Diffuser

0001The present invention relates to a diffuser for diffusing volatile substances by application of water vapour.

0002It is known to bubble steam through an essential oil for diffusing the oil into the atmosphere of the room containing the diffuser.

0003Many volatile substances are contained in dried organic/plant/vegetable matter and gums & resins; and can be released by passing water vapour over the matter.

0004The object of the invention is to provide a diffuser for diffusing such volatile substances.

0005According to the invention there is provided a diffuser comprising: <ul id="ul0001" list-style="bullet" compact="compact"><li>a housing;</li><li>a liquid container in the housing;</li><li>a heater for the liquid container, adapted to heat the container sufficiently to vaporise liquid in the container; and</li><li>a support for holding volatilisable-substance matter above the liquid container.</li></ul>

0006Whilst it can be envisaged particularly for automotive use that the liquid container be substantially closed - with of course a water vapour outlet - normally the liquid container will be open within the housing.

0007Also, although it can be envisaged that the support could be integral with the liquid container, it is preferably provided on an extension of the housing above the container.

0008A perforate member, such as a grid or grill, could be provided for the volatilisable-substance matter. This will normally be provided as the original organic/plant/vegetable form, albeit dried. In an alternative, it may be provided in the form of an extract such as an essential oil. For volatilisation, the extract may be applied to an absorbent pad- such as of foam or felt material - supported on the grid, or into a smaller container - such as a dish - again supported on the grid. However, the volatilisable-substance matter is preferably provided in a disposable packet, itself supportable directly on the support.

0009Normally a perforate cover will be provided over the support.

0010According to another aspect of the invention there is provided a disposable packet of volatilisable-substance matter for use with the diffuser of the invention, the packet comprising: <ul id="ul0002" list-style="bullet" compact="compact"><li>a porous envelope, which is at once sufficiently porous to allow passage of steam and sufficiently strong to retain its integrity in steam,</li><li>a rim adapted to fit the diffuser's support and</li><li>a quantity of volatilisable-substance matter enclosed within the porous envelope.</li></ul>

0011In the preferred embodiment, the envelope comprises an upper web and a lower web, each of tissue and each attached to the rim. Preferably, the webs and the rim we of cellulose material.

0012To help understanding of the invention, a specific embodiment thereof will now be described with reference to the accompanying drawing, in which: <ul id="ul0003" list-style="none" compact="compact"><li>Figure 1 is a cross-sectional side view of diffuser of the invention, with a packet of volatilisable-substance matter in position and</li><li>Figure 2 is a top view of the packet.</li></ul>

0013The diffuser 1 has a housing 2 of moulded plastics material and based on a shell moulding 3. This has two internal ledges 4,5. To the lower, smaller diameter ledge 4, a stainless steel or treated alloy bowl 6 is attached at a rim 7 of the bowl by interference fit or odourless adhesive. An extension 8 of the shell has the other ledge 5 at its top. A perforate moulded dome rests 9 on the upper ledge 5. A moulded base 10 closes the bottom of the shell.

0014Attached to its underside, the bowl has a temperature controlled heater 11 in the form of a PTC (positive temperature coefficient) heater. An ON/OFF switch 12 is mounted in the wall of the housing, as is a therapeutically coloured light 13.

0015In use a disposable packet 20 of volatilisable-substance matter - an aroma packet - is mounted on the upper ledge, with the base of the dome locking on its card rim 21, the dome and the housing being provided with a non-shown twist lock. The packet has a upper and lower cellulose tissue webs 22,23. These are adhered to the rim by odourless adhesive, with dried vegetable matter 24 captivated between them. Typically dried lavender blooms may be used. The rim is sized to fit the ledge 5. When the aroma of lavender is to be diffused, the bowl is filled until it contains water to a mark 14 and the diffuser is switched on. The water is boiled, causing water vapour to heat the lavender. The lavender's volatile substances are thus diffused via the perforations 15 in the dome into the room where the diffuser has been set up. Any condensate on the dome runs down inside it, past the rim of the packet and returns to the bowl. Typically the water will last for two hours, by which time all the aroma will have been volatised.

0016To ease fitting and removal of the packet, it is provided on the rim 21 with a pair of diametrically opposed lugs 25, which fit into cut-outs 26 in an up-stand 27 from the ledge 5. The up-stand serves to locate the dome 9. To encourage use of volatilisable material packets which are recommended, they and the rim 5 are preferably provided with complementary formations such as slots 28 in the rim 21 and spigots 29 on the ledge 5. It should be noted that whilst Figure 2 shows an envisaged arrangement of the lugs and slots around the packet's rim, Figure 1 illustratively shows on opposite sides a cut-out 26 and a spigot 29, which would not be positioned diametrically opposite each other when the aroma packet is made as shown in of Figure 2.

0017The invention is not intended to be restricted to the details of the above described embodiment. For instance a wide variety of aromatic material may be used in the diffuser packet. The packet itself may be of synthetic material. Therapeutic as well as scented materials may be packed. A measuring cup for water to be placed in the bowl can be housed within the dome between uses. Alternatively, a cover can be provide for covering the dome between uses. Where the aromatic material is expected to be released over a longer period than the heater would take to evaporate the amount of water in the container, a controller for intermittently switching the heater on and off may be provided, whereby the water can be made to last longer before it is all evaporated.