FOLDABLE STRUCTURES

Abstract

A foldable system is described. The system includes a panel consisting of at least two layers, a first flexible layer and a second non-flexible layer, the first and the second layer being attached to each other such that they form a whole, the panel including folds, the folds being applied in the second layer such that the panel can be folded into a predetermined shape. In addition, the first flexible layer includes material with a higher melting temperature than the melting temperature of the second layer.

Claims

1.-17. (canceled)

18. A foldable system, the system having a panel consisting of at least two layers, a first flexible layer and a second non-flexible layer, the first and the second layer being attached to each other such that they form a whole, the panel containing folds, the folds being applied in the second layer such that the panel can be folded into a predetermined shape, the first flexible layer including a material with a melting temperature that is higher than the melting temperature of the second layer.

19. A system according to claim 18, wherein the melting temperature of the first layer at least 80 C. is higher than the melting temperature of the second layer.

20. A system according to claim 18, the first layer comprising at least one of the following materials: PET, polyester, COC (cyclic olefin copolymer), polyamide, polystyrene, polycarbonate, PVC or a mixture thereof.

21. A system according to claim 18, the second layer comprising at least polypropylene.

22. A system according to claim 18, the first and the second layer being adhered to each other prior to the application of the folds.

23. A system according to claim 18, the fold being a groove in the second layer.

24. A system according to claim 18, the desired form being a shape of a boat.

25. A system according to claim 18, the cross-section of a fold being an angle.

26. A system according to claim 25, wherein two fold lines are located next to each other and wherein the distance between the two fold lines is smaller than the width of a fold line.

27. A system according to claim 18, the second layer including material which has a cell structure.

28. A system according to claim 18, wherein at least one fold is applied in the panel such that the panel can be folded up into a more compact form than the desired form.

29. A system according to claim 28, the folds being arranged such that hollow spaces are provided in the more compact form.

30. A system according to claim 28, wherein the folds are arranged so that the more compact form is folded according to a double spiral.

31. A method for applying folds in a panel, the panel consisting of a first layer and a second layer, the first layer having a higher melting temperature than the second layer, and the folds only being applied in the second layer by means of scoring, locally melting away of material or locally pushing away of material, wherein the second layer is indirectly melted locally by locally heating, at the location where the fold is to be applied, the first layer, below the melting temperature of the first layer, but above the melting temperature of the second layer, and by conduction of the applied heat to the second layer.

32. A method according to claim 31, the folds being applied with a CNC-controlled machine.

33. A method according to claim 32, the local heating being done by means of a thermal source mounted on the CNC-controlled machine.

34. A method according to claim 31, the local heating taking place at a temperature that is between 15% and 50% of the temperature difference between the melting temperature of the first layer and the second layer lower than the melting temperature of the first layer.

35. A method according to claim 31, wherein the locating heating taking place at a temperature that is between 20% and 40% of the temperature difference between the melting temperature of the first layer and the second layer lower than the melting temperature of the first layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 shows the cross-section of a panel, including a fold line with an angle of 90, according to embodiments of the present invention.

[0044] FIG. 2 shows the cross-section of a panel, including two fold lines, each with an angle of 90, according to embodiments of the present invention.

[0045] FIG. 3 shows the cross-section of a panel, including a fold line with an angle of 0, according to embodiments of the present invention.

[0046] FIG. 4 shows a 3D-drawing of a folded panel, according to embodiments of the present invention.

[0047] FIG. 5 shows the top view of a panel according to embodiments of the present invention.

[0048] FIG. 6 shows the top view of a boat according to an embodiment of the present invention.

[0049] The drawings are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes.

[0050] Any reference signs in the claims shall not be construed as limiting the scope. In the different drawings, the same reference signs refer to the same or analogous elements.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0051] Although the present invention will hereinafter be described with respect to particular embodiments and with reference to certain drawings, the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.

[0052] Furthermore, the terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0053] Moreover, the terms top, bottom, above, front and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

[0054] It is to be noticed that the term includes, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression a device including means A and B should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

[0055] Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases in one embodiment or in an embodiment in various places throughout this specification do not necessarily all refer to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0056] Similarly, it should be appreciated that in the description of illustrative embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

[0057] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0058] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0059] Where in embodiments of the present invention reference is made to the folding corners, the angles in the panel are meant which are formed when the panel is fully unfolded to form the intended system, for example, a boat form, or compact form. These are the angles along the folds.

[0060] Where in embodiments of the present invention reference is made to the width of a fold line, the distance will be measured between the two extreme points of the diagonals of the cross-section of the fold line.

[0061] Where in embodiments of the present invention reference is made to the distance between two fold lines, this distance will be measured between the extreme points of the diagonals of the cross sections of the fold lines, the diagonal of the one fold line and the diagonal of the other fold line being chosen such that it will be these diagonals that are closest together.

[0062] When in embodiments of the present invention reference is made to a fold, it may therefore be built up of a single or a double fold line (or possibly even further fold lines).

[0063] In a first aspect, the present invention provides a foldable system, for example, a system that can be folded into a vessel. Alternative systems may be, for example, parts of a folding caravan, temporary enclosures, sturdy watertight packaging, roofs for mobile homes, loading compartments of vans, toys for children, etc. By way of illustration, the aspect will be mainly illustrated with reference to a vessel. The vessel may be, for example, a kayak or a canoe. The system includes a panel, the panel being made up of at least a first layer and a second layer. The first layer is a flexible layer and can, for example, be made of PVC and/or polyester. The first flexible layer can, for example, be a coated cloth. In a specific example, the first flexible layer is, for example, made of the material commercially known by the name Curv. The first layer can be a watertight layer.

[0064] The first layer may comprise at least one of the following materials: PET, polyester, COC (cyclic olefin copolymer), polyamide, polystyrene, polycarbonate, PVC or a mixture thereof. However, embodiments are not limited thereto.

[0065] In embodiments of the present invention, there is typically at least one non-flexible layer and a flexible layer. The one layer is typically also more rigid than the other layer.

[0066] According to embodiments of the present invention, the first flexible layer includes a material with a higher melting temperature than the melting temperature of the second layer. The first layer may also be made entirely from a material having a melting temperature higher than the first layer. In some embodiments, the melting temperature of the first layer can be at least 80 C., for example, at least 100 C., higher than the melting temperature of the second layer.

[0067] The second layer may comprise at least polypropylene or consist entirely of this material.

[0068] It is to be understood that the first layer and the second layer can each consist of multiple layers.

[0069] According to embodiments of the present invention, the first and second layer can be advantageously adhered to each other prior to the application of the folds. The first layer can be applied to the second layer, for example, via lamination. This can be, for example, hot or cold lamination. In some examples, the two layers are, for example, melted together under elevated pressure and elevated temperature (hot lamination). Optionally, additional use can be made of an intermediate layer of adhesive in this process. The first layer can also be glued on the second layer or the second layer can be applied on the first layer using 3D printing techniques. Panels according to the present invention also include folds which are positioned in such a way that the panel can be folded into a particular pattern, for example, into a boat. The size of the system, for example, the boat, can be, for example, between 2 and 6 m. In the case of a boat, it may, for example, have a length of about 5 m (typically a large boat), or it may, for example, have a length of about 3 m (typically a small boat). It is an advantage of embodiments of the present invention that the weight of the object can be limited.

[0070] In embodiments of the present invention, folds are provided which allow folding the panel up into a more compact form than when the panel is fully unfolded into the desired form of the system, for example, in boat form. Such a more compact form can, for example, be a beam-shaped double spiral with cavities. By applying a cover plate or tarpaulin to the hollow sides of this more compact form the whole can be transformed into a box and the sides of the plate can be protected.

[0071] In some embodiments, the panel comprises a plurality of folds in the transverse direction of the object so that the panel can be folded up into a transport form for transporting the foldable object, the length of the transport form corresponding to the width of the unfolded panel.

[0072] In embodiments of the present invention, the second layer has a thickness of between 0.3 mm and 2.0 mm, preferably between 0.6 mm and 0.8 mm. The advantage of a thicker second layer is that a greater rigidity can be obtained. Preferably, an optimum is chosen between a layer with high rigidity and a layer with good pliability and sufficiently low weight. Because the panel according to the present invention typically consists of two layers, a combination of good rigidity, pliability and water resistance is in any case obtained.

[0073] The second layer may have a honeycomb pattern. The cells herein are each individually sealed cells. If a hole is made in the panel, the other cells remain intact and still contain air so that the buoyancy of the cells that are not impacted by the hole is not diminished.

[0074] Because of the thickness of the second layer, and the fact that the second layer is made of a rigid material (for example, with a honeycomb pattern), the second layer is not foldable. Moreover, a honeycomb pattern is equally rigid in all directions; in other words, it doesn't fold easier in one direction relative to another direction. If the structure is a boat, this results, for example, in a high stability in the water, in both the transverse and longitudinal direction. In order to make the panel foldable, the panel is made of a second layer having thereon a first layer that is foldable. On the folds, material of the second folding layer is removed or it is arranged during production that less material is present thereeither over a part of the thickness of the second layer, or completelyso that space is released to fold the panel around the folds and such that, due to the reduced thickness of the second plate, it becomes foldable. By removing the material, the stress, which would be built up in the second plate when folding it, is reduced or even completely removed. The flexible first layer serves as a hinge point. No notches need to be made herein in order to allow the folding so that the panel 110 will remain watertight, if the first layer is watertight.

[0075] In some embodiments of the present invention, a fold is made by removing a wedge shape from the second layer, or by applying a corresponding groove. The angle of the wedge can be located, for example, between 20 and 130, for example, between 40 and 110, for example, between 80 and 100, for example 90. An example of this can be seen in FIG. 1. FIG. 1 shows the cross section of a panel 110 according to an embodiment of the present invention. The panel consists of a first flexible watertight layer 114 and a second stiffer layer 112, which is shielded by a third layer 116. In this example, the first layer 114 is a 0.8 mm thick, dark grey PVC-coated polyester layer. In the example, the second layer 112 is a 7 mm thick layer with a honeycomb pattern. A third layer 116 of flexible PVC material is applied to this. This can be done, for example, by means of lamination. In some embodiments, a PVC-coated polyester layer is attached on a polyester non-woven micro fleece layer.

[0076] A fold 120 is applied in the second layer 112, and in this example, through the third layer 116. This fold 120 has an angle of 90. As a result, the panel can be folded such that the plane along the one side of the fold forms an angle of 90 with the plane along the other side of the fold. In embodiments of the present invention, a fold in this direction is also referred to as an inner fold. In this case, after folding, the first layer 114 is on the outside of the angle. The angle that can be formed in this case by the folded panel is at an angle of 90.

[0077] FIG. 2 shows an embodiment of the present invention in which two fold lines are arranged next to one another in panel 110. In this embodiment, both fold lines 120 touch each other. Both fold lines 120 have an angle of 90. When folding is done according to these fold lines, an inner fold will be formed again. As a result, the one side of the panel can be folded parallel with the second side of the panel. In other words, an inner fold of 180 is formed. In such a situation the fold is such that the outside of the folded panel 110 is formed by the first layer 114.

[0078] In some embodiments of the present invention, the fold is made by making an incision in the second layer or cutting through it completely, as a result of which there will be no angle present in the incision. This incision with an angle of 0, in other words, does not allow an inner fold to be made, but it does allow an outer fold to be made. With an outer fold, the panel is folded around the fold such that the first layer 114 is located on the inside of the angle. FIG. 3 shows an embodiment of the present invention in which the fold 120 is an incision in the second layer. The panel 110 can be folded such that the one side of the panel 110 is parallel to the second side of the panel 110, and the first layer 114 is located on the inside of the fold.

[0079] FIG. 4 shows a 3D-drawing of a folded panel 110 according to embodiments of the present invention. The panel is folded according to the folds 120.

[0080] FIG. 5 shows a panel 110 according to embodiments of the present invention. The individual continuous lines in the figure are folds through a number of fold lines 120. By folding the panel along these lines, a canoe is obtained. The dotted lines or folds 610 which serve for folding up the boat. In this example, the panel has a size of 365125 cm. This results in a canoe with a length of about 3 m.

[0081] In embodiments of the present invention, the folds 610 for the folding up of the panel 110 are arranged such that the panel can be folded up into a double spiral. Inside the spiral, spaces can thereby be provided in which additional material may be placed. FIG. 6 shows the top view of a specific object, in this case a boat, according to an embodiment of the present invention. Tensioning straps 1540 are applied in the boat which are tensioned from one side to the other side of the folded boat. These tensioning straps 1540 are so arranged in this embodiment of the present invention that they cross each other in the middle of the boat. Over the entire length of the boat, four pairs of tensioning straps 1510 are applied. The tensioning straps 1510 that are closer to the bow or at the stern of the boat are tensioned over a shorter longitudinal distance of the boat than the tensioning straps that are located more towards the centre. Depending on the shape of the vessel, the position of the tensioning straps 1510 and the number of tensioning straps can be different. For example, the tensioning straps may be attached to the vessel by means of ratchet buckles. The tensioning straps can be, for example, polyester tensioning straps with a width of 2.5 mm.

[0082] The intersection of two tensioning straps 1510 can be used to support the buttocks when rowing (for example, when rowing in the kneeling position). It is an advantage of embodiments of the present invention that the kneeling position is the most ergonomic way of canoeing. The position of the intersection of the tensioning straps can be changed by means of the ratchet buckles. As a result, even when sailing, the position of the rower can be adjusted slightly (for example, in the vertical direction over a distance of 10 cm) to avoid stiffness. Depending on whether one or two people are sailing, the position of the intersecting straps can be changed. In FIG. 6, at the height of the intersection of the middle tensioning straps 1510, seats 1530 are applied. These seats rest on the tensioning straps 1510 and can be used as support when rowing. These seats 1530 may be made of, for example, EVA (ethylene vinyl acetate).

[0083] FIG. 6 also shows a spacer 1520 which is placed between the one side of the vessel and the other side of the vessel. This spacer 1520 can be, for example, an aluminium tube. Other materials such as wood, PVC (polyvinyl chloride) or reinforced polypropylene are also possible. In other embodiments of the present invention, this spacer 1520 can also be, for example, a telescopically extendable walking stick or a photo monopod. In this case, additional accessories can optionally be provided which make it possible to place the walking stick or the monopod on the side walls of the vessel. In embodiments of the present invention, multiple spacers and additional tensioning straps can be applied. Embodiments according to the present invention include a corner plate 1550 which can be placed in the front or back of the vessel. An example of this is shown in FIG. 6. When placed, the corner plate abuts the inner side of the folded boat. In this example, the folded boat has a main fold 1560 both at the front (the bow) and at the rear (the stern). A main fold 1560 can be realised by means of two double folds and one incision whose angle is 0. Here, a portion of the panel 110 is folded inwardly in order to make the bow and the stern point-shaped. With this main fold 1560, a portion of the panel on the one side of the fold abuts closely with the portion of the panel on the other side of the fold when the panel is folded into boat form. Both sides are then parallel with each other. In embodiments of the present invention, a slot 1570 is provided in the corner plate 1550. This slot 1570 is positioned such that it fits around the main fold 1560 when the corner plate is placed at the front or rear of the vessel. It is furthermore an advantage of embodiments of the present invention that the main fold 1560 is held together by the slot 1570 in the corner plate. A corner plate 1550 may, for example, be secured in the vessel with tensioning straps.

[0084] Embodiments of the present invention include slide-over edges 1540 that can be slid over the sides of the vessel (the gunwale). These slide-over edges serve to reinforce the vessel. The above example concerned a canoe by way of illustration of the foldable watertight structures. However, it should be noted that the present invention is not limited thereby. It is to be understood that the panel can also be used for other objects, such as for other boats, or for other structures such as folding caravans, temporary enclosures, sturdy watertight packaging, roofs for mobile homes, loading compartments of vans, toys for children, etc.

[0085] In a second aspect, the present invention provides a method for making a fold in the panel. The method is typically applicable to a panel consisting of a first layer and a second layer, the first layer having a higher melting temperature than the second layer, and the folds only being applied in the second layer by means of scoring, locally melting away of material or locally pushing away of material. According to embodiments of the present invention, to this end, the second layer is indirectly melted locally by locally heating, at the location where the fold is to be applied, the first layer, below the melting temperature of the first layer, but above the melting temperature of the second layer, and by conduction of the applied heat to the second layer.

[0086] In embodiments of the present invention, the fold is applied through scoring, for example with a blunt blade or wheel. In embodiments of the present invention, the folds can be applied by means of a scoring technique, for example, by means of a CNC (Computerised Numerical Control) scoring technique. The latter method is used, for example, for the application of a fold in a twin-walled polypropylene plate having a honeycomb structure inside. The groove can be formed by pressing down or pressing in of a line or blunt object, such as a blunt wheel. Alternatively, material may also be removed by melting away. In a further alternative, the material may be pressed to the side of the fold line. In advantageous embodiments wherein the non-flexible material consists of a honeycomb structure, no local thickening is caused by this pressing away to the side of the fold line.

[0087] The local heating can, for example, be done by means of a thermal source mounted on the CNC-controlled machine. Alternatively, a separate device may be provided for heating.

[0088] The local heating can take place at a temperature that is between 5% and 95% of the temperature difference between the melting temperature of the first layer and the second layer lower than the melting temperature of the first layer, for example, between 15% and 50% of the temperature difference between the melting temperature of the first layer and the second layer lower than the melting temperature of the first layer, or preferably between 20% and 40% of the temperature difference between the melting temperature of the first layer and the second layer lower than the melting temperature of the first layer.

[0089] The various aspects can easily be combined with each other, and the combinations thus also correspond with embodiments according to the present invention.

[0090] By way of illustration, embodiments of the present invention not limited thereby, a specific example will be described of a material and a method for creating folds in such a material.

[0091] The material in the present example concerns a layered structure of PET-coated Propex Cury on a polypropylene honeycomb structure having a thickness of 8 mm. The PET layer has a thickness of 0.04 mm. The Propex Cury layer has a thickness of 0.36 mm. It is to be understood that polyester, COC (cyclic olefin copolymer), polyamide, polystyrene, polycarbonate, or a mixture thereof, may be used as an alternative to the PET coating.

[0092] An example of a process for creating a fold, as used in the present example, is illustrated below. For the present example, the melting temperature of PET is 260 C., while the melting temperature of polypropylene is only 130 C.

[0093] In the process for making a fold, heat is added locally, just before a groove is made with a blunt object. 230 C. was the temperature chosen for the local heating. This is sufficient to weaken the PET and Propex Cury layer, but not to break it when the incision is made, while the inner polypropylene honeycomb structure does melt locally. At that temperature, the PET coating is also sufficiently strong to prevent the Propex Cury material from deforming.

[0094] By only adding heat locally the material cools off quickly, as a result of which the created groove retains its shape. If a temperature were to be used that was too high, the cooling would be too slow and the groove would not retain its shape. If a temperature for local heating is chosen which is too low, the honeycomb layer won't melt and the PET layer won't weaken, whereby the outer layer may break. The honeycomb layer will then just return to its original state after the scoring.

[0095] It is an advantage of embodiments of the present invention that a CNC technique can be used for making folds in the material, which allows for fast prototyping. In this way the need for hot pressing in order to make folding patterns in the material can be avoided. The applicability of CNC not only allows rapid prototyping, but also allows for simpler cooling conditions to be used, making the overall production process faster. This is also the case when a press technique is used.