a frame or to a wall of the container as described.

In figure 3b, a cross sectional view of the embodiment of figure 3a is illustrated. The cross sectional view illustrates the perimeter 62 of the flexible foil 61 , and a second flexible layer 67 forming the bottom of the flexible element 60. In between the second layer 67 and the flexible foil 61 , a foam or other flexible filling 68 is present in a sandwich configuration.

Figures 4a and 4b provide a perspective view of the flexible element 60 of figures 3a and 3b. The specific shape of the second layer 67 is illustrated. As a result of the shape of layer 67, and the filling 68 of the element, flexible foil 61 on the top side comprises a convex shape which is also described in relation to the embodiment disclosed in figure 1 .

In figures 5a and 5b, a further embodiment of a flexible element in accordance with the present invention is illustrated. Here, the flexible element 70 comprises a flexible foil 71 having a perimeter 72 comprising a plurality of holes 74, similar to the embodiment illustrated in figure 3a. However, the bottom side of the embodiment 70 of figures 5a and 5b differs from flexible foil 60 and figures 3a and 3b, and 4a and 4b. The bottom side of flexible foil 71 of flexible element 70, which in use will face the interior side of the container, comprises a plurality if ribs 75 extending transfers to the flexible foil 71 . The plurality of ribs 75 also provide a convex shape to the flexible foil 71 to some extend. As will be appreciated, the flexible element 70 illustrated in figure 5a has a very straight forward and easy to create configuration, which provides similar benefits with respect to the convex shape of the flexible element 70 as flexible element 60 in figures 3a and 3b, but for which the manufacturing costs are lower. In figures 6a and 6b, again a prospective top view and bottom view of the flexible element 70 is illustrated, revealing the ribs 75 extending transfers to the flexible foil 71 on the bottom side thereof.

Yet a further embodiment is illustrated in figures 7a and 7b. The flexible element 80 of figure 7a comprises a flexible foil 81 and a perimeter 82. On the bottom side of flexible foil 81 , a plurality of ribs 85, 86 and 87, similar to the ribs 75 of flexible element 70, extend transfers to the flexible foil 81 of flexible element 80. In addition to the ribs 85, 86 and 87, flexible element 80 comprises further ribs such as rib 90 extending also transfers to the flexible foil 81 , but in a direction perpendicular to the ribs 85, 86 and 87. As a result, a more rigid construction is achieved, which more strongly pushed the top side of flexible foil 81 in the desired convex shape. Figure 7b illustrates the cross sectional view of flexible element 80 of figure 7a.

A further embodiment of the flexible element is illustrated in figures 8a and 8b. Here, in figure 8b, a small ridge 100 on the exterior side of the element is visible. The ridge 100 is in use contiguous to the edge of the periphery of the impact portion. Any water on the flexible element will run off the convex side, and due to the fact that the ridge forms a fluent transition to the roof of the container (without height differences), the water will run off the flexible element clearing the rubber parts. This prevents damage of the rubber due to for example freezing.

As will be appreciated, any of the embodiments described, in particular the flexible elements 60, 70 and 80 described above, may be preattached to a frame that enables easy replacement of the flexible element in use.

Figure 9 illustrates a cross section of a further embodiment of the impact corner of the present invention. In figure 9, the flexible element 109 of the impact corner is attached to the frame element 15 comprising, in accordance with the present invention, the rigid periphery 10 which extends partly over the flexible element 109. The flexible element 109 is attached to the periphery using fixing elements 19 and 20. These may be separate elements, or may alternatively be formed from a single frame.

Similar to the flexible element 80 of figures 7a and 7b, the flexible element 109 in figure 9 comprises a plurality of ribs 1 15, 1 16, 1 17 and 120 facing the interior side of the container. The ribs 1 15, 1 16, 1 17 and 120 maintain the flexible element 109 in a convex shape to prevent build up of water on the impact corner in use. In the embodiment illustrated, the flexible element 109 has a very similar shape as the flexible element 80 in figures 7a and 7b (i.e. without the ridge 100). As will be appreciated, flexible element 109 may optionally comprise an additional ridge 100 such as illustrated in figures 8a and 8b to more effectively prevent build up of water.

In the embodiment illustrated in figure 9, the flexible element 109 is made of a flexible material (such as mentioned hereinbefore, e.g. rubber) comprising short lengths of fibres 1 12 (typically of length < 4mm) embedded therein. The weight percentage of fibres 1 12 embedded in the flexible material is preferably smaller than 10%, and more preferable smaller than 6% in case the flexible material is or primarily contains natural rubber or smaller than 4% in case the flexible material is or primarily contains ethylene propylene diene monomer (EPDM) rubber. Promising results have been obtained by using an amount of fibres relative to weight of the material to be approximately 5% of weight in case the flexible material is or primarily contains natural rubber, and 3% of weight in case the flexible material is or primarily contains EPDM. The fibres 1 12 are preferably not aligned to each other, and more preferably do not have a dominant direction. The fibres 1 12 may for example be embedded in a randomly oriented direction. Also, or in addition, the fibres 1 12 may be embedded in a curly or non-stretched, fashion. The fibres may also be aligned differently in different layers, such that overall, more or less most or all directions or dominant directions may be present. The above criteria regarding the direction of the fibres 1 12 maintain the material flexibility of the element 109. The embedded fibres 1 12 reinforce the material of the flexible element 109, making it for example more resistant to cutting or tearing. As appreciated, the use of embedded fibres 1 12 is not limited to application in either natural rubber or EPDM only, but could be applied as embedded in other flexible materials mentioned or suggested throughout this teaching. Moreover, also the length range of the fibres 1 12 mentioned above, the amount of fibres per weight of material, or their orientation, is not to be interpreted as a limitation of the teaching but as a suggestion to the skilled person. In figure 9, the fibres 1 12 have been illustrated in the middle part of the flexible element 109 only, however, these fibres are preferably present everywhere in the flexible element 109, also in the edges and the parts underneath the periphery 10. In the figure, underneath the periphery 10, an additional and optional reinforcement inlay 107 is present in the element 109, for reinforcing the attachment of the flexible element 109 to the frame element 15. The optional inlay 107 may for example be made of polyamide fiber, such as polyhexamethyleenadipamide (nylon ^® ), or other suitable material.

Figure 10 illustrates a further embodiment of an impact corner in accordance with the present invention. In figure 10, a flexible element 123 is attached to rigid periphery 10 of frame element 15 using a fixing frame 121 . A flexible element 123 comprises a flexible first layer 125, for example made of rubber, and a spiral type or spring type flexible second layer 126. In between the first and second flexible layers

125 and 126, a flexible foam 128 is interposed (alternatively this may be a different compressible material). The layers 125 and 126 and flexible foam filling 128 together form a sandwich configuration as described hereinbefore. The flexible foam filling 128 ensures that the flexible first layer 125 is kept in a convex shape to prevent the build up of water on top of the impact corner. The spiral type or spring type flexible second layer

126 renders the impact corner to be highly resistant to cutting or tearing. To prevent damage to the flexible foam filling 128 in use, a protection layer 129, for example a braided or a non-woven fiber mat, forms the bottom side of the flexible foam filling. The protection layer 129 prevents the springs or spirals of flexible layer 126 to damage the foam of the filling 128 in case the second layer 126 springs back after impact of an object on the impact corner in use. Spiral type or spring type flexible second layer 126 is attached directly to the fixing frame 121. In figure 1 1 , a close up of a spiral type flexible second layer 126 is schematically illustrated. A flexible second layer 126 consists of a plurality of spirals 130, 131 , 132, 133, 134 and 135, which are mutually interconnected. The spirals 130- 135 are preferably made of metal wire or a similar material.

In accordance with another embodiment, the spring type flexible second layer 126 may be designed in accordance with the schematic principle illustrated in figure 12. In figure 12, a plurality of springs 141 in a first direction and a plurality of springs 140 in a second direction may be interconnected by means of connections 143. Such connections 143 may be of any suitable type providing a sufficiently strong connection, for example by welding (either direct or using some kind of stiff material) or using a ring where one can hook on the springs to create even more flexibility or directly hook up de springs to each other. Around the periphery of the layer 126, the springs are connected to frame 121 illustrated in figure 10. As will be appreciated, other suitable configurations of springs, spirals or the like may be used for foring flexible second layer 126 of figure 10.

Figure 13 is an exploded view of the embodiment of figure 10, illustrating the flexible first layer 125, the flexible filling 128, the protection layer 129, and the flexible second layer 126a/b. The flexible second layer may either be implemented as spiral type flexible layer 126a or spring type flexible layer 126b; figure 13 shows both options.

To achieve the required impact energy resistance, the flexible elements in the embodiments of the present invention preferably have a modulus of elasticity of at least 1 MPa, more preferably at least 3 MPa, even more preferably at least 5 MPa and most preferably at least 10 MPa. Preferably, the modulus of elasticity is no more than 1000 MPa, more preferably no more than 500 MPa, even more preferably no more than 200 MPa and most preferably no more 100 MPa. Higher modulus values may result in poor dampening efficiency (i.e. increased chance of failure due to brittle fracture), while lower modulus values may not be sufficient to prevent excessive deformation, which may result in damage to the payload.

The above description and the drawings are directed to different alternative embodiments for the flexible element. The flexible element may for example be a monolithic layer or may be a sandwich construction. Preferably, the sandwich construction comprises an outer layer, a flexible filling and an inner layer. Properties and dimensions of preferred embodiments of the monolithic layer construction and the sandwich construction are provided herewith. In case the flexible element is formed as a monolithic layer construction, it is preferred (but not essential) to form the element as a sheet or layer of natural rubber having a weathering resistant rubber top layer forming in use the exterior side relative to the container. Although other materials may be used, such as polyurethane rubber, it has been experimentally found that a natural rubber layer with a neoprene top layer is preferred with respect to the material properties, the neoprene top layer protecting the natural rubber base layer from sunlight. The thickness of the monolithic layer is preferably smaller than 12 mm, more preferably between 2 and 10 mm. Good results have been achieved with a 4 mm thick natural rubber base layer having a 1 mm thick neoprene top layer, in total thereby having a thickness of 5 mm within the abovementioned range.

Preferably, the monolithic layer construction comprises, at an interior side with respect to said container in use, a plurality of ribs such as is shown in the embodiments depicted in figures 5B, 6B, 7A, 7B, 8A and 8B. The monolithic layer construction in total, as measured from the end of the most extending rib to the top of the convex shaped exterior side comprising the neoprene top layer, a total thickness which is smaller than 100 mm. The upper limit of this range being chosen such as to prevent the flexible element from taking away loading capacity for freight inside the container. More preferably, this total thickness is within 50 through 75 mm (this provides suitable material properties), and good results have been achieved with a total thickness of 65 mm for the monolithic layer construction described. The number of ribs, the thickness and the height of the ribs should be determined in relation to the surface dimensions of the flexible element, and in relation to the material used, at the choice of the person skilled in the art such that a self bearing construction can be obtained.

The monolithic layer construction may be manufactured by means of any suitable manufacturing method, although good results have been achieved by applying a step of vulcanization. This may be performed by stacking the natural rubber base layer on top of the ribs, and the neoprene layer on top of the natural rubber layer (or of course in the reverse order), e.g. in a mould. Subsequently, by applying heat to the mould, melting causes the ribs to attach to the rubber base layer, and the neoprene layer to melt with the rubber base layer such as to provide the desired monolithic layer construction.

In the embodiment of figures 1 , 3A, 3B, 4A and 4B, the flexible element is a sandwich construction comprising two flexible foil layers having a flexible filling in between. The total thickness of the sandwich construction from bottom to top is smaller than 100 mm. This again is to prevent the flexible element from taking away loading capacity for freight inside the container. Preferably the total thickness of the sandwich construction is between 30 and 60 mm, more preferably between 40 and 55 mm. Good results have been achieved with a sandwich construction having a total thickness of 50 mm.

In case the flexible element is made of a sandwich construction, preferably (but not essentially), at least one layer of the sandwich construction comprises natural rubber. More preferably, the laminate comprises an outer layer, a core formed by the flexible filling and an inner layer, whereby the inner and outer layer of the laminate construction comprise natural rubber. Although other materials may be used, such as polyurethane rubber, it has been experimentally found that a natural rubber layer is preferred with respect to the material properties. Again, the natural rubber outer layer forming in use the exterior side with respect to the container, and which is exposed to sunlight, harsh weather conditions, and (sea) water, may comprise a neoprene top layer. The neoprene top layer protects the natural rubber.

Preferably, the flexible element preferably has an elongation at break (determined at 23°C and 5 mm/min, according to ISO 527) in the range between 2 to 700%, more preferably in the range between 100 to 500% and even more preferably in the range between 300 to 400%.

The flexible filling preferably comprises a polymeric material that provides a relatively light (in terms of weight) means of providing flexibility to the wall. The polymeric material is preferably a polymeric foam as this provides a low density structural material. Suitable foamed materials include plastic foams, for example polyurethane foam, polyethylene foam, polypropylene foam, a foam of an ethylene - propylene copolymer, phenolic foam, or any other plastic foam known to the person skilled in the art may also be used. Suitable polymeric foams exist as closed cell, syntactic cellular polymer compositions, which in a preferred embodiment have a density of about 20 to 100 kg/m ³ . The density of the foam may comprise a gradient, with the region immediately adjacent to the attachment point having the highest density. For the purposes of the present invention, foamed materials include materials comprising polymeric or ceramic hollow microballoons or hollow microspheres.

Preferably, the foam has a glass transition temperature (T _g ) equal or less than 0°C with a change in the ratio of the loss modulus to the stored modulus of no more than 50% from the median value measured over the temperature range of from about -40°C to about 70°C. This ensures that the foam has good impact resistance over its operating range.

Preferably, the T _g is less than -10 and more preferably less than - 40°C. The change in tan delta between about -20°C to about 50°C is preferably no more than 40% and even more preferably no more than 30%.

The glass transition temperature (T _g ) is preferably determined by Dynamic Mechanical Thermal Analysis (DMTA) in accordance with ASTM D4065-93, adapted to measure T _g at the onset of the drop in the elastic modulus.

Preferably, the flexible filling of the impact resistant portion is made of a closed cell polyethylene foam as such foams have excellent energy dissipating properties.

The present invention has been described in terms of some specific embodiments thereof. It will be appreciated that the embodiments shown in the drawings and described here and above are intended for illustrative purposes only, and are not by any manner or means intended to be restrictive on the invention. The context of the invention discussed here is merely restricted by the scope of the appended claims.