FR2758957A3 - Shock absorber esp for part of human body - Google Patents

Abstract

A shock absorber, such as a cushion or mattress, is made from two outer layers (1, 2) of a foam material, and an inner layer (3) of a foam which is impregnated to make it slow to return to its original shape. The layers are joined together to form a homogenous assembly which is enclosed in a sleeve (4) which is waterproof but air permeable, such as a polyurethane membrane The two outer layers (1, 2) can be of the same or different densities, and they are thicker than the inner layer. The three layers can be assembled by adhesion, and the three layers with the sleeve can be contained in a protective cover.

Description

Damping complex for a part of the human body in particular
The invention relates to the technical sector of the comfort elements of the various parts of the human body.

 It is known to make cushions, mattresses or other comfort elements, from foam of various densities. For example, the foams used are of the type known under the brand BULTEX.

Generally, these foams, whatever their density, tend to repel the bearing force or other that they are likely to receive.

In other words, if a bearing force is exerted on this type of foam, a resulting force will occur which will oppose the applied force and the intensity of which will depend on the density and thickness of the foam.

 Generally, this foam, whatever the applications envisaged (cushions, mattresses or others), is used alone. It follows that if the foam is placed directly on the support surface of hard material, the reaction force will not be damped, so that the resulting comfort is not optimum.

 Conversely, there are known impregnated foams with slow remanence, which, by definition, not only absorb shocks, but store the forces applied, by restoring them only relatively slowly.

 These impregnated foams are of high cost and can hardly be used in isolation to form a cushion, for example, given, as indicated, that they will take the shape of the body or the like, bearing on the latter. Furthermore, the impregnated foams always have the same density.

 From this state of the art, the problem which the invention proposes to solve is to produce a damping complex capable of constituting a cushion, a mattress, a carpet or the like, which is particularly comfortable and reversible.

 To solve such a problem, a shock absorbing complex has been designed and developed for a part of the human body in particular, characterized in that it comprises two external layers of a foam material between which an internal layer of a foam material impregnated with slow remanence, said layers being assembled together to form a homogeneous whole of any shape.

 From this basic design, either the two outer layers are of different densities, or the two outer layers are of the same density.

 The internal layer of impregnated foam with slow persistence is of reduced thickness compared to the other two external layers.

 Another problem which the invention proposes to solve is to protect the entire complex, in particular by avoiding any proliferation of mites or the like.

To solve such a problem, the assembly is wrapped in a waterproof and air permeable sheath, said sheath being shaped to constitute a protective envelope without any connection with the different layers. The sheath is made up of a polyurethane membrane.

To solve the problem of achieving a homogeneous whole, the different layers are assembled by gluing.

 From this basic design, the complex according to the invention can have different forms falling within the field of foam processing and depending on the envisaged applications: mattresses, cushions, carpets ...

The invention is set out below in more detail with the aid of the figures of the appended drawings, in which:
Figure 1 is a perspective view of an exemplary embodiment of the damping complex according to the invention.

 Figure 2 is a longitudinal sectional view of the damping complex.

 FIGS. 3 to 11 are views of a purely schematic nature, showing different scales for crushing the complex according to the loads applied and according to the selection and the density of the foams constituting the external layers.

 The damping complex, according to the invention, results from the combination of different layers of so-called repellent foam, that is to say which repels the charges and of slow-absorbing impregnated foam, called absorbent.

 More particularly, the damping complex comprises two external layers (1) and (2) of repellent foam, between which is interposed an internal layer (3) of impregnated foam with slow persistence.

These different layers (1) (2) (3) are assembled by gluing or otherwise, to form a homogeneous whole of any shape, depending on the applications envisaged.

 As indicated, the outer layers (l) and (2) of repellent foam, for example consist of foam known under the brand BULTEX.

 Advantageously, the two outer layers (1) and (2) have different densities. For example, the layer (1) can have a density of 20 kg per m3, while the layer (2) can have a density of 35 kg per m3. The outer layers (1) and (2) are thicker than the inner layer (3), made of impregnated foam.

 Given the difference in density between the outer layers (1) and (2), a reversible complex is obtained, the damping effects and therefore of comfort, will be different, depending on the layer (1) or (2) which will be subjected directly to the applied load.

We refer to the diagrams in Figures 3 to 11. For example, if the load is applied to the outer layer (1), whose density is lower than that of the layer (2), it is this layer (1) which will be strongly crushed compared to the layer (2) of higher density, which will also be crushed but in lesser proportions.

 Conversely, if the load is applied directly to the layer (2) of higher density, in this case, the layer (1) which will therefore be located below, will be more strongly crushed than the outer layer (2).

 Whatever the case, the intermediate layer (3) of impregnated foam, will absorb the applied load and distribute the forces, so that the reaction forces generated by the external layers (1) and (2) will be transmitted d 'in an indirect way.

 It can be seen that, as a function of the differences in thickness and density between the outer layers (1) and (2), in combination with the absorbent intermediate layer (3), damping effects are obtained and consequently a comfort d which will be different and variable.

 In a particularly advantageous manner, it is also seen that with the same complex, two different damping effects can be obtained having regard to its reversible nature, on the one hand, to the difference in density between the outer layers, of somewhere else.

 Obviously, without departing from the scope of the invention, it is not excluded to produce a damping complex in which the two outer layers (1) and (2) are of the same density.

According to another important characteristic of the invention,
The entire damping complex, as defined, is wrapped in a sheath (4), selected to be waterproof and breathable. For example, this sheath (4) is constituted by a polyurethane membrane.

 The sheath (4) is shaped to constitute a protective envelope, without any connection with the general volume defined by the damping complex. In other words, the envelope (4) closely follows the shape of the damping complex, without however being intimately linked with respect to the latter, but being, on the contrary, perfectly free.

 These constructive provisions avoid any transmission and proliferation of mites and other impurities.

 Obviously, as already indicated, the complex damping assembly, according to the characteristics of the invention, is suitably cut and shaped according to the specific applications sought, among which there may be mentioned, by way of non-limiting indication, the cushions, mattresses, carpets ...

The advantages clearly emerge from the description, in particular it is emphasized and recalled:
the shock absorbing effect obtained and the comfort resulting therefrom from the combination of layers of so-called repellent foam with a layer of so-called absorbent foam,
- the reversible nature,
- the resulting comfort and hygiene,
Obviously, the entire damping complex, with the casing (4) can also be housed in a protective cover of any known and appropriate type and capable of being made of different materials.

Claims (8)

-1- Damping complex for a part of the human body in particular, characterized in that it comprises two external layers (1) and (2) of a foam material between which an internal layer (3) of a material is interposed made of impregnated foam with slow persistence, said layers (1) (2) (3) being assembled together to form a homogeneous whole of any shape. -2- Complex according to claim 1, characterized in that the two outer layers (1) and (2) are of different densities. -3- Complex according to claim 1, characterized in that the two outer layers (1) and (2) are of the same density. -4- Complex according to claim 1, characterized in that the assembly is wrapped in a sheath (4) waterproof and breathable, said sheath being shaped to constitute a protective envelope without any connection with the different layers. -5- Complex according to claim 4, characterized in that the sheath is constituted by a polyurethane membrane. -6- Complex according to claim 1, characterized in that the outer layers (1) and (2) are of thickness greater than the thickness of the inner layer (3). -7- Complex according to claim 1, characterized in that the different layers are assembled by gluing. -8- Complex according to claims 1 and 4, characterized in that the assembly (1) (2) (3) with the sheath (4) is housed in a protective cover.