WO2024231232A1

WO2024231232A1 - Shipping container

Info

Publication number: WO2024231232A1
Application number: PCT/EP2024/062158
Authority: WO
Inventors: Daniel MERLIN DE ANDRADE; Bruno Alberto DE OLIVEIRA VIEIRA
Original assignee: Aeler Technologies Sa
Priority date: 2023-05-05
Filing date: 2024-05-02
Publication date: 2024-11-14

Abstract

Shipping container (1) comprising a frame (2) including a door frame (14), a floor (9), a roof and wall panels (3) fixed to the frame (2), and doors (4) including a left door (4L) and a right door (4R), the left door comprising a door panel coupled via hinges (28) to a left side vertical beam of the door frame (14) and the right door (4R) comprising a door panel (5) coupled via hinges (28) to a right side vertical beam of the door frame (14), said hinges comprising at least one top hinge (28) and one bottom hinge (28b), the right door (4R) and left door (4L) joined together at a centre vertical interface (46) when the doors are closed, the doors further comprising a closing mechanism (7). The door panel (5) of each door comprises at least a first external panel layer (18) and a second external panel layer (18) forming a gap (19) therebetween and a filler positioned within the gap (19), the doors (4) further comprising a web skeleton structure (6) mounted within the gap and attached to at least one of the first and second external panel layers, the web skeleton structure including a plurality of tensile interconnect elements (22) extending at an angle relative to the horizontal direction from a position proximate an edge of each door adjacent said vertical beams (14v) of the door frame (14), to a position proximate the centre vertical interface (46), each tensile interconnect element comprising a continuously wound fibre string wound around at least two winding nodes (26h, 26c) and a polymer binding matrix coated around said wound fibre string configured to render the wound fibre string rigid and self-supporting.

Description

SHIPPING CONTAINER

The present invention relates to a shipping container for the transportation of goods by ship, road, and rail.

Shipping containers are typically provided in a standard size that allow the containers to be arranged side by side, end to end and stacked with other containers of maritime transport companies. Conventional shipping containers are typically made of steel frames and walls, however it is known to provide containers with composite side and end walls as described in WO 2022058873. The use of composite side walls reduces the container weight and allows to provide side walls with greater bending strength, in particular when a container is used with flexible liquid containers mounted within the shipping container, the liquid applying pressure on the container side walls. In the afore-mentioned document, the doors which are not subject to the pressure exerted via the flexible liquid container, are provided as conventional steel doors that are hinged to the steel frame of the shipping container.

There is however the desire to decrease the weight and/or increase the strength and durability of shipping containers, which would allow to carry heavier goods per shipping container and increase the useful lifetime of the shipping container.

It is an object of the invention to provide a shipping container for maritime, rail and road transport of goods that is light weight, yet robust and durable.

It is advantageous to provide a shipping container that is cost effective to manufacture.

It is advantageous to provide a shipping container that allows to carry goods securely.

It is advantageous to provide a shipping container that can easily integrate electrical and electronic systems for tracking, storage, maintenance and other functions.

Objects of the invention have been achieved by providing a shipping container according to the independent claims.

Dependent claims set forth various advantageous embodiments of the invention.

Disclosed herein is a shipping container comprising a frame including a door frame, a floor, a roof and wall panels fixed to the frame, and doors including a left door and a right door, the left door comprising a door panel coupled via hinges to a left side vertical beam of the door frame and the right door comprising a door panel coupled via hinges to a right side vertical beam of the door frame, said hinges comprising at least one top hinge and one bottom hinge, the right door and left door joined together at a centre vertical interface when the doors are closed, the doors further comprising a closing mechanism.

According to a first aspect of the invention, the door panel of each door comprises at least a first external panel layer and a second external panel layer forming a gap therebetween and a web skeleton structure mounted within the gap and attached to at least one of the first and second external panel layers, the web skeleton structure including a plurality of tensile interconnect elements extending at an angle relative to the horizontal direction from a position proximate an edge of each door adjacent said vertical beams of the door frame, to a position proximate the centre vertical interface, each tensile interconnect element comprising a continuously wound fibre string wound around at least two winding nodes and a polymer binding matrix coated around said wound fibre string configured to render the wound fibre string rigid and self-supporting.

In an advantageous embodiment of the first aspect, the web skeleton structure of the left door is substantially in mirror image symmetry with the web skeleton structure of the right door.

In an advantageous embodiment of the first aspect, said hinges are attached or integrally formed with the winding nodes positioned proximate the edge of the door adjacent said vertical beams of the door frame.

In an advantageous embodiment of the first aspect, said hinges comprising at least the top hinge and the bottom hinge each comprise an internal fixing plate having at least one surface attached against an inner side of at least one of the external panel layers one winding node being integrally formed with, or fixed to, the internal fixing plate.

In an advantageous embodiment of the first aspect, said hinges comprising at least the top hinge and the bottom hinge each comprise an external hinge fixing plate having at least one surface attached against an outer side of an outer external panel layers, the external hinge fixing plate and internal fixing plate clamping the outer external panel layers therebetween.

In an advantageous embodiment of the first aspect, the internal fixing plate comprises opposed fixing surfaces, each bonded or clamped to an inner side of an adjacent one of the external panel layers.

In an advantageous embodiment of the first aspect, at least one of the plurality of tensile interconnect elements is attached to the top hinge and at least one other of the plurality of tensile interconnect elements is attached to the bottom hinge.

In an advantageous embodiment of the first aspect, the doors comprise a second top hinge positioned between the top hinge and a vertical middle of the door and, a second bottom hinge formed between the bottom hinge and the vertical middle of the container door, at least one of the plurality of tensile interconnect elements is attached to the second top hinge and at least one other of the plurality of tensile interconnect elements is attached to the second bottom hinge.

In an advantageous embodiment of the first aspect, the doors further comprise a centre coupling mechanism comprising a first coupling part on the left door and a second coupling part on the right door, the first and second coupling parts engaging together when the doors are closed configured to prevent vertical sliding of the left and right doors at the centre interface.

In an advantageous embodiment of the first aspect, one of first coupling part and the second coupling part of the centre coupling mechanism comprises a tapered protuberant male part and the other of the first coupling part and the second coupling part comprises a tapered recessed female part.

In an advantageous embodiment of the first aspect, the tapered protuberant, respectively recessed, parts, comprise conical surfaces.

In an advantageous embodiment of the first aspect, at least two of the plurality of tensile interconnect elements are attached to the centre coupling mechanism.

In an advantageous embodiment of the first aspect, said at least two of the plurality of tensile interconnect elements attached to the centre coupling mechanism include one attached to the top hinge and the other attached to the bottom hinge.

In an advantageous embodiment of the first aspect, the web skeleton structure includes further tensile interconnect elements extending between additional hinges and the centre coupling mechanism. In an advantageous embodiment of the first aspect, the web skeleton structure of each door comprises at least one tensile interconnect element extending from a top left corner to a bottom right corner of the door, and at least one tensile interconnect element extending from a top right corner to a bottom left corner of the door.

According to a second aspect of the invention, the doors comprise a centre coupling mechanism comprising a first coupling part on the left door and a second coupling part on the right door, the first and second coupling parts engaging together when the doors are closed configured to prevent vertical sliding of the left and right doors at the centre interface.

In an advantageous embodiment of the second aspect, one of first coupling part and the second coupling part of the centre coupling mechanism comprises a tapered protuberant male part and the other of the first coupling part and the second coupling part comprises a tapered recessed female part.

In an advantageous embodiment of the second aspect, the tapered protuberant, respectively recessed parts comprise conical surfaces.

In an advantageous embodiment of the second aspect, each left and right door comprises a web skeleton structure including a tensile interconnect element extending between at least the top hinge and the centre coupling mechanism and between the bottom hinge and centre coupling mechanism, the tensile interconnect element comprising a continuously wound fibre string wound around at least two winding nodes and a polymer binding matrix coated around said wound fibre string configured to render the wound fibre string rigid and self-supporting.

In an advantageous embodiment of the second aspect, the web skeleton structure includes further tensile interconnect elements extending between additional hinges and the centre coupling mechanism.

In an advantageous embodiment of the second aspect, the doors comprise a second top hinge positioned between the top hinge and a vertical middle of the door and the second bottom hinge formed between the bottom hinge and the vertical middle of the container door.

In an advantageous embodiment of the second aspect, the web skeleton structure of the left door is substantially in mirror image symmetry with the web skeleton structure of the right door. In an advantageous embodiment of the second aspect, at least the top hinge and the bottom hinge each comprise an internal fixing plate having at least one surface attached against an inner side of at least one of the external panel layers one winding node being integrally formed with, or fixed to, the internal fixing plate.

In an advantageous embodiment of the second aspect, the internal fixing plate comprises opposed fixing surfaces, each bonded or clamped to an inner side of an adjacent one of the external panel layers.

In an advantageous embodiment of the second aspect, at least the top hinge and the bottom hinge each comprise an external hinge fixing plate having at least one surface attached against an outer side of an outer external panel layers, the external hinge fixing plate and internal fixing plate clamping the outer external panel layers therebetween.

In an advantageous embodiment of the second aspect, the web skeleton structure comprises intermediate fixing elements fixed to the tensile interconnect elements in between the extremities of the tensile interconnect element.

In an advantageous embodiment of the second aspect, the hinge comprises a hinge portion extending from the external hinge fixing plate for mounting to a complementary hinge portion fixed to the vertical beam of the door frame.

In an advantageous embodiment of the first or second aspect, the fibre strings are selected from a group consisting of carbon fibre, aramid fibre, glass fibre, basalt fibre and the polymer binding matrix is selected from a thermosetting or thermoplastic polymer, for instance epoxy resins, polyamide 6, polyamide 12, polyvinyl chloride, polypropylene, polystyrene, acrylonitrile butadiene styrene.

In an advantageous embodiment of the first or second aspect, the materials of the external panel layers are selected from a group consisting of aramid epoxy composites, and thermoplastics including polyamide 6, polyamide 12, Polyvinyl chloride, Polypropylene, Polystyrene, and Acrylonitrile Butadiene Styrene, with or without fibre reinforcement, said fibre reinforcement including carbon fibre, glass fibre, aramid fibre, basalt fibre.

In an advantageous embodiment of the first or second aspect, at least one of the external panel layers consists of or comprises a fibre reinforced composite material, for instance a carbon fibre reinforced material. In an advantageous embodiment of the first or second aspect, both of the external panel layers consist of or comprise a fibre reinforced composite material.

In an advantageous embodiment of the first or second aspect, the shipping container further comprises a filler positioned within the gap between the external panel layers.

In an advantageous embodiment of the first or second aspect, the filler comprises or consists of a polymeric foam such as polyurethanes, polystyrene, polyethylene terephthalate and polyolefin foam materials.

Further advantageous features of the invention will be apparent from the following detailed description of embodiments of the invention and the accompanying illustrations.

Brief description of the figures

Figure 1a is a perspective view of a shipping container according to an embodiment of the invention;

Figure 1 b is a view similar to figure 1a showing the doors of the container in an open position;

Figure 1c is an enlarged view of a portion of the container showing the doors;

Figure 2 is a detailed view of a hinge of a door of the container of figure 1a;

Figure 3 is a plan view of the container of figure 1a showing the end with the doors, and illustrating in dotted lines a web skeleton structure within the door;

Figure 4a is a plan view of a left door of the embodiment of figure 3;

Figure 4b is a plan view of a right door of the embodiment of figure 3;

Figure 5a is a cross-sectional view through line Va-Va of figure 4b;

Figure 5b is a detailed schematic cross-sectional view of a door panel of the door of figure 5a;

Figure 5c is a cross-sectional view through line Vc-Vc of figure 4b;

Figure 6a is a perspective view of a web skeleton structure of the left door according to an embodiment of the invention;

Figure 6b is a perspective view of a web skeleton structure of the right door according to an embodiment of the invention;

Figure 7a is a front view of the web skeleton structure of the doors of the embodiment of figure 3;

Figure 7b is a rear view of the web skeleton structure of the doors of figure 3;

Figure 7c is a detailed enlarged view of a centre coupling mechanism of the web skeleton structure of figure 7a;

Figure 7d is a detailed enlarged view of the centre coupling mechanism of the embodiment of figure 7b;

Figure 8 is cross-sectional view through a coupling mechanism of the doors in a slightly open position;

Figure 9a is a partial cross-sectional exploded view and figure 9b is a perspective exploded view of components of the door coupling mechanism;

Figure 10 is a plan view of the container end with the doors illustrating in dotted lines a web skeleton structure within the door according to another embodiment of the invention;

Figure 11a is a front view of one of the web skeleton structures of the doors of the embodiment of figure 10;

Figure 11 b is a perspective view of the web skeleton structure of figure 11a of the left door; Figure 11c is a perspective view of the web skeleton structure of figure 11a of the right door;

Figure 11d is a perspective view of the web skeleton structure of figure 11b seen from the opposite side;

Figure 11e is a perspective view of the web skeleton structure of figure 11c seen from the opposite side;

Figure 12 is a plan view of the container end with the doors illustrating in dotted lines a web skeleton structure within the door according to yet another embodiment of the invention;

Figure 13a is a front view of the web skeleton structures of the doors of the embodiment of figure 12;

Figure 13b is a rear view of the web skeleton structures of the doors of the embodiment of figure 12;

Figures 13c and 13d are front and rear perspective views of the web skeleton structure of figure 13a of one of the left or right doors;

Figures 14a to 14k illustrate schematically different configurations of web skeleton structures of doors according to embodiments of the invention.

Referring to the figures, a shipping container 1 having a standard size configured for maritime, rail and road transport similar to conventional standard containers for use in existing shipping and transport networks, has outer dimensions that conform to the existing conventional shipping containers. Standard shipping containers have outer dimensions of about 8ft (2.43m) wide, 8.5ft (2.59m) high and come in three standard lengths 10ft (3.01m), 20ft (6.06m) and 40ft (12.2m). Extra tall shipping containers called high-cube containers are available at 9.5ft (2.9m) high.

The shipping container 1 comprises a frame 2, a floor 9, wall panels 3 including side walls 3s, end wall 3e and a roof 3r, and doors 4, consisting of a left door 4L and a right door 4R. The frame 2 comprises beams 12 that extend between corners 10 of the rectangular prismatic shape of the container. The wall panels 3 and floor 9 are attached to the frame and with the doors 4 fully surround and enclose a storage chamber 11 formed within the shipping container 1.

The side walls 3s are preferably made of a composite structure for instance as disclosed in WO2022058873. The roof 3r and end wall 3e are preferably also formed of a composite material, such composite materials including for instance at least first and second opposed outer fibre reinforced composite layers and a filling material therein, optionally a fibre reinforced filling material.

The beams 12 of the frame 2 may be made of steel, the beams being welded or bolted together at corners 10 of the shipping container 1. The beams 12 may also be made of other metals such as aluminum. The beams may also be made of composite structures such as fibre glass reinforced composite structures or carbon fibre reinforced composite structures. Various composite materials are perse known and need not be further described herein, it being noted that the frame and walls and floor may have a configuration as described in the aforementioned application WO 2022058873.

The doors 4 comprise a left door 4L and a right door 4R, each door being pivotally coupled to vertical beams 14v of a door frame 14, forming part of the frame 2. The doors 4R, 4L have a joining interface 46 in a middle between the vertical beams similar to the general configuration found in conventional container doors. The doors 4 may further comprise door closing mechanisms 7 similar to conventional door closing mechanisms, comprising pivotable rods 30 having closing hooks 32 at their top and bottom ends that engage in corresponding closing rods receiving holes in the top and bottom door frame beams, the door closing mechanism further comprising a closing handle 34 for manually pivoting the pivotable rods 30 and associated closing hooks 32 at the extremities of the pivoting rods for opening and closing the container doors similar to a conventional door closing mechanism found in existing shipping containers. As in existing shipping containers, a first door closing mechanism may be provided proximate the closing interface 46, and a second door closing mechanism (per door 4L, 4R) approximately centrally positioned between the closing interface 46 and the vertical doorframe 14v.

According to an aspect of the invention, the doors 4 each comprise a door panel 5 comprising external first and second panel layers 18 spaced apart from each other by a gap 19, and a web skeleton structure 6 arranged inside the gap 19. The doors may further comprise a filler material 20 also arranged inside the gap 19 between the external panel layers 18.

In a preferred embodiment, the external panel layers 18 are made of a fibre reinforced composite material. The fibre reinforced composite material is preferably a carbon fibre reinforced panel layer, but in variants may include a glass fibre reinforced panel layer, Aramid epoxy composites, and thermoplastics PA6 (polyamide 6), PA12 (polyamide 12), PVC (polyvinyl chloride), PP (polypropylene), PS (polystyrene), ABS (acrylonitrile butadiene styrene) with or without fibre reinforcement. It may be noted that the inner and outer external panel layers 18i, 18o may be made of different materials and/or the same materials but with different thicknesses or surface structures, whereby the panel layer 18o on an outer side of the container is preferably provided with geometrical and material properties that have a higher or equal resistance to the panel layer 18i on an inside of the container 1 , considering that external solicitation (shocks, bumps) are more likely and more prevalent on the outer surfaces of the shipping container.

The filler 20 may comprise a low density filler material such as a polymeric foam, for instance polyurethanes, polystyrene, PET (polyethylene terephthalate) and polyolefin foam materials, that may advantageously be injected into the gap between the panel external layers also around the web skeleton structure and other components within the gap 19 and subsequently solidified in a curing reaction. The filler 20 may also be provided as a preformed panel insert that is assembled together with the panel external layers.

In addition to the web skeleton structure mounted within the gap, spacer elements of a material with a higher rigidity than the filler material may be positioned in a few discrete positions to increase the bending resistance of the panels in a direction orthogonal to the plane of the surface of the panels.

The filler 20 not only provides support to the external panels 18, but in combination with the external composite panels 18, and the composite structure of the roof and other walls of the container, also advantageously provides thermal insulation to reduce temperature variations and peak temperatures inside the container.

The filler 20 and panels 18, and the composite structure of the roof and other walls of the container, may also serve to reduce vibration and noise in the container which may be useful in certain applications, such as for applications in which the shipping container is used as a mobile laboratory or mobile or temporary office or building site shelter. The doors 4 comprise hinges 28 including at least a top hinge 28T and a bottom hinge 28B, each hinge comprising a fixing plate 41 that is mounted against at least one of the external panel layers 18, whereby the attachment may comprise a bonding and/or riveting and/or screwing of the hinge fixing plate 41 against an outer surface of at least one of the panel layers and further coupled to an internal fixing plate 42, positioned within the gap between the external panel layers 18. The external panel layer 18 is thus clamped between the hinge fixing plate 41 and the internal fixing plate 42. Rivet, screw or bolt connections 49 extending from the hinge fixing plate 41 to the internal fixing plate, passing through orifices in the external panel layer 18, may be provided alone or in addition to a bonding connection between the panel layer and fixing plates.

In an advantageous embodiment, the internal fixing plate 42 may have opposed surfaces that engage the opposed inner surfaces of the external panels 18i, 18o, whereby the opposed surfaces are preferably bonded to the inner surfaces of the adjacent panel layers. The hinges 28 comprise a hinge portion 44 extending from the hinge fixing plate 42 and configured for mounting to a complementary hinge portion fixed to the vertical beams 14v of the door frame 14, whereby the hinge portion 44 may either be a hinge pin engaging in a cylindrical hinge orifice on the door frame, or vice-versa a ring into which a pin extending from the door frame is inserted.

The door according to an advantageous embodiment of the invention preferably comprises at least third and fourth hinges (intermediate top and bottom hinges 28Ti, 28Bi), with an identical or similar configuration to the above described first and second hinges (top and bottom hinges 28T, 28B) that may be positioned substantially symmetrically about a horizontal centre line of the doors in the respective upper and lower halves of the door as best illustrated in figure 3. A fifth hinge 28M, or yet further hinges, may be provided in embodiments. The

According to an aspect of the invention, the door closing mechanism 7 further comprises one or more centreline coupling mechanisms 8, 8c, 8t, 8b, arranged at the interface between the left and right doors that forms a substantially vertical centreline of the door side of the shipping container.

According to a preferred aspect of the invention, the door closing mechanism 7 comprises a centre coupling mechanism 8c provided at, or approximately at, the middle between the top horizontal edge and bottom horizontal edge of the doors (i.e. approximately in the middle of the height of the vertical interface / centreline 46). The coupling mechanism 8, 8c, 8t, 8b includes a first coupling part 8L on the left door and a second coupling part 8R on the right door, the first and second coupling parts configured to engage with each other when the doors are closed.

In an advantageous embodiment, one of the coupling parts 38L is a male part comprising a tapered protuberant surface 39L, and the other of the coupling parts 38R is a female part comprising a complementary tapered recessed surface 39R, such that when the doors are closed, the tapered surface 39L of the male part 38L engages the complementary tapered surface 39R of the female part 38R, configured to ensure that the left and right doors at their vertical closing interface can not shift relative to each other. This provides additional rigidity for the container against racking forces, which are forces that would tend to displace the top beam and bottom beam of the door frame 14 horizontally in opposite directions.

In a preferred embodiment provided with the centre coupling mechanism 8c, the centre of the interface 46 of the left door 4L is registered with the centre of the interface 46 of the right door 4R. In other words, when the doors are closed the tapered parts ensure that the left and right doors are coupled together mechanically at their centre and rigidly locked together in a rigid centre located position such that the left and right door interfaces can not slide or move vertically with respect to each other.

The coupling mechanism 8, 8c, 8t, 8b in preferred embodiments comprises a tapered protuberant part 38L that comprises a conical protuberance, which may engage in a conical recess constituting the tapered recessed part 38R. It may be noted that the term "conical" is not intended to mean a continuous surface, it being understood that there may be for instance grooves or other features in the conical surface, whereby the important property is that the engaging mating surfaces of the male and female conical parts allow the guiding of the left and right doors when they are being closed to a centre located position, and a rigid engagement that prevents movement between the coupling parts in any direction within the plane of the door, in the fully closed position.

According to an aspect of the invention, the web skeleton structure 6 comprises tensile interconnect elements 22 that extend from a position proximate the edge of each door hinged to the vertical beams 14v of the door frame 14, to a position proximate the joining interface (door vertical centreline) 46, in an angled direction from top to bottom or vice versa. Various arrangements of tensile interconnect elements are illustrated in figures 3 to 7d and 10 to 14k. According to a preferred aspect of the invention provided with the centre coupling mechanism 8c, the web skeleton structure 6 comprises tensile interconnect elements 22 that extend between the hinges 28 of the respective door 4L, 4R and the centre coupling mechanism 8c of the respective door 4L, 4R. In other words, the hinges 28 of the left door 4L are connected by the tensile interconnect elements 22 of the web skeleton structure to the first coupling part 8L on the left door, and the hinges 28 of the right door 4R are coupled with the tensile interconnect elements 22 of the web skeleton structure 6 to the second coupling part 8R of the right door. There are two web skeleton structures, one in the left door and one in the right door, having a substantially symmetrical mirror image configuration. The web skeleton structure of each door thus comprises a plurality of tensile interconnect elements whereby if each door has only two hinges, namely top and bottom hinges 28T, 28B, then the web skeleton structure comprises two tensile interconnect elements 28, and if the door comprises four hinges 28T, 28B, 28Ti, 28Bi, as illustrated in figure 3, then each web skeleton structure of one door may comprise four tensile interconnect elements 22.

In variants it may however be noted that each door may comprise more hinges than tensile interconnect elements, in other words not every hinge is necessarily connected to the centre coupling mechanism with a tensile interconnect element.

Nevertheless, in a preferred aspect of the invention there are at least two tensile interconnect elements 22, one interconnecting the top hinge 28T to the centre coupling mechanism 8c and the other interconnecting the bottom hinge 28B to the centre coupling mechanism 8c.

When the doors are closed and the centre coupling mechanism engaged and securely fixing the centre of the left and right doors together, the tensile interconnect element 22 from the top hinge 28T of the left door 4L can interconnect under a tractive force to the tensile interconnect element 22 interconnecting the centre coupling mechanism 8c of the right door 4R to the lower hinge 28B of the right door 4R, and similarly the top hinge 28T of the right door 4R is connected under a tractive force to the bottom hinge 28B of the left door 4L via the centre coupling mechanism 7 and tensile interconnect elements 22. Thus, if there is a racking force tending to shift the top horizontal beam of the door frame to the left relative to the floor 9, a traction force will be applied to the tensile elements 22tl and 22rb, which will thus provide resistance to counter racking against such deformation. The same applies in the opposite racking direction with the other pair of tensile elements extending between the bottom left corner to the top right corner.

Since these tensile interconnect elements only need to support high traction forces in order to accomplish the function of providing rigidity to the container against racking forces, they may be made with light weight structures.

In an aspect of the invention, the tensile interconnect element 22 comprises a continuously wound fibre string 24 interconnecting at least two nodes 26, the wound fibre string coated with or embedded in a binding matrix material.

The fibre string is preferably a string made of carbon fibre threads or aramid fibre threads. In variants, other fibre materials may also be used, including glass fibre threads, basalt fibre threads.

The fibre string 24 is continuous in the sense that a single string (having of course two ends) is wound, under a traction force, from one winding node 26 to the opposite winding node 26 and back again such that the single fibre string forms a plurality of windings around the at least two nodes 26h and 26c. The fibre string 24 is preferably wound at least twice around the pair of winding nodes 26h, 26c such that a cross-section of the tensile interconnect elements includes at least four fibre strings, but preferably there are more than two windings, for instance in a range of four to fifty fibre string windings.

After the winding operation under tension, the fibers of the tensile element are coated by a polymer matrix (e.g. an epoxy resin) that is cured to harden around the fibres rendering them self-supporting (rigid). Such structure is particularly light weight but extremely strong against tensile forces and thus forms an ideal racking interconnect element in conjunction with the centre coupling mechanism to provide high rigidity against racking of the container door frame 14.

The racking resistance also provides greater overall structural strength to the shipping container 1 which may thus be provided with a lighter frame 2, saving weight not only from the lighter doors, but also from the lighter frame.

As illustrated in the embodiment of figure 3, a second pair of hinges 28Ti, 28Bi with tensile interconnect elements 22 may further increase the rigidity of the door frame 14 against racking forces.

In an example, the fibre strings may comprise a threaded carbon or aramid fibre string having a diameter of between fifty micrometers and three millimeters, and the polymer matrix may comprise various thermoset (e.g. epoxy resins) or thermoplastic (e.g. polyamides such as PA6 or PA12) polymers. It may however be noted that various fibre strings resistant to traction forces, and different polymer matrixes for binding the fibre strings together to render them self- supporting/rigid as per se known in the art of composite materials, may be provided without departing from the scope of the invention.

The winding nodes may comprise bushings with end flanges to ensure the wound fibre is remained within the groove of the bushing. The bushing may for instance comprise a rounded surface portion against which the wound fibre string is in contact, for instance the bushing may be in the form of a cylinder, and for instance comprise a hole or pin for fixing on a jig of a winding machine to hold the winding nodes in fixed positions corresponding to the final installed positions in the door until the polymer matrix has been cured. The hole or pin may in addition or alternatively serve to fix the winding node to structural elements of the door. The bushing may be may of various materials, for instance metals such as steel, brass, aluminium and various polymers.

Respective winding nodes 26 may be formed integrally with, or rigidly fixed (e.g. welded, bonded, bolted) to respective hinge internal fixing plates 42 and support plates 43 of the centre coupling mechanism 8c.

In a variant, the tensile interconnect elements 22 may comprise a continuous wound fibre string 24 that extends from the top hinge 28T to the centre coupling mechanism 8c and further to the second intermediate top hinge 28Ti such that there are, in such configuration, three nodes 26 for a single fibre string, the three nodes 26 and tensile interconnect elements 22 substantially forming a “V” shape. Similarly, the tensile interconnect elements 22 may comprise a continuous wound fibre string 24 that extends from the bottom hinge 28B to the centre coupling mechanism 8c and further to the second intermediate bottom hinge 28Bi.

Various winding orders and configurations may be provided to provide the tensile interconnect elements 22 extending between the centre coupling mechanism and hinges without departing from the scope of the invention. In this respect it may be noted that the important aspect of this invention is that the centre node is coupled to the upper and lower hinges and interconnects through the centre coupling mechanism to the lower and upper hinges respectively of the opposite door, whereby whether the tensile interconnect elements are formed of a continuous fibre string between only two nodes or a single continuous fibre string between more than two nodes, this does not make in essence a fundamental difference to the resistance against racking forces provided that the opposite corners of the door frame are interconnected by tensile interconnect elements 22 in traction against forces that tend to increase the distance between the diametrically opposed corners.

According to an aspect of the invention, in another embodiment illustrated in figures 10 to 11e, the doors comprise two centreline coupling mechanisms St, 8b, a first centreline coupling mechanism 8t positioned in a vertical upper half of the interface between the left and right doors, and a second centreline coupling mechanism 8b positioned in a vertical lower half of the interface between the left and right doors. The centreline coupling mechanisms 8t, 8b, may have the same structure as the centre coupling mechanism 8c previously described and illustrated in figures 8 to 9b.

The web skeleton structure 6 comprises tensile interconnect elements 22 that extend between each centreline coupling mechanism 8t, 8b of the respective door 4L, 4R and at least two of the hinges 28 of the respective door 4L, 4R. The web skeleton structures in the left and right doors may have a substantially symmetrical mirror image configuration about the vertical centreline defined by the joining interface between the right and left doors.

In the embodiment illustrated in figures 10 to 11e each door comprises at least four hinges 28T, 28B, 28Ti, 28Bi, whereby the two upper hinges 28T, 28Ti in the upper half are connected to the upper centreline coupling mechanism 8t with the tensile interconnect elements 22, and the two lower hinges 28B, 28Bi in the lower half are connected to the lower centreline coupling mechanism 8b with the tensile interconnect elements 22.

According to an aspect of the invention, in another embodiment illustrated in figures 12 to 13d, the web skeleton structure 6 of each door 4L, 4R comprises tensile interconnect elements 22 that extend between a top hinge 28T and a bottom anchor plate 37b positioned in a corner formed by the bottom edge and vertical centreline of the door (the centreline being at the interface between the right and left doors), and between a bottom hinge 28B and a top anchor plate 37t positioned in a corner formed by the top edge and vertical centreline of the door. The web skeleton structures in the left and right doors may thus each have a general “X” shape and have a substantially symmetrical mirror image configuration about the vertical centreline defined by the joining interface between the right and left doors. The top and bottom anchor plates 37t, 37b are positioned within the gap between the external panel layers 18 and may be mounted between against at least one of the external panel layers 18, whereby the attachment may comprise a bonding and/or riveting and/or screwing of the anchor plate 37t, 37b against an inner surface of at least one of the panel layers.

In an advantageous embodiment, the anchor plate 37t, 37b may have opposed surfaces that engage the opposed inner surfaces of the external panels 18i, 18o, whereby the opposed surfaces are preferably bonded to the inner surfaces of the adjacent panel layers. The anchor plates 37t, 37b are preferably provided opposite holders 36 of the pivotable rods 30 of the door closing mechanism 7, proximate the closing hook 32. Winding nodes 26 may be integrally formed with the anchor plates or assembled thereto similarly to the winding nodes attached to the hinge internal fixing plates 42 previously described.

When the doors are closed, the tensile interconnect elements 22 of each door 4L, 4R connect the top hinge 28T to the bottom corner anchor plate 37B under a tractive force and the bottom hinge 28B to the top corner anchor plate 37T under a tractive force. Thus, if there is a racking force tending to shift the top horizontal beam of the door frame to the left relative to the floor 9, a traction force will be applied to the tensile elements in both the left door and the right door that extend from the top left to the bottom right (indicated as tensile elements 22TIBr), which will thus provide resistance to counter racking against such deformation. The same applies in the opposite racking direction with the other pair of tensile elements extending between the bottom left corner to the top right corner of each door (indicated as tensile elements 22BITr).

Various arrangements of tensile interconnect elements 22 and centreline coupling mechanisms 8 and corner anchor plates 37 may be provided as illustrated schematically in figures 4a to 4k. In figures 4a to 4k, the web skeleton structure is illustrated in only the left door, it however being understood the right door also has the same web skeleton structure (in mirror image symmetry).

For instance, the web skeleton structure of the embodiment of : figure 14d corresponds to a combination of the web skeleton structures of figures 3 and 10, figure 14g corresponds to a combination of the web skeleton structures of figures 3 and 12, figure 14i corresponds to a combination of the web skeleton structures of figures 10 and 12, figure 14k corresponds to a combination of the web skeleton structure of figure 12 and a centre coupling mechanism 8c, figure 14d is a variant of the web skeleton structure of figure 14d, figure 14f is a variant of the web skeleton structure of figure 14g, figures 14b, 14c, 14e, 14h, 14j are various other variants of web skeleton structures. List of references

Shipping container 1

Storage chamber 11

Frame 2

Corner 10

Beam 12

Door frame 14

Side beams 14v

Top beam

Bottom beam

Wall panels 3

Side 3s

End 3e

Roof 3r

Floor 9

Doors 4

Left door 4L

Right door 4R

Joining interface 46

Door panel 5

External panel layers 18

Inside layer 18i

Outside layer 18o

Filler 20

Web skeleton structure 6 tensile interconnect element 22 linear tensile interconnect element

Fibre string 24

Winding node 26

Bonding matrix (resin)

Hinge 28

Hinge fixing plate 41

Internal fixing plate 42

Hinge portion 44

Bolt 49

Door closing mechanism 7

Pivotable rods 30

Closing hook 32

Closing handle 34

Holders 36

Anchor plate 37t, 37b

Top anchor plate 37t

Bottom anchor plate 37b

Centreline coupling mechanism 8c, 8t, 8b

Centre coupling mechanism 8c

Top, bottom centreline coupling mechanisms 8t, 8b

First coupling part 8L

Tapered protuberant part (male part) 38L

Conical protuberance

Second coupling part 8R

Tapered recessed part (female part) 38R

Conical recess

Support plate 43

Centre Locking mechanism (not shown)

Claims

1. Shipping container (1) comprising a frame (2) including a door frame (14), a floor (9), a roof and wall panels (3) fixed to the frame (2), and doors (4) including a left door (4L) and a right door (4R), the left door comprising a door panel coupled via hinges (28) to a left side vertical beam (14v) of the door frame (14) and the right door (4R) comprising a door panel (5) coupled via hinges (28) to a right side vertical beam (14v) of the door frame (14), said hinges comprising at least one top hinge (28) and one bottom hinge (28b), the right door (4R) and left door (4L) joined together at a centre vertical interface (46) when the doors are closed, the doors further comprising a closing mechanism (7), characterized in that the door panel (5) of each door comprises at least a first external panel layer (18) and a second external panel layer (18) forming a gap (19) therebetween, a web skeleton structure (6) mounted within the gap and attached to the first and second external panel layers, and a filler positioned within the gap, the web skeleton structure including a plurality of tensile interconnect elements (22) extending at an angle relative to the horizontal direction from a position proximate an edge of each door adjacent said vertical beams (14v) of the door frame (14), to a position proximate the centre vertical interface (46), each tensile interconnect element comprising a continuously wound fibre string wound around at least two winding nodes (26h, 26c) and a polymer binding matrix coated around said wound fibre string configured to render the wound fibre string rigid and self-supporting.

2. The shipping container according to the preceding claim wherein the fibre strings are selected from a group consisting of carbon fibre, aramid fibre, glass fibre, basalt fibre and the polymer binding matrix is selected from a thermosetting or thermoplastic polymer, for instance epoxy resins, polyamide 6, polyamide 12, polyvinyl chloride, polypropylene, polystyrene, acrylonitrile butadiene styrene.

3. The shipping container according to any preceding claim wherein the materials of the external panel layers (18) are selected from a group consisting of aramid epoxy composites, and thermoplastics including polyamide 6, polyamide 12, Polyvinyl chloride, Polypropylene, Polystyrene, and Acrylonitrile Butadiene Styrene, with or without fibre reinforcement, said fibre reinforcement including carbon fibre, glass fibre, aramid fibre, basalt fibre.

4. The shipping container according to any preceding claim, wherein the filler (20) for instance comprises or consists of a polymeric foam such as polyurethanes, polystyrene, polyethylene terephthalate and polyolefin foam materials.

5. The shipping container according to any preceding claim wherein said hinges are attached or integrally formed with the winding nodes (26) positioned proximate the edge of the door adjacent said vertical beams (14v) of the door frame (14).

6. The shipping container according to any preceding claim wherein said hinges comprising at least the top hinge (28T) and the bottom hinge (28B) each comprise an internal fixing plate (42) having at least one surface attached against an inner side of at least one of the external panel layers (18) one winding node (26) being integrally formed with, or fixed to, the internal fixing plate.

7. The shipping container of the preceding claim wherein said hinges comprising at least the top hinge (28T) and the bottom hinge (28B) each comprise an external hinge fixing plate (41) having at least one surface attached against an outer side of an outer external panel layers (18o), the external hinge fixing plate (41) and internal fixing plate clamping the outer external panel layers (18o) therebetween.

8. The shipping container according to any preceding claim wherein at least one of the plurality of tensile interconnect elements is attached to the top hinge (28T) and at least one other of the plurality of tensile interconnect elements is attached to the bottom hinge (28B).

9. The shipping container according to the preceding claim wherein the doors comprise a second top hinge (28Ti) positioned between the top hinge and a vertical middle of the door and, a second bottom hinge (28Bi) formed between the bottom hinge and the vertical middle of the container door, at least one of the plurality of tensile interconnect elements is attached to the second top hinge (28Ti) and at least one other of the plurality of tensile interconnect elements is attached to the second bottom hinge (28Bi).

10. The shipping container according to any preceding claim wherein the doors (4) further comprise a centre coupling mechanism (8) comprising a first coupling part (8L) on the left door and a second coupling part (8R) on the right door, the first and second coupling parts engaging together when the doors are closed configured to prevent vertical sliding of the left and right doors at the centre interface (46).

11 . The shipping container according to the preceding claim wherein one of first coupling part and the second coupling part of the centre coupling mechanism (8) comprises a tapered protuberant male part (38L) and the other of the first coupling part and the second coupling part comprises a tapered recessed female part (38R), for instance wherein the tapered protuberant, respectively recessed parts comprise conical surfaces.

12. The shipping container according to either of the two directly preceding claims wherein at least two of the plurality of tensile interconnect elements (22) are attached to the centre coupling mechanism.

13. The shipping container of the preceding claim wherein said at least two of the plurality of tensile interconnect elements (22) attached to the centre coupling mechanism include one attached to the top hinge and the other attached to the bottom hinge.

14. The shipping container according to the preceding claim wherein the web skeleton structure includes further tensile interconnect elements (22) extending between additional hinges (28Ti, 28Bi) and the centre coupling mechanism (8).

15. The shipping container according to any preceding claim wherein the web skeleton structure (6) of each door comprises at least one tensile interconnect element extending from a top left corner to a bottom right corner of the door, and at least one tensile interconnect element extending from a top right corner to a bottom left corner of the door.

16. Shipping container (1) comprising a frame (2) including a door frame (14), a floor (9), a roof and wall panels (3) fixed to the frame (2), and doors (4) including a left door (4L) and a right door (4R), the left door comprising a door panel coupled via hinges (28) to a left side vertical beam of the door frame (14) and the right door (4R) comprising a door panel (5) coupled via hinges (28) to a right side vertical beam of the door frame (14), said hinges comprising at least one top hinge (28) and one bottom hinge (28b), the right door (4R) and left door (4L) joined together at a centre vertical interface (46) when the doors are closed, the doors further comprising a closing mechanism (7), characterized in that the door panel (5) of each door comprises at least a first external panel layer (18) and a second external panel layer (18) forming a gap (19) therebetween and a filler positioned within the gap (19), the doors (4) further comprising a centre coupling mechanism (8) comprising a first coupling part (8L) on the left door and a second coupling part (8R) on the right door, the first and second coupling parts engaging together when the doors are closed configured to prevent vertical sliding of the left and right doors at the centre interface (46).

17. The shipping container according to the preceding claim wherein at least one of the external panel layers consists of or comprises a fibre reinforced composite material, for instance a carbon fibre reinforced material.

18. The shipping container according to the preceding claim wherein both of the external panel layers (18) consist of or comprise a fibre reinforced composite material.

19. The shipping container according to any preceding claim 16-18 wherein the filler (20) comprises or consists of a polymeric foam such as polyurethanes, polystyrene, polyethylene terephthalate and polyolefin foam materials.

20. The shipping container according to any preceding claim 16-19 wherein one of first coupling part and the second coupling part of the centre coupling mechanism (8) comprises a tapered protuberant male part (38L) and the other of the first coupling part and the second coupling part comprises a tapered recessed female part (38R).

21. The shipping container according to the preceding claim wherein the tapered protuberant, respectively recessed parts comprise conical surfaces.

22. The shipping container according to any preceding claim 16-21 wherein each left and right door comprises a web skeleton structure (6) including a tensile interconnect element (22) extending between at least the top hinge (28T) and the centre coupling mechanism (8) and between the bottom hinge (28B) and centre coupling mechanism (8), the tensile interconnect element comprising a continuously wound fibre string wound around at least two winding nodes (26h, 26c) and a polymer binding matrix coated around said wound fibre string configured to render the wound fibre string rigid and self-supporting.

23. The shipping container according to the preceding claim 16-22 wherein the web skeleton structure includes further tensile interconnect elements (22) extending between additional hinges (28Ti, 28Bi) and the centre coupling mechanism (8).

24. The shipping container according to either of the two directly preceding claims wherein the fibre strings are selected from a group consisting of carbon fibre, aramid fibre, glass fibre, basalt fibre and the polymer binding matrix is selected from a thermosetting or thermoplastic polymer, for instance epoxy resins, polyamide 6, polyamide 12, polyvinyl chloride, polypropylene, polystyrene, acrylonitrile butadiene styrene.

25. The shipping container according to any preceding claim 16-24 wherein the materials of the external panel layers (18) are selected from a group consisting of aramid epoxy composites, and thermoplastics including polyamide 6, polyamide 12, Polyvinyl chloride, Polypropylene, Polystyrene, and Acrylonitrile Butadiene Styrene, with or without fibre reinforcement, said fibre reinforcement including carbon fibre, glass fibre, aramid fibre, basalt fibre.

26. The shipping container according to any preceding claim 16-25 wherein the doors comprise a second top hinge (28Ti) positioned between the top hinge and a vertical middle of the door and the second bottom hinge (28Bi) formed between the bottom hinge and the vertical middle of the container door.

27. The shipping container according to any of the five directly preceding claims wherein the web skeleton structure (6) of the left door is substantially in mirror image symmetry with the web skeleton structure (6) of the right door.

28. The shipping container according to any of the six directly preceding claims wherein at least the top hinge (28T) and the bottom hinge (28B) each comprise an internal fixing plate (42) having at least one surface attached against an inner side of at least one of the external panel layers (18) one winding node (26) being integrally formed with, or fixed to, the internal fixing plate.

29. The shipping container according to the preceding claim wherein the internal fixing plate (42) comprises opposed fixing surfaces, each bonded or clamped to an inner side of an adjacent one of the external panel layers.

30. The shipping container of the preceding claim wherein at least the top hinge and the bottom hinge (28) each comprise an external hinge fixing plate (41) having at least one surface attached against an outer side of an outer external panel layers (18o), the external hinge fixing plate (41) and internal fixing plate clamping the outer external panel layers (18o) therebetween.