Inflatable product with an internal tensioning structure

Description

Background of the invention

1. Technical field

[0001] The present disclosure relates to an inflatable article structure, and more particularly to an inflatable article structure that is lightweight and cheap.

2. State of the art

[0002] Inflatable articles are light, easy to store and easy to carry. The technologies of such products have been applied to outdoor appliances and toys, as well as various household items including inflatable beds, inflatable sofas and the like.

[0003] Many inflatable articles use internals to produce the product in its intended, predetermined shape when inflated. For example, one type of inflatable bed, referred to as a wave-shaped rectilinear inflatable bed or I-shaped inflatable bed, may have a belt tension type internal structure positioned along wavy, straight or I-shaped paths inside the inner chamber. Another type of inflatable bed, called an inflatable column type bed, has tension belts arranged in honeycomb structures or cylindrical structures within the inflatable chamber.

[0004] Such internal structures of the tension strands placed in the inflatable bed shape the bed as the internal pressure increases and thus prevent the inflatable bed from spreading evenly in all directions in a balloon manner. Namely, to maintain the rectangular shape of the inflatable bed, tension belts connect the top and bottom surfaces of the inflatable bed to each other. To allow compressed air to flow on both sides of these connecting structures, the tension belts may be formed as strips extending between the top and bottom surfaces or as vertical material spaces with columns of air formed inside. The number and arrangement of the tensioned straps is proportional to the sharpness of the outline of the rectangularity of the inflatable article. This means that the greater number and / or the linear spacing of the tension belts within the compressed chamber results in a "flatter bed surface."

[0005] In known inflatable articles, such as the inflatable beds described above, the tension belts are made of PVC sheets of sufficient thickness to distribute the forces while reducing stresses in the material of the article. For example, the tension belts in known inflatable beds or couches may be about 0.36 mm thick. For some known water holding devices, such as inflatable swimming pools, the internal tension straps may be about 0.38 mm thick, while inflatable sandwich-type swimming pools may be 0.7-0.8 mm thick.

[0006] Thus, known inflatable structures with tension belts or sheet-like PVC tension belts meet the load requirements of the product by varying the thickness of the tension belts. However, where continuous plastic belts or belts are used, such tension belts add to the weight of the inflatable article. Likewise, increasing the thickness and / or spatial density of the fixed blade of the tensioned belts also increases the volume of the flattened / folded deflated inflatable structure.

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Examples of such known structures are disclosed in DE 102006053666. This application discloses inflatable articles with first and second sheets spaced apart to form a gap and related to form an inflatable chamber.

summary

[0008] The present disclosure provides an inflatable article having a tensioning structure. This tensioning structure has the primary function of keeping two adjacent inflatable surfaces in the desired geometric pattern after the inflatable article has been compressed.

[0009] Various configurations of the tensioning structure are contemplated within the scope of the present disclosure. According to the present invention, an inflatable article is provided as claimed in claim 1. Advantageous features of the invention are set forth in the dependent claims.

[0010] In one example, a pair of parallel plastic strips has a plurality of bundles extending therebetween to connect the plastic strips to one another, the bundles being substantially parallel to each other and substantially perpendicular to the plastic strips. In a further example, a similar arrangement of two parallel plastic strips is connected by a plurality of bundles, with each adjacent pair of such bundles converging to a point at one of the plastic strips in the "V" configuration. Each example can be used for a tensioning structure with one of a number of geometric patterns within the inflatable cavity, such as linear, cylindrical, undulating, etc.

[0011] According to one example, the present disclosure describes an inflatable article, comprising: a first sheet and a second sheet placed opposite the first sheet, the first sheet and the second sheet spaced apart to form a spacing space when the inflatable article is inflated. The inflatable article further comprises a tensioning structure having a spacer portion extending into the spacing space between the first and second sheets to maintain a spatial relationship between the first and second sheets when the inflatable article is inflated. The spacer portion has an extent as measured along the surface of at least one of the first sheet and the second sheet. The spacer part occupies a volume and has a working area occupied by the spacer part of the tension structure defined as the total area of ​​the spacer space between the first sheet and the second sheet as measured along the course of the spacer part of the tension structure. The spacing portion of the tensioning structure defines the working area to volume ratio of at least 10 square millimeters per cubic millimeter.

[0012] According to a further example, the present disclosure describes an inflatable article comprising: a first sheet and a second sheet placed opposite the first sheet.

The first sheet and the second sheet are spaced apart from each other to provide a spacing space when the inflatable article is inflated. The inflatable article further comprises a tensioning structure having a spacer portion extending into the spacing space between the first and second sheets to maintain a spatial relationship between the first and second sheets when the inflatable article is inflated. The spacer portion has an extent as measured along the surface of at least one of the first sheet and the second sheet. The spacer portion has a working area occupied by the spacer portion of the tension structure defined as the total area of ​​the spacer space between the first sheet and the second sheet as measured along the course of the spacer portion of the tension structure. The spacer portion of the tensioning structure has such a total weight that the structure

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ΕΡ 2 674 070 Β1 Tensioning designates the working area to weight ratio of at least 6,000 square centimeters per kilogram.

[0013] According to a further example, the present disclosure describes an inflatable article comprising: a first sheet and a second sheet placed opposite the first sheet.

The first sheet and second sheet are spaced apart from each other to provide a spacing space when the inflatable article is inflated. The inflatable article further comprises a tensioning structure having a spacer portion extending into the spacing space between the first and second sheets to maintain a spatial relationship between the first and second sheets when the inflatable article is inflated. The spacing portion of the tension structure has an average thickness of less than 0.125 mm.

[0014] According to yet another example, the present disclosure describes an inflatable article comprising: a first sheet, a second sheet placed opposite the first sheet, the first and second sheets spaced from each other to form a spacer space, a tension structure extended in the spacer space between the first sheet and the second sheet, the tension structure comprising a plurality of uniformly spaced bundles arranged essentially parallel to each other, and a plurality of heat seal strips spaced apart and substantially perpendicular to the plurality of bundles, each of the plurality of heat seal strips being attached to each of the plurality of bundles, and each of the plurality of heat seal strips being attached to at least one of the first sheet and the second sheet.

[0015] According to yet another example, the present disclosure describes an inflatable article comprising: a first sheet, a second sheet facing the first sheet, the first and second sheet spaced apart to form a gap; a tension structure occupying the spacing space between the first sheet and the second sheet, the tension structure comprising: a plurality of evenly spaced and parallel-spaced bundles, and a first welded sheet having a plurality of bundles attached to its upper surface.

[0016] According to yet another example, the present disclosure describes an inflatable article comprising: a first sheet, a second sheet facing the first sheet, the first and second sheet spaced apart to form a gap; a tension structure occupying the spacing space between the first sheet and the second sheet, the tension structure comprising: a top weld strip; a lower weld strip disposed substantially parallel to the upper weld strip and spaced apart from the upper weld strip to occupy the gap between the first sheet and the second sheet; and a plurality of V-shaped bundles end-to-end disposed between the welding strips, each of the V-shaped bundles having upper and lower ends attached to the upper and lower welded strips, respectively.

[0017] According to yet another example, the present disclosure provides an inflatable product comprising a first sheet, a second sheet placed opposite the first sheet, the first and second sheets spaced apart to form a spacing space, and the first sheet and second sheet cooperate with each other. yourself to at least partially create an inflatable chamber, a plurality of tension structures welded to the respective inner surfaces of the first and second sheets such that the plurality of tension structures span in a spacing space, each of the plurality of tension structures comprising: an upper weld strip attached to one of

- 3ΕΡ 2 674 070 dol1 of the first sheet and the second sheet, a bottom heat seal attached to the second of the first sheet and the second sheet, and a plurality of bundles joining the top and bottom weld strips together.

[0018] According to yet a further example, the present invention describes an inflatable article comprising: a first sheet, a second sheet placed opposite the first sheet, the first and second sheets spaced apart to form a spacing space, and the first sheet and second sheet cooperate with each other. with each other, at least partially delimiting the inflatable chamber; a plurality of tension structures welded to the inner surfaces of the first and second sheets such that the plurality of tension structures span in a spacing space, each of the plurality of tension structures comprising: a sheet to be welded; a plurality of bundles, the plurality of bundles being substantially uniformly spaced and disposed substantially parallel to each other, and the plurality of bundles being attached to the sheet to be sealed; and a weld strip attached to each end of the sheet to be welded such that the longitudinal run of the strip to be welded is generally perpendicular to the plurality of bundles, the respective ends of the plurality of bundles are attached to the strip to be welded, and each of the weld strips is welded to one of the first sheet and the second sheet.

[0019] According to yet another example, the present invention describes a method of making a tension structure for an inflatable article, the method comprising: positioning at least one heat sealer downstream of a beam guide; delivering the plurality of bundles to the sealer via the bundle guide such that the bundles provided are substantially uniformly spaced and spaced substantially parallel to each other; placing the welded strips on a first die of a welding machine or adhesive device, the welded strips having a longitudinal extent corresponding to the total width of the plurality of bundles; moving the second matrix of the welding machine or gluing device to the working position,। wherein first and second dies are positioned on opposite sides of the welding strips, activating a welding machine or adhesive device to permanently connect the welded strips to the plurality of bundles such that the welded strips are secured to the plurality of bundles in a spaced and substantially parallel configuration, and such that the welded strips are substantially perpendicular to the plurality of beams. and

[0020] According to yet another example, the present invention describes a method of making a tension structure for an inflatable product, comprising: positioning a hot roll behind a beam guide; delivering the plurality of bundles to the hot roll via the bundle guide such that the supplied bundles are substantially uniformly spaced and substantially parallel to each other; locating a guide roller behind the tether guide, the guide roller being actuated to supply at least one sheet to be welded to the hot roll, the at least one sheet to be welded having a width corresponding to the total width of the plurality of bundles; and passing the plurality of bundles and the at least one sheet to be sealed through the hot roll such that the plurality of bundles are attached to the at least one sheet to be sealed.

[0021] According to yet another example, the present invention describes a method of manufacturing a tensioning structure, the method comprising: placing the first pair of welded strips parallel to each other on the joining device, wrapping the at least one continuous bundle around a plurality of members and positioned along a pair of rows adjacent the first pair of welded strips, respectively, each pair of rows of members being offset from the other of the pair of rows members, and the wrapping step comprises an alternation between a pair of rows such that at least one continuous bundle forms and

multiple V-shaped bundles pointing towards each other; and using a connecting device for connecting

The first pair of welded strips with a plurality of bundles at respective V-shaped corners formed by at least one continuous bundle such that the tension structure has a tensile strength along a direction perpendicular to the longitudinal span of the first pair of welded strips. Brief description of the drawing

[0022] The above-mentioned and other features and advantages of this disclosure, and how to obtain them, will become more apparent, and the invention itself will be better understood with reference to the following description of embodiments of the invention given in connection with the accompanying drawings, wherein:

Figure 1 is an exploded perspective view of an inflatable structure with an exemplary tensioning structure;

Figure 2 is an enlarged perspective view of the tensioning structure shown in Figure 1; Figure 3 is an exploded perspective view of an inflatable bed incorporating the tensioning structure shown in Figure 1;

Figure 4 is an assembled view of the inflatable bed of Figure 3 in which the material of the inflatable bed is transparent to show the internal arrangement of the tension structures;

Figure 5 is an exploded perspective view of an inflatable bed having an alternate geometric arrangement of exemplary tension structures;

Figure 6 is an assembled view of the inflatable bed of Figure 5 in which the material of the inflatable bed is transparent to show the internal spatial arrangement of the tension structures;

Figure 7 is a perspective view of an apparatus for producing bulk material for the tensioning structures shown in Figures 3-6;

Figure 8 is an exploded perspective view of a first example of bulk material produced by the device of Figure 7;

Figure 9 is a perspective view of a first example of bulk material produced by the device of Figure 7;

Figure 10 is a perspective view of a second example of a finished bulk material weight produced by the device of Figure 7;

Figure 11 is a perspective view of a second example of bulk material formed by the device of Figure 7;

Figure 12 is an exploded perspective view of a first alternative exemplary tensioning structure;

Figure 13 is a perspective view of the assembled tensioning structure shown in Figure 12;

Figure 14 is an exploded perspective view of a tensile structure for an inflatable product made in accordance with the present disclosure;

Figure 15 is an exploded perspective view of a second alternative exemplary tension structure;

Fig. 16 is an assembled perspective view of the exemplary tensioning structure shown in Fig. 15;

Fig. 17 is an exploded perspective view of a third alternative exemplary tension structure;

Fig. 18 is an exploded perspective view of a fourth alternative tensioning structure.

Figure 19 is a juxtaposed perspective view of the tensioning structure shown in Figure 18;

Figure 20 is an exploded perspective view of an inflatable bed with alternative tensioning structures made in accordance with the present disclosure;

Figure 21 is a juxtaposed view of the inflatable bed of Figure 22, the material of which is transparent for showing the internal arrangement of the tension structures;

Figure 22 is an exploded perspective view of an inflatable bed with alternative tension structures made in accordance with the present disclosure configured with an alternative geometry;

Figure 23 is a juxtaposed view of the inflatable bed of Figure 22 in which the material of the inflatable bed is transparent to show the internal spatial arrangement of the tension structures;

Figure 24 is a perspective view of an apparatus for producing bulk material for the tensioning structures shown in Figures 12-19;

Figure 25 is an exploded perspective view of a fifth alternative exemplary tensioning structure for an inflatable product.

Fig. 26 is a stacked perspective view of the fifth alternative tensioning structure shown in Fig. 25;

Fig. 27 is an exploded perspective view of an inflatable bed with the tensioning structure shown in Fig. 25;

Figure 28 is a stacked view of the folded-up inflatable bed of Figure 27 wherein the material is transparent to show the internal arrangement of the tension structures;

Figure 29 is a perspective view of an apparatus for producing bulk material for the sixth alternative tension structures shown in Figures 25-28;

Figure 30 is an exploded perspective view of a sixth alternative exemplary tensioning structure;

Fig. 31 is a juxtaposed perspective view of the assembled tensioning structure shown in Fig. 30;

Figure 32 is a perspective view of an apparatus for producing bulk material for the tensioning structures shown in Figures 30 and 31;

Figure 33 is a top view of the tension structures gathered together during the welding process;

Figure 34 is a plan view of the collapsed portions of the tension structure as the mattress is deflated for storage or transportation;

Fig. 35 is a view similar to Fig. 33 showing parts of the tension structures with bundles stacked during the welding process; and Fig. 36 is a view similar to Fig. 33 showing parts of the tension structures moved relative to each other during the welding process.

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[0023] Corresponding references indicate corresponding parts in several views. The examples presented herein illustrate exemplary embodiments of the invention, and these examples are not given in any way to limit the scope of the invention.

[0024] The terms up, down, up, down, upper, lower and similar positional language have been used throughout this description according to the relative positions of the features when the present invention is used. In the present context "are used is meant to mean that the inflatable the product is inflated and oriented in the position of the arrangement shown in Fig. 4. It should be understood that the device can be used, stored and transported in any orientation, not only as shown in the figures.

Detailed description

[0025] The present disclosure provides an inflatable article with tension structures that give shape to inflatable devices such as inflatable sofas, beds, or swimming pools. The tension structures here are lightweight and take up minimal volume when the device is deflated and packed, while also functioning as a strong and durable internal support after inflation and during use of the inflatable device.

An exemplary tension structure of an inflatable product according to the present disclosure employs thin and flexible string or similar bundles that connect two surfaces of the fabric to each other. The bundles are firmly attached to adjacent material through an intermediate material such as a sheet with or without additional straps, and the intermediate is in turn firmly attached to the fabric. The contact area between the intermediate material and the bonded bundles can be controlled to impart bond strength proportional to the tensile strength of the bundle. Likewise, the contact area between the intermediate material and the adjacent fabric may also be controlled to impart strength to the fabric / tension structure bond proportional to the combined tensile strength of all bundles in the tension structure.

[0027] Various tension structures and methods of making them are described in detail later. It is contemplated that any of the tension structures described today may be used in any inflatable article alone or as a group or in combination with each other as required or needed for a particular project. Additionally, it is contemplated that the tension structures of the present disclosure can be used in other contexts, such as camping equipment, or in any other context where a lightweight, packable structure is needed to join two pieces of material that are repelled in use by one. from the second.

1. Welded belts connected by spaced bundles

Figures 1 and 2 show a tension structure 3 joining upper material 1 to lower material 2. The tensioning structure 3 comprises upper and lower welded bands 31 connected to each other by a plurality of substantially parallel bundles 32 that form a spacer between the upper material. and the bottom sheet 1, 2. The upper and lower welded bands 31 are in turn welded to the upper material 1 and lower material 2, respectively, whereby the forces acting on the upper and lower materials 1, 2 are transmitted by the stresses in the bundles 32.

[0029] Optionally, reinforcement bundles 5 (Fig 3) may be positioned along the longitudinal extent of welded strip 31 (i.e. substantially perpendicular to the bundles 32). The reinforcement bundles 5, when present, may be connected to the stretching bundles 32, for example by folding the bundles 32 onto

-7ΕΡ 2 674 070 Β1 reinforcement bundles 5, bonding bundles 5, 32 to each other or by gluing reinforcement bundles 5, 32 to each other. The combined reinforcement bundles 5 create an additional contact surface with the welded strips 31 and thus improve the resistance of the reinforcement bundles 5 to the freedom to pull away from the welded strips 31. Moreover, the presence of the reinforcement bundles 32 inside the welded strips 31 increases the tensile strength of the welded strips 31 over their longitudinal extent.

[0030] The plurality of bundles 32 of the tension structure 3, as shown in Figures 1 and 2, are arranged such that the bundles 32 are substantially parallel to each other when stretched (i.e., when the welded strips 31 are pulled apart). In addition, adjacent pairs of bundles 32 may be equally spaced from one another, thereby maintaining a substantially constant tensile strength of the tensioning structure 3 over the longitudinal span of the welded strips 31. In an example, the bundles 32 may extend along the full width of the welded strips 31 as shown in Figs. 1 and 2, which gives a large contact area between the bundles 32 and the welded strips 31. For clarity, Figures 1 and 2 only show a limited number of bundles 32 attached to the belts 31 in this way, and it is obvious that all the bundles 32 of the tension structure 3 can be so attached.

[0031] In one embodiment shown in Figures 3 and 4, a plurality of tension structures 3 have been used in an inflatable structure such as an air mattress 10, which includes a sleeping surface on the upper material 1, and a ground contact surface on the lower material 2. the band 4 is permanently connected or welded to the periphery of the upper material 1 and the lower material 2 to form an inflatable chamber. A valve 6 may be provided to facilitate the filling and emptying of the mattress 10.

[0032] Although the mattress 10 is shown as a single layer, double layers can also be provided. Additional mattress features may also be incorporated, as set forth in US Patent No. 7,591,036 entitled Air Inflatable Mattress. Besides the mattresses, the tension structure can be used in other inflatable products such as inflatable boats, inflatable islands, float devices, swimming pools, inflatable slides and any other inflatable devices.

[0033] Each of the plurality of tensioning structures 3 is welded to the opposing inner surface portions of the top and bottom material 1, 2 as described in detail above. As shown in Figures 3 and 4, the tension structure 3 in the example shown forms a complete longitudinal extent (i.e., along the longitudinal direction of the welded strips 31), corresponding to the width or length of the sleeping material 1 and the backing material 2 in the mattress 10.

[0034] As mentioned above, the tension structures 3 are connected to the upper material 1 and to the lower material 2 by welding strips 31. Such welding is carried out by resting one welding strip 31 on one of the upper and lower materials 1, 2, and then applying heat to melt and bond the material of the welded strips 31 to the material of the abutment. In the example, the welded bands 31 and the upper and lower materials 1, 2 are made of PVC, and the welding is done by applying a temperature of 105 degrees Celsius for about 0.5 seconds. The top and bottom sheets 1, 2 and the welded strips 31 have thicknesses ranging from 0.15 to 1.0 mm, with a thickness of 0.34 mm being preferred for the top and bottom sheets 1, 2, and a thickness of 0.18 mm preferred for the welded straps 31. The width of the welded strips 31 is preferably 12.7 mm and may range from 1 to 100 mm in width. The PVC used preferably has a tensile strength of at least 7 kg / cm to

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73 kg / cm2 and a density ranging from 0.8-2.5 grams per cubic centimeter, with a preferred density of 1.5 grams per cubic centimeter.

[0035] The tension structures 3 shown in Figures 3 and 4 are welded to the top and bottom material 1, 2 along a substantially linear path, with a plurality of structures 3 substantially parallel to each other and equidistantly spaced in the materials 1, 2. it is understood that the welding geometry may adopt any other suitable geometry, such as an undulating track, an I track, a Z track or a V track. One exemplary alternative geometry is a cylindrical or columnar arrangement as shown in Figures 5 and 6. In this arrangement, the top and bottom weld strips 31 are butt-joined at their ends to form an arcuate ring such as a circular ring as shown. in the drawing. The plurality of bundles 32 between the upper and lower welded strips 31 thus form a closed columnar circumference, thereby forming a columnar body. During assembly of the inflatable bed 10, the column is welded to the upper and lower material 1, 2 in a similar manner as described in relation to the linear arrangement of the tension structure 3.

[0036] As the mattress 10 is inflated, the introduction of compressed air into the mattress chamber pushes the top material 1 and the bottom material 2 away from each other. When sufficient pressure is applied, the bundles 32 are tensioned and the tension structures 3 prevent the top and bottom material 1, 2 from moving apart from each other in the vicinity of each tension structure 3. A further increase in pressure creates greater tensile stresses in the tensioning structures 3 and additional forces in the welds between the tensioning structures 3 and adjacent materials.

[0037] In the illustrative example of the mattress 10, the tension structure 3 includes only one bundle for every two centimeters, 1, 2, 3, 4 bundles per centimeter of the longitudinal span of the welded strips 31, or 5, 10, 15, 20, 30, 40, 50 or more beams per centimeter, or may include any number of beams per centimeter within any any range defined by any of the above values. Preferably, there is a distance of about 2.8 mm between the beams (i.e. 3.6 beams per centimeter). The bundles 32 may be plain cotton, polyester, a nylon thread formed of multiple filaments twisted together, of the type commonly used in garment seams, or may be any other type of bundle. These regular threads provide considerable tensile strength at very low cost. According to alternative examples, the bundles 32 may be woven together to form a fabric. According to another example, a non-woven fabric may be used to form the part of the tension structure 3 extending through the spacing between the sheets 1, 2.

[0038] In accordance with the present disclosure, the threads may have a diameter of 0.1 to 1.0 mm. Preferably, the thread has a diameter of 0.2 mm. In accordance with the present disclosure, the tensile strength of the thread may be from 0.2 kg to 10 kg per thread. Preferably, the thread has a tensile strength of 3 kg per thread. Preferably, the threads have a density ranging from 0.01 to 0.3 g per meter. Preferably, the threads have a density of 0.085 grams per meter. It is of course to be understood that other materials such as strands, metal wires or plastic cords and the like may be used.

[0039] The exemplary embodiment of the tension structure 3 described above provides a strong final product suitable for use in a wide variety of inflatable articles. In other illustrative examples, the tension structure 3 has bundles 32 with an overall axial span of between 5 cm and 65 centimeters, resulting in bundles 32 suitable for covering the respective gaps formed between spaced welded strips 31. Therefore, this example is suitable for a mattress application.

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ΕΡ2 674 070 Β1 ο an inflated thickness approximately equal to the axial span of the beams 32. This example further uses the regular beam material given above, with beam densities within the above ranges. The resulting exemplary tensioning structure 3 has a total tensile strength of between 5.9 and 23.3 kgf per linear centimeter (where the linear centimeters are measured along the longitudinal extent of the welded strips 31).

[0040] When the mattress 10 is inflated, the tension structure defines the working surface along its longitudinal extent and across the interval between the upper and lower materials 1, 2. In particular, the area occupied by the tension structure 3 is defined as the area of ​​the gap between the sheets of material joined by the tension structure 3, with a spacing measured along the longitudinal extent of the tension structure such that the measured surface covers each of the plurality of bundles 32. Where the tension structure 3 is arranged linearly and the upper and lower fabrics 1, 2 are parallel to each other (as shown for example in Fig. 3 and 4), the surface is simply the longitudinal extent of the tension structure 3 multiplied by the space between the upper and lower materials 1 and 2. Where the tension structure 3 adopts a non-linear track (such as a pillar track, an arcuate track shown for example in Fig. 5 and 6) and the upper and lower materials 1 and 2 are non-parallel, the above-described surface measurement method continues to apply to an arcuate working area.

[0041] The above-described embodiment of the tensioning structure 3 obtains a high tensile strength while favoring lightness and a low packing volume of the finished inflatable article. In accordance with the present disclosure, the bundles 32 and the area between the bundles 32 form a spacer 33 (see Fig. 1) a tension structure 3, spanning between the upper and lower material sheets 1, 2, which maintains a spatial relationship between the first and second sheets when the mattress 10 is inflated. As shown in Fig. 1, the plurality of bundles 32 that define this spacer 33 has a span 35 measured along the surface of at least the first sheet 1 and / or the second sheet 2. The bundles 32 of this spacer 33 of tension structure 3 collectively occupy a volume. The spacer 33 has an operating surface defined by the span 35 of the spacer 33 (also closely related to the length of the welded strips 31) and the length of the 37 bundles 32. The operating surface is occupied by bundles 32 of the tensioning structure 3 and defines the total area of ​​the gap between the first sheet 1 and the second sheet. sheet 2, measured along the span 35 of the spacer 33 of the tensioning structure 3. For example, if the bundles 32 of the exemplary tension structure have a length 37 of 100 mm between the first and second sheets 1, 2 and the span 35 of the spacer 33 is 100 mm, then the operating area of ​​the spacer 33 defined by the bundles 32 is 10,000 square millimeters. Assuming 3.6 beams per centimeter, there are 3,571 millimeters of 32 beams per 10,000 square millimeters of the working surface. If the bundles 32 have a diameter of 0.2 mm, the total volume occupied by the bundles 32 would be 112.2 cubic millimeters. In this example, the spacer 33 of the tension structure 3 defines an area to volume ratio of 89.13 square millimeters per cubic millimeter (e.g., 10,000 square millimeters / 112.2 cubic millimeters). In accordance with the present disclosure, the working surface area to volume ratio may be 10 to 3,000 square millimeters per cubic millimeter.

[0042] The use of the bundles 32 in place of the PVC sheets also allows the overall weight of the mattress 10 to be reduced. The spacing portion 33 of the tension structure 3 defined by the bundles 32 has a weight.

- ΙΟΕΡ 2 674 070 Β1 total and working area as specified above. In the example above, the working area was 10,000 square mm (100 millimeters by 100 millimeters) and there were 3.6 beams per centimeter. This is 3.571 mm of thread. With a density of 0.085 grams per meter of thread, the total weight of the thread is 0.304 grams. As a result, the work area to weight ratio in the preferred example is about 32,941 square millimeters per gram (or 329,412 square centimeters per kilogram) (e.g., 10,000 square millimeters / 0.304 grams). According to some examples of the present disclosure, the work surface area to weight ratio is between 8,000 and 5,000,000 square centimeters per kilogram. According to other examples, the working area to weight ratio is between 12,500 and 2,500,000 square centimeters per kilogram. According to other examples, the work area-to-weight ratio is 20,000 to 1,000,000 square centimeters per kilogram.

[0043] By using the bundles 32 instead of the PVC sheets, it is also possible to reduce the average thickness of the spacer 33 of the tensioning structure 3 extending between the first and second sheets 1, 2. The spacer 33 of the tensioning structure 3 defined by the bundles 32 has an average thickness and a working area. as described above. The average thickness will be reduced by the nominally circular cross-sectional area of ​​the bundles 32 and the spacing between each bundle 32.

[0044] For example, the maximum thickness of spacer 33 will be the diameter of the bundles 32 (0.2 millimeters in the example above). The minimum thickness of the spacer 33 is zero in unoccupied areas between the bundles 32. Averaged over the total area of ​​spacer 33 occupied by bundles 32 and the total area of ​​spacer 33 without bundles 33, the average thickness is less than the diameter of bundle 32. Moreover, as the distance between the bundles 32 increases, the average thickness decreases as most of the spacer 33 is unoccupied by the bundles (i.e., the size of the spacer 33 with zero thickness increases, which reduces the average thickness of the spacer 33).

[0045] In the above example, the working area was 10,000 square millimeters (100 millimeters times 100 millimeters) with 3.6 beams per centimeter (or 2.8 millimeters from bundle 32 to bundle 32). Contrary to the maximum thickness of a circular thread, which is the diameter, the average thickness of a circular thread is pi * diameter / 4. The use of bundles 32 with a diameter of 0.2 mm gives an average thickness of 0.157 mm for each bundle 32. Due to the spacing between the bundles 32, the average thickness of the spacer 33 defined by the bundles 32 and the spacing between them is 0.0112 millimeters (i.e. 2.8 millimeters between the bundles 32 is zero thickness, which reduces the average thickness of the spacer 33 to much smaller than that). average thickness of the bundles 32). In accordance with some examples of the present disclosure, the mean thickness of the spacer portion of the tension structure 3 is from 0.0003 to 0.1 millimeters. According to other examples, the average thickness is from 0.001 to 0.05 mm. According to other examples, the average thickness is between 0.005 and 0.02 mm.

Turning now to Fig. 7, an apparatus 20 for producing a tension structure 3 is shown. The apparatus 20 is supplied with a plurality of bundles 32 from a thread source 11, which may be, for example, a yarn store containing a plurality of spools of yarn. The thread source 11 continuously feeds the plurality of bundles 32 through the thread guide A with the plurality of openings through which the individual bundles 32 pass after being fed from the thread source 11 and prior to incorporation into the bulk material 30 of the tension structure (shown in Fig. 9 and described below). The thread guide A maintains an even spacing between the bundles 32 and arranges the bundles 32 parallel to each other such that multiple bundles 32 are substantially flat. The width of the welding strips 31, the distance between adjacent pairs of the welding strips 31 and the spacing

Between adjacent pairs of beams 32 can be set to whatever values ​​are required or desired for their intended use as in a particular inflatable article.

[0047] The flat, parallel, and evenly spaced bundles 32 are then fed to a heat sealer 40 as shown in Figure 7. Heat sealer 40 may be a thermofusion device that uses heat to bond two different plastic materials together, or it may be a high frequency heat sealer. in which electromagnetic waves use excited chemical dipoles in a plastic material to soften and bond the materials together. In addition, any suitable welding method may be used on heat sealer 40 as required or desired for a particular material and method.

[0048] Welded strips 31 with a length corresponding to the width of the distributed plurality of bundles 32 are placed on the lower dies B1 of the sealer 40. The bundles 32 are inserted over the welded strips 31 as shown and then the upper dies B2 are lowered into contact with the welded strips 31. Energy (i.e., heat or electromagnetic waves) is applied to permanently connect the welded strip 31 to each of the plurality of bundles 32 such that the respective bundles 32 are secured at a distance from each other and in a parallel configuration dictated by the bundle guide A. When secured, the bulk material 30 ( Fig. 9) is finished and ready for use.

[0049] The finished bulk material 30 is then delivered to a take-up device (not shown) such as a spool or roll. This allows the bulk material 30 to be produced continuously and stored for later use. The bulk material 30 can be converted to the tension structure 3 (Fig. 2) by cutting after the strip welding station 31. The tension structure 3 can then be applied to a variety of inflatable articles by trimming its length and width according to the dimensions of the article.

[0050] As mentioned above, a reinforcement bundle 5 may be added to the tensioning structure 3 to further improve the strength of the structure, including the tensile strength of the welded strips 31. To add at least one reinforcement bundle 5 to the bulk material 30, reinforcement bundles 5 are placed perpendicular to the plurality of bundles 32, resting on corresponding welded strips 31. The upper die B2 of the sealer 40 is pressed to permanently join the welding strips 31 to both the reinforcement bundles 5 and the plurality of bundles 32 as described above. The amplification beams 5 are shown in Fig. 3 but omitted in Fig. 4 for clarity.

As shown in Fig. 4, tension structures 30 are positioned within band 4 and welded to the bottom and top sheets 1, 2. Although shown perpendicular to sheets 1, 2 in Fig. 4, the welded strips 31 are After being sealed, they lie flat against the sheets 1, 2 as shown in the lower part of Fig. 1. Likewise, in the mattresses 10 of Figs. 6, 21, 23, and 28, the welded strips 31 are shown as perpendicular to sheets 1, 2 but lying flat. on the sheets 1, 2 after welding, as shown in the lower part of fig. 1.

[0052] As shown in Figures 8 and 9, bulk material 30 (Figure 9) may be formed using a single layer of heat sealing strips 31 joined to bundles 32. In another illustrative example shown in Figures 10 and 11, bulk material 30 may be produced as a two-layer structure, with the use of welded stripes both above and below the bundles 32. The use of two opposing mutually welded strips includes a grasping action to "catch or grasp the bundles 32 therebetween, which contributes to greater bond strength. When used in an inflatable article, the resulting double-layer tensioning structure 3

-12ΕΡ 2 674 070 Β1 has greater strength and can be welded to top or bottom material 1,2 (Figs. 1, 3 and 4) on either side. As shown in Figures 10 and 11 and described above, at least one reinforcement bundle 5 may also be gripped between the welded strips 31.

2. Sheet assisted tension structures with attached bundles

[0053] The alternatively positioned tensioning structure in Figures 12 and 13 is shown as the tensioning structure 103. Structure 103 is substantially similar to the tensioning structure 3 described above, with the numbering of the references used in structure 103 being analogous to the numbering used in structure 3, except that the number is added. 100. Elements of construction 103 correspond to like elements marked with the corresponding construction reference numerals 3, except where otherwise stated.

[0054] The tensioning structure 103 includes a plurality of bundles 32 that are uniformly spaced and substantially parallel to one another in a manner similar to the tensioning structure 3 described above. However, the tensioning structure 103 includes a welded strip 131 in place of the welded strips 31 of the structure 3. Instead of attaching the ends of the bundles 32 to the welded strip 31, the entire lengths of the bundles 32 are attached to the welded strip 131. The welded sheet 131 serves to ensure proper placement and protection of the plurality of bundles 32, for example to avoid kinks or damage to the bundles 32 during practical use. Since the tension structure 103 includes the bundles 32 embedded therein, the sheet 131 to be welded need not bear significant tensile loads and can be kept to a minimum thickness. For example, heat seal sheet 131 may be 0.10 millimeters thick.

[0055] In Figures 12 and 13, a single heat seal sheet 131 is used, although other solutions are contemplated. Fig. 14 shows an example of the tensioning structure 103 (Fig. 13) with an additional welded sheet 131 placed against the first welded sheet 131. Similar to the Tension 3 design using mutually opposing welded strips 31 (Figs. 10 and 11) to enclose the bundles 32, mutually opposing welded strips 131 may be used.

[0056] Figs. 15 and 16 show a tensioning structure 203 which is substantially similar to the tensioning structure 3 described above, with the numbering of the structure reference numbers 203 analogous to the numbering in the structure 3, except for the addition of the number 200. The elements of the structure 203 correspond to like elements denoted by corresponding construction reference numerals 3, except where otherwise stated. However, the structure 203 represents a hybrid solution of the connecting members of the tension structures 3 and 103 in which a plurality of welded strips 31 are used to enclose a portion of the bundles 32 between the strips 31 and the welded sheet 131. The addition of the welded strips 31 to the welded sheet 131 improves the strength of the welded connection between the tension structure 203 and adjacent article material (e.g., the top and / or bottom material 1, 2 of the inflatable bed 10 as shown in Fig. 2 and 3).

[0057] Fig. 17 shows a tensioning structure 303 which is substantially similar to the tensioning structure 3 described above, with the numbering of the reference numbers used in the structure 303 analogous to the numbering in the structure 3, except for the addition of the number 300. The elements of structure 303 correspond to similar elements denoted by corresponding construction reference numbers of 3, except where otherwise stated. Moreover, the structure 303 includes all the elements of the tension structure 203, but adds a second lower layer of strips 31 attached to the welded sheet 131 against the first upper layer of the welded strips 31. It is therefore a two-layer structure of opposing welded strips.

-13ΕΡ 2 674 070 Β1

31, further widening the welded sheet 131, which makes the tension structure 303 very strong and durable, both along the spacing of the bundles 32 and in the weld between the bundles 32 and adjacent material, e.g., material 1, 2 of the inflatable bed 10 (Figures 3 and 4).

[0058] Figures 18 and 19 show yet another tensioning structure 403.

Tension Structure 403 is substantially similar to Tension Structure 3 described above, with the numbering of the footnotes used in structure 403 analogous to the numbering in structure 3 except for the addition of 400. The elements of structure 403 correspond to like elements denoted by the corresponding reference numerals in structure 3, except if stated otherwise. However, the plurality of bundles 32 used in construction 403 are discontinuous. As shown in Fig. 13 and 14, the plurality of bundles 32 can be trimmed to any desired length, and then attached to the heat-stamped sheet 131 by hot pressing. When mounted in the inflatable article, the attached bundles 32 may be cut lengthwise and welded in place as described above. Therefore, the use of the tensile structures 403 allows to reduce the consumption of material used in the bundles 32 and to avoid unnecessary waste, and thus reduce material costs.

[0059] Alternatively, as shown in Fig. 20, each end of heat-sealed sheet 131 (i.e. the ends of the bundles 32) may include reinforcement bundles 5 arranged similar to the tension structure 3 as described above. The reinforcement bundles 5 are omitted in Fig. 21 for clarity.

[0060] The sheet-supported embodiment of the tensioning structure 103 and other examples of the tensioning structures 203, 303 and 403 in Figs. 12-19 may be integrated into the inflatable device in a similar manner to the tensioning structures 3 described above. For example, Figures 20 and 21 show the integration of the tension structures 103 in an inflatable bed 10, which was achieved in the same manner as described above.

[0061] The tension structures 103, 203, 303 and 403 can also be made in many different geometric configurations as described above with respect to the tension structure 3. These configurations include an undulating track, an I track, a Z track or V-shaped track As shown in Figures 22 and 23, a cylindrical or columnar configuration may also be used. In this arrangement, the welded sheet 131 (and the upper and lower welded bands 31, if any) are butt-connected at their ends to form an arcuate ring, for example a circular ring, as shown. The plurality of bundles 32 cooperate with the material of the welded sheet 131 to form a closed columnar circumference, thus forming the columnar body. The axial ends of the columnar structure can then be welded to the top material 1 and the bottom material 2, respectively, of the inflatable bed 10.

Figure 24 shows an apparatus 120 for producing the tensioning structures 103, 203, 303, or 403. The apparatus 120 is supplied with multiple bundles 32 from a yarn store or other yarn storage as described above for apparatus 20. The bundles 32 are fed from continuously through the bundle guide A, described above, which supplies the uniformly spaced and parallel bundles 32 to the downstream sealer 140.

[0063] The sealer 140 includes transfer rollers C below the bundle guide A, which continuously provide a welded sheet 131 of sufficient width to match the width of the plurality of bundles 32. Behind roll C, multiple bundles 32 are adjacent to the sheet or abut against the welded sheet 131.

-14ΕΡ 2 674 070 Β1

[0064] The plurality of bundles 32 and the sheet 131 to be welded then pass together through a hot roll D which heats and presses the material so that the bundles 32 are attached to the softened material of the sheet 131 to be welded. After passing through the roll D, the tension structure 103 is ready as it is. shown in Fig. 13. Bulk material of the tension structure 103 may be wound on a take-up reel for subsequent cutting of the tension structure 103 to the appropriate size for a particular application.

[0065] When using a tensioning structure 103 for an inflatable product such as an inflatable bed 10 (Figures 21 and 22), heat-seal sheet 131 may have a relatively low thickness given for the internal pressure level (and therefore tension) expected to be transferred by structure 103 during pumping and use of the product. For example, the thickness can be reduced by 20% -40% compared to known internal tension structures without ties 32. Since the bundles 32 are positioned and configured to bear the tensile loads inherent in the tension structure 103, the welded sheet 131 is only intended to ensure that the plurality of bundles 32 are correctly positioned and secured to avoid knots or damage to the bundles 32 during practical use. In one embodiment, the heat sealed sheet 131 may be only 0.10 millimeters thick.

[0066] In the event that a second welded sheet 131 as shown in Figure 14 and described above is added to the tension structure 103, a second roll C (not shown) may be provided opposite roll C shown in Figure 24, so that rolls C will be disposed on both sides of the bundles 32. The two sheets 131 to be welded then pass through a hot roll D, capturing the bundles 32 between two layers of plastic sheets.

[0067] In the event that a plurality of welded strips 31 as shown in Figs. 15 and 16 and described above are added to form the tension structure 203, then the tension structure 103 may be further processed in apparatus 120 using apparatus 20 as shown in Figs. 7 and described above. When a sheet blank equivalent to the tension structure 103 exits the hot rolls D, welded strips 31 can be added on one or both sides of the blank. If desired or on request, at least one reinforcement bundle 5 can be added so that the reinforcement bundles 5 are perpendicular to the plurality of bundles 32, as detailed above.

[0068] When welded strips 31 are added to both sides of the sheet blank to form the tension structure 303, a method similar to the above is used, in which the product blank receives additional welded strips 31 after exiting the rolls D. However, the welded strips 31 are added to the both sides, instead of on one side, according to a method of making a two-ply version of the bulk material 30 using a heat sealer 40 as described above. Of course, at least one reinforcement bundle 5 may be added in a similar manner as described above.

3. Welded belts connected by V-shaped bundles

[0069] In Figs. 25 and 26, an alternately arranged tension structure is shown as the tension structure 503. Structure 503 is substantially similar to the tension structure 3 described above, with the numbering of the reference numbers of structure 503 analogous to the numbering of the references used in structure 3, except for the addition of numbers 500. Elements of construction 503 correspond to like elements marked with the corresponding construction reference numerals 3, except where otherwise stated

-15ΕΡ 2 674 070Β1

[0070] However, the bundle 532 in the tensioning structure 503 has a V-zigzag pattern and may be formed from a single bundle forwards and backwound, instead of using, for example, multiple separate and distinct bundles in the tensioning structure 3. As described below in connection with the method for producing the tension structure 503, bundle 532 may be a single, continuous woven bundle between the heat sealing strips 31, 3 ', with the top of each "V attached to at least one of the heat sealing strips 31, 31 | [0071] Referring to Fig. 29, an apparatus 220 for producing a tension structure 503 is shown. In the apparatus

220 the lower pair of welding strips 31 is positioned so that the lower pair is substantially parallel and spaced apart in the connecting device 540. In the illustrated embodiment, the welded strips 31 are unrolled from a roll of welding strip material placed in the pair of unwinding devices 550.

[0072] The continuous bundle 532 is then successively wrapped around a set of adjacent hook members 541 disposed on either side of the linking device 540, with a plurality of hook members 541 arranged in two rows corresponding to the position of the previously placed lower pair | of welded belts 31. In this example, the hook members 541 are spaced evenly apart and positioned on the outer sides of the lower pair of welded bands 31, with each row of hook members 541 offset from the second row. In this arrangement, the continuous bundle 532 µl forms a plurality of strands of V-shaped butt bundles as they are wrapped around successive 'hook-shaped elements 541 in alternating rows as shown. That is, the vertex of each "V" is formed on the respective hook-shaped members 541 and the vertices of the successive members following the continuous bundle 532 alternate between the rows of hook-shaped members of II.

541. '

[0073] The second pair of welding strips 31 'are then positioned over the first pair of welded strips 31, respectively, and attached thereto such that each vertex "V" formed by the bundle 532 is positioned between the top of the first pair of welded strips 31 and the adjacent vertex!

the second pair of 3Γ welded strips. The second pair of welded strips 31 'can also be unwound from the unwinding devices 550.

[0074] Finally, adjacent pairs of welded strips 31, 31 'are joined to each other and to the bundle 532, for example by welding or by one of the other joining methods described above. For example, the welded strips 31, 31 'may be joined by a resistance high frequency welder or other thermofusion device.

[0075] As with the other tension structures discussed above, the tension structure 503 may be manufactured and stored as bulk material and later used for a variety of inflatable articles. The length and width of the tension structure 503 can be cut to accommodate the inner length or width of the inflatable article.

[0076] In one alternative example, it may not be necessary to provide a second layer of heat sealing strips 31 'and instead only the first layer of heat sealing may be secured. ¹ the straps 31 to the bundle 532. The attachment of the bundle 532 to a single layer of welded strips 31 can be done in a similar manner as in the single layer welded strip and weld sheet embodiments described above.

[0077] As shown in Figs. 30-32, the tension structure 503 may also be provided with at least one reinforcement bundle 5 extending along the longitudinal axis of at least one of the

-16ΕΡ2 674 070Β1 welded strips 31.3,. As with the use of the reinforcement bundle 5 in the solutions described above, the reinforcement bundles 5 may be positioned on one of the welded bands 31 of the lower pair and / or between the lower and upper pair of heat sealable bands 31,3Γ.

[0078] The tensioning structure of the present disclosure, including the tensioning structures 3, 103, 203, 303, 403 and 503 described above, has a high tensile strength in the axial direction of the webs 32, 532, extending between corresponding heat sealing strips and / or along the sheets to be sealed. This high tensile strength is complemented by the full strength of the weld between adjacent material of the inflatable article, which is facilitated by the full surface contact provided by the butt joint of the weld strip and / or sheet welded between the bundles 32, 532 and the adjacent material. In this way, the tensioning structure adequately forms the internal structure of the inflatable product while allowing an overall reduction in weight and the deflated / composite volume of the inflated product. For example, the loose arrangement of the bundles 32 is considerably lighter than a one-piece sheet of comparable size and tensile strength.

[0079] When heat-sealed sheets 131 are used, they function to ensure the coherent position and arrangement of the plurality of bundles 32 (or 532), and thus prevent the bundles from being wound up or otherwise entangled together. The welded strips 31 can serve to form a strong structure for welding the tension structure in the inflatable article, thereby providing high tensile strength for the bundled tension structure. Additionally, the use of heat-sealed sheet 131 can significantly reduce the weight of the entire inflatable product compared to the traditional, relatively thicker one-piece sheet, which is also responsible for carrying the tensile load, in other words, heat-sealed sheet 131 is 20% -40% less thick compared to existing tension structures of comparable thickness 0.36mm to 0.8mm as stated above.

As shown in Fig. 33, the tension structures 3 form a distance 39 between adjacent tension structures 3. As discussed above, the bundles 32 have a length 37 which approximates the height 37 of the tension structures 3 when the mattress 10 is inflated. When constructing typical mattresses using PVC tension structures (not shown), the height of the PVC tension structures is practically limited by the distance between adjacent PVC tension structures. This limitation is due to the typical manufacturing method in which all PVC tension structures are aligned on the bottom sheet 2 and simultaneously welded to the bottom sheet 2. If the PVC tension structures are too high, they will overlap adjacent PVC tension structures causing adjacent PVC tension structures to be welded together, which interferes with the operation of the structures. To increase the height of the PVC tension structures, these structures can be folded in half along their length while welding one edge. By assembling the PVC tension structures, the maximum height can be increased to slightly less than twice the distance between adjacent PVC tension structures (e.g. 15 mm less than twice the height of the PVC tension structure). Creating more than one bend is impracticable.

[0081] Since the spacers 33 in the tensioning structures 3 are made of bundles 32 instead of the typical PVC sheets described above, they are much more flexible than typical

-17ΕΡ 2 674 070 Β1 PVC tensioning structures. As a result of this flexibility, mattresses 10 with a height 37, which is greater than the distance 39 between adjacent tension structures 3, can be easily produced.

[0082] During production, the welded strips 31 of each of the plurality of tensioning structures 3 are aligned in their respective position for welding to the bottom sheet 1. The other welded strips 31 of these tensioning structures 3 are transferred to the vicinity of the strip 31 to be welded as shown in Fig. 33. Due to their flexibility, the bundles 32 are stacked on top of each other or on top of adjacent bundles 32, which facilitates multiple layers of bundles 32 on top of each other. By allowing multiple layers of bundles 32 to be stacked on top of each other, the height 37 of the tension structures 3 may be greater than twice the distance 39 between the tension structures 3. According to the examples, the length 37 of the bundles 32 may be 2, 2.5, 3, 3.5. , 4, 4.5, 5, 5.5, 6 or more times the distance 39 between the tension structures 3.

[0083] As shown in Fig. 33, loops 41 form in the bundles 32 during deflection, and portions of the bundles 32 can be placed under the strap 31, which is not welded at this point. While each bundle 32 shown in FIG. 33 has only one loop 41 and only overlaps one other bundle 32, each bundle 32 may have multiple loops 41, and may overlap multiple other bundles 32, especially when the distance between bundles 32 along the welded strips 31 is shorter than the distance shown in Fig. 33.

[0084] In addition to the deflection pattern shown in Fig. 33 to facilitate welding of the strips 31 to the backsheet 2, other orientations of the long bundles 32 may be used to prevent parts of one tension structure 3 from overlapping an adjacent tension structure 3 during welding. For example, as shown in Fig. 35, bundles may be collected in piles 43 to allow the welded strips 31 of each tension structure 3 to move in their vicinity. The turns of the piles 43 make it possible to reduce the distance between the welded strips 31 as the welded strips 31 move together. According to another example, the welded strips 31 of each tensioning structure 3 slide along the span or length of the tensioning structures 3 as shown in Fig. 36. The offset creates sharp angles of the bundles 32 with the welded strips 31 and allows the distance between the welded strips 31 to be reduced. By adapting the bundles 32, which are longer than the distance between adjacent tension structures 3, the tension structures 3 can be made taller without disturbing the welding of the tension structures 3 to the top and bottom sheets 1, 2. As mentioned above, the bundles 32 can be made longer than shown in Figures 33-36. With longer bundles 32, more loops or larger loops 41 (Fig. 33), larger and / or higher stacks 43 (Fig. 35), or a larger offset (Fig. 36) to accommodate the longer bundles 32 to avoid overlapping of the tension structures 3 during welding.

[0085] In preparation for transport or storage, the mattresses 10 are deflated. When emptying, the bundles 32 may stack as shown in Fig. 33. Furthermore, the bundles 32 of adjacent tension structures 3 will contact each other and may intertwine with bundles 32 of the tension structure 3 interposed between bundles 32 of the second tension structure. Moreover, because the bundles 32 are very flexible, they easily collapse on contact with other structures when the mattress 10 is emptied for shipping or storage. For example, when the bundles 32 contact the top or bottom sheets 1,2 in an empty state, they will align with the top and bottom sheets 1, 2 to allow for a more compact folding of the top and bottom sheets 1, 2. As a result of this compaction at least in part, the total volume of the emptied mattress 10 will be reduced compared to mattresses with PVC sheet tension structures. When the collapsed bundles 32 from

-18ΕΡ 2 674 070 Β1 of the tensioning structure 3 will be interlaced with bundles 32 of the same tensioning structure 3, then loops 41 may form, piles 43 may form and / or bundles 32 may be arranged at an angle to the welded strips 31 in a similar manner to that shown in Fig. 36.

As shown in Figure 34, after collapse, the bundles 32 may be oriented in different directions with some superimposed as shown in the two lower bundles 32 and others in substantially the same direction as shown in the three upper bundles 32. Some the bundles 32 collapse in directions that are not perpendicular to the span of the welded strip 31. For example, the lowest bundle 32 in Fig. 34 exits the leftmost welded strip 31 in a direction perpendicular to the welded strip 31, turns upwards parallel to the welded strip 31, returns perpendicular to the welded strip 31, turns downwards parallel to the welded strip 31 and then forms a loop under the welded strip 31 a strip 31 to join another weld strip 31 in a direction perpendicular to the other weld strip 31. According to some solutions, the total volume of the folded or deflated mattress 10 may be 8-25% less than a comparable mattress with tension structures made of PVC sheet. According to a preferred solution, this volume is approximately 16% smaller.

[0087] The tensioning structure of the present disclosure is also an economical solution for imparting the desired structure and shape to the inflatable device. For example, a large reduction in the amount of PVC material can be achieved by using the current tension structure, compared to a one-piece sheet of similar size and tensile strength.