An inflatable airbed and a method of its construction

Abstract

The invention is an inflatable airbed and a method of constructing same. The inflatable airbed includes an inflatable shell defining an air chamber and which is inflatable via a valve provided to a surface of same. The airbed includes a layer of self-inflating material, preferably, self-expanding / self-inflating foam, one side of which is bonded to the upper side of the shell and the other side to a top cover that forms the sleeping surface of the inflatable airbed. The layer of self-inflating material provides improved thermal efficiency compared to a conventional airbed.

Description

[0001] AN INFLATABLE AIRBED AND A METHOD OF ITS CONSTRUCTION

[0002] 1. FIELD OF THE TECHNOLOGY

[0003] The present invention relates to an inflatable airbed and a method of its construction. The invention has particular application to an inflatable airbed that includes a self-inflating layer and is suitable for camping, and the method of constructing same.

[0004] 2. BACKGROUND TO THE TECHNOLOGY

[0005] Inflatable airbeds are a common form of sleeping equipment used when camping. When not in use, they are compact and easily transported, and can be readily inflated through the use of electric or mechanical hand pumps when needed. Once inflated, they provide a degree of elevation and cushioning from the substrate. As such, inflatable air beds can provide potentially increased comfort for the user when sleeping, compared to a conventional thin sleeping mat or similar.

[0006] However, inflatable airbeds do have problems. For example, they can be relatively bouncy, with even minor movements causing considerable displacement of the surfaces of the airbed in use. Another problem with inflatable airbeds is that they are thermally inefficient; the filling medium, air, easily conducts temperatures.

[0007] Inflatable airbeds are often constructed from fabrics composed of, or coated with, polyvinyl chloride. These types of materials are relatively noisy as they deform, so when a use shifts position the resulting sounds of the fabric changing position can disrupt sleep. Such materials are also not conducive for bonding to noise reducing or damping materials in order to resolve this issue without unduly compromising the structural integrity of the PVC.

[0008] To at least partially remedy these issues, some inflatable airbeds integrate a self-inflating foam layer to the sheet of material defining the upper side of the air chamber. This self-inflating foam layer is overlaid by a cover, which forms the top side of the inflatable airbed, i.e. the sleeping surface. This provides a degree of insulation from the ground, and thus improved thermal efficiency, but also has some damping properties to alleviate, to an extent, the bounciness of the airbed.

[0009] However, the manufacture of inflatable airbeds that include a layer of self-inflating foam can be problematic and compromises in the overall height of the mattress may have to be made.

[0010] In some instances, there can be issues in binding the layer of foam to the shell of the airbed so as to not unduly affect its self-inflating properties. Such issues may be alleviated by using a relatively thin layer of self-inflating foam but then the thermal efficiency of the airbed is reduced as is the damping effect provided. A seam is formed through connecting the cover to the appropriate edge of the upper side of the air chamber. The presence of this seam can complicate manufacture of the airbed since for its formation, it may require the layer of foam to be compressed prior to securing the cover. The self-inflating layer may since be somewhat under tension, particularly about its perimeter, even once the cover is secured, and this may affect airflow through same.

[0011] Alternatively, the layer of self-inflating foam may be reduced in surface area, such that it does not abut the edge of the upper side of the air chamber. However, this may compromise the comfort performance of the inflatable airbed. A solution to these problems is desired.

[0012] 3. OBJECT OF THE TECHNOLOGY

[0013] It is an object of the present technology to provide an inflatable airbed for camping and a method of constructing same.

[0014] Alternatively, it is an object of the present technology to provide an inflatable airbed for camping which is comfortable when a person is resting upon same.

[0015] Alternatively, it is an object of the present technology to provide an inflatable airbed for camping which has good thermal efficiency compared to conventional inflatable airbeds.

[0016] It is an object of the present technology to provide an inflatable airbed for camping that includes an integrated self-inflating layer.

[0017] Alternatively, it is an object of the present technology to provide an inflatable airbed with an integrated self-inflating layer that is cost-effective to manufacture.

[0018] Alternatively, it is an object of the technology to provide an inflatable airbed that is suitable for its intended use.

[0019] At the very least, it is an object of the technology to at least provide the public with a useful choice.

[0020] 4. SUMMARY OF THE TECHNOLOGY

[0021] According to one aspect of the invention, there is provided an inflatable airbed comprising: an air chamber defined by a shell having a lower side and an upper side, the air chamber also defined by a side wall connecting said lower side to said upper side; and a self-inflating layer, wherein the self-inflating layer comprises: a layer of self-inflating material having an upper side and a lower side; and a top cover, wherein the top cover is provided to the upper side of the layer of self-inflating material, characterised in that the lower side of the layer of self-inflating material is bonded to the upper side of the shell of the air chamber, and wherein the layer of foam is arranged relative to the air chamber such that the top cover provides a sleeping surface for a user.

[0022] The invention is an inflatable airbed and a method of constructing same. The inflatable airbed includes an inflatable shell defining an air chamber and which is inflatable via a valve provided to a surface of same. The airbed includes a layer of self-inflating material, preferably, self-expanding / self-inflating foam, one side of which is bonded to the upper side of the shell and the other side to a top cover that forms the sleeping surface of the inflatable airbed. The layer of self-inflating material provides improved thermal efficiency compared to a conventional airbed.

[0023] Although reference is made throughout this specification to the invention as being an inflatable airbed, in some jurisdictions these are referred to as an inflatable mattress.

[0024] The inflatable airbed includes a shell with a length dimension and width dimension.

[0025] The shell should be understood to form the air chamber of the inflatable airbed. The shell comprises of a first panel forming the upper side of the shell, a second panel forming a lower side of the shell, and a side wall which connects the first panel to the second panel about the perimeter of same.

[0026] In some examples, the side wall may be integrally formed with one of the first or second panels.

[0027] It should be understood that the sides of the inflatable airbed are defined, at least partially, by the side wall that bounds the upper and lower surfaces of the shell substantially about the respective perimeters of the first and second panels.

[0028] In an example, the shell is comprised of, or is coated with, a substantially impermeable material such as polyester, nylon, polyurethane (PU), polyvinyl chloride (PVC), among others, or a blend of one or more of such materials.

[0029] In a preferred example, the shell is comprised of a non-stretch fabric coated or otherwise treated with a thermoplastic material such as thermoplastic polyurethane (TPU). In other examples, the shell may be comprised of PVC or a fabric / material coated with PVC.

[0030] In an example, the respective first and second panels and side wall are formed from the same material. In alternative examples, one or more of the respective first and second panels and the side wall of the shell may be comprised of a material different to that used for the other of the first and second panels and side wall.

[0031] In some examples, the second panel, forming the lower side of the shell and as such, being potentially in contact with the substrate in use, may be formed from a material, or grade of material, of greater durability and robustness compared to the material used for the first panel and / or the side wall of the shell.

[0032] In an example, the exterior surface of the side wall is provided with a valve or similar structure, the valve being communicative with the interior of the air chamber. This provides a means by which the air chamber may be inflated or deflated as required.

[0033] In an example, the valve is configured with at least one direction of flow control.

[0034] In a preferred example, the valve is a one-way valve configured to permit ingress of air and removable to allow egress of air. In another example, the valve is a 360° double-way valve which, depending on its orientation, is operable to permit ingress and egress of air as required. The valve may be formed from a suitable durable plastics material as will be readily selected by a person skilled in the art.

[0035] The self-inflating layer should be understood to be a layer or sheet of self-inflating or self-expanding material. The self-inflating layer has a length dimension and width dimension substantially corresponding to those of the shell.

[0036] In a preferred example, the self-inflating material is an open cell foam. These types of foam should be understood to be comprised of a material that can be compressed upon application of a force, and then the force is removed, be returned to its original state.

[0037] In examples the open cell foam may be formed or otherwise made from materials such as polyurethane, latex, viscoelastic, ethylene vinyl acetate (EVA), high resilience foam (HR), among others.

[0038] In one example, the self-inflating layer of the inflatable airbed is comprised of a single layer or sheet of foam. In other examples, the single layer may be formed from two or more sheets of foam laid end-on- end to form the layer.

[0039] The layer of self-inflating material is bonded or otherwise secured to the upper panel of the shell. This may be achieved by coating one or both of the respective contact surfaces of the first layer and upper panel with an adhesive. In one example, the adhesive may be polyurethane (PU) adhesive although this is not meant to be limiting. In another example, the self-inflating layer of the inflatable airbed is comprised of a first layer and second layer, each layer being comprised substantially of the self-inflating or self-expanding material.

[0040] In this example, each layer is formed from a single sheet of foam. In other examples, one or both of the first and second layers of foam may be formed from two or more sheets of foam; for example, two sheets may be laid end-on-end to form the first layer.

[0041] In this example, each layer of the self-inflating layer is formed from sheets of the same grade of foam. In other examples, one of the layers may be formed from a different grade of foam. For example, the second layer, may be of a denser grade of foam compared to the first layer, thus conferring improved thermal efficiency to the side of the inflatable airbed on which the user sleeps.

[0042] In this example, the second layer is thicker than the first layer. In this example, the second layer may include cores from which foam material has been removed. This could be useful for reducing the weight of the inflatable airbed but may compromise its ability to self-inf late.

[0043] The first layer of self-inflating material is bonded or otherwise secured to the upper panel of the shell. This may be achieved by coating one or both of the respective contact surfaces of the first layer and upper panel with an adhesive. In one example, the adhesive may be PU adhesive although this is not meant to be limiting.

[0044] In alternative examples, an intermediary layer may be disposed between the upper panel of the shell and the first layer of self-inflating material and chemically reacts, upon application of, for example, heat, to bond the first layer and the upper panel.

[0045] In embodiments where it is present, the second layer of self-inflating material is bonded or otherwise secured to the first layer of self-inflating material. This may be achieved by coating one or both of the respective contact surfaces of the first layer and second layer with an adhesive. In one example, the adhesive may be PU adhesive although this is not meant to be limiting.

[0046] In an example, an intermediary layer may be disposed between the first layer and the second layer and chemically reacts, upon application of, for example, heat, to bond the respective layers.

[0047] In an example, the side wall is a first side wall and the airbed includes a second side wall.

[0048] In an example, the first side wall forms part of the shell and the second side wall forms the self-inflating layer.

[0049] In an alternative example, the first side wall forms part of the shell and part of the self-inflating layer and the second side wall forms another part of the self-inflating layer. In an example, the second side wall is comprised of a material having stretching properties. In a particularly preferred example, the second side wall is comprised of a stretch fabric, coated with TPU, preferably in a non-laminated form.

[0050] In an example, the second side wall, in use, covers at least a portion of the sides of the self-inflating layer of the airbed.

[0051] In an example, the exterior surface of the second side wall is provided with a valve or similar structure, the valve being communicative with the interior of the self-inflating layer. This provides a means by which the additional air may be introduced into the self-inflating layer or allowed to egress from same.

[0052] In an example, the valve of the second side wall is configured with at least one direction of flow control.

[0053] In a preferred example, the valve of the second side wall is a one-way valve configured to permit ingress of air and removable to allow egress of air. In another example, the valve of the second side wall is a 360° double-way valve which, depending on its orientation, is operable to permit ingress and egress of air as required. The valve may be formed from a suitable durable plastics material as will be readily selected by a person skilled in the art.

[0054] In an example, the top cover is comprised of a stretch fabric coated or otherwise treated with a thermoplastic material such as TPU. In a particularly preferred example, the cover is a laminated TPU stretch fabric.

[0055] In an example, the top cover has a perimeter defined by two pairs of opposing edges, each pair corresponding to the width dimension and the length dimension of the shell and self-inflating layer.

[0056] In an example, the perimeter of the top cover is bonded to an upper edge of the second side wall.

[0057] In an example, a lower edge of the second side wall is bonded to an edge of the first panel of the shell.

[0058] In an example, the bonding is achieved through the use of a TPU weld.

[0059] According to another aspect of the present invention, there is provided a method of manufacturing an inflatable airbed, the inflatable airbed including a shell forming an air chamber and having an upper side, a self-inflating layer comprised of a layer of self-inflating material, wherein the method includes the steps of:

[0060] • bonding a lower edge of a first side wall to a perimeter of a lower surface of the shell;

[0061] • bonding a lower edge of a second side wall to one or both of: a) an upper edge of the first side wall or b) a perimeter of the upper side of the shell;

[0062] • bonding the layer of self-inflating material to the upper side of the shell; • providing a top cover to an upper side of the layer of self-inflating material; and

[0063] • bonding an upper edge of the second side wall to a perimeter of the top cover.

[0064] According to another aspect of the present invention, there is provided a method of manufacturing an inflatable airbed, the inflatable airbed including a shell forming an air chamber and having an upper side, a self-inflating layer comprised of a layer of self-inflating material, wherein the method includes the steps of:

[0065] • bonding a lower edge of a first side wall to a perimeter of a lower surface of the shell;

[0066] • bonding an upper edge of the first side wall to a perimeter of the upper side of the shell to form an air chamber;

[0067] • bonding the layer of self-inflating material to the upper side of the shell;

[0068] • bonding a lower edge of a second side wall inwards of the perimeter of the upper side of the shell;

[0069] • providing a top cover to an upper side of the layer of self-inflating material; and

[0070] • bonding an upper edge of the second side wall to a perimeter of the top cover.

[0071] In an example, the bonding of the lower edge of the first side wall to the lower surface of the shell is achieved through the application of a TPU weld.

[0072] In an example, the bonding of the upper edge of the first side wall to the perimeter of the upper side of the shell is achieved through the application of a TPU or weld.

[0073] In an example, the bonding of the layer of self-inflating material to the upper surface of the shell is achieved through the application of adhesive. In another example, the bonding may be achieved through the application of a PU or TPU laminate.

[0074] In an example, the bonding of the lower edge of the second side wall to the perimeter of the upper side of the shell is achieved through the application of a TPU weld.

[0075] In an example, the bonding between the first side wall and the perimeter of the upper side of the shell is in a region distal and laterally offset from the bonding between the second side wall and the perimeter of the upper side of the shell.

[0076] In an example, the bonding between the first side wall and the perimeter of the upper side of the shell is on an under side of the panel forming the upper side of the shell and the bonding between the second side wall and the perimeter of the upper side of the shell is on a top side of the panel forming the upper side of the shell. In an example, the bonding of the upper edge of the second side wall to the perimeter of the top cover is achieved through the application of a TPU weld.

[0077] In an example, there may be an additional step of bonding one or more bracing structures to the upper surface and lower surface of the shell, prior to bonding of the first side wall to the perimeter of one of the lower surface of the shell and the upper surface of the shell.

[0078] It should be understood that certain steps as itemised above may be performed in a different order to that recited. For example, the step of providing the top cover to an upper side of the self-inflating material may be performed before the step of bonding the lower edge of the first side wall to the perimeter of the lower surface of the shell.

[0079] In an example, the material of the lower side of the shell, the upper side of the shell and the first side wall is a TPU coated non-stretch fabric, preferably in a non-laminated form.

[0080] In an example, the material of the second side wall is a TPU coated stretch fabric, preferably in a nonlaminated form.

[0081] In an example, the material of the top cover is a TPU coated stretch fabric, preferably in a laminated form.

[0082] In an example, the layer of self-inflating material is a sheet of open cell foam.

[0083] According to another aspect of the present invention, there is provided a method of manufacturing an inflatable airbed, the inflatable airbed including a shell forming an air chamber and having an upper side, self-inflating layer comprised of a first layer of self-inflating material and a second layer of self-inflating material, wherein the method includes the steps of:

[0084] • bonding a lower edge of a first side wall to a perimeter of a lower surface of a shell;

[0085] • bonding an upper edge of the first side wall to a perimeter of an upper surface of the shell to form an air chamber;

[0086] • bonding a first layer of self-inflating material to the upper surface of the shell;

[0087] • bonding a lower edge of a second side wall to the upper edge of the first side wall;

[0088] • bonding a second layer of self-inflating material to an upper side of the first layer of selfinflating material;

[0089] • providing a top cover to an upper side of the second layer of self-inflating material; and

[0090] • bonding an upper edge of the second side wall to a perimeter of the top cover. In an example, there may be an additional step of bonding one or more bracing structures to the upper surface and lower surface of the shell, prior to bonding of the first side wall to the perimeter of one of the lower surface of the shell and the upper surface of the shell.

[0091] It should be understood that certain steps as itemised above may be performed in a different order to that recited. For example, the step of providing the top cover to an upper side of the second layer of selfinflating material may be performed before the step of bonding the lower edge of the first side wall to the perimeter of the lower surface of the shell.

[0092] In an example, the bonding of the first side wall to the lower surface of the shell is achieved through the use of a TPU weld.

[0093] In an example, the bonding of the first side wall to the upper surface of the shell is achieved through the use of a TPU weld.

[0094] In an example, the bonding of the first layer of self-inflating material to the upper surface of the shell is achieved through the application of adhesive. In a particularly preferred example, the adhesive may be PU adhesive.

[0095] In an example, the bonding of the upper edge of the first side wall to the lower edge of the second side wall is achieved through the use of a TPU weld.

[0096] In an example, the bonding of the second layer of self-inflating material to the first layer of self-inflating material is achieved through the application of adhesive. In a particularly preferred example, the adhesive may be PU adhesive.

[0097] In an example, the bonding of the upper edge of the second wall to the cover is achieved through the use of a TPU weld.

[0098] In an example, the material of the lower side of the shell, the upper side of the shell and the first side wall is a TPU coated non-stretch fabric, preferably in a non-laminated form.

[0099] In an example, the material of the second side wall is a TPU coated stretch fabric, preferably in a nonlaminated form.

[0100] In an example, the material of the top cover is a TPU coated stretch fabric, preferably in a laminated form.

[0101] In an example, the first and second layers of self-inflating material are sheets of open cell foam. 5. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] One or more embodiments of the technology will be described below byway of example only, and without intending to be limiting, with reference to the following drawing, in which:

[0103] Figure 1 is a perspective view showing a first embodiment of an inflatable airbed in accordance with one aspect of the present invention;

[0104] Figure 2 is a schematic cross-sectional view of one example of the inflatable airbed of Figure 1;

[0105] Figure 3 is a schematic cross-sectional view of a second embodiment of an inflatable airbed in accordance with another aspect of the present invention; and

[0106] Figure 4 is a schematic cross-sectional view of a third embodiment of an inflatable airbed in accordance with yet another aspect of the present invention.

[0107] Like reference numerals are assigned to like features.

[0108] 6. DETAILED DESCRIPTION OF EXEMPLARY FORMS OF THE TECHNOLOGY

[0109] 6.1. Inflatable Airbed

[0110] An example of the invention in the form of one embodiment of an inflatable airbed (generally indicated by arrow 100) is depicted in a perspective view in Figure 1. The airbed has a length dimension L and a width dimension W, the latter being shorter than the former.

[0111] In use, the upper surface (US) of the airbed 100 provides the surface on which the user sleeps or otherwise reclines on the mattress. The lower surface (not visible but indicated by LS) of the airbed contacts the underlying ground or substrate; it may alternatively contact a groundsheet of a tent or the frame of a camp bed.

[0112] In this exterior view of the airbed 100, it has two distinct portions: a shell 102 that includes the air chamber 104, which includes the lower surface LS, and a self-inflating layer 106, which includes the upper surface US. The presence of the self-inflating layer provides an added degree of comfort and thermal efficiency to the airbed.

[0113] The shell 102 of the air chamber 104 is formed by a bottom panel (not visible), which functions as the lower surface LS, a first side wall 108 bounding the perimeter of the bottom panel and connecting this to the upper panel (covered by the self-inflating layer 106 in this view). The inside or interior of the shell is the air chamber. In the illustrated example, the side wall 108 of the air chamber includes a seam 110 closer to the lower surface LS; this is for sake of aesthetics and ease of manufacture.

[0114] Positioned on the side wall 108 of the airbed 100, along its width dimension W (which in use would correspond to one of the head or foot of the airbed) is a valve 112 which is operable to allow for the ingress and egress of air to the shell 102 upon inflation and deflation. The valve may be a two-way valve that can be actuated by the user to control the direction of airflow.

[0115] The self-inflating layer 106 is enclosed on its sides with a second side wall 114 and on its top side with a cover 116. As with the shell 102, a valve 118 is provided to the side wall of the self-inflating layer along its width dimension W. This is operable to allow for the ingress and egress of air to the self-inflating layer.

[0116] While the self-inflating layer 106 automatically expands or inflates upon release of the compressive force constraining it, this process can be accelerated or enhanced by adding additional air into the self-inflating layer via a pump (not shown). Conversely, when packing the airbed 100, which involves substantial compression of both the shell 102 and self-inflating layer, air is able to escape the self-inflating layer via the valve.

[0117] The airbed 100 as shown may be constructed in such a way that it has good thermal efficiencies compared to a conventional inflatable airbed, and without significantly affecting its inflation / deflation performance.

[0118] One example of how the airbed 100 may be constructed is best understood from Figure 2, which is a schematic of the cross-section along the length dimension L of an end of the airbed.

[0119] Dealing first with the shell 102, this consists of the bottom panel 120 and top panel 122, together with the side wall 108. Collectively, these define an airtight structure that defines the air chamber 104. The respective panels and side wall of the shell may be comprised of a substantially impermeable material such as polyester, nylon, polyurethane or polyvinyl chloride (PVC). The side wall may be integrally formed with one of the bottom or top panels, or alternatively may be a separate component.

[0120] In preferred examples, a non-stretch fabric coated with a thermoplastic polyurethane (TPU) in a nonlaminated form, may be used. It is a desirable characteristic of the material selected for fabrication of the shell 102 that it be used to contain or confine a gas, i.e. air, under pressure for the purposes of maintaining the airbed in an inflated state. A person skilled in the art will readily identify materials that are suitable for use in the present invention.

[0121] The side wall 108 is bonded to the respective bottom 120 and top panels 122 through the use of TPU welds (not visible), which is a particularly robust and durable technique for bonding adjacent panels of TPU material using heat and pressure. However, this is not meant to be limiting and other suitable bonding techniques as determined by the skilled addressee may readily be employed in the construction of the shell.

[0122] It is desirable to control the extent of the inflation of the shell 102 in such a way to maintain its substantially rectangular form. To assist in this, the interior of the shell includes a bracing structure in the form of bracing struts or baffles 126. This are configured from strips of non-stretch fabric. The respective ends of the bracing struts are bonded to the respective panels through the use of TPU welds 124 or another appropriate method, such as adhesive.

[0123] As previously noted, the self-inflating layer 106 is formed from self-expanding or inflating material; this is in the form of an open cell foam manufactured from materials such as polyurethane, latex, viscoelastic, ethylene-vinyl-acetate (EVA), high resilience foam (HR), among others. These materials have a natural tendency to rebound / inflate after being in a compressed state.

[0124] As can be seen, the self-inflating layer 106 is comprised of two discrete self-inflating layers, each being composed of sheets of open cell foam, a first sheet forming the first layer 106a and a second, thicker, sheet 106b forming the second layer. Providing the second layer in a thicker sheet of foam confers this portion of the airbed, effectively the side on which the user sleeps, with relatively good thermal efficiency. The respective thicknesses may vary depending on manufacturing preferences and the properties of the selected foam; in the illustrated example, the first layer has a thickness of approximately 25 mm and the second layer has a thickness of approximately 75 mm. These are not meant to be limiting.

[0125] It should be appreciated that the respective first 106a and second layers 106b of foam may be comprised of two sheets having different performance characteristics. For example, the second layer, closest to the user, have been composed of a foam that is softer and less dense than the first layer. This could provide greater comfort for the user. Conversely, the opposite may be preferred; the second layer may be composed of a foam that is denser than the first layer.

[0126] In a further example not shown here, the second layer being thicker than the first layer may contain one or more die-cuts, preferably running between opposing sides of the foam sheet forming the second layer. This can be useful in reducing weight of the airbed and improving self-inflation properties; however, there may be a trade-off in user comfort.

[0127] The bottom side of the first layer of foam 106a is bonded to the top panel 122 of the shell 102 through the use of a suitable adhesive 128A. A factor in the suitability of the adhesive to be used is its performance at low temperatures. For example, polyurethane adhesive is more flexible than polyvinyl chloride adhesive when at lower temperatures; as such, PU adhesive is preferred for use in the manufacture of the invention. However, this is not meant to be limiting and other adhesives, and indeed bonding techniques, identified by persons skilled in the art as being suitable may be used instead.

[0128] In turn, the bottom side of the second layer of foam 106a is bonded to the top side of the first layer of foam. Again, this may be achieved through the use of a suitable adhesive 128B with the appropriate performance characteristics as noted above. As will be appreciated, this integrates the self-inflating layer 106 with the shell 102 to form the airbed 100.

[0129] Forming the self-inflating layer 106 from two distinct layers of foams 106a, 106b is advantageous as it allows for the manufacturer a greater degree of customisation for the airbed 100, for example by providing a range of airbeds having increasingly firmer (or softer) self-inflating airbeds.

[0130] The self-inflating layer 106 is enclosed on its edges with a side wall 114 of a stretch fabric coated with a non-laminate TPU. The lower edge of this wall is bonded through the use of a weld 130 to the upper edge of the wall 108 of the shell 102.

[0131] An important aspect of the construction of the airbed 100 is the relative height of the wall 108 of the shell 102; as can be seen, the wall is welded to the top panel 122 at a position 132 that is below the upper edge of the wall. This creates a shallow recess into which the first layer of foam 106a may be placed. The side wall of the shell at least partially overlaps the edge of the first layer of foam. This facilitates an easier manufacturing process, since the first layer of foam can be bonded to the upper side of the shell prior to welding of the side wall to the top panel.

[0132] The upper side of the self-inflating layer 106 includes a cover 134 formed from a panel of a stretch fabric that is coated with TPU in a laminated form. The use of laminated TPU for the cover provides a degree of protection from wear and tear, given that this is the surface of the airbed on which the user sleeps. The perimeter of the panel of the cover is welded 136 or otherwise bonded to the upper edges of the second wall.

[0133] This airbed 100 configuration confers the self-inflating layer 106 with a distinct three-dimensional profile, particularly about its perimeter. There is no tapering off in the depth of the self-inflating layer towards the edges, which may contribute to a greater sense of security and support for the user when sleeping. It also eases manufacture, since the cover 134 may not necessarily need to be tensioned as strongly, since it is now secured to the side wall 114 of the self-inflating layer instead of being secured to the panel 122 of the shell 102.

[0134] Another example of how the airbed 100 may be constructed is shown in Figure 3. As with the previous figure, Figure 3 is a schematic of the cross-section along the length dimension L of an end of the airbed. In contrast to the embodiment of Figure 2, the airbed 100 only has a single layer or sheet of foam forming the self-inflating layer 106. This is bonded to the top panel 122 of the shell 102 using PU adhesive 128A as discussed above in respect of the first layer of foam of the embodiment of Figure 2. This may simplify construction of the airbed.

[0135] A further point of difference is the manner of bonding of the respective side walls of the airbed 110. In preferred embodiments, this is the last, or close to last, stage of the manufacturing process for the airbed.

[0136] As can be seen the first side wall 108, forming and defining part of the shell 102, is bonded at its upper edge to the underside of the perimeter of the panel 122. The second side wall 114, covering the selfinflating layer 106, is bonded at its lower edge to the top side of the panel 122. However, the respective bonding regions, Rl, R2 do not overlap and instead are offset from each other.

[0137] The method of bonding the respective side walls 108, 114 to the top panel 122 is through the use of PU welds; as heating is required for this bonding technique, having the respective bonding regions Rl, R2 offset from each other means that when welding the second of the side walls to the panel, the integrity of the weld of the already bonded side wall is unaffected (irrespective of whether the first side wall 108 is the first to be bonded or the second).

[0138] Although the bonding region Rl is shown here as being more distal to bonding region R2, in some examples not shown here this may be reversed. Additionally, while bonding region R2 is shown as being substantially continuous with the adhesive 128A used to bond the self-inflating layer 106 to the top panel 122 of the shell 102, in some examples it may be distinct and separate from this.

[0139] Yet another embodiment of the airbed 100, shown as a schematic cross-section view along the length dimension L of an end of the airbed, is shown in Figure 4. This differs from the previous embodiments in certain aspects as will be understood from the following.

[0140] As discussed above with respect to the embodiment of Figure 3, the self-inflating layer 106 is formed as a single sheet of foam. An advantage of using a single layer of foam for the self-inflating layer is that its centre may be cored out at regular intervals through the width dimension. This removes cylindrical portions of foam, thus creating empty pockets 138 along the length of the airbed 100.

[0141] The presence of these empty pockets 138 is useful as it allows the self-inflating performance of the foam material forming the self-inflating layer 106 to be improved, i.e. it inflates more quickly. Additionally, the overall weight of the airbed 100 may be reduced. It should be appreciated that the self-inflating layer, due to its density, comprises a significant proportion of the overall weight of the airbed. Such a configuration may not be practical for the embodiment of Figure 2, in which the self-inflating layer is formed from two (or more) thinner sheets or layers of foam. More cores would be required to achieve the same weightsaving but at a potential cost in user comfort since there may be less support when sleeping.

[0142] In Figure 4, the illustrated embodiment of the airbed 100 also differs in the manner of construction of the shell 102, particularly the internals of same. It will be recalled that in the shell 102 of the airbed 100 shown in Figure 2, a bracing structure in the form of bracing struts 126 spans the top panel 122 and bottom panel 120. These act to control the distance between the respective panels.

[0143] In the airbed 100 of Figure 4, TPU drop stitch construction techniques, as will be understood by a person skilled in the art, may be employed for the bracing structure. As can be seen, this involves the use of many hundreds of TPU or TPU-coated filaments 140 extending between opposing sheets 142, 144 of fabric. These opposing sheets are in turn anchored to the side wall 108, top panel 122 and bottom panel 120 of the shell 102 via PU adhesives or TPU welds 146 and intermediary bracing 148. The presence of an extensive array of filaments is useful in providing support for the shell, conferring greater stiffness, and therefore support, for the person using the airbed 100. Additionally it can also be helpful in reducing the overall weight of the airbed.

[0144] A further point of difference is in the bonding of the first side wall 108, the second side wall 114 and the top panel 122. It will be seen that the first side wall is bonded directly to the second side wall via a TPU weld at bonding region Rl. This is in contrast to what is shown in Figure 3, in which the first side wall is bonded to the underside of the top panel.

[0145] Returning to Figure 4, the second side wall is, as previously described, secured to the upper side of the top panel at bonding region R2. It will be noted that there is no overlap with bonding region Rl.

[0146] 6.2. Construction

[0147] When constructing the airbed 100, one approach is to do so from the lower surface LS up; as such, the shell 102 is fabricated first, by welding or otherwise bonding the side wall 108 at its respective lower and upper edges to the bottom and top panels 120, 122, along with the bracing 126 (the latter may be done prior to the bonding of the side wall).

[0148] The airbed 100 of Figure 2 may then have the first layer 106a of self-inflating foam be applied to the top panel 122 of the shell 102, and secured in place with adhesive 128A. The second layer 106b of self-inflating foam is then secured using adhesive 128B to the first layer 106a, either before, concurrently with, or after the bonding of the side walls 108, 114 enclosing the air chamber 104 and self-inflating layer 106 respectively. The application of the layer of self-inflating foam 106 is more straightforward for the airbed 100 of Figure 3; it is simply laid across the top panel 122 of the shell 102 and secured with a suitable adhesive, such as PU adhesive 128A. Alternatively, a TPU laminate may be used.

[0149] The final step involved in the construction of the airbed 100 is the welding of the upper edge of the side wall 114 of the self-inflating layer 106 to the perimeter of the sheet of material 134 forming the cover protecting the upper surface US of the airbed 100.

[0150] However, strict compliance with the above recited sequence of steps is not required.

[0151] For example, the construction of the airbed 100 of Figure 3 may commence with its cover 134 being welded about its perimeter to the layer of self-inflating foam 106 before construction begins on the shell 102. The bracing 126 is welded to the respective bottom and top panels 120, 122, before the side wall 108 is welded in place.

[0152] The lower surfaces of the layer 106 of self-inflating foam is coated with PU adhesive 128A, 128B and then placed onto the top panel 122 partially defining the air chamber 104. The side wall 114 of the self-inflating layer are then welded along their lower and upper edges to the upper edge of the side wall of the shell 102 and perimeter of the cover 134 respectively. Finally, the side wall 108 of the shell 102 is bonded with a TPU weld at its upper edge to the top panel about bonding region Rl, taking care to not overlap bonding region R2.

[0153] 6.3. Use

[0154] As will be apparent from the preceding discussion, the usage of the illustrated invention 100 of Figures 1, 3 and 4 is straightforward. Starting from a compressed state, generally this will involve the airbed being in a rolled up and packed configuration for transport. When use of the mattress is desired, it is then unpacked and unrolled and the respective valves 118, 112 (shown in Figure 1 only) for the self-inflating layer 106 and the shell 102 opened to allow for ingress of air, which in the case of the latter, may be via a pump (not shown). If extra inflation of the self-inflating layer is desired, the pump may be used to achieve this. Deflation of the airbed 100 involves the actuation of the respective valves 112, 118 such that the egress of air is allowed. The airbed can then be compressed, expelling the air within the shell 102 and selfinflating layer 106, usually into a rolled configuration, for compact storage and transport.

[0155] The use of a shell 102, defining an air chamber 104, and self-inflating layer 106 is useful as it provides an airbed 100 which can have differing cushioning properties. For example, the air chamber may be inflated to a relatively high pressure, for greater stability, while the self-inflating layer may deliberately be kept soft, for user comfort. Additionally, due to its relative lack of density compared to the self-inflating layer, condensation between the bottom side and the underlying substrate may be reduced compared to a conventional self-inflating mat. Furthermore, the manner of construction, in which the airbed is provided with a discrete sidewall to which the top cover is secured, allows the self-inflating layer to have a consistent thickness / depth across the entire length and width dimension of the airbed.

[0156] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

[0157] The entire disclosures of all applications, patents and publications cited above, if any, are herein incorporated by reference.

[0158] Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.

[0159] The technology may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

[0160] Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

[0161] It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the technology and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present technology.

Claims

7. CLAIMSWhat we claim is:

1. An inflatable airbed comprising: an air chamber defined by a shell having a lower side and an upper side and a side wall connecting said lower side to said upper side; and a self-inflating layer, wherein the self-inflating layer comprises an upper side and a lower side; and a top cover, wherein the top cover is provided to the upper side of the layer of selfinflating material, characterised in that the lower side of the layer of self-inflating material is bonded to the upper side of the shell of the air chamber, and wherein the layer of foam is arranged relative to the air chamber such that the top cover provides a sleeping surface for a user.

2. The inflatable airbed as claimed in claim 1, wherein the shell includes a first panel forming the upper side of the shell, a second panel forming a lower side of the shell, and a side wall which connects the first panel to the second panel about the perimeter of same3. The inflatable air bed as claimed in claim 2, wherein the respective first and second panels and side wall are formed from the same material.

4. The inflatable airbed as claimed in any one of claims 1 to 3, wherein the shell is comprised of, or is coated with, a substantially impermeable material.

5. The inflatable airbed as claimed in claim 4, wherein the substantially impermeable material is a non-stretch fabric coated or otherwise treated with thermoplastic polyurethane (TPU).

6. The inflatable airbed as claimed in any one of claims 1 to 5, wherein the exterior surface of the side wall of the shell is provided with a valve or similar structure, wherein the valve is communicative with the interior of the air chamber.

7. The inflatable airbed as claimed in any one of claims 1 to 5, wherein the layer of self-inflating material is comprised of an open cell foam.

8. The inflatable airbed as claimed in claim 7, wherein the open cell foam is formed or otherwise comprised of one or more of: polyurethane, latex, viscoelastic, ethylene vinyl acetate (EVA), and / or high resilience foam (HR).

9. The inflatable airbed as claimed in claim 7 or claim 8, wherein the layer of self-inflating material is formed from a single sheet of foam.

10. The inflatable airbed as claimed in any one of claims 1 to 9, wherein the layer of self-inflating material is bonded to the upper side of the shell by an adhesive.

11. The inflatable airbed as claimed in claim 10, wherein the adhesive is a polyurethane adhesive.

12. The inflatable airbed as claimed in any one of claims 1 to 11, wherein the side wall is a first side wall and the airbed includes a second side wall.

13. The inflatable airbed as claimed in claim 12, wherein the first side wall forms part of the shell and the second side wall forms part of the self-inflating layer.

14. The inflatable airbed as claimed in claim 12 or claim 13, wherein the second side wall is comprised of a material having stretching properties.

15. The inflatable airbed as claimed in claim 14, wherein the second side wall is comprised of a stretch fabric coated with TPU.

16. The inflatable material as claimed in claim 15, wherein the TPU is in a non-laminated form.

17. The inflatable airbed as claimed in any one of claims 12 to 16, wherein the exterior surface of the second side wall is provided with a valve or similar structure, wherein the valve is communicative with the interior of the self-inflating layer.

18. The inflatable airbed as claimed in any one of claims 12 to 17, wherein an upper edge of the first side wall is bonded to a lower edge of the second side wall.

19. The inflatable airbed as claimed in claim 18, wherein the bond between the first side wall and the second side wall is a TPU weld.

20. The inflatable airbed as claimed in any one of claims 12 to 17, wherein an upper edge of the first side wall is bonded to a lower side of an edge of the upper side of the shell.

21. The inflatable airbed as claimed in claim 20, wherein a lower edge of the second side wall is bonded to an upper side of the edge of the upper side of the shell.

22. The inflatable airbed as claimed in claim 21, where the bonding of the first side wall and the second side wall are in non-overlapping regions of the edge of the upper side of the shell.

23. The inflatable airbed as claimed in any one of claims 12 to 22, wherein the top cover is bonded to an upper edge of the second side wall.

24. The inflatable airbed as claimed in any one of claims 1 to 23, wherein the top cover is comprised of a stretch fabric coated or otherwise treated with a thermoplastic material.

25. The inflatable airbed as claimed in claim 24, wherein the thermoplastic material is TPU.

26. The inflatable airbed as claimed in claim 25, wherein the thermoplastic material is laminated TPU.

27. The inflatable airbed as claimed in any one of claims 1 to 26, wherein the shell includes a bracing structure to connect the lower side and the upper side of the shell.

28. The inflatable airbed as claimed in claim 27 wherein the bracing structure includes TPU drop stitch construction.

29. A method of manufacturing an inflatable airbed as claimed in any one of claims 1 to 28, wherein the method includes the steps of: a) bonding a lower edge of a first side wall to a perimeter of a lower surface of the shell; b) bonding a lower edge of a second side wall to one or both of: i) an upper edge of the first side wall or ii) a perimeter of the upper side of the shell; c) bonding the layer of self-inflating material to the upper side of the shell; d) providing a top cover to an upper side of the layer of self-inflating material; and e) bonding an upper edge of the second side wall to a perimeter of the top cover30. The method as claimed in claim 29, wherein the bonding of the layer of self-inflating material to the upper surface of the shell is achieved through the application of adhesive.

31. The method as claimed in any one of claims 28 to 30, wherein the bonding of one or more of i) the first side wall to the lower surface of the shell; ii) the second side wall to the first side wall and / or upper side of the shell; and iii) the second side wall to the top cover; is achieved through TPU welding.

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