EP0510523B1 - Mattress - Google Patents

Abstract

The invention relates to a support mattress, in particular for hospital beds, consisting of foam material with several layers of the same or different specific density and different compression hardness. In this case, the lying surface (1) of the upper layer (2) is divided by longitudinal and transverse grooves {incisions} (3 and 4) into squares (10) of defined size depending on the loading of the body, and the lower surface of the first layer (2) has an undulating structure (12) which extends into a corresponding undulating structure (13) of the upper surface of a lower layer (11) and interacts therewith flexibly. The surface area of the squares (10) in the region of the head, back and buttocks zones of the lying surface (1) is greater than in the other regions in proportion to the surface loading by these parts of the body. The surface area of the squares (10) decreases starting from the central region up to the longitudinal edge region of the lying surface (1) and is larger once again in the outermost longitudinal edge region. The cross-sections of the grooves (3) bounding the squares are of rectangular and/or pear-shaped and/or droplet-shaped construction. <IMAGE>

Description

The invention relates to a positioning mattress, in particular for hospital beds, consisting of foam with several layers of the same or different specific density and different compression hardness, the lower surface of an upper layer having a corrugated structure which extends into a corresponding corrugated structure of the upper surface of a lower layer and cooperates with this elastically.

Human health largely depends on the body regenerating itself sufficiently through sleep. For this, a physiologically correct lying is an important prerequisite, since lying in a body-appropriate manner supports important bodily functions, such as the blood circulation in the tissue, the support or relief of the spine and muscles. In a corresponding manner, improper bedding causes damage to the body and its functions. For a body-appropriate bedding, two essential characteristics of the body have to be taken into account, namely the spine formed in a healthy person and the different weights of the individual body areas. The head area as well as the back and buttocks areas form the heavy parts of the body, which in the known lying systems transfer the entire body weight of the pad, while the back areas are often not supported. To compensate for this deficiency, slats and base frames are adapted to the S-shaped body shape and can also be adjusted to achieve an individual adjustment. However, hospital beds do not yet have such an individual adjustment.

However, the spring properties are the same across the length and width of the lying surface in systems with slats and base frames and also the spring mattresses, so that different pressure loads occur despite the geometric adaptation to the body. If the external contact pressure is greater than the pressure of the blood circulation, there are circulatory disorders, which in a healthy person are of relatively short duration during the sleep phase, since the body is continuously rearranged during sleep. A bedridden person who is disabled, for example in an intensive care unit or after an operation, has body pressure points that can lead to a life-threatening condition.

The causes of this and the shortcomings of the known lying systems are known per se and various systems have already been tried to eliminate them, but these do not solve the known problem perfectly.

For example, "water mattresses" were developed, which should largely adapt to the body shape. However, since the water is inelastic and the required elasticity can only be provided by the water bag, the results are unsatisfactory. Added to this is the fact that the mattress should have sufficient ventilation to promote breathability. This is particularly important for people who suffer from sweating due to their state of health or their disability. A non-breathable mattress hinders evaporation, which can lead to skin damage in the worst case.

From EP-A-0 062 915 a generic mattress made of foam is known, which has several layers of the same or different compression hardness, in which the lower surface of the upper layer has a corrugated structure that fits into a corresponding one Wavy structure of the upper surface of a lower layer extends and cooperates with this elastically. There is an air channel between the wave crests of the lower waves and the valleys of the upper waves. When the mattress is loaded, only the wave crests of the upper layer act in the first phase, so that they are subjected to strong compression until the other surfaces of the waves also touch each other. This results in a short spring travel with a steeply increasing compression hardness.

From EP-A-0 421 272 it is known to divide the longitudinal and transverse grooves into cuboids of defined size depending on the body load. In this way, a more even pressure distribution is achieved, but the compressibility is not or only slightly influenced thereby.

The object of the invention is therefore to propose a mattress of the type mentioned, which has a progressive spring behavior depending on the partial load on the parts of the body, which at the same time provides adequate ventilation and breathability over the entire lying surface.

The solution to this problem is according to the invention in that the lying surface of the upper layer is divided by longitudinal and transverse grooves or incisions in cuboids of a defined size, depending on the physical load, and the amplitudes A of the waves of the lower layer are greater than the amplitudes B of the waves the upper layer and that the wave crests are each wider than the opposite wave troughs (C> D), such that the waves form air channels, jam each other under load and have a progressive spring action.

Since the lower foam layer has a greater specific density and strength and thus a greater rigidity than the upper layer, the corrugated structure of the upper layer can penetrate into the corrugated structure of the lower layer with increasing pressure, the corrugated system also increasing Counterforce develops and thus develops a progressive force curve.

In one embodiment of the invention, the two layers are not glued to one another, so that a movement is made possible between the layers which is braked by the uneven waveforms.

The cross sections of the grooves are rectangular, and / or pear and / or teardrop-shaped according to the invention, so that different sized supports of a cuboid and thus different spring force effects are present. At the same time, horizontal air channels of different sizes are created, which significantly promote the breathability of the mattress. The cross-sectional shapes mentioned can be combined as required, for example in such a way that a rectangular groove is provided on the surface, the base of which has a dome or pear shape.

In a further development of the invention, the lower layer of the mattress has a higher specific density and strength and thus a lower spring elasticity than its upper layer, so that a progressive increase in spring elasticity is achieved.

In a modified embodiment of the invention, the layers can also be glued at points. With this measure, however, the following must be observed. A thermal treatment is carried out to disinfect the mattresses, at which temperatures of up to 105 ° C are reached. Different behavior can occur between the adhesive and the foam, which must be avoided as far as possible by selecting the adhesive. The solvent released can also have an adverse effect.

The foam of the mattress has open-pore cells in at least one layer, which ensures sufficient breathability in addition to the air channels.

In a further embodiment of the invention, the entire mattress is located in an elastic network in such a way that all foam layers are fixed. This completely avoids the use of glue. According to the invention, the net is so elastic that the surface tension of the mattress foam is not increased, but its surface friction is reduced to a minimum. This significantly improves the covering and removal of the mattress cover, since the foam surface exerts a high level of friction on the textile.

FIG. 1

eine perspektivische Darstellung des oberen Teils einer Schaumstofflage einer Matratze,

FIG. 2

einen Teilschnitt durch eine obere und untere Schaumstofflage einer Matratze, und

FIG. 3

eine Draufsicht auf Matratze in schematischer Darstellung zur Veranschaulichung der Verteilung der Quaderflächen.

The invention is explained in more detail with reference to the drawing, in which several exemplary embodiments are shown. Here show:

FIG. 1

a perspective view of the upper part of a foam layer of a mattress,

FIG. 2nd

a partial section through an upper and lower foam layer of a mattress, and

FIG. 3rd

a plan view of the mattress in a schematic representation to illustrate the distribution of the cuboid areas.

As can be seen from FIG. 1, the lying surface 1 of the foam layer 2 is traversed in the longitudinal and transverse directions with grooves or incisions 4 and 3, as a result of which cuboids 10 are formed. The longitudinal and transverse grooves 4 and 3 have mutually identical and partly different distances, as will be explained in more detail with reference to FIG. 3.

The shape of the grooves or the cuts contributes significantly to the resilient property of the cuboids 10 formed. Pear-shaped or teardrop-shaped grooves or grooves with parallel side walls can be formed. Combinations of these forms of training can also be produced, depending on which resilient sizes are desired. For example, the groove can be shaped as a rectangle with a base in the form of a spherical cap or pear.

As can be seen from FIG. 1, the pear-shaped, dome-shaped and also teardrop-shaped incisions or grooves 7 and 8 form a cuboid with a narrow root or foot region 9, which causes a correspondingly lower spring force. As a result, any desired spring force variation can be produced in the required areas. At the same time, however, the pear or dome shape provides a correspondingly large air channel, which advantageously promotes ventilation and thus breathability.

As can be seen from FIG. 2, in this exemplary embodiment of the invention, the mattress consists of two parts or layers 2 and 11, which are connected without adhesive by means of a wave-shaped structure. The wave structure 12 of the upper layer, which is located on the opposite side of the lying surface 1, engages in the wave structure 13, which is located on the upper surface of the lower layer 11. The material of the lower layer 11 has a higher specific density and strength and thus a lower spring elasticity than the material of the upper layer.

The shaft structures 12 and 13 differ geometrically from one another in such a way that sufficient spring travel is still available when pressure is applied to the upper layer. This is achieved in that the amplitudes A of the waves of the lower layer 11 are greater than the amplitudes B of the waves of the upper layer 2 and the wave crests C are wider than the width of the opposite wave troughs D, so that the waves air channels 14 and 15 are different Form size and jam each other under load. This creates a progressive spring action, that is, a steady increase in spring force with increasing load. Since the two layers are not glued together, there is a movement under pressure given. Because of the different geometries of the shaft structures, the smaller air channels 15 first close when pressure is applied, as a result of which the contact surfaces and thus the spring forces increase progressively. The same applies if the load increases further until the channels 14 also close. In addition to this advantageous spring action, these air channels also contribute to ventilation and thus to increased breathability.

Figure 3 shows the mattress in plan view. The spacing of the grooves or incisions 4, which extend in the longitudinal direction over the lying surface 1, is different in size from the grooves or incisions running parallel to it, depending on the different loads on the different body parts. Thus, the distance between the grooves 4 in the central region is approximately the same size over three cuboid areas and decreases towards the edge of the mattress, so that smaller cuboid areas are formed. The outer cuboid areas running around the mattress, however, again have a larger cuboid area, which corresponds approximately to the size of the central areas of each transverse row. This measure increases the seat stability.

The spacing of the grooves or incisions 3 extending transversely to the lancing surface 1 is greater in the region of the heavy body parts, namely in the head 16 and buttocks region 17, so that larger cuboids 18 are formed, while in the shoulder and leg regions 19 and 20 of the lying surface 1, the distance between the transverse grooves 3 is smaller, and as a result smaller cuboids 19 are present.

The part of the lying surface 1 of the mattress provided for the lighter shoulder area 19 is thus softer than the lumbar spine and buttocks area 17. As a result, the mattress is adapted to the different loads caused by the body parts lying on it, so that all the body parts lying on it are carried along and the specific surface load is thereby reduced.

With this configuration it is thus achieved that the depth of impression in the lying surface 1 of the heavy body parts is not or only slightly larger than in the lighter body parts, so that the entire body surface comes to rest and the specific surface pressure of the heavy body parts is reduced ver.

Claims (7)

1. Support mattress, in particular for hospital beds, consisting of foam with several layers of the same or varying specific density and differing degrees of firmness under compression, in which the underside surface of an upper layer (2) has a wave-shaped structure (12) which extends into a matching wave-shaped structure (13) of the upper surface of a lower layer (11) and co-operates resiliently therewith, characterised in that the support surface area (1) of the upper layer (2) is divided by means of length-wise and cross-wise grooves or slits (3 or 4) into squares of a defined size related to body weight and the amplitudes A of the waves of the lower layer (11) are greater than the amplitudes B of the waves of the upper layer (2) and that the peaks of the waves are respectively broader than the oppositely lying wave troughs (C>D) so that the waves form air channels (14, 15), reciprocally constrict under weight and exhibit a progressive spring-like effect.
2. Mattress as claimed in claim 1, characterised in that the cross-section of the grooves (3) delineating the squares is rectangular and/or pear-shaped and/or droplet-shaped.
3. Mattress as claimed in claim 1 or 2, characterised in that the cross-section of the grooves in the length-wise direction of the mattress is shaped differently from the cross-section of the grooves in the cross-wise direction.
4. Mattress as claimed in claim 1 or in one of the previous claims, characterised in that its lower layer (11) is of a higher specific density and/or firmness and thus has a lower elastic resilience than the upper layer (2).
5. Mattress as claimed in claim 1 or one of the previous claims, characterised in that the foam has at least one layer of open-pored cells.
6. Mattress as claimed in claim 1 or one of the previous claims, characterised in that the mattress is located in a resilient net or cover in such a way that all the layers of foam are in a fixed position.
7. Mattress as claimed in claim 1 or one of the previous claims, characterised in that the lower surface of the upper layer (2) has a wave-shaped structure, which extends into a matching wave-shaped structure (13) of the upper surface of the lower layer (11) and is bonded or welded at several points thereto.

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