The present invention relates to an improved pillow.

More specifically the invention relates to a pillow of the type that is essentially constructed from a core composed of foam springs made of a viscoelastic material and a foam layer affixed around this core as a jacket.

Such pillows have the advantage that, thanks to the use of viscoelastic foam springs, when used the pillow adopts a shape that perfectly fits the shape of the head, and this under the influence of the weight and heat of the head of the user, which creates a feeling of considerable comfort. The springs also ensure good air circulation that is required within the pillow.

The jacket generally has a thickness of one to five centimetres and is generally manufactured from a soft polyurethane foam, also known as PU or PUR foam or a latex foam.

However, these materials present the disadvantage that they quickly return to their original shape and that, in other words, a pillow compressed during sleeping quickly springs back, which is inconvenient when the sleeping position changes, as the head must be further lifted whenever the head is moved or turned. Sometimes viscoelastic foam is also used for the jacket, which does not have this last disadvantage, but which is more expensive, however. In any case all known foam varieties of the aforementioned types present a great disadvantage in that they have a large number of closed cells, which prevents good air circulation through the pillow. Nevertheless, good air circulation is of considerable importance for a good sleep, as otherwise, in the absence of good air circulation, the parts of the head that are in contact with the pillow warm up due to the body heat, whereby the user begins to sweat, which can lead to the user tossing and turning to adopt a different more comfortable position, or even waking up as a result. Repeatedly waking up and tossing and turning during sleep means that the user is not well rested and the quality of sleep deteriorates.

It is indeed known that a good pillow is just as important as a good mattress for a good night's rest.

The known foam varieties of the aforementioned type also have the disadvantage of being hydrophobic, or in other words repel moisture and thus cannot absorb moisture.

This presents the disadvantage that moisture and damp air that penetrates into the pillow is trapped in the open cells of the foam, where the accumulated moisture impedes the good air circulation, and where the accumulated moisture can form a possible breeding ground for all kinds of mould and pathogens, which in time can give rise to unpleasant odours and/or a variety of allergies or other symptoms.

The purpose of the present invention is to provide a solution to a least one of the aforementioned and other disadvantages .

To this end the invention concerns an improved pillow that is essentially constructed from a core composed of foam springs that are at least partially manufactured from a viscoelastic material and a foam layer is affixed around this core as a jacket, characterised in that the jacket is manufactured from an air permeable foam or a foam made air permeable with an open cell structure and hydrophilic properties, and that the jacket is fastened to at least part of the foam springs so that the jacket follows the deformations of the foam springs fastened to it.

An advantage of such a pillow according to the invention is that the user will sweat less in the contact zone with the pillow and that, moreover, the smaller amount of sweat and moist air when sleeping will be quickly absorbed by the foam jacket because the moisture in the cells is absorbed in the material of the foam itself, via the wall of the cells, and is trapped in there for the rest of the night.

The moisture thus does not stay in the cells and does not form an obstacle to good air circulation. During the day or during periods that the pillow is not used for sleeping, no extra moisture gets in and the absorbed moisture can be quickly carried away by the good air circulation that is enabled by the good air permeability of the jacket on the one hand, and the core composed of foam springs on the other.

Another advantage is that during sleep, when the head is turned or moved, the pillow returns to its original shape more slowly than a conventional pillow, and this is also due to the fact that the viscoelastic springs return to their original position slowly, and consequently also the jacket fastened to these springs which thus follows the slow expansion of the springs.

In other words, an indentation that is formed in the pillow during sleep will disappear more slowly when the head is moved or turned, such that the user will have to lift his head less in order to be able to do this without discomfort, such that the waking of the user upon such movements is as good as ruled out.

Preferably the jacket is manufactured from a reticulated foam.

A simple and cheap preferred way to fasten the jacket to the springs is by gluing, although other techniques are not excluded such as sewing, stapling, or other fastening techniques . A pillow according to the invention enables a thinner jacket to be provided than with conventional pillows, and this without a loss of comfort. A layer no thicker than 3 to 4 centimetres will be sufficient. This of course means a cost saving in the material needed to produce a pillow according to the invention.

A foam that is highly suitable for use as a material to manufacture the jacket is a foam based on polyether polyols that are mixed with TDI or MDI and activators, silicones and water to make the foam.

This type of foam provides the additional advantage that it is durable and as good as indestructible.

With the intention of better showing the characteristics of the invention, a preferred embodiment of an improved pillow according to the invention is described hereinafter by way of an example, without any limiting nature, with reference to the accompanying drawings, wherein: figure 1 schematically shows a cross-section through an improved pillow according to the invention;

figure 2 shows a perspective view of a separate spring as indicated by F2 in figure 1;

figure 3 shows the part indicated by F3 in figure 1 on a larger scale;

figures 4 and 5 show the pillow of figure 1 during use . The pillow 1 shown in figure 1 is made up of a core 2 composed of foam springs 3 and a foam layer affixed around this core 2 as a jacket 4. The foam springs 3 from which the core 2 is composed are made from a viscoelastic material that has the property that under the influence of pressure and heat, for example from a part of the body, it takes on a shape that closely fits the body part concerned, and which gradually returns to its original shape when the pressure is removed.

In this case the foam springs 3 are of a cylindrical form with a central passage 5 that extends from one end 6 of the foam spring 3 to the other end 7 of the foam spring 3, and radial passages 8 that connect the central passage 5 to the outer surface 9 on the periphery of the foam spring 3 concerned.

In the example shown, the foam springs 3 are affixed in a layer adjoining one another, whereby the passages 8 and 9 in the foam springs 3 and the spaces 10 between the foam springs 3 ensure good air circulation inside and through the core 2. According to the invention, the jacket 4 is manufactured from an air permeable foam layer with an open cell structure and hydrophilic properties, and a thickness D of around three to four centimetres. The central passages 5 of the foam springs 3 are oriented from one side 11 of the pillow 1 to the other side 12 of the pillow 1, and one or both ends 6-7 are fastened to the jacket 4, so that the jacket 4 follows the deformations by compression of the foam springs 3 fastened to it. The jacket 4 and the foam springs 3 are, for example, glued together by means of an adhesive layer 13, or are connected together by any other fastening technique.

Although it is preferable that all foam springs 3 are fastened to the jacket 4, it is not excluded that only the foam springs 3 in the central zone A of the pillow 1 are fastened to the jacket 4.

It is also not excluded that only the ends 6 of the springs 3 are fastened to the jacket 4 at one side 11 of the pillow and the other ends 7 of the springs are not fastened to the jacket 4. In this case the pillow can be used with a side 11 that reacts slowly to deformations and with a faster reacting side 12, depending on the preference of the user.

For the rest, not all of the foam springs 3 need to be identical, but can differ from place to place with regard to dimensions, composition and/or elastic characteristics. Notwithstanding the fact that it is preferable for the foam springs 3 to be made completely from viscoelastic foam, it is not excluded that they are only partially made from such a foam. For example, the jacket is preferably manufactured from a reticulated foam with a cross-linked open cell structure. The foam from which the jacket 4 is made can for example be a soft PU or PUR foam, which due to its composition, when manufacturing the foam layer, yields directly and completely an open cell structure, or a more conventional PUR foam, of which at least a part of the cells are closed and which has been subsequently treated to break open the closed cells. Such a subsequent treatment can for example consist of putting the PUR foam to be treated in a gas container with a 'small quantity of gas, and this gas is made to explode thereby burning away the membranous cell wall of the cells. Another subsequent treatment can consist of immersing the foam layer to be treated in a chemical bath in order to dissolve the cell walls.

From a cost point of view the preference is to select a foam that does not require a subsequent treatment.

A very suitable foam is a recently developed foam based on polyether polyols, which when making the foam to be used are mixed with the traditional activators, silicones and water in the reaction with TDI (toluene diisocyanate ) and with MDI (methylene diphenyl diisocyanate) .

The jacket 4 does not necessarily have to extend over the entire periphery of the pillow 1 and could for example be limited to one side 11 of the pillow 1, i.e. the side 11 of the pillow 1 that is intended to come into contact with the head 14 of the user, and the core 2 and the jacket 4 are enclosed by a pillow-slip or another covering.

The use of a pillow 1 according to the invention is simple and is illustrated on the basis of figures 4 and 5.

During sleep the pillow 1 will be pressed in by the weight and heat of the head 14 of the user. As a result, both the foam springs 3 and the jacket 4 are compressed, as shown in figure 4 and a hollow 15 is thus formed.

Thanks to the viscoelastic foam, the head 14 sinks as it were into the pillow 1, which provides a comfortable support for the head 14.

Sweat and moist air are absorbed by the pillow such that the pillow 1 always feels dry and pleasant for the user, which fosters the quality of sleep.

When the user raises his head 14 to adopt another position, then the springs 3 of viscoelastic material gradually expand to return to their original unloaded shape with a certain delay as it were.

This means that, after lifting the head 14, the springs 3 first maintain their compressed shape and as a result the jacket 4 at the location of the hollow 15 is held downwards by the springs 3 as they are mutually glued together. The hollow 15 thus only disappears with a certain delay, whereby the movement of the head 14 is not impeded.

In the new position of the head 14, the shape of the pillow 1 will gradually adapt to this new position.

It is clear that such a pillow 1 will provide optimum comfort in all respects while sleeping.

During and after sleeping, the moisture stored in the pillow 1 is easily evacuated by the good air permeability of both the jacket 4 and the core 2.

The present invention is by no means limited to the embodiment described as an example and shown in the drawings, but an improved pillow according to the invention can be realised in all kinds of variants, without departing from the scope of the invention.