ARTICLES OF BEDDING

Abstract: An article of bedding, in particular a mattress, including air pathways therein for circulation of air therethrough and a source of air serving to direct the air through the air pathways.

Description: ARTICLES OF BEDDING The present invention relates to articles of bedding, and in particular to mattresses for use by asthma sufferers. A substantial proportion of the population suffers from asthma, often as a result of an allergic reaction to house dust mites. House dust mites reside in very large numbers in materials used within the home such as bedding materials including mattresses, pillows, duvets and the like, and have become more common as a result of homes becoming warmer. A typical bed will contain 20,000 to 30,000 house dust mites which will emerge from the mattress in response to warmth caused by occupancy of the bed. Tests have shown that, by controlling house dust mites, asthmatics will suffer less. In these tests, house mites were eliminated by an "initial kill" using liquid nitrogen. Such a treatment is not practically possible for most sufferers. It is known that the house dust mite survives and reproduces best in an atmosphere of relatively high humidity. It is also known that the number of mites found in houses located in mountainous regions is much less than the number of house mites found in houses located at sea level where humidity is much higher. Dust mite populations start to decline at about 1200 metres, and the population reaches it maximum decline above 1600 metres. It is believed that dust mite populations begin to die out when the relative humidity level within the air falls below 60% at 20°C. It has been proposed to fit a de-humidifler within a bedroom which will extract stale air containing dust mite dung pellets from the room while a heat exchanger uses the warmth of the outgoing air to dry incoming air. The humidity of air within a bedroom is, therefore, maintained at a low level thereby causing a substantial reduction m the house dust mite population within that bedroom. The use of such a de-humidifler in a bedroom must be switched on for most of the day m order to maintain the humidity level within the room at a low level. Also, whilst the humidity level in the air within the room is maintained at a low level, pockets of air within the bedroom, for example beneath the bed remain at a high level. Most of the house mites which cause asthma to occur reside within the mattress and bedding of a bed. While the air within the room may be kept at a low humidity, the air within the mattress and bedding will only reduce in humidity over time. Again, this means that the de-humidifler in the room must be left on for a considerable period before the dust mite population is effectively reduced. Another disadvantage of the proposed bedroom de- humidifier is that the air within the bedroom will become very dry causing discomfort for any occupants. According to a first aspect of the present invention, an article of bedding includes air pathways therein for circulation of air therethrough, a source of air serving to direct the air through the air pathways, and a layer of air-impermeable material serving to separate a person using the bedding from the air circulating through the air pathways. Preferably, the article of bedding is a mattress. It is also preferred that the source of air includes a de-humidifier operable to direct de-humidified air through the air pathways. Articles of bedding according to this invention permit a reduction in the humidity of air within the bedding thereby reducing the population of house dust mites disposed within the article of bedding. Dust mites are believed to absorb water from surrounding air, and this water absorbing ability is greater nearer the dew point of air. At 20 Celsius, mites have difficulty absorbing water at a relative humidity below 60%. Optionally, a mattress according to the invention further comprises a layer of material which is non- permeable to air, but which will permit passage of water vapour therethrough. This will improve the maintenance of a low humidity level within the mattress adjacent to the occupant of the bed. The article of bedding preferably includes walls therein for guiding the air therethrough, and these walls would normally include a dividing wall disposed across the article of bedding for directing the air through substantially the whole length of the bedding before returning along the bedding on the opposite side of the dividing wall. According to a second aspect of the invention, a humidity reducing apparatus comprises a closable body for holding articles to be treated, and a source of reduced humidity air for directing reduced humidity air into the body to treat the articles contained therein. Embodiments of a mattress constructed in accordance with the invention will now be described by way of example and with reference to the accompanying drawings in which: Figure 1 is a schematic perspective view of the mattress; Figure 2 is a side elevation of the mattress according to the present invention; Figure 3 is a schematic plan view of the mattress; Figure 4 is a schematic plan view of the present apparatus; and Figure 5 is a schematic view of a dehumidifier used in the embodiment. In order to reduce the population of house dust mites within a mattress, reduced humidity air is circulated within the mattress since a high population of house dust mites cannot be sustained in a low humidity atmosphere. Referring to Figure 1 , the mattress 1 includes pathways 9 therein through which air is able to circulate. The mattress includes a divider wall 7 which extends from one end of the mattress almost to the opposite end, being broad enough to stretch the entire width of the mattress when the mattress is considered laid flat. The divider wall 7 forms an air barrier dividing the upper half of the mattress when considered laying flat from the lower half of the mattress. At the end of the mattress where the divider wall 7 reaches the end of the mattress, a manifold is located into which air is blown and out of which air is exhausted. The manifold 2 includes an air inlet port 3 through which air is blown, the manifold directing the air into the lower half of the mattress beneath the divider wall 7. The manifold 2 also includes an air exit port 8 through which air is exhausted from the upper half of the mattress 1, above the divider wall 7. Reduced humidity air is blown into the manifold 2 via the air inlet port 3 from a de-humidifier unit (not shown) of conventional construction. In use, the de-humidifier unit blows air into the manifold 2 via the air inlet port 3 whereupon the manifold 2 directs the reduced humidity air into the lower half of the mattress 1 beneath the divider wall 7. This air flow leaving the manifold is shown by arrow 4. The reduced humidity air passes beneath the divider wall 7 until it reaches the end of the mattress whereupon the reduced humidity air passes into the top half of the mattress 1 as indicated by arrow 6. The reduced humidity air then returns to the manifold 2 as indicated by arrow 5. Once the reduced humidity air has reached the manifold 2, the air is exhausted from air exit ports 8. The reduced humidity air blown into the mattress reduces the humidity within the entire structure of the mattress causing a reduction in the population of house dust mites. The de-humidifier unit may be located next to or within the mattress, although if the de-humidifier unit is of a type which generates sufficient noise to disturb a sleeper, the de-humidifier unit may be located in a different room, the reduced humidity air being supplied to the air inlet port 3 via a length of tube. The de-humidifying unit does not need to remove all of the humidity from the air, but just to a level, such as 60% at 20°C, which will cause the population of house dust mites to reduce. The reduced humidity inhibits the life cycle of the mites, and that of the fungi which is also present and which breaks down the fat in discarded human skin scales which is a major source of food for the house dust mite. The outer material of the mattress is a material which is non-permeable to air (not shown) in order to promote air flow within the mattress without leakage. Such a material is preferably constructed from a coated fabric which whilst it is not air permeable, permits water vapour generated by the body to disperse through the fabric so that any temporary increase in humidity is rapidly reduced by the flow of low humidity air within the mattress. In this way, the mattress remains comfortable for the patient to sleep on, and any water vapour entering the upper air pathway of the mattress is quickly taken out of the mattress. Such a material would also prevent free water from entering the mattress, and could be made fire proof by virtue of special treatments of the materials concerned. Removable filters (not shown) are attachable to the air inlet port 3 and the air exit port 8 in order to trap any material in the flow of low humidity air. The inlet and outlet ports of the mattress may be disposed at the sider end or below of the mattress allowing for a number of mounting positions for the tubing connecting the mattress to the de-humidifier unit. It has been found that further advantageous effects can be achieved by varying the temperature of the air passing through the mattress. The mites, once they have been subjected to low humidity air, are significantly reduced in number. However, the dead mites leave behind materials which constitute allergens which sensitise a person, particularly a small child, sleeping on the mattress to that substance. The person may therefore suffer an allergy to that substance for some time. The allergens can also be destroyed, but only if they are subjected to a period of high temperatures. Thus, as shown in Figure 5, in addition to the dehumidifier element 13, the dehumidifier unit includes an electric heater element 14, typically in the form of a coil which heats the dehumidified air. The heater element 14 will be operated on a heater timer (not shown) which is set to heat the air for a set period of time. The heating cycle is timed to take place during the day when the bed is unoccupied. In addition, reduction in the dust mite population of a mattress is enhanced by cooling the mattress below 10°C for a predetermined period. In this embodiment, the dehumidifier 10 includes an optional cooling element 15 which cools the dehumidified air. The cooling element 15 is operated by a cooler timer (not shown) which switches the cooling element 15 on for a set period of time. If a heating element 14 is included, the heating and cooling element 14, 15 should not be operated together. According to another embodiment of this invention (not shown) the exit port of the manifold may be connected via tubing to the de-humidifier so that the air passing through the mattress is re-circulated. An advantage of this is that, once the humidity of the re-circulating air has dropped below a certain reduced humidity level, the air may be re-circulated without the expense of running the de-humidifier. De-humidification is only required once the humidity has reached a predetermined level. According to a further embodiment of the invention, a closed box is connected to the de-humidifier via tubing so that children's toys, bedding and the like may be placed in the box into which a flow of reduced humidity air is directed from the de-humidifier in order to reduce the population of dust mites within such toys and bedding. The box is preferably lidded for simple loading and unloading the box. In a further embodiment of the invention, the de¬ humidifier is of a sufficient size and power that de- humidification of the bedroom occurs as a result of reduced humidity air being exhausted into the room via the air exit ports. In another embodiment, the article of bedding may be any of a duvet, a bedstead or base for a bed, a pillow or any other article of bedding.

Claims: CLAIMS 1. An article of bedding including air pathways therein for circulation of air therethrough, a source of air serving to direct the air through the air pathways, and a layer of air-impermeable material serving to separate a person using the bedding from the air circulating through the air pathways. 2. An article of bedding according to claim 1 wherein the source of air includes a de-humidifier for directing de-humidified air through the air pathways. 3. An article of bedding according to claim 1 or 2 further comprising an inlet filter. 4. An article of bedding according to any preceding claim further comprising an outlet filter. 5. An article of bedding according to any preceding claim further comprising a manifold for leading air into the air pathways. 6. An article of bedding according to any preceding claim further including walls within the article of bedding for guiding the air therethrough. 7. An article of bedding according to claim 6 wherein the walls include a dividing wall disposed across the article of bedding for directing the air through the whole length of the article of bedding before returning along the article of bedding on the opposite side of the dividing wall. 8. An article of bedding according to any preceding claim wherein the layer of air-impermeable material is permeable to water vapour. 9. An article of bedding according to any preceding claim wherein the article of bedding is a mattress. 10. An article of bedding according to any of claims 1 to 8 wherein the article of bedding is a duvet. 11. An article of bedding according to any of claims 1 to 8 wherein the article of bedding is an eiderdown. 12. An article of bedding according to any of claims 1 to 8 wherein the article of bedding is a base of a bed. 13. An article of bedding according to any preceding claim wherein the source of air includes a heater for heating the air supplied to the air pathways. 14. An article of bedding according to claim 13 further comprising a heater timer for periodically operating the heater. 15. An article of bedding according to any preceding claim wherein the source of air includes a cooling element for cooling the air supplied to the air pathways. 16. An article of bedding according to claim 15 further comprising a cooling timer for periodically operating the cooling element. 17. A humidity reducing apparatus comprising a closable body for holding articles to be treated, and a source of reduced humidity air for directing reduced humidity air into the body to treat the articles contained therein. AMENDED CLAIMS [received by the International Bureau on 11 April 1997 (11.04.97); original claim 7 amended; remaining claims unchanged (1 page)] 7. An article of bedding according to claim 6 wherein the walls include a dividing wall disposed across the article of bedding for directing the air through substantially the whole length of the article of bedding before returning along the article of bedding on the opposite side of the dividing wall. 8. An article of bedding according to any preceding claim wherein the layer of air-impermeable material is permeable to water vapour. 9. An article of bedding according to any preceding claim wherein the article of bedding is a mattress. 10. An article of bedding according to any of claims 1 to 8 wherein the article of bedding is a duvet. 11. An article of bedding according to any of claims 1 to 8 wherein the article of bedding is an eiderdown. 12. An article of bedding according to any of claims 1 to 8 wherein the article of bedding is a base of a bed. 13. An article of bedding according to any preceding claim wherein the source of air includes a heater for heating the air supplied to the air pathways. 14. An article of bedding according to claim 13 further AME OED SHEET (ARTICLE 19) STATEMENT UNDER ARTICLE 19 1) The amendment hereby effected relates only to claim 7. Claim 7 has been amended so as to insert the word "substantially" so as to bring the claim into line with the description of the application as originally filed on page 3, lines 23 to 28.

Inventors: HOUSE DAVID HOWARD, HOUSE, DAVID, HOWARD
Applicants: HOUSE DAVID HOWARD, HOUSE, DAVID, HOWARD
Application year: 1996
Main classification: A47C21
IPC codes: A47C21, A47C27