Improved cushioning material

Abstract

A cushioning material (20) comprising a microcoil sheet (14) comprising an array of wire springs held between two layers of fabric, the fabric layers being joined together to form discrete pockets containing springs; and a surface cover material (22); wherein the surface cover material (22) is secured to the microcoil sheet (14) by one or more seams (24). There is also provided a cushioning article or upholstered item (such as a mattress, mattress topper, seat cushion, chair cushion or loose cushion) comprising a cushioning material according to any preceding claim. There is also provided a method of manufacturing a cushioning material (20) comprising a microcoil sheet (14) comprising an array of wire springs held between two layers of fabric, the fabric layers being joined together to form discrete pockets containing springs; and a surface cover material (22); the method comprising securing the surface cover material (22) to the microcoil sheet (14) by one or more seams (24).

Description

TECHNICAL FIELD

[0001] The present invention relates to cushioning materials, more particularly microcoil based cushioning materials. It is particularly suitable for, but not limited to, use in mattresses and mattress toppers, seat cushions / chair cushions (which can be fixed or loose on a seat or chair). It is also possible to apply it to other types of cushioning articles or furniture upholstery as well as gravity blankets. BACKGROUND

[0002] Referring first to Figure 1 , a mattress 10 or seat cushion is generally composed of two main elements: a comfort layer 11 and a support core 16. It will be appreciated that in some mattresses or cushions there are multiple such comfort layers 11. For simplicity, the present disclosure will refer to a mattress or cushion having a single comfort layer 11, but it will be appreciated that the present principles can be extended directly to mattresses, cushions or other articles having multiple comfort layers 11. Reference to a "cushion" herein should be understood to apply to various furniture upholstery, loose or fixed on a chair or seat.

[0003] Some mattresses and cushions use or can use a microcoil array 14 in the comfort layer 11. As Figure 2 shown, a microcoil array 14 (as known from the prior art) is a two-dimensional array of relatively small wire springs 17 (each about 2-5 cm in diameter) held between two layers of fabric (typically synthetic fabric), the two layers of fabric being welded together along seams 18 to form discrete pockets 19 containing the springs 17. Such a microcoil array 14 can also be referred to as a "microcoil sheet". The figures of the present invention illustrate the microcoil array primarily in cross-section (so it might appear one-dimensional at first glance), but it will be naturally understood by the skilled person that the microcoil array is a two-dimensional (nxm) array, where n and m are typically tens or hundreds. Thus, depending on its overall dimensions, a microcoil array 14 can comprise hundreds or thousands of individual wire springs 17.

[0004] As Figure 1 shown, which illustrates a typical construction of a microcoil mattress 10, the microcoil sheet 14 is used in the comfort layer 11 of the mattress 10, sandwiched between two transition layers 13, 15 of cushioning material (such as polyurethane foam, memory foam, latex or natural fibre). On top of this is typically a quilted cover 12.

[0005] To the best of the inventors' knowledge, microcoils have not been used in the manufacture of seats, although there is potential for this application from their use.

[0006] The inventors have identified that the potential of microcoils to provide comfort lies in their ability to compress in one direction and move from side to side. Figure 3A single wire microcoil spring 17 is depicted and shown to pivot from side to side in the x and y directions (or combinations thereof) and / or to elastically compress or extend in the z direction. Thus, if a person sits or lies directly on a layer of microcoil pieces, each spring will react independently to the body part it contacts without affecting adjacent springs. This is an important feature of microcoil pieces. However, when an additional piece of material (including a cover) is placed on top of the springs or stretched over the springs (which is the prevalent way microcoil springs are currently configured in a mattress), the ability of the microcoil springs to move independently is compromised.

[0007] Another important feature of microcoil is the pressure change between the area above the coil and the area between the coils. This pressure change can contribute to blood circulation in the skin; it can contribute to a positive feeling of well-being when sitting or lying directly on a piece of microcoil. However, when a piece of material is placed on the microcoil, this pressure change is reduced.

[0008] The present inventor has found that microcoil pieces, when combined with a suitable support core, can significantly reduce the interface pressure, which is an important parameter for comfort and reducing the risk of tissue damage when lying or sitting for long periods of time. To illustrate this, Figure 4a A pressure map is shown of an individual's buttocks sitting directly on a 90 mm thick piece of high resiliency foam cushion (without a cover), Figure 4b A pressure map is shown of the addition of a piece of microcoil between the individual's buttocks and the foam cushion. In this example, the microcoil reduced the peak pressure index (the highest average pressure measured within a 9 cm 2 area) by 40%. This shows the potential of microcoil to reduce interface pressure, but the realization of this potential requires the use of microcoil high up in the comfort layer and direct connection to the cover, and configured in a way that allows the springs to move independently and respond.

[0009] However, the problem with using microcoil high up in the comfort layer (i.e. close to the top of the comfort layer, close to where the user contacts it) is that, generally speaking, this is not visually acceptable and therefore not considered a commercially viable option in the design of a mattress or seat cushion.

[0010] It is therefore an object of the present invention to enable the use of microcoil high up in the comfort layer, to provide a cover that does not impede the independent movement of the springs, and to do so in a way that is visually acceptable and commercially viable. SUMMARY

[0011] Various aspects of the present invention are set out in the accompanying independent claims, while details of specific embodiments are set out in the accompanying dependent claims.

[0012] According to a first aspect of the application, there is provided a cushioning material comprising a microcoil sheet and a surface cover material, the microcoil sheet comprising an array of wire springs held between two layers of fabric, the fabric layers being joined together to form discrete pockets containing the springs; wherein the cover material is secured to the microcoil sheet by one or more seams. More particularly, the cover material is secured to the fabric of the microcoil sheet, between the springs themselves - for example, along the inherent weld lines of the microcoil sheet.

[0013] This arrangement advantageously enables the microcoils to be positioned closely beneath the outwardly visible, user-contactable surface provided by the cover material, and allows the springs to move independently, whilst also being visually acceptable.

[0014] Attaching the surface cover material to the microcoil sheet in this way can also improve the strength and durability of the overall structure (including the strength and durability of the microcoil sheet itself).

[0015] In certain embodiments, the seam can be continuous through the cushioning material. This can be used to give the cushioning material an appearance with grooves.

[0016] In other embodiments, the seam can be discontinuous across the cushioning material.

[0017] In presently preferred embodiments, the seam coincides with the inherent weld lines of the microcoil sheet, which join the fabric layers together. Where the seam is discontinuous, the seam can be in the form of cross-stitch lines coinciding with the intersection points of the weld lines of the microcoil sheet.

[0018] By passing the seam along the inherent weld lines of the microcoil sheet, the inherent weld lines of the microcoil sheet are reinforced, thereby improving the strength and durability of the microcoil sheet and the overall structure.

[0019] In certain embodiments, the cover material can be in direct contact with the microcoil sheet (i.e. there is no interlayer material between them). Alternatively, the cushioning material can comprise one or more interlayer materials between the cover material and the microcoil sheet, for example to provide additional cushioning or fire resistance.

[0020] In certain embodiments, the seam can be formed by stitching through the cover material and the microcoil sheet material. Where there is an interlayer material between the cover material and the microcoil sheet, the stitching can also pass through the interlayer material; nevertheless, the microcoil sheet and the cover material are still secured to each other by the seam.

[0021] In other embodiments, the interlayer material can be arranged in discrete regions between the seams.

[0022] In presently preferred embodiments, the stitching is machine needle stitching.

[0023] As an alternative to stitching, the seam can be formed, for example, by welding.

[0024] The seams can define pockets in the cover material that separate individual springs or groups of springs, or elongate grooves that separate groups of springs.

[0025] According to a second aspect of the application, there is provided a cushioning structure comprising a first sheet of cushioning material according to the first aspect of the application, attached to a second sheet of cushioning material according to the first aspect of the application by a further seam.

[0026] If the first and second sheets of cushioning material comprise elongate grooves, the elongate grooves of the first sheet of cushioning material can be oriented, for example, parallel or perpendicular to the elongate grooves of the second sheet of cushioning material.

[0027] Optionally, the surface cover material and / or the microcoil sheet of the first sheet of cushioning material can be different to the surface cover material and / or the microcoil sheet of the second sheet of cushioning material, in order to suit the required end product.

[0028] In certain embodiments, the further seam can be along only one edge of the first and second sheets of cushioning material.

[0029] In other embodiments, the further seam can be along at least two edges (and preferably along at least three edges) of the first and second sheets of cushioning material, the first and second sheets of cushioning material overlapping one another. In order to provide a high level of cushioning, the microcoil sheet of the first sheet of cushioning material can face the microcoil sheet of the second sheet of cushioning material.

[0030] Optionally, the cushioning structure can further comprise an insert between the microcoil sheet of the first sheet of cushioning material and the microcoil sheet of the second sheet of cushioning material, the insert comprising one or more of:

[0031] a sheet of foam or moulded foam;

[0032] a rigid or semi-rigid former;

[0033] one or more structural members that form part of a furniture structure;

[0034] a heating element, or a vibration or massage element;

[0035] one or more securing structures or brackets; or

[0036] a further microcoil sheet.

[0037] According to a third aspect of the application, there is provided a cushioning article or furniture cushion comprising a cushioning material according to the first aspect of the application or a cushioning structure according to the second aspect of the application.

[0038] In the case where the article is a mattress, the cushioning material or cushioning structure can be attached to a mattress support core. In the case where the article is a mattress, the cushioning material or cushioning structure can be attached to a mattress support core.

[0039] Alternatively, the article can be, for example, a mattress cover, a gravity blanket, a fixed seat cushion or a fixed chair cushion, or a separate cushion.

[0040] According to a fourth aspect of the application, there is provided a method of manufacturing a cushioning material comprising a microcoil sheet and a surface cover material, the microcoil sheet comprising an array of wire springs held between two layers of fabric, the layers of fabric being joined together to form discrete pockets containing the springs; the method comprising securing the cover material to the microcoil sheet (in particular to the fabric thereof) by one or more seams.

[0041] In certain embodiments, when forming each seam, the cover material is first folded to form a double layer of cover material immediately after the cover material has passed over a predetermined location of the seam, the double layer of cover material is then secured to the microcoil sheet to form the seam, and the cover material is then unfolded and pulled over a group of springs; before the next seam is formed. This facilitates the concealment of the seams from view in the final product.

[0042] In further embodiments, the first and second sheets of cushioning material can be joined together by a further seam.

[0043] For example, the further seam can follow at least two edges (and preferably at least three edges) of the first and second sheets of cushioning material, the first and second sheets of cushioning material overlapping one another. Furthermore, an opening can be provided in the further seam, the first and second sheets of cushioning material can be initially attached by the further seam such that the microcoil sheets of the first and second sheets of cushioning material face away from one another, thereby forming an intermediate product. The method can then further comprise turning the intermediate product inside out through the opening such that the microcoil sheets of the first and second sheets of cushioning material face one another. In this way, an enclosed cushioning structure can be produced which is capable of providing a high level of pressure relief to a user. BRIEF DESCRIPTION OF DRAWINGS

[0044] Embodiments of the application will now be described, by way of example only, and with reference to the accompanying drawings in which:

[0045] Figure 1 shows a cross-sectional side view of a typical microcoil mattress structure;

[0046] Figure 2 shows a cross-sectional side view of a typical microcoil array;

[0047] Figure 3 shows a typical movement of an individual microcoil spring;

[0048] Figure 4a is a pressure map of an individual sitting directly on a foam cushion;

[0049] Figure 4b In the context of Figure 4a Pressure maps under the same conditions, but with micro-coil sheets added at the interface between the individual's buttocks and the foam pad;

[0050] Figure 5 A cross-sectional side view of an embodiment of a microcoil-based cushioning material is shown, the cushioning material comprising microcoil sheets with a surface covering material;

[0051] Figure 6 The stitching method for attaching surface covering material to a micro coil sheet using vertical stitching is shown in cross-section.

[0052] Figure 7 Another stitching method for attaching surface covering material to a micro coil sheet using vertical stitching is shown in cross-section;

[0053] Figure 8 A stitching method for attaching surface covering material to a micro coil sheet using horizontal stitching is shown in cross-sectional form;

[0054] Figure 9 It shows the use of, as Figure 5 A cross-sectional side view of a microcoil mattress construction based on microcoil cushioning material is shown.

[0055] Figure 10 Showing Figure 5 The surface design of the cushioning material based on microcoils is shown, wherein crosshairs are formed at the intersections of the inherent weld lines in the microcoil sheet (to attach the covering material to the microcoil sheet) to form a bag;

[0056] Figure 11 Showing Figure 5 The surface design of the microcoil-based cushioning material shown includes parallel seams (attaching the cover material to the microcoil sheet) stitched along the inherent weld lines in the microcoil sheet to form a groove, and also shows that tension can be applied in the direction of the seams, for example, if used to accommodate a support to enhance the groove.

[0057] Figure 12a The basics are shown as follows Figure 11 A plan view of a grooved, micro-coil-based buffer material;

[0058] Figure 12b It shows Figure 12a A cross-sectional side view of a micro-coil-based cushioning material stretched around a foam pad and fixed to a wooden base;

[0059] Figure 13a and 13brespectively, of a microcoil-based cushioning material having recesses in a first panel and a second panel joined together by another seam, Figure 13c showing a microcoil-based cushioning material panel that has been opened up to lie flat, Figure 13b

[0060] Figure 14 showing a plan view of a combined first panel and second panel of a microcoil-based cushioning material having recesses, wherein the recesses of the first panel and the second panel are (a) parallel to each other, and (b) perpendicular to each other;

[0061] Figure 15a and 15b respectively, of a microcoil-based cushioning material having recesses in a first panel and a second panel joined together in an overlapping manner by a peripheral seam having an opening on one side, the microcoil panels being on the outside, thereby forming an intermediate product;

[0062] Figure 15c showing Figure 15a and 15b a cross-sectional view of the intermediate product, which has been turned over so that the microcoil panels of the first and second cushioning material panels are on the inside, facing each other.

[0063] In the drawings, like elements are denoted by the same reference numerals throughout. DETAILED DESCRIPTION

[0064] The embodiments represent the best way of putting the invention into practice known to the applicant at the present time. However, they are not the only way(s) in which the invention can be practised.

[0065] As shown in Figure 5 , an embodiment of the invention provides a microcoil-based cushioning material 20 (e.g. for a furniture cushion or a mattress), in which a surface cover material 22 (which is outwardly user-visible and in use user-contactable) is attached to the microcoil panels 14, e.g. by stitching or welding, so that the cover material 22 and the microcoil panels 14 are fixed to each other by a seam (i.e. a joint line) 24.

[0066] The seam 24 can be continuous or it can be discontinuous (e.g. only at discrete places) through the cushioning material 20.

[0067] ​The cover material 22 can be in direct contact with the microcoil sheet 14 (i.e., there is no interlayer material between them). Alternatively, in some variations, one or more interlayer materials can be provided between the microcoil sheet 14 and the cover material 22 to provide, for example, additional cushioning or fire resistance. However, even when one or more interlayer materials are provided between the microcoil sheet 14 and the cover material 22, the microcoil sheet 14 and the cover material 22 are still secured to one another by the seams 24 - e.g., by stitching through the microcoil sheet 14, through the interlayer material, and through the cover material 22; or by disposing the interlayer material in discrete areas between the seams 24, in turn causing the seams 24 to bypass the interlayer material.

[0068] In more detail, embodiments of the present invention provide a new configuration of cushioning material 20, with microcoil pocketed springs 14 engaged with a cushioning pad surface cover material 22, wherein the microcoil sheet 14 is secured directly to the cover material 22 along seams 24 (e.g., by stitching or welding), and wherein a plurality of areas are defined between the seams 24, allowing constituent springs of the microcoil sheet 14 to move independently within the areas.

[0069] The microcoil sheet 14 and the cover material 22 are secured together along the seams 24, in turn forming respective pockets or elongated grooves that separate individual springs or groups of springs. By way of example only, such pockets can contain a single spring, or a 1x2, 2x2, 1x3, 2x3, or 3x3 group of springs. Naturally, other numbers of springs can also be in such pockets. On the other hand, in a groove arrangement (obtained using a continuous seam), the grooves can separate springs arranged in continuous rows, which can be a single spring width, or two, three, four, or more spring widths.

[0070] A typical commercially available microcoil pocketed spring sheet 14 includes two synthetic fabrics (of the same or different types) welded together by the manufacturer along seams to form discrete pockets containing springs. The inventors of the present invention have discovered that the size of such pockets (typically on the order of 2-4 cm x 2-5 cm) is suitable for passing through a needle and thread sewing machine or a weld seam sewing machine. This, in turn, enables the cover material 22 to be stitched in parallel lines to the microcoil pocketed spring sheet 14 along the inherent pre-existing weld seams of the microcoil sheet 14. Alternatively, the cover material 22 can be stitched to the microcoil pocketed spring sheet 14 at intersections of the inherent weld seams.

[0071] In the currently preferred embodiment, the seam 24 is formed by a needle and thread sewing machine, passing the micro-coil sheet 14 and the covering material 22 together through the sewing machine to form the seam 24 along the inherent, pre-existing weld seam of the micro-coil sheet 14 between adjacent spring rows. For the inventors, the ability to pass a micro-coil sheet with its inherent metal thread component through such a sewing machine is a surprising and counterintuitive discovery, as such sewing machines are generally understood to be designed only for sewing fabrics, and it is a natural assumption that the springs of the micro-coil sheet 14 might jam, bend, or break off the sewing machine needle or other precision components around the sewing machine presser foot.

[0072] Figure 6 An example of the position and orientation of the seam relative to the micro-coil piece 14 is shown. The seam attaches the covering material 22 to the micro-coil piece 14 and forms a seam 24 (the joining line between the covering material 22 and the micro-coil piece 14). Here, the seam is vertical and is inserted in a parallel line along the pre-existing weld of the micro-coil piece 14, between adjacent spring-loaded bags of the micro-coil piece 14, using a needle 30 (e.g., a needle from an industrial sewing machine).

[0073] Figure 7 It shows Figure 6 Another sewing method, used to attach the surface covering material 22 to the micro-loop sheet 14, also uses vertical sewing. However, in this case, before sewing each seam 24 with needle 30, as shown, after the covering material 22 has passed the predetermined position of the seam 24, the covering material 22 is immediately folded back to form a partial double layer of the covering material 22. The partial double layer of the covering material 22 is then sewn to the micro-loop sheet 14 to form the seam 24. The covering material 22 is then unfolded and pulled over the next row (or more rows) of spring-loaded bags, and then folded back to prepare for forming the next seam 24. The sewing process is then repeated for the next seam 24, and so on. Figure 6 In contrast, the advantage of this technology is that, in this case, the seam 24 can be hidden in the final product so that it cannot be seen.

[0074] Or, such as Figure 8 As shown, the micro coil sheet 14 can be manufactured with multiple rows of empty pockets to provide space for folding the micro coil sheet 14, thereby enabling horizontal stitching to form a seam 24. This technique also allows the seam 24 to be concealed in the final product.

[0075] use Figure 6 , 7And 8, for non-weldable cover materials, the stitching can be formed using a needle and thread sewing machine; or if the cover material 22 is weldable to the microcoil sheet 14, the stitching can be welded. An additional interlayer material can be stitched between the microcoil sheet 14 and the cover material 22 to provide, for example, additional cushioning or flame resistance. In this case, the microcoil sheet 14 and the cover material 22 are still secured to each other by the stitching that passes through the joint of the microcoil sheet 14, the interlayer material, and the cover material 22. Alternatively, the interlayer material can be disposed in discrete regions between the stitching 24, such that the stitching 24 passes around the interlayer material.

[0076] It has been found that the stitching joint 24 through the microcoil sheet 14 significantly increases the strength and durability of the overall assembly (including the strength and durability of the microcoil sheet itself). This can be particularly important if the assembly is to be located at the end of a mattress or bed pad and is not protected by a layer of foam or the like (as is customary). This can be even more important in applications where the seat is accessed, which can add additional wear. For example, automotive seat cushions need to be more durable than bed pads.

[0077] The above techniques can be used to manufacture a cushioning material 20 for a range of uses, in which the surface cover material 22 and the microcoil sheet 14 are secured to each other by the stitching 24. With reference to Figure 9 In the case where the cushioning material 20 is used for a bed pad, the cushioning material 20 of the present invention can be assembled to a bed pad support core 16 (optionally with a transition layer 15 of cushioning material therebetween) in a conventional manner to form a new type of microcoil bed pad 40. The support core 16 can be made, for example, of larger springs, memory foam, high resilience polyurethane foam, latex foam, natural fibers, or combinations thereof.

[0078] Exemplary surface designs

[0079] Figure 10 A surface design of one embodiment of the cushioning material 20 is shown in (a) plan view and (b) / (c) cross-sectional side view, in which the stitching 24 is discontinuous, in the form of cross-stitch lines 50, implemented only at the intersections of the welds in the microcoil sheet 14 to create corresponding pockets. It will be appreciated that in this embodiment, the cross-stitch lines 50 are located at every intersection of the welds in the microcoil sheet 14, such that each pocket created contains a single microcoil spring. However, in variations of this design, the cross-stitch lines can be less frequent - for example: at every second intersection of the welds in the microcoil sheet 14, such that each pocket created contains four microcoil springs (in a 2x2 group).

[0080] Figure 11Another surface design of an embodiment of cushioning material 20 is shown in (a) plan view and (b) / (c) cross-sectional side view, in this case parallel seams 24 are stitched along the weld seams in the microcoil sheet to form a channel 52. Such a channel can contain a single row of springs or multiple rows of springs. In the embodiment shown, the channel contains two rows of springs, though other numbers of springs are possible. As shown, tension applied in the direction of seams 24 can enhance the channel effect - for example, if the cushioning material 20 is to be installed to a support.

[0081] Exemplary Applications

[0082] Embodiments of the present invention are particularly suitable, though by no means limited, for use in bed mattresses and bed toppers, as well as seat cushions / chair cushions (which can be fixed to a seat or chair, or loose). Applications in other types of upholstered furniture and cushioning are also possible. For example, it is envisaged that embodiments can be used to make consumer-grade bed mattresses, consumer-grade bed toppers, medical bed mattresses, medical bed toppers, fixed seat / chair upholstery, loose seat cushions / chair cushions, seat cushion toppers, gravity blankets, medical fixed seat / chair upholstery, medical loose seat cushions / chair cushions, and medical seat cushions. Embodiments can also be used to provide cushioning in non-furniture items such as backpacks and baby carriers.

[0083] To provide additional explanation regarding gravity blankets, on a bed, one purpose of the present invention is to reduce the interfacial pressure of a bed mattress acting on a user's body. Interfacial low pressure distribution is associated with improved sleep quality. Some gravity blankets claim to help sleep disorders such as insomnia, and work by increasing the pressure of the overlay to reduce the pressure differential across the user's body. Thus, a gravity blanket embodying the present invention, which interacts with the user using the same pressure redistribution techniques as a bed mattress, will reduce the pressure differential across the user's body, distribute pressure evenly across all contact areas, and reduce any peak pressures that can exist in other gravity blankets.

[0084] Another exemplary application relating to upholstered furniture will now be described with reference to Figure 12a and 12b Figure 12a A plan view of a piece of channelled, microcoil-based cushioning material 20 is shown substantially as described in Figure 11 However, as shown in the cross-sectional view in Figure 12b , in this case the surface cover material 22 extends beyond the area occupied by the microcoil sheet 14. This arrangement of the surface cover material 22 relative to the microcoil sheet 14 provides a way of securing the cushioning material 20 around an underlying structure, in this embodiment a foam pad 60 and a wooden (e.g. plywood) base 62. More particularly, the surface cover material 22 is stretched around the foam pad 60 and attached to the underside of the wooden base 62 by means of staples 64a, 64b or tacks. ​

[0085] Cushioning structures comprising links of microcoil-based cushioning material

[0086] For example, as Figure 13a shown in Figs. 14 and 15a-c, a cushioning structure can be manufactured that comprises multiple pieces of microcoil-based cushioning material connected together by one or more additional seams.

[0087] Figure 13a and 13b respectively show a first piece of grooved, microcoil-based cushioning material 20 connected to a second piece of grooved, microcoil-based cushioning material 20' by another seam 70 to form a combined cushioning structure 80 as shown in cross-section in Fig. 15c. Figure 13c respectively show a first piece of grooved, microcoil-based cushioning material 20 connected to a second piece of grooved, microcoil-based cushioning material 20' by another seam 70 to form a combined cushioning structure 80 as shown in cross-section in Fig. 15c.

[0088] In more detail, and with particular reference to Figure 13b , the first and second pieces of microcoil-based cushioning material 20, 20' are initially placed back-to-back, i.e. the respective pieces of cover material 22, 22' are in contact with each other, and the respective pieces of microcoils 14, 14' are facing outwards. Seam 70 is then sewn (or welded) to connect the two pieces of cover material 22, 22' together, over one edge of the pieces of microcoils 14, 14' (i.e. along one edge of the first and second pieces of cushioning material 20, 20').

[0089] The junctions of the microcoil-based cushioning material 20, 20' of Figure 13b are then opened (as shown by the curved arrows) so as to lie substantially flat, thereby forming the combined cushioning structure 80 shown in Figure 13c It will be appreciated that when the opened cushioning structure 80 is viewed from the side of the cover materials 22, 22', the seam 70 is hidden.

[0090] This combined cushioning structure 80 makes it possible to selectively configure the constituent pieces of microcoil-based cushioning material to suit the requirements of the desired end product. For example, as shown in Figure 14 , the grooves of the first and second pieces 20, 20' can be oriented (a) parallel to each other, or (b) perpendicular to each other, to suit the design and load support / pressure relief requirements of the end product. It will of course be appreciated that one or both of the first and second pieces 20, 20' need not have grooves, and can have different surface designs (for example, as shown in Figure 10 ).

[0091] Furthermore, the surface coverings 22 of the first piece of cushioning material 20 and / or the microcoil pieces 14 can be different from the surface coverings 22' of the second piece of cushioning material 20' and / or the microcoil pieces 14', again in order to suit the design and load support / pressure relief requirements of the final product. For example, the surface coverings 22, 22' can be different fabrics. In addition, the microcoil pieces 14, 14' can have different characteristics, for example in terms of spring stiffness, spring height, spring density (number of springs per unit area), etc.

[0092] Figure 15a - c shows another embodiment of a combined cushioning structure comprising a first and a second piece of microcoil-based cushioning material 20, 20' connected together in an overlapping manner by one or more additional seams 72. The resulting cushioning structure 90 is shown in cross-section in Figure 15c where the microcoil pieces 14, 14' of the first and second pieces of microcoil-based cushioning material 20, 20' are located on the inside of the structure, facing each other. This cushioning structure 90 can be formed starting from the structure shown in Figure 15a and 15b .

[0093] More specifically, Figure 15a and 15b show a cross-sectional view and a plan view, respectively, of a first piece of grooved, microcoil-based cushioning material 20 connected to a second piece of grooved, microcoil-based cushioning material 20' by a peripheral seam 72 in an overlapping manner, where the peripheral seam 72 extends along at least two edges of the first and second pieces of cushioning material 20, 20' and beyond the edges of the microcoil pieces 14, 14'. Preferably, the peripheral seam 72 extends along at least three edges of the cover of the cushioning material 20, 20' and, in addition, can extend along a portion (but not all) of the fourth edge, as shown. There is an opening 74 in one edge of the peripheral seam 72 that is large enough for the purpose of a "turning inside out" described below. In the embodiment shown, the opening 74 in the peripheral seam 72 is about one-third the length of the edge of the microcoil piece 14 therein. Initially, as shown in Figure 15a , the microcoil pieces 14, 14' are located on the outside of the structure, facing away from each other, when the first and second pieces of cushioning material 20, 20' are connected together by the peripheral seam 72. The structure of Figure 15a can be considered to be an "intermediate product".

[0094] Referring to Figure 15b and 15c , the above "intermediate product" is then turned inside out through the opening 74 in the peripheral seam 72 to form Figure 15cthe microcoil pieces 14, 14' of the first and second pieces of cushioning material 20, 20' face each other. By virtue of this manufacturing method, once the cushioning structure 90 is formed, the microcoil pieces 14, 14' and the perimeter seam 72 are hidden from view. The structure 90 encases the microcoil pieces 14, 14' and can be used as a standalone pillow or cushion, or can be attached to a frame or other structure. Furthermore, since the microcoil pieces 14, 14' abut each other without being particularly laterally constrained (thus allowing a high degree of mobility of the springs), the resulting cushioning structure 90 is able to provide a high level of pressure relief.

[0095] Figure 15c the cushioning structure 90 in Figure 12b is improved over the "fixed" furniture cushion shown in Figure 12b the furniture cushion in nails or staples the surface cover material 22 of the cushioning material 20 to the wooden base 62. One problem with this "fixed" furniture cushion is that the mobility of the cushioning units is poor, and the mobility of the cushioning units is key to the pressure-relieving performance of the product. For example, with reference to Figure 12b the fabric of the cover material 22 can be tensioned to reduce the build-up of fabric and wrinkles, but for a general quality, this tensioning reduces the movement of the springs of the microcoil pieces 14 even if a knitted fabric with bi-directional elasticity is used. The foam pad 60 can also trap the springs of the microcoil pieces 14, further reducing the movement. By effectively embodying the present invention as a loose cushioning pad, Figure 15c the cushioning structure 90 in This greatly improves the freedom of movement of the springs of the microcoil pieces 14, 14', enabling them to fully conform to the user's body without being constrained by the wooden base 62. As a result, the user can be more deeply immersed in the product. Greater immersion and greater contact area, combined with the ability of the microcoil pieces 14, 14' and the combined springs to move and conform to the user's body, results in a significant reduction in peak pressure.

[0096] The enclosed cushioning structure 90 as a standalone product can be used as a pressure-relieving pad for a seat (e.g. a wheelchair, a vehicle seat, an office chair, etc.), a mattress, a mattress topper, or a gravity blanket.

[0097] If desired, the cushioning structure 90 can be modified by providing an insert between the microcoil pieces 14 of the first piece of cushioning material 20 and the microcoil pieces 14' of the second piece of cushioning material 20'. The insert can include one or more of the following:

[0098] a sheet of foam or molded foam (to change the thickness of the structure 90 and create contours);

[0099] a rigid or semi-rigid former (to provide focused support, e.g. to support the lower spine of the user in a seat - the position of such a former can be adjusted);

[0100] one or more structural members (e.g. tubular backrest frame) that make up part of the furniture structure;

[0101] a heating element, or a vibrating or massaging element;

[0102] one or more fixing structures or brackets (through which the cushioning structure 90 can be attached to the furniture structure component); or

[0103] a further (i.e. third) microcoil sheet.

[0104] When introducing a third microcoil sheet between existing microcoil sheets 14, 14', the third microcoil sheet can be stitched, for example along its edges, to either of the existing microcoil sheets 14, 14'. This will, for example, make the user more immersed in the backrest area. If a third microcoil sheet with stronger (i.e. stiffer) springs is to be used, this will also provide more support to these areas of the backrest.

Claims

1. A method for manufacturing a cushioning material, the cushioning material comprising microcoil sheets and a surface covering material, The micro coil sheet is a pre-made, commercially available micro coil bag spring sheet, comprising an array of wire springs fixed between two layers of fabric, the fabric layers being joined together by weld lines to form a separate bag containing springs; The method includes subsequently securing the covering material to the micro coil sheet via one or more seams; The seam is formed by machine needle and thread stitching, which passes through the covering material and the micro coil sheet; The seam extends along the weld line of the micro coil sheet and is located between the springs of the micro coil sheet, the weld line connecting the fabric layers together.

2. The method according to claim 1, wherein, The seam extends continuously through the cushioning material.

3. The method according to claim 1, wherein, The seam is discontinuous on the cushioning material.

4. The method according to claim 3, wherein, The seam is a cross-shaped seam that coincides with the intersection of the weld line of the micro coil sheet.

5. The method according to any one of claims 1 to 4, wherein, The covering material is in direct contact with the micro coil sheet.

6. The method according to any one of claims 1 to 4, further comprising providing an interlayer material between the covering material and the microcoil sheet.

7. The method according to claim 6, wherein, The machine needle and thread also pass through the interlayer material.

8. The method of claim 6, further comprising arranging the interlayer material in a separate area between the joints.

9. The method according to any one of claims 1 to 4, wherein, The seam defines a bag in the covering material that separates individual springs or spring groups.

10. The method according to any one of claims 1 to 4, wherein, The seam defines elongated grooves in the covering material that separate the spring components.

11. The method according to claim 10, wherein, When forming each seam, the covering material is first folded immediately after it exceeds the predetermined position of the seam to form a double-layer covering material. The double-layer covering material is then fixed to the micro coil sheet to form the seam. The covering material is then unfolded and pulled through a set of springs to form the next seam.

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