The present invention relates to a nozzle for conventional vacuum cleaners.

A mite is an arachnid that lives in domestic dwellings. The mites may be as small as 0.1 mm and are present in large quantities.

Excretion from mites is allergenic and can cause allergies and asthma in susceptible persons.

Mites prefer to live in bedclothes, mats, upholstered furniture and other textiles used in the home and in the dust generated therein. Mites live mainly on human skin epithelium.

Mites hold firmly to the textile materials in which they are present, and cannot therefore be sucked into a conventional vacuum cleaner nozzle. Although dust that contains mites will be sucked into the vacuum cleaner when vacuum cleaning textile materials, only a small number of the mites present in the materials will be drawn into the nozzle. Thus, the problem is that mites cannot be removed to the desired extent.

The present invention solves this problem with the aid of a vacuum cleaner nozzle by means of which mites present in textile materials can be removed essentially completely, or at least to a large extent.

The present invention thus relates to a vacuum cleaner nozzle of the kind that includes a casing and a plate which is fitted to the bottom of the casing and which includes suction grooves that are surrounded by flat parts, and an aperture that communicates

with a source of vacuum through the medium of a suction passage, and is characterized in that the casing encloses a space which is delimited downwardly by that surface of the plate which faces towards the casing interior; and in that said space accommodates a cooling element which is intended to lie against said plate surface, or substantially against said surface, in order to cool the surface.

The invention will now be described in more detail with reference to an exemplifying embodiment thereof and also with reference to the accompanying drawing, in which

Figure 1 is a side view of an inventive vacuum cleaner nozzle; - Figure 2 is a sectional view of the nozzle taken on the line A-A in Figure 3; and Figure 3 shows the nozzle from beneath.

Figure 1 illustrates a vacuum cleaner nozzle that includes a casing 1 and a plate 2 attached to the bottom of the casing. The plate includes suction grooves 3, 4 surrounded by planar parts 5, 6, 7. As best seen from Figure 3, the nozzle also includes an aperture 8 which is intended to communicate with a suction source via a suction passage 9, i.e. via a vacuum cleaner hose connected to the cleaner.

In accordance with the invention, the casing 1 encloses a space 10 which is delimited downwardly by the plate surface 11 that faces towards the casing interior. The space 10 accommodates a cooling element 12, which is dotted in Figure 2. The cooling element 12 is intended to lie against the plate surface 11, or essentially lie against said surface, so as to cool the same.

According to one preferred embodiment, the cooling element can be dismantled from the nozzle. Alternatively, the cooling element may be permanently mounted in the nozzle or formed integrally therewith. The embodiment in which the cooling element can be dismantled from the nozzle will now be described.

The plate 2 is normally made of thin stainless metal sheet. Because the plate is relatively thin, the surface 13 of the plate facing towards the surroundings will rapidly be cooled to a temperature that is only slightly higher than the surface temperature of the cooling element.

According to one preferred embodiment, the nozzle side-wall 14 includes an opening through which the cooling element 12 can be inserted into and removed from the nozzle. As will be seen from Figure 1, the opening is covered by a hinged flap or like device 17 mounted on hinges 15, 16. A cooling element is inserted into the nozzle, by opening the flap 17 and introducing the cooling element from one side of the nozzle, i.e. perpendicularly downwards in the plane of the paper in Figure 1.

According to a further preferred embodiment, each of the two mutually opposing side-walls 14, 18 is provided with an opening through which a cooling element can be inserted into and removed from the nozzle, and in which two similar cooling elements 12, 19 inserted into the nozzle will essentially cover the inner surface of said plate.

Figure 3 shows the two inserted cooling elements in broken lines. As will be evident from Figure 2, that surface of the cooling element 12 which faces towards the plate has the same shape as the plate. It will also be seen from Figure 3 that the two elements essentially cover the entire surface of said plate. When

two cooling elements are used, the elements will surround the aperture 8.

The cooling elements 12, 19 are preferably of the kind used, among other things, for cooling liquids or for domestic ice-cream machines and which are intended to be cooled down to a tempera¬ ture of about -18°C to -22°C in a domestic freezer.

Prior to use, the cooling elements are placed in the freezer until they reach the freezer temperature. When the cooling element is a permanent fixture and cannot be removed from the nozzle, it is necessary to place the entire nozzle in the freezer.

The cooling elements are inserted into the nozzle prior to using the vacuum cleaner to extract dust from textiles, mats, bed¬ clothes, upholstered furniture, etc.. The cooling elements will therewith immediately cool the plate down to a low temperature.

As the nozzle is passed over a surface, mites present on the surface are subjected to a cold shock. As a result, the mites will be so dazed as to release their hold on the textile material in question. Mites will also die as a result of the cold shock and therewith release their hold on the material. All mites that release their hold on the material will be sucked into the nozzle and into the vacuum cleaner bag, and therewith removed.

The precise upper temperature limit at which mites are not subjected to a sufficiently severe cold shock to cause the mites to release their grip is not known, although it is probably above minus ten degrees Celsius.

It is known to construct cooling elements of the aforesaid kind that will maintain a surface temperature of below minus ten

degrees Celsius for a long period of time, for instance from 0.5 hour or longer and from a starting temperature of -18°C.

Because textiles have poor thermal conductivity, it will take a relatively long time for the cooling element or elements to be heated as a result of passing the plate over the textiles.

Thus, the person skilled in this art will be able to readily dimension a cooling element that will maintain the surface of said plate at a temperature sufficiently low to subject mites to said cold shock, over a time period of at least 0.5-1 hour.

If only a greater part of the mites are removed, the environment will, nevertheless, be considerably improved with respect to persons susceptible to allergenics.

In one preferred embodiment, a temperature indicator 20 is mounted on the cooling element or on a surface that is cooled by said element. An example of one such surface is the flap 17.

The indicator 20 is preferably constructed to alternate from one colour to another at a predetermined temperature.

Optical indicators that change colour at different temperatures are well known and are used as thermometers, among other things. Such devices need no additional energy in the form of electrical energy. Indicators of this kind are based on liquid crystals.

The use of such an indicator enables the user to see when the cooling elements need to be changed to fully cooled or chilled elements.

Although the present invention has been described above with reference to a vacuum cleaner nozzle of a particular kind, it

will be understood that the invention can be applied to all types of vacuum cleaner nozzles. This also applies to powered so-called whipping vacuum cleaner nozzles.

As will be understood, the nozzle may be constructed so that the major part, if not all, of the surface of said plate will be covered by a single cooling element.

The invention can thus be modified in this and other ways apparent to one of normal skill in this art.

Accordingly, the present invention shall not be considered to be limited to the aforedescribed and illustrated embodiment, since variations and modifications can be made within the scope of the following Claims.