FI73359B - I HUVUDSAK SKIVLIG BOLSTER- L. DYL. Byggnad. - Google Patents

Description

73359

MAINLY PLATE MATTRESS- TMS. STRUCTURE - I HUVUDSAK SK IVLIG BOLSTER- L. DYL. Byggnad

The invention relates to a mainly plate-like mattress-like structure comprising two surface layers of soft foam which form the surfaces of the plate.

5 Foam mattresses consisting of a single layer of foam are already known. Mattresses are further known which consist of two identical layers of foam plastic, the opposite sides of the layers being provided with an air duct system.

10 The hardness of known foam mattresses cannot be adjusted in any way. If desired, a mattress with different hardness has previously had to be purchased new. Furthermore, mattress sellers have had to store mattresses of different hardness in their stocks in order to satisfy different needs.

It is an object of the present invention to obviate the above drawbacks. In particular, it is an object of the invention to provide a novel, mainly plate-like foam structure, primarily for mattress use, which makes it possible to change the hardness of the mattress.

With regard to the features characteristic of the invention, reference is made to the claims.

The invention is based on the basic idea that the plate-like structure comprises two surface layers of soft foam of different hardness, which form the surfaces of the plate, and a middle layer which is harder than both surface layers. In this case, the hardness of the respective plate used as a mattress can be changed by turning the mattress. The purpose of the middle layer is to distribute the point load on the uppermost layer over a wider area to the lower surface layer.

As mentioned above, the resilient properties of the plate-like structure according to the invention are substantially more advantageous in said mattress use than the known corresponding structures.

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The invention will now be described in detail by way of example with reference to the accompanying drawing, in which Figure 1 schematically shows a section of a plate-like mattress structure according to the invention 5, and Figures 2 and 3 show graphically the elastic properties of a previously known mattress and a mattress according to the invention.

Figure 1 shows a vertical section of a horizontally placed plate-like mattress structure according to the invention, which includes the former, i. the uppermost surface layer 1 and the latter, i.e. the lowest surface layer 2 and the middle layer 3 interposed therebetween. According to the invention, the former surface layer 1 is harder than the latter, i.e. the latter surface layer 2 is softer than the former. The middle layer 3 is harder than both surface layers. The surface layers 1, 2 and the middle layer all consist of soft foam, in the illustrated application polyurethane foam, sold e.g. under the applicant's trademark 20 SUPERLONR.

The hardness of the mattress structure shown in Figure 1 and the previous surface layer is e.g. 140-170 N, the hardness of the latter surface layer 00-150 N: the hardness number is the force F required to compress a 50 mm thick foam sheet 25% of its initial height with a sole P area = 0.0323 m '(ASTM D-1564). The volume weight of the middle layer 3 3 is e.g. 100-170 kg / m or stiffer.

In Figure 1, the lower surface of the previous layer and likewise the upper surface of the latter layer, i.e. the surfaces of the surface layers against the middle 30 layers are provided with an air duct system. Said air duct system consists of concave spaces between the protrusions formed on the respective surfaces. In the illustrated embodiment, the surface layers are of equal strength, with the middle layer being substantially thinner than each of the 35 surface layers, on the order of about half the thickness of the surface layer. 1 3 73359

Figure 2 shows graphically the hardness of a conventional single-layer foam mattress (hardness as a function of compression, F = f (compression /%). The solid line represents a 15 cm thick plate, hardness about 130 N, bulk density 5 about 24 kg / m3; one thick plate, hardness about 160 N, bulk density about 33 kg / m3). Figure 3 shows the hardness of a mattress according to the invention according to the invention, which consists of the foam grades according to Figure 2.

The solid line represents the situation with the softer layer on top 10 and the dashed line the situation with the harder layer on top.

According to Figures 2-3, the mattress according to the invention (Figure 3) is initially softer than the mattresses shown in Figure 2. However, as the compressive force increases, the mattress according to the invention is harder, i.e. more load-bearing than the mattresses shown in Figure 2.

The embodiments are intended to illustrate the invention without limiting it in any way as the embodiments of the invention vary within the scope of the appended claims. In this case, the surface layers can be of different thicknesses, and air ducts formed on the sides of the surface layers against the middle layer, i.e. the profiling of the surface layers can vary to change and adjust the softness properties of the surface layers as desired. The function of the middle layer is, on the one hand, to break off the effect of the surface softness of the uppermost surface layer, and, on the other hand, to equalize the point load over a wider area to the lower surface layer. Thus, the properties and material of the middle layer, as well as the properties and material of the surface layers, may vary, however, with the middle layer always being harder than either surface layer.

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