NL2023913B1

NL2023913B1 - Body support assembly

Info

Publication number: NL2023913B1
Application number: NL2023913A
Authority: NL
Inventors: Franciscus De La Haye Cornelis
Original assignee: Ubed B V
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2021-05-27

Abstract

Body support assembly having a top surface and a spaced away bottom surface defining a cushion volume and defining side walls. The air permeability ofthe top surface is higher than the air permeability of the bottom surface. The cushion volume comprises an upper cushion zone nearest and a lower cushion zone and separated by a separation sheet. The upper cushion zone and the lower cushion zone comprise of a compressible material which is permeable for air in all directions. The cushion volume further comprises a flow path for air comprising an air inlet in the bottom surface, air displacement means, a heat exchanger, a flow path through the compressible material ofthe lower cushion zone, through openings in the separation sheet and through the compressible material of the upper cushion zone and multiple air outlets as present in the top surface.

Description

BODY SUPPORT ASSEMBLY The invention is directed to a body support assembly having a top surface for supporting a body and a spaced away bottom surface defining a cushion volume and defining side walls, wherein the cushion volume comprises a heating element.

US2017/0325595 describes a mattress having foam layers and a coil spring layer provided with upwardly directed channels for directing a flow of conditioned air towards the sleeps surface.

W02015106258 describes a mattress and bed combination wherein the bed is provided with fans to draw air from the top surface through the mattress downwardly to a lower positioned air conditioning layer. The conditioned air is discharged to the surroundings of the mattress — bed combination with the object to influence the temperature adjacent to the sleep surface.

W02018022760 describes a mattress to support a body wherein within the mattress resistive heating elements are positioned. Such resistive heating elements may be a resistive heating coil as present between two layers in a looping or serpentine arrangement. The cooling is by a separate mechanism wherein air is pulled and the associated heat and moisture from the contact area supporting a body via one or more channels equipped with a fan.

wO2014204934 describes a mattress provided with numerous Peltier effect heating and cooling elements which are positioned near the top surface of the mattress in a continuous layer of a flexible foam. The top side of the elements either directly heat or cool the top side of the mattress while the opposite side of the Peltier effect elements are heated or cooled at their lower side by a flow of air being drawn through the mattress. A disadvantage of such a mattress is that the Peltier effect elements have to be positioned relatively near the surface in order to directly heat or cool the surface which supports the body. This may result in a less comfortable mattress as the body may feel the single Peltier effect elements.

KR20060124553 describes a body support assembly with an upper zone and a lower zone. The upper zone is provided with a compressible material. The lower zone is provided with metal springs. An air heater is partly outside the support assembly and can provide warm air to the body support assembly to heat up the upper side of the assembly. The person being supported by the support assembly will feel the warmth when laying on the support sheet of the support assembly. This because hot air flowing along the lower side of the non-air permeable support sheet will heat up this support sheet.

The body support described in either W02018022760 or W02014204934 is advantageous in that the heating element is positioned within the cushion volume. This avoids that separate heating elements have to be connected to the body support assembly apart from a power supply and a control system to regulate the heating and cooling.

The present invention aims to provide a body support assembly wherein a heating unit is positioned within the cushion volume and which does not have the disadvantage of the known matrass in terms of comfort.

This is achieved by the following body support assembly. Body support assembly having a top surface for supporting a human body and a spaced away bottom surface defining a cushion volume and defining side walls, wherein the air permeability of the top surface is higher than the air permeability of the bottom surface and higher than the air permeability of the side walls, wherein the cushion volume comprises, an upper cushion zone nearest to the top surface and a lower cushion zone and separated by a separation sheet, wherein the upper cushion zone and the lower cushion zone comprise of a compressible material which is permeable for air in all directions and a flow path for air comprising an air inlet in the bottom surface, air displacement means, a heat exchanger, a flow path through the compressible material of the lower cushion zone, through openings in the separation sheet and through the compressible material of the upper cushion zone and multiple air outlets as present in the top surface.

Applicants found that such a body support assembly provides a comfortable sleeping experience in moderate climate environments.

This may be explained by the fact that a small flow of heated air flows through the top surface and past the user of the body support assembly.

It has been found that when the temperature of the air flowing through the upper cushion zone is just below that of the body temperature of the user a comfortable sleep experience is achieved. it has also been found that the volume of air required to achieve this effect may be low.

This results in that the capacity of the air displacement means may be low and therefore the resulting noise may be low to almost non-detectable for the user.

A further advantage is the larger components of the body support assembly such as the air displacement means and heat exchanger are positioned within the body support assembly.

This is possible because applicant found the optimal volume and temperature required to pass the top surface which did not require larger high capacity air displacement means and heat exchangers.

An advantage of having all components within the cuboid body support assembly is that the body support assembly can be stored, stacked and transported more easier.

Further advantages will be described when describing the invention in more detail below.

In this description and claims terms like above, below, upper, lower and horizontal, vertical will be used to describe the body support assembly in its position in which it is most likely used.

It should be understood that these terms are used for purposes of illustration, and are not intended to limit the invention.

A term like inwards or inwardly is used to describe a horizontal direction towards the core of the body support assembly.

This heated air flow may also be used to exterminate dust mite which may be present inthe cushion volume.

By increasing the temperature of the circulating air to above 50 °C and preferably above 60 °C, for a certain time while the body support assembly is not used to support a human body, all of the dust mites which are exposed to this higher temperature will be exterminated.

The cushion volume comprises the upper cushion zone nearest to the top surface and the lower cushion zone and separated by the separation sheet.

The upper cushion zone and the lower cushion zone comprise of a compressible material which is permeable for air in all directions. Preferably more than 70 vol.%, more preferably more than 80 vol% and even more preferably more than 90 vol.% of the upper cushion zone consists of the compressible material which is permeable for air.

Such an upper and lower cushion zone allow conditioned air to freely flow from a point within the lower cushion zone to the openings in the separation sheet into the upper cushion zone. The air permeability of the material is suitably higher than 100 cm3/s/cm2 and preferably higher than 200 cm3/s/cm2 as measured by the Standard Test Method for Air Permeability of Textile Fabrics, ATSM D737-96. Suitable materials are non-encased mattress coils, non-woven fabrics and knitted materials. In this invention non-encased mattress coils, such as steel spiral springs, the so called Bonell-springs or equivalents, may also be used as the compressible material which is permeable for air in all directions. Non- encased mattress coils are preferably used in the lower cushion zone while non-woven fabrics and knitted materials are preferably used in the upper cushion zone.

An example of a suitable knitted material is the so-called warp knitted spacer fabric as described in WO2015/140259 and 2018187348. Such warp knitted spacer fabrics have a first planar warp-knit layer and a second planar warp-knit layer joined by spacer yarns.

A more preferred material for the lower and especially the upper cushion zone is a so- called random loop bonded structure of a thermoplastic resin. Such materials are for example Breathair® as obtainable from Toyobo Co. and described in for example EP2848721 and EP3064627. Such materials have excellent air permeability properties which exceeds 200 cm3/s/cm2. The random loop bonded structures are advantageous because their weight per volume is low. One suitably applies this material as sheets of random loop bonded structures having an upper and lower planar sheet. These surfaces are almost as permeable for air as the air permeability of the bulk of the material. This in contrast to the earlier mentioned warp knitted fabrics.

Random loop bonded structures are made in a continuous process wherein a continuous linear structure of a polymer in a near molten state are poured into a shallow layer of for example water. The polymer will form random loops and mutually contact and connect ate these contact points to form bonded points. At the bottom and at the surface a planar random bonded structure results and between these planar surfaces a three dimensional randomly bonded structure results. This production technigue limits the 5 thickness of the sheets of random loop bonded material. The distance between these planar surfaces may for example be between 1 cm and 10 cm. Depending on the desired thickness, ie distance between top surface and bottom surface of the body assembly and the thickness of the separate cushion zones one or more layers of such random loop bonded structures may be used. In order to obtain optimal cushion properties it may be preferred to combine different layers with different compression hardness of these materials.

The number of bonded points per unit weight of the three-dimensional random loop bonded structure is between 550 and 1150 bonded points per gram, preferably between 600-1100, more preferably between 650-1050 and even more preferably between 700 - 1000 /g. The number of bonded points per unit weight (unit: the number of bonded points/gram) is a value obtained by a measuring method described in EP2848721. In this method a piece in the form of a rectangular parallelepiped is prepared by cutting a network structure into the shape of a rectangular parallelepiped measuring 5 cm in length x 5 cm in width so that the rectangular parallelepiped includes two surface layers of the sample but does not include the peripheral portion of the sample, dividing the number of bonded points per unit volume (unit: the number of bonded points/cm3} in the piece by the apparent density {unit: g/cm3) of the piece. The number of bonded points is measured by a method of detaching a welded part by pulling two linear structures; and measuring the number of detachments.

A random loop bonded structure has an average apparent density within a range of preferably 0.005 g/cm3 to 0.200 g/cm3. The random loop bonded structure having an average apparent density within the above range is expected to show the function of a cushioning material. The average apparent density of less than 0.005 g/cm? fails to provide repulsive force, and thus the random loop bonded structure is unsuitable for a cushioning material. The average apparent density exceeding 0.200 g/cm3 gives great repulsive force and reduces comfortableness. This is not preferable. The apparent density in the present invention is more preferably 0.010 g/cm3 to 0.150 g/cm3, even more preferably within a range of 0.020 g/cm3 to 0.100 g/cm3.

The 25%-compression hardness of the three-dimensional random loop bonded structure is between 10 and 30 kg/$200-mm. The 25%-compression hardness is a stress at 25%-compression on a stress-strain curve obtained by compressing the network structure to 75% with a circular compression board measuring 200 mm in diameter.

The thermoplastic resin may be a soft polyolefin or a polyester thermoplastic elastomer. A preferred resin is the so-called P-type PELPRENE® obtainable from Toyobo Co. which is a copolymer composed of an aromatic polyester as a hard element and an aliphatic polyether as a soft element.

As explained above the compression hardness of the material used may be different in for example the upper and lower cushion zone. For example, the lower cushion zone may comprise of a material having a somewhat hard linear structure while an upper cushion zone may comprise of material having a linear structure with a somewhat thin fineness and a high density. The lower cushion zone material may be a layer that serves to absorb vibration and retain the shape. A preferred material which is permeable for air in all directions for the lower cushion zone are metal springs, for example Bonnell springs. The Bonnell spring has an hour glass shape (wider at the bottom and the top than the middie) and are interconnected with a mesh of metal to make the spring system. These metal springs are preferred because they on the one hand provide the required vibration absorption and ability to retain its shape and on the other hand allow air to easily flow through the metal springs without any noticeable pressure drop. The non-encased metal springs are not individually packed in a textile wrapping as for example pocket springs.

The upper cushion zone material may be a layer that can uniformly transmit vibration and repulsive stress to the lower cushion zone so that the whole body undergoes deformation to be able to convert energy, whereby comfortableness can be improved and the durability of the cushion can also be improved. it may also be preferred to impart a thickness and tension to the side portion of the cushion material, wherein the fineness may be somewhat reduced partially and the density may be increased near the side wall. In this way, each layer may have any preferable density and fineness depending on its purpose. It should be noted that the thickness of each layer of the network structure is not particularly limited. In a preferred embodiment the upper the upper cushion volume comprises the non- woven fabrics and/or knitted materials, such as the three-dimensional random loop bonded structure of a thermoplastic resin and wherein the compressible material in the lower cushion zone are metal springs as described above. Applicants found that the pressure drop the air encounters in the lower cushion zone is very low and a good distribution of the air will result when the air flows to the upper cushion zone. The separation sheet may be any sheet which covers the metal springs within the lower cushion zone, Such a separation sheet may be woven or non-woven sheets, like for example coconut fibre sheets. The separation sheet may also be the lowest layer of compressible material of the upper cushion zone. An example of a suitable compressible material for use as such a lower layer, for use as the separation sheet, is a sheet of a warp knitted spacer fabric as described above. Such a layer may be between 1 and 2 cm thick and suitably has a compression hardness which is higher than the compression hardness of the compressible material positioned above this layer in the upper cushion zone. The warp knitted fabric preferably has enough structural strength to support the metal springs within the lower cushion volume.

When a material, such as the random loop bonded structure, is used for the lower cushion zone which has a larger pressure drop than the metals springs described above it may be preferred to take additional measures to distribute the heated air as it flows from the lower cushion zone to the upper cushion zone via the separation sheet. it is preferred that the air is about evenly distributed along the length and width of the body support assembly or at least evenly distributed in the area of the top surface where a user may be positioned. To achieve such an evenly distribution it is found that an even distribution of heated air through the separation sheet is desired. To achieve such an even distribution through the separation sheet various measures may be taken independently or in combination. One such preferred measure is wherein the heat exchanger is fluidly connected to an air outlet system with multiple air outlet openings within the compressible material of the lower cushion zone such that air is substantially evenly distributed within said lower cushion zone. Such an even distribution in the lower cushion zone will result in an even distribution through the separation sheet. The air outlet system may be comprised of multiple conduits, for example having the design of a tree, wherein at the end of the branches air is discharged. A next preferred measure is wherein the heat exchanger is fluidly connected to an air outlet within the compressible material of the lower cushion zone and wherein the openings per area of separation sheet increases for positions on the separation sheet which are spaced further away from the air outlet of the second heat exchanger. This design is advantageous because it requires only one air outlet, suitably near the heat exchanger. The separation sheet may be a board of wood or a polymer provided with cut out openings of for example between 1 and 6 cm in diameter.

A disadvantage of both of these measures is that it requires additional conduits or specially adapted and manufacture separation sheets. A more preferred measure is wherein the separation sheet is made of a gas permeable woven or non-woven material. By choosing a suitable dense material and of a minimal thickness a pressure drop will result for the volumes that pass the separation sheet. This pressure drop results in that the air is evenly distributed along the surface of the separation sheet. Therefore suitably the gas permeability of the separation sheet is lower than the gas permeability of the top surface. A preferred separation sheet is made of coconut fibres. This material is advantageous because of its durability and strength. The thickness of the layer of woven or non-woven separation sheet is suitably between 1 and 2 cm.

The body support assembly has a top surface, side walls and a bottom surface. The top surface will face the human body which is being supported by the body support assembly. This top surface is permeable for air. It has been found important that the air permeability of the top surface is higher than the air permeability of the bottom surface. The air permeability of the top surface is also higher than the average air permeability of the side walls. In some embodiments the air permeability of the side walls at the elevation of the upper cushion zone is about the same as the air permeability of the top surface. Because the air permeability of the side walls at the elevation of the lower cushion zone is lower than the top surface the average air permeability of the side walls will be lower. Preferably the air permeability, as measured using ASTM D 737-96, of the top surface is at least 3 times and more preferably 4 times more air permeable than the bottom surface. An example of a material suited for such a top surface is a 3D knitted ventilating textile as for example obtainable from Bekaert Deslee, Belgium or Innofa, The Netherlands. The side walls, especially at the elevation of the lower cushion zone, is preferably made of a flexible material which allows that the cushion volume to be compressed to a certain extend when the assembly is used to support a human body. Materials suited for such side walls are tightly woven or knitted textiles. The bottom surface may be composed of the same material as the side walls. Because the bottom surface does not necessarily have to be as flexible as the side walls also more stiff materials may be used for the bottom surface. This is advantageous because the bottom surface requires to have enough strength to carry the contents of the cushion volume and provide a support for the metal springs in the preferred embodiment. Materials suited for use for the bottom surface are dense non-woven textiles. Examples of dense non-woven textiles are felt and felt equivalents. Wool or more preferably polyester felts are used. Dense woven textiles and felts will be referred to as felt like textiles in this description. The thickness of such a felt like textiles may be between 0.2 and

0.5 cm. To reduce the air permeability of the felt or felt like textiles it may be preferred to add a dense woven textile layer to the interior side of the felt or felt like textiles.

Preferably the bottom surface and the part of the side walls at the elevation of the lower cushion zone is comprised of a layer of felt like textile and wherein the top surface and the part of the side walls is comprised of a textile layer, preferably a 3D knitted ventilating textile layer, and wherein the air permeability of the textile is higher than the air permeability of the felt like textile.

Preferably the felt like textile layer is comprised of a single sheet of felt like textile and the textile layer is comprised of a single sheet of textile. Using a single sheet of material is advantageous when manufacturing the body support assemblies. Even more preferably the upper end of the single sheet of felt layer is folded inwards and attached to the upper end of the separation sheet. In this folding of a sheet only a part of the sheet covers the separation sheet thereby leaving enough area for air to flow to the upper cushion zone. Preferably more than 80 % of the upper area of the separation sheet is not covered.

Especially when the lower cushion zone comprises of metal springs a lower part of the bed is thus obtained comprising elements of the body support assembly having a long lifetime. Further the lower part will comprise the more complex and durable elements like the air displacement means and the heat exchanger. In contrast the lifetime of the non-woven fabrics and knitted materials, such as the three-dimensional random loop bonded structure of a thermoplastic resin, which are preferably used in the upper cushion zone is shorter. This because in time the ability of such cushion materials to return to their original shape becomes less. The above felt encased lower part of the body support assembly can now be advantageously be reused and combined with a upper part of the body support assembly comprising new compressible material.

Preferably the lower end of the textile layer extends to the bottom surface of the body support assembly and is folded inwards thereby covering the side walls made of a layer of felt or felt like textile and part of the bottom surface made of felt or felt like textile. In this manner the majority of the outer surface and especially the visible part of the body support assembly when in use will be covered by this textile layer. This textile layer thus holds the body support assembly zone together.

Applicants found that the above described concept of providing a lower part of a body support assembly including more durable elements like the metal springs and an upper part having a less durable but preferred compressible material can also be used without the air flow elements, like the air displacement means and heat exchangers, of the present invention. The invention is thus also directed to the following body support assembly.

Body support assembly having a top surface for supporting a human body and a spaced away bottom surface defining a cushion volume and defining side walls, wherein the cushion volume comprises an upper cushion zone nearest to the top surface comprising of a compressible material and a lower cushion zone comprising of metal springs, suitably

Bonnell spring, as present between the bottom surface and a separation sheet, wherein the bottom surface and the part of the side walls at the elevation of the lower cushion zone is comprised of a single sheet of a felt or felt like textile and wherein the top surface and the part of the side walls is comprised of a single sheet of a textile layer, wherein the upper end of the felt layer is folded inwards and attached to the upper end of the separation sheet and wherein the lower end of the textile layer extends to the bottom surface and is folded inwards thereby covering the side walls of felt or felt like textile and covering part of the bottom surface made of felt or felt like textile.

Preferred materials, shapes and combinations for this body support assembly are the same as described for the body support assembly provided with the heat exchanger according to this invention. Especially the compressible material is a three-dimensional random loop bonded structure of a thermoplastic resin. The separation sheet is suitably made of coconut fibres.

Suitably the body support assembly has an end for placement of the head of the human body and an end for placement of the feet of the human body. The air displacement means and the heat exchanger are then suitably positioned at the end for the feet. This to minimise the hinder of any noise generated by the air displacement means. This further enables one to have more cushion material, like Bonnell springs, below the possible position of the head in the lower cushion zone.

The heat exchanger may be any device which is capable of increasing the temperature of a gas, like air. The heat exchanger may be a Peltier element or may explicitly not be a Peltier element. Suitably the heat exchanger comprises electric-resistance heating coils. Air flowing along the surface of the resistance heating will increase in temperature. More preferably the heat exchanger is a Positive Temperature Coefficient (PTC) Air Heater. Such PTC air heaters are advantageous because the temperature will not exceed a certain value which provides a user safe solution.

The air displacement means may be any means capable of moving air from the exterior of the body support assembly via the heat exchanger, the lower cushion zone, the separation sheet and upper cushion zone and top surface. A suitable air displacement means is a tangential fan, also referred to as a cross-flow fan.

The air inlet in the bottom surface of the body support surface comprises an opening inthe bottom surface. This opening is suitably provided with a detachable air filter. Such an air filter may be non-woven or paper sheet suited to avoid dust and the like to enter the body support assembly. Such a filter will be required to be replaced by a new filter after using the body support assembly for some time. Preferably air filter is held into place by a planar spring, which planar spring can be manually removed when detaching the air filter.

The new filter can be secured by replacing the planar spring.

When the air inlet in the bottom surface comprises an opening in a felt or felt like textile bottom surface it may be preferred to connect a frame to the lower end of the felt bottom surface and connected to a matching frame positioned above the felt bottom surface. In this manner a strip of felt layer at the opening is sandwiched by the two frame parts. The connected frames provide for an opening for the air inlet. The matching frame may be the support for the heat exchanger-fan combination. This enables a simple configuration for positioning the heat exchanger and fan within the lower cushion zone.

The body support assembly is preferably used as a mattress. The invention is therefore also directed to a bed comprising a body support assembly according to this invention. The bed will have some sort of structure to support the mattress. This mattress support should leave an opening or openings at its lower end to allow air to flow into the air inlet opening or openings at the bottom surface of the support assembly. Examples of suited mattress supports are a spiral wire support, a slatted bed base or a wooden board.

The power supply for the heat exchanger and air displacement means may be provided by means of a cable directly connected to the mattress or via the mattress support. A small power adaptor may be externally present. if the power supply is performed via the mattress support simple power exchange surfaces may be present at the exterior of the mattress which connect with power supply surfaces present on the mattress support. This may be preferred when one wishes a mattress without any cables extending from the mattress.

The invention is also directed to a method to heat a body support assembly having a top surface for supporting a human body and a spaced away bottom surface defining a cushion volume and defining side walls, wherein the cushion volume comprises, an upper cushion zone nearest to the top surface and a lower cushion zone and separated by a separation sheet, wherein the upper cushion zone and the lower cushion zone comprise of a compressible material which is permeable for air in all directions, and wherein ambient air flows in a flow path via an air inlet, air displacement means, a heat exchanger, a flow path through the compressible material of the lower cushion zone, through openings in the separation sheet, through the compressible material of the upper cushion zone and through the top surface.

Preferably the temperature of the air as it flows through compressible material of the upper cushion zone has a temperature of between 27 and 35 °C. The optimal temperature will depend on the body temperature of the person being supported by the body support assembly. This temperature may vary per person and suitably this temperature may be varied by the user such to obtain the optimal conditions by means of trail and error. The desired temperature may be the input of a measurement and control algorithm of the body support assembly using an input console. This console may be directly contacted or indirectly contacted with the measurement and control algorithm, for example using an app on a smartphone. Once a desired temperature is chosen a measurement and control algorithm is used to reach this temperature. Preferably the temperature of the air in the upper cushion zone is controlled by measurement of the temperature of the air in the upper cushion zone and in case of a required adjustment changing the performance of the heat exchanger and/or the performance of the air displacement means.

Preferably the method uses a body support assembly according to this invention.

The invention will be illustrated making use of the following Figures 1-7.

Figure 1 shows a body support assembly (1) according to the invention in a 3D presentation as seen from above. The assembly (1) has a top surface (2) for supporting a human body and a spaced away bottom surface (3) defining a cushion volume {4} and defining side walls (5). The air permeability of the top surface (2) is higher than the air permeability of the bottom surface (3) and higher than the average air permeability of the side walls (5).

Figure 2 shows the body support assembly (1) of Figure 1 as seen from below showing an air inlet {6).

Figure 3 shows the cross-sectional view AA’ of Figure 1 of the body support assembly {1). In this Figure an upper cushion zone {7) nearest to the top surface (2) and a lower cushion zone (8) and separated by a separation sheet (9) made of coconut fibres is shown. The upper cushion zone (7) comprises of Breathair® as the compressible material (10). The lower cushion zone is comprised of Bonnell springs (11). In this figure the bottom surface (3) and the part (13) of the side walls (5) at the elevation of the lower cushion zone (8} is comprised of a single sheet (14) of a felt textile. The upper end (15) of the sheet of felt layer is folded inwards and attached to the upper end (16) of the coconut separation sheet (8). Attachment may by for example by means of an adhesive. The folding of the single sheet may be performed using well known Origami folding techniques. As shown a large part of the coconut separation sheet (8) is not fully covered by the sheet (14) of felt leaving enough area through which air can flow from the lower cushion zone (8) to the upper cushion zone (7).

Figure 3 also shows the top surface (2) and the part (17) of the side walls (5) is comprised of a single sheet of a textile layer {18), for example a 3D knitted ventilating textile. The lower end (19) of the textile layer {18) extends to the bottom surface (3) and is folded inwards thereby covering the entire side walls {5} and the felt covered part {13} of the side walls (5} at the elevation of the lower cushion zone (8). The lower end {19) is attached to the sheet (14) of felt by for example by a hook and loop type connection, such as for example a Velcro type connection. The folding of the single sheet may be performed using well known Origami folding techniques. The textile layer (18) thereby holds together the upper (7) and lower (8) cushion zone. By removing the textile layer (18) it is possible to simply remove the compressible material {10) of the upper cushion zone after which new compressible material (10) may be provided. In this manner the felt encapsulated lower cushion zone (8) can be reused in combination with a new upper cushion zone. The single sheet of a textile layer is thus detachably wrapped around the cushion volume. When detached from the cushion zone the sheet of textile layer is suitably a flat sheet which is not sewed into a three dimensional shape. This enables easier cleaning of the sheet and a simpler manufacture of the textile sheet itself.

Figure 4 shows the cross-sectional view BB’ of Figure 2 of the body support assembly (1). In addition to the elements shown in Figure 3 an air inlet (6), a fan (20) and a heat exchanger (21) is schematically shown. Further a heated air outlet{22} in fluid communication with the lower cushion zone (8) is present through which heated air flows from the heat exchanger (21) to the lower cushion zone (8). The dimensions and properties of the coconut fibre separation sheet are so chosen that air flowing to the upper cushion zone is evenly distributed. A suitable coconut fibre separation sheet may have a thickness of between 1 and 2 cm. The height of the lower cushion zone (8) may be between 8 and 15 cm. The height of the upper cushion zone (7) may be between 4 and 8 cm. The distance between top surface {2} bottom surface {3} may be between 14 and 25 cm.

Figures 5 and 6 show the fan {20}-heat exchanger combination {21} in more detail. The various elements are shown in an exploded view in Figure 5. In Figure 6 a cross section of the fan (20)-heat exchanger combination {21} is shown. The heat exchanger and fan are placed in a box like casing (24). Heat exchanger (21) is provided with electric-resistance heating coils (23) as placed in heated air outlet (22). The air inlet (6) in the bottom surface (3) comprises an opening (25) in the felt layer (14) bottom surface. To this opening (25) a frame (26) is connected to the lower end of the felt bottom surface (3) and a matching frame (27) is positioned above the felt bottom surface. The two frames (26,27) are connected by means of multiple connectors (28), for example plug (28a) and lock rings {28b}, thereby sandwiching a strip of felt layer at the opening (6). The two frames (26,27) as present in opening (25) form air inlet (6). In this opening (6) an air filter (29) is positioned as shown in Figure 6. The matching frame (27) serves as support for the box like casing (24). The fan (20) is a tangential fan.

Figure 7 shows a cut open body support assembly of Figures 3 and 4.

Claims

CONCLUSIONS

A body support assembly comprising an upper surface for supporting a human body, and a spaced lower surface defining a cushion volume and side walls, wherein the air permeability of the upper surface is greater than the air permeability of the lower surface, and is greater than the air permeability of the side walls, wherein the cushion volume comprises: an upper cushion zone closest to the upper surface, and a lower cushion zone separated by a separator sheet, wherein the upper cushion zone and the lower cushion zone comprise a compressible material comprising is permeable to air in all directions, as well as a flow path for air, having an air inlet in the lower surface, air moving means, a heat exchanger, a flow path through the compressible material of the lower cushion zone, through openings in the separator sheet, and through the sam and printable material of the upper cushion zone and multiple air outlets present in the upper surface.

The body support assembly of claim 1, wherein the compressible material permeable to air in all directions has an air permeability greater than 100 cm 3 /s/cm 2 measured in accordance with ASTM D737.

The body support assembly of claim 2, wherein the compressible material is a three-dimensional random loop bonded structure of a thermoplastic resin.

The body support assembly of any of claims 2 to 3, wherein the upper pad volume comprises the material of claim 2 or 3, and wherein the compressible material in the lower pad volume is metal springs.

The body support assembly of claim 4, wherein the metal springs are Bonnell springs.

The body support assembly of claim 5, wherein the separator sheet is a sheet of a warp-knit spacer fabric.

The body support assembly of any one of claims 1 to 5, wherein the release sheet is made of a gas-permeable woven or non-woven material.

The body support assembly of claim 7, wherein the gas permeability of the separating sheet is less than the gas permeability of the top surface.

A body support assembly according to any one of claims 7 to 8, wherein the release sheet is made of coconut fibres.

A body support assembly according to any one of claims 1 to 9, wherein the lower surface and the part of the side walls at the height of the lower cushion zone are formed from a layer of felt, and wherein the upper surface and the part of the side walls consist of a layer of textile, and wherein the air permeability of the textile is greater than the air permeability of the layer of felt.

The body support assembly of claim 10, wherein the layer of felt consists of a single sheet of felt, and the layer of textile consists of a single sheet of textile.

The body support assembly of any one of claims 10 to 11, wherein the top end of the layer of felt is pleated inwardly and joined to the top end of the release sheet.

A body support assembly as claimed in any one of claims 10 to 12, wherein the lower end of the fabric layer extends to the lower surface and is pleated inwardly so that the side walls made of felt and a portion of the lower surface are is made of felt, are covered.

A body support assembly according to any one of claims 1 to 13, wherein the body support assembly includes an end for locating the head of a human body and an end for locating the feet of a human body, and wherein the air displacing means and the heat exchanger are positioned at the height of the end in front of the feet.

The body support assembly of any one of claims 1 to 14, wherein the heat exchanger is a Positive Temperature Coefficient (PTC) air heater.

A body support assembly according to any one of claims 1 to 15, wherein the air displacing means is a tangential fan.

The body support assembly of any one of claims 1 to 16, wherein the air inlet in the lower surface comprises an opening in the lower surface provided with a releasable air filter.

The body support assembly of any one of claims 10 to 17, wherein the air inlet in the lower surface comprises an opening in the lower surface of the layer of felt, a frame joined to the lower end of the lower felt surface, and which is connected having a mating frame positioned above the lower felt surface so that a strip of the layer of felt is sandwiched at the opening, and wherein the joined frames provide an opening for the air inlet, and wherein the mating frame is the support for the heat exchanger .

A method of heating a body support assembly having an upper surface for supporting a human body, and a spaced lower surface defining a cushion volume and side walls, wherein the cushion volume comprises: an upper cushion zone closest to the upper surface and a lower cushion zone separated by a separator sheet, wherein the upper cushion zone and the lower cushion zone comprise a compressible material permeable to air in all directions, and wherein ambient air flows along a flow path through a air inlet, air moving means, a heat exchanger, a flow path through the compressible material of the lower cushion zone,

through openings in the release sheet, through the compressible material of the top pad zone, and through the top surface.

A method according to claim 19, wherein the temperature of the air as the latter flows through the compressible material of the upper cushion zone has a value comprised between 27°C and 35°C.

The method of claim 20, wherein the temperature of the air in the upper cushion zone is controlled by measuring the temperature of the air in the upper cushion zone, and, if an adjustment is required, by altering the performance. of the heat exchanger and/or of the performance of the air displacement means.

A method according to any one of claims 19 to 21, wherein use is made of a body support assembly according to any one of claims 1 to 18.

A bed, a body support assembly according to any one of claims 1 to 18, and comprising a mattress support.

24. Body support assembly having an upper surface for supporting a human body, and having a spaced lower surface defining a cushion volume and side walls, wherein the cushion volume includes an upper cushion zone closest to the upper surface and consisting of a compressible material, as well as a lower cushion zone consisting of Bonnell springs present between the lower surface and a separator sheet, wherein the lower surface and the portion of the sidewalls at the level of the lower cushion zone consist of a single sheet of a layer of felt, and in which the upper surface and part of the sidewalls consist of a single sheet of a layer of textile, in which the upper end of the layer of felt is pleated inwardly and joined to the upper end of the separating sheet, and in which the lower end of the textile layer extends to the lower surface, and is pressed inwards tanned so that the side walls made of felt and a part of the lower surface made of felt are covered.

The body support assembly of claim 24, wherein the compressible material is a three-dimensional random loop bonded structure of a thermoplastic resin.

The body support assembly of any one of claims 24 to 25, wherein the release sheet is made of coconut fibres.

The body support assembly of any one of claims 24 to 25, wherein the release sheet is a sheet of a warp-knit spacer fabric.

The body support assembly of any one of claims 24 to 27, wherein the single sheet of fabric layer is releasably wrapped around the cushion volume, and wherein the sheet of the fabric layer is a flat sheet which is not sewn in a three-dimensional shape when it is formed. is detached from the cushion zone.