A MATTRESS OR OTHER SUPPORTING UNIT

Abstract: A mattress or other supporting unit comprises a number of layers of filling (1; 5, 7, 5', 7') and an outer covering (4, 6, 10). A barrier (4, 6, 9, 18, 19; 21, 22, 23) to the passage of infectious agents is provided adjacent to at least one of the layers and within the outer covering.

Description: A MATTRESS OR OTHER SUPPORTING UNIT This invention relates to mattresses and other supporting units. The invention is particularly applicable to mattresses and to supporting units constituting mattress-components, that is to units of the kind which can be stacked or otherwise assembled with an additional unit or with additional units to form an assembly of supporting units which together constitute a mattress, it being understood that the additional supporting unit or at least one of the additional units may be similar to the supporting unit with which the present invention is primarily concerned. In addition to its being concerned with mattresses and mattress-components the present invention is also applicable to other kinds of supporting units such as pillows and cushioning for seats. It is known that the house dust mite thrives in conditions existing inside a standard mattress and that skin shed by an occupant of a bed provides a convenient food source. It is accepted that an allergic response to the house dust mite or faeces thereof can aggravate or cause an asthmatic reaction in an occupant. In GB-A- 213 053 we describe a removable cover for a mattress the cover in use providing a barrier to the passage of mites between the interior of a mattress and the food source, and so depriving the mites of their food source. Recent research has shown that house dust mites may also be implicated in the transmission of a number of diseases particularly those which can be passed on through a fluid vector. These findings will be of particular concern in institutions, such as hospitals and hotels, where the same bed may be occupied by a large number of people. According to a first aspect the present invention consists in a mattress or other supporting unit comprising a number of layers of filling and an outer covering, in which a barrier to the passage of infectious agents is provided adjacent to at least one of the layers and within the outer covering. A particular advantage of a mattress in accordance with the present invention is that a barrier is provided to the passage of the house dust mite and its antigen. In a conventional mattress the filling may comprise a series of layers of materials such as wool felts, cotton, foam, polyester fibre, and wool. Traditionally the outer covering comprises a fabric ticking such as damask. Preferably the barrier comprises at least one layer of material, at least a substantial portion of which is vapour permeable, that is impermeable to liquid water but permeable to water-vapour. The vapour permeable material may comprise polyethylene film such as that marketed under the trade mark PLATILON. Alternatively the vapour permeable material may comprise a textile fabric provided with a coating that is impermeable to liquid water but permeable to water vapour. A suitable material is marketed under the trade mark "VENTFLEX" . Another suitable material is sold under the trade mark "GORE-TEX" and comprises a textile fabric laminated by a bonding process to a micro-porous material. The materials referred to above are merely examples of materials suitable for use in a mattress or other supporting unit in accordance with the present invention. Other materials which fulfil the requirement of providing a barrier to infectious agents may be substituted for the materials referred to. The mattress may comprise a spring unit supporting a number of layers of filling. It is envisaged that a sheet of vapour permeable material may be incorporated at any desired location in the mattress construction. It is preferred to position the sheet as close to the occupant as possible so as to reduce the habitat available to the house dust mite. Suitable sealing means should also be provided in the sides and base of the mattress so as to seal off the interior of the mattress. In one embodiment a layer of vapour permeable material may be incorporated above and below the spring unit, a suitable sealing means being provided along each side of the spring unit. The sealing means may comprise a panel of vapour permeable material or a panel of an air tight material. Alternatively upper and lower layers may extend such that their peripheries may be sealed together. In another embodiment at least an upper layer of vapour permeable material may be incorporated into the layers of filling. The upper layer of vapour permeable material may be incorporated into the filling in a process referred to as quilting in which a number of layers of filling and the ticking are joined together in such a way as to give a lofted appearance. It is necessary to ensure either that the upper layer of vapour permeable material is not punctured during the quilting process or that if it is it is adequately sealed after the quilting process is complete. Alternatively a number of layers may be quilted together to form a quilted layer and after the quilting process is complete a layer of vapour permeable material may be laminated to the underside of the quilted layer. In other embodiments the upper layer of vapour permeable material may be stretched over a layer of filling in a conventional manner. A lower layer of vapour permeable material may be incorporated below the spring unit. The lower layer may be laminated to a layer of filling or to the inner side of the ticking or may be stretched over the spring unit in a conventional manner. From a second aspect the present invention consists in a mattress or other supporting unit comprising a flexible, yielding body enclosed within a container, at least one main face of the container, constituting a working face, comprising a flexible film of a material that is impermeable to liquid water but is permeable to water-vapour. The working face of the mattress or other supporting unit is that face of the unit which the user bears against when the unit is in use; for example, the upper main face of a mattress is the working face of the mattress, while the forwardly directed face of an upright seat-back is the working face of the seat-back. The flexible material may comprise polyethylene film. A flexible material suitable for use in carrying out the present invention is a polyurethane film 30μ thick marketed under the trade mark PLATILON by Plate Bonn G. .b.h. of Bonn, West Germany. That film has a 2 water-vapour permeability of more than lOOOgm /24h at 37°C and 100% relative humidity as measured by the Payne's cup method, a method described in: Payne HS. The permeability and structure of films. Off. Dig Fed Paint Varnish Production Clubs 1936; 8: 297-304. The container may be fully closed or substantially fully closed so that in normal use the amount of air or other gas within it remains constant or alters only very slowly with the result that the supporting unit tends to provide at least some pneumatic support for a user of the unit. An additional advantage of using a container that is fully closed or substantially fully closed is that any bed mites or the like that might enter the container or be trapped inside the container are normally prevented from colonising the body owing to the fact that they are starved of nourishment. Nevertheless, in an alternative construction the container is not fully closed so that in normal use the supporting unit tends not to provide any pneumatic support for a user or tends to provide such support for no longer than a short period. The flexible, yielding body within the container may be of any suitable nature and may be of unitary or compound form. In particular it preferably comprises a layer of resilient foam material of which at least one of the main faces is of so-called 'convoluted' form, that is the face is shaped to afford a regular array of peaks and hollows; those formations or 'convolutions' are preferably of a rounded form so that the surface of the face (apart from the marginal edges) includes no sharp or angled edges but is of a continuously and smoothly undulating shape. The body may consist solely of a layer of resilient foam material, at least one main face of which is preferably of convoluted form. Alternatively the body may consist solely of a pad of fibrous material such as a pad of polyester fibre. Alternatively the body may comprise two or more components; for example it may comprise a layer of foam material and a pad of fibrous material, the pad preferably being closer than the foam material to the working face of the unit. That main face of the layer of foam material adjacent to the pad is preferably of convoluted form. A flexible diaphragm may be provided between the layer of foam material and the pad of fibrous material this being particularly desirable when the face of the layer of foam material adjacent to the pad is of convoluted form; the diaphragm may conveniently comprise a film or films of material that is impermeable to water but permeable to water-vapour, the material preferably being similar to that from which the workinσ face of the container is formed. From a third aspect the present invention consists in a mattress or other supporting unit comprising a flexible, yielding body enclosed within a container in such a manner that in normal use the amount of air or other gas within it remains constant or alters only very slowly with the result that the supporting unit tends to provide at least some pneumatic support for a user of the unit, at least one main face of the container, constituting a working face, comprising or containing a flexible material that is impermeable to water but is permeable to water vapour. A supporting unit in accordance with this third aspect of the present invention, unlike a supporting unit in accordance with the second aspect of the present invention, necessarily tends to provide some pneumatic support for a user of the unit but has a working face that is not necessarily in the form of a film. In fact the working face may be afforded by a flexible sheet material of the kind comprising a textile fabric provided with a coating of which is impermeable to liquid water but is permeable to water-vapour. Suitable materials are those marketed under the trade marks "VENTFLEX" and "GORE-TEX" . Apart from those differences, a supporting unit in accordance with the third aspect of the present invention may incorporate any of the optional or preferred features outlined above in relation to a supporting unit in accordance with this second aspect of the present invention. Embodiments of the present invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which:- Figure 1 is a diagrammatic cross-section through a supporting unit embodying the present invention; Figure 2 is a diagrammatic cross-section through another form of supporting unit embodying the present invention; Figure 3 is a cross-section through another form of supporting unit embodying the present invention; Figure 4 is a cross-section through a mattress embodying the present invention; and Figure 5 is a cross-section through another form of mattress embodying the present invention. The supporting unit shown in Figure 1 comprises a rectangular body of flexible and resilient foam material 1 of which the underside 2 is planar but the upper surface 3 is of convoluted form, as referred to above. The body 1 is enclosed within a container 4 comprising a sealed bag made of polyurethane film 30u thick that is impermeable to liquid water but permeable to water-vapour, the film being of the kind marketed under the trade mark "PLATILON". In use the user obtains some pneumatic support from the air (or other gas) sealed within the container 4, as well as support from the body 1. The supporting unit shown in Figure 2 may be used as a palliasse and comprises a body 5 in the form of a flexible and resilient pad of polyester fibre, typically 50mm thick. The body 5 is sealed within a container 6 similar to the container 4. If desired, a mattress of compound form may be made by stacking or superimposing a unit of the kind shown in Figure 2 on top of a unit of the kind shown in Figure 1. In that case each of the units may be considered as constituting a mattress-component. Straps or other securing means (not shown) may be employed to secure the units together. The supporting unit shown in Figure 3 comprises a body of compound form consisting of a layer 7 of resilient foam material similar to the body 1 and a pad 8 of polyester fibre similar to the body 5 superimposed on the layer 7. A sheet 9 of polyurethane film, similar to that from which the containers 4 and 6 are made, is interposed between the layer 7 and the pad 8 to provide a positive barrier between the layer and the pad. The compound body this formed is sealed within a container 10 similar to the containers 4 and 6. In a modified kind of construction the container 4, 6 or 10, as the case may be, is replaced by a sealed bag which still tends to afford some pneumatic support for the user but is composite form and of which the working surface, that is the upper surface in each of these cases, is made of a film that is impermeable to liquid water but is permeable to water-vapour. At least part of the remainder of the bag is made from some different material or from more than one different materials. In a further modified construction the container is formed with a few very small apertures so that it is no longer sealed and in use, or at least in prolonged use, affords little or no pneumatic support for the user. At the same time, the access to the interior of the container is restricted enough to prevent the ingress of perspiration, and dust etc. to an extent sufficient to enable bed-mites to colonise the body inside the container. In a different type of modification the container is fully sealed but at least its working surface is made from a textile fabric provided with a coating which is impermeable to liquid water but is permeable to water-vapour, a suitable material being one marketed under the trade mark "VENTFLEX" or"GORE-TEX" . It is to be understood that while the supporting units described above all constitute mattresses or other articles on which a user may lie down, supporting units of other sizes and shapes but of similar constructions may be provided for other purposes such as for sitting on or reclining against, such units constituting pillows or cushions or being incorporated in seats, chairs or the like. Alternatively a supporting unit in accordance with the invention may constitute only part of a mattress or the like. For example, a supporting unit may comprise a lower part of a mattress, that is a part in which the user's body rather than the user's head is intended to lie, the user's head resting on some other form of supporting unit. Thus, the lower part of a cot-mattress for a baby may be in accordance with the present invention while the upper part of the mattress, on which the baby's head rests, may be afforded by a resilient body which is formed with an array of through air-holes or is otherwise formed to reduce the likelihood of a baby having difficulty breathing when its face is applied directly to the resilient body. Figure 4 shows an alternative embodiment incorporating a typical mattress construction comprising a spring unit 11 supporting a number of layers of fillings and an outer covering 12. The layers of filling comprise a first layer of wool felt 13, a layer of resilient foam material 7 and a layer of polyester fibres 5. The outer covering 12 comprises a layer of fabric ticking. The fabric ticking extends around and totally encloses the interior upholstery. The outer covering 12 comprises an upper panel 14, a lower panel 15 and side panels 16 joining the upper and lower panels. The mattress is constructed such that lower and upper halves of the mattress comprise the same fillings. Accordingly below the spring unit 11 there is provided a second lower layer 17 of wool felt and lower layers of resilient foam 7 ' and polyester fibres 5 ' . In the embodiment of Figure 4 a barrier to the passage of infectious agents is provided in the form of a sheet 18, 19 of vapour permeable material encapsulating the first and second layers 13, 17 of wool felt. A side panel 20 of the vapour permeable material joins the sheets 18 and 19 such that the spring unit 11 is contained within an integral barrier and each of the two wool felt layers 13, 17 are encapsulated within a barrier. The sheets 18, 19 may be sealing joined to the panel 20 by heat sealing or other means ensuring an adequate barrier is maintained. In a further embodiment shown in Figure 5 a sheet 21 of vapour permeable material is incorporated in the quilting process below the layer 5 of polyester fibres. The sheet 21 may be secured to the layer 5 of polyester fibres and ticking 13 by the quilting process. If this is done the apertures created by the quilting needles are sealed by suitable means such as a spray coating of a vapour permeable substance. Alternatively the sheet 21 may be laminated to the layer of polyester fibres. The sheet 21 is sealingly joined to side panels 22 which are also joined to a lower sheet 23 located between the lower layer 5' of polyester fibres and the lower layer of wool felt 17. The mattress illustrated in Figure 5 of the accompanying drawings is otherwise the same as that of Figure 4 and corresponding reference numerals have been applied to corresponding parts.

Claims: CLAIMS 1. A mattress or other supporting unit comprising a number of layers of filling (1; 5; 7; 5', 7') and an outer covering (4, 6, 10) in which a barrier (4, 6, 9, 18, 19; 21, 22, 23) to the passage of infectious agents is provided adjacent to at least one of the layers and within the outer covering. 2. A mattress or other supporting unit according to claim 1, characterised in that the barrier (4, 6,9, 18, 19; 21, 22, 23) comprises at least one layer of material, at least a substantial portion of which is vapour permeable, that is impermeable to liquid water but permeable to water-vapour. 3. A mattress or the supporting unit according to claim 2, characterised in that the vapour permeable material comprises polyethylene film. 4. A mattress or other supporting unit according to claim 2, characterised in that the vapour permeable material comprises a textile fabric provided with a coating that is impermeable to liquid water but permeable to water vapour. 5. A mattress or other supporting unit according to claim 2, characterised in that the vapour permeable material comprises a textile fabric laminated by a binding process to a micro-porous material. 6. A mattress cr other supporting unit as claimed in any of claims 2-5, in which the mattress comprises a spring unit (11) supporting at least one layer of filling (5, 7; 5' , 7') characterised in that a sheet of vapour permeable material (18, 19; 21, 22, 23) is incorporated at any desired location in the mattress or unit construction. 7. A mattress or other supporting unit according to claim 6, in which the interior of the mattress or unit is sealed off by the use of suitable sealing means. 8. A mattress or other supporting unit according to claim 6 or claim 7, characterised in that a layer of vapour permeable material (18, 19, 21, 23) is incorporated above and below the spring unit (11) . 9. A mattress or other supporting unit according to claim 8, characterised in that sealing means (20, 22) is provided along each side of the spring unit (11) . 10. A mattress or other supporting unit according to claim 8 , characterised in that the sealing means (20, 22) comprises a panel a vapour permeable or air tight material. 11. A mattress other supporting unit according to claim 8, characterised in that the two layers (18, 19, 21, 23) are extended, and sealing means seal the peripheries of the two layers together. 12. A mattress or other supporting unit according to any of claims 6-11, characterised in that at least an upper layer of vapour permeable material (18, 21) is incorporated into layers of filling (5, 7, 13) . 13. A mattress or other supporting unit according to claim 12, characterised in that the upper layer of vapour permeable material (18, 21) is incorporated into the filling(5) quilting. 14. A mattress or other supporting unit according to claim 12, characterised in that a number of layers (5) are quilted together to form a quilted layer and, after the quilting process is complete, a layer of vapour permeable material (21) is laminated to the underside of the quilted layer. 15. A mattress or other supporting unit according to claim 12, characterised in that the upper layer of vapour permeable material (18, 21) is stretched over a layer (13) of filling. 16. A mattress or other supporting unit according to any of claims 12-16, characterised in that a lower layer (19, 23) of vapour permeable material is incorporated below the spring unit (11) . 17. A mattress or other supporting unit comprising a flexible yielding body (1, 5, 7; 5', 7', 13) enclosed within a container (4, 6, 10, 12, 18, 21) , at least one main face of the container, consituting a working face, comprising a flexible film of a material that is impermeable to liquid water but is permeable to water-vapour. 18. A mattress or other supporting unit according to claim 17, characterised in that the container (4, 6, 10, 12, 18, 21) is fully closed so that in normal use the amount of air or other gas within it remains constant or alters only very slowly with the result that the supporting unit tends to provide at least some pneumatic support for a user of the unit. 19. A mattress or other supporting unit according to claim 17, characterised in that the container (4, 6, 10, 12, 18, 21) is not fully closed so that in normal use the mattress or supporting unit tends not to provide any pneumatic support for a user or tends to provide such support for no longer than a short period. 20. A mattress or other supporting unit according to any of claims 16-19, characterised in that the body consists solely of a layer of resilient foam material (1) . 21. A mattress or other supporting unit according to claim 20, characterised in that at least one main face (3) of the layer (1) is of convoluted form. 22. A mattress or other supporting unit according to claim 20, characterised in that the body consists solely of a pad (5) of fibrous material. 23. A mattress or other supporting unit according to claim 20, characterised in that the body is of compound form comprising a layer of foam (7) , and a pad (8) of fibrous material. 24. A mattress or other supporting unit according to claim 23, characterised in that the pad (8) is closer to the working face that the layer of foam (7) , and a flexible diaphragm (9) of a material similar to that of the working face of the container (10) is disposed between the layer of foam (7) and the pad (8) . 25. A mattress or other supporting unit comprising a flexible, yielding body (1, 5, 7, 8; 5', 7') enclosed within a container (4, 6, 10, 12) in such a manner that in normal use the amount of air or other gas within it remains constant or alters only very slowly with the result that the supporting unit tends to provide at least some pneumatic support for a user of the unit, at least one main face of the container, constituting a working face, comprising a flexible material that is impermeable to water but is permeable to water vapour. 26. A mattress or other supporting unit according to claim 25, characterised in that the working face is afforded by flexible sheet material of the kind comprising a textile fabric provided with a coating of which is impermeable to liquid water but is permeable to water-vapour.

Inventors: BUCKLEY PETER, BUCKLEY, PETER
Applicants: SLUMBERLAND PLC
Application year: 1991
Main classification: A47C27
IPC codes: A47C21, A47C27, A47G9