WO1990014032A1

WO1990014032A1 - Mattress

Info

Publication number: WO1990014032A1
Application number: PCT/FR1990/000358
Authority: WO
Inventors: Bernard Taravel; Jean Robert
Original assignee: Bernard Taravel; Jean Robert
Priority date: 1989-05-22
Filing date: 1990-05-22
Publication date: 1990-11-29
Also published as: FR2647000A1; FR2647000B1

Abstract

The mattress structure includes an expanding surface skin (1) cooperating, by means of a series of vertical shafts (40) sliding vertically, with at least one first element which can be elastically distorted, for example, a membrane (10) in such a way as to convert the distributed pressures applied to the surface skin into pinpoint pressures applied to said first element, preferably, three elements which can be elastically distorted, such as membranes (10, 20, 30) are mutually superimposed and spaced apart. Said elements show a degree of rigidity which increases from top to bottom so that the deflection/force characteristic of the structure has three sections of increasing rigidity, corresponding, respectively, to an elongate position, a seated position, and a standing position.

Description

MATTRESS

The present invention relates to a mattress, which can be used both in actual bedding and in other areas of furniture (in particular benches, sofas, rest chairs, lounge chairs, etc.).

The first characteristic of a mattress, which is its degree of hardness, must meet a number of requirements which are often contradictory.

In fact, it is desirable for the surface of the mattress to be deformed in order to best match the shape of the body of the person lying on it, which leads to choosing a relatively deformable and soft mattress (wool mattress for example); on the other hand, the mattress must be able to compensate for the weight of the elongated person by opposite stress, which imposes a certain elasticity (in the case of spring or foam mattresses), and even a relatively high firmness if one wishes to preserve satisfactory comfort not only when lying down but also when sitting. The latter case is typically that of sofa beds and sofas, where the point pressure exerted on the mattress by a seated person is much greater than that exerted when the same person is lying on it - typically several tens of times greater. It is the same all the more so in the extreme case of a person standing on the mattress.

These contradictory requirements have so far been unable to be satisfactorily achieved with known conventional mattresses.

One of the aims of the present invention is to provide a mattress which overcomes this difficulty thanks to a structure which occasionally provides a variable degree of firmness as a function of the pressure applied.

It will thus be seen that, in the lying position (low local pressure), the mattress of the invention is relatively flexible, which allows its outer surface to match the shape of the body of the lying person and therefore to provide the latter high comfort without feeling of excessive firmness. On the other hand, in a sitting position (strong local pressure) the degree of firmness will be much higher, thus providing the satisfactory comfort desired for this position. Finally, in the limiting case of a person standing on the mattress, the firmness will be even greater than in the case of the sitting position, in order to be able to better support this position without excessive deformation.

To this end, the mattress according to the invention comprises, at least over part of its surface, a structure successively having an extensible, essentially horizontal surface skin and at least one first elastically deformable element extending parallel to the surface skin and connected to it by a series of vertical movable rods, guided in vertical sliding, directly transmitting the forces applied to the surface skin. The distributed pressures applied to the surface skin are thus transformed into point pressures applied, in line with each of the respective rods, to the first elastically deformable element.

This first elastically deformable element can be a block of foam, which the forces transmitted by the mobile rods essentially deform in compression, or preferably a membrane, which the forces transmitted by the mobile rods deform essentially in elongation and which is therefore more able for a block of foam to deform punctually, that is to say to preserve mutual independence in the respective movements of the movable rods.

In the latter case, there may also be provided at least one second elastically deformable element, of stiffness greater than that of the first element and extending parallel to it at a first distance, this second element only receiving the forces applied punctually. to the surface skin at the level of each of the respective rods only after the travel of the first element has exceeded the value of said first distance. The stiffness of the membrane then constituting the first elastically deformable element is preferably chosen so as to obtain a clearance substantially equal to said first distance for a punctual force corresponding approximately to that exerted punctually by a person lying on the mattress.

In this way, the characteristic deflection / punctual force of said structure has at least two sections of respective increasing stiffnesses, each corresponding to the successive deformation of each of the two elastically deformable elements.

The second elastically deformable element can be a block of foam or a membrane.

In the latter case, there may also be provided a third elastically deformable element, advantageously a block of foam, of stiffness greater than that of the second element, placed at a second distance from the latter, this third elastically deformable element not receiving the forces applied punctually to the surface skin at the level of each of the respective rods only after the travel of the second element has exceeded the value of said second distance. The stiffness of the membrane then constituting the second elastically deformable element is then preferably chosen, so as to obtain a clearance close to said second distance for a punctual force corresponding substantially to that exerted by a person seated on the mattress.

In this way, the characteristic deflection / point force of said structure has three sections of increasing respective stiffnesses, each corresponding to the successive deformation of each of the three elastically deformable elements.

The stiffness of the third elastically deformable element, which may be a block of foam or a membrane, is preferably chosen so as to obtain wine determined maximum deflection of this element for a punctual force corresponding substantially to that exerted by a person standing on the mattress.

In a first embodiment, the structure according to the invention is produced on almost the entire surface of the mattress.

In a second embodiment, the structure according to the invention is produced only on localized areas of the mattress, in particular the areas of the mattress corresponding to the position of the lumbar and / or cervical regions of a person lying on the mattress.

In either case, the structure according to the invention can be formed of similar substructures, of smaller dimensions, juxtaposed on either side of common intermediate anchoring and support points of the membrane or membranes, respectively. According to a number of other advantageous features:

- the density of rods per unit area of the mattress is of the order of 1 rod / cm ² ;

- The ends of the rods in contact with the first elastically deformable element are in non-integral contact with the latter, while the ends of the rods in contact with the surface skin are in integral contact with the latter;

- There are provided means for adjusting the tension of the membrane or membranes, respectively.

- In the case where the first elastically deformable element is a membrane, there is further provided at least one counter-grid attached to the membrane and having at the right of each rod an orifice receiving the homologous end of the rod.

This membrane can then be formed of a plurality of individual elastic discs, in a number equal to that of the rods, coaxial with the orifices and secured at their periphery to the counter-grid, or else of an element common to a plurality of rods and locally secured to the counter-grid along circular contours coaxial with the orifices.

In another embodiment, the structure of the invention is a reversible structure formed by two substantially symmetrical similar substructures extending on either side of a median plane. Preferably, the respective rods of the first and second substructures are offset mutually in the transverse direction of a half step.

We will now describe an embodiment of the invention, with reference to the accompanying drawings.

Figure 1 is a sectional view of a first embodiment of the mattress of the invention.

Figure 2 is a schematic perspective view of the mattress of the invention. Figure 3 is a detail of Figure 1 showing the structure of the movable rods.

FIG. 4 illustrates the characteristic giving, for the mattress of FIG. 1, the clearance as a function of the point pressure.

FIG. 5 is a more detailed representation of FIG. 1, explaining the role of the various elements of the structure of the mattress of FIG. 1.

Figure 6 is a section, homologous to Figure 1, of a second embodiment of the invention.

FIG. 7 illustrates a modular embodiment of the mattress of the invention.

FIG. 8 is a detailed view, at the level of the heads of the rods, of the first membrane provided with a counter-grid.

FIG. 9 is a plan view of the counter-grid / membrane assembly when the latter consists of individual elastic discs.

FIGS. 10 and 11 are variants of the counter-grid / membrane structure of FIG. 8.

Figure 1 illustrates, in cross section, a mattress made according to the teachings of the invention.

This comprises an extensible surface skin 1, which will be the generally horizontal or approximately horizontal surface on which the person using the mattress will lie down or sit. This surface skin is mounted on a rigid peripheral frame 2 (for example, a wooden frame or a plastic shell) closed by a bottom 3, will equal rigid.

Typically, there are provided inside this mattress three elastically deformable elements 10, 20, 30, urged successively as the local deformation of the surface skin, and with increasing stiffness. These elements 10, 20, 30 are themselves generally horizontal or approximately horizontal.

Note, however, that this structure with three successively deformed elastic elements is not in itself limiting, the invention can be generalized to a structure with a single element (for example foam or preferably membrane) or two elements (for example membrane + foam, the foam then constituting the lower element, or membrane + membrane).

The element 10, which will be called in the following "flexible membrane", is a membrane connected to the surface skin 1 by a series of vertical movable rods 40 (shown in more detail in FIG. 3) guided in vertical translation by rigid guide means placed above and at a distance from the flexible membrane 10, in a generally horizontal or approximately horizontal orientation.

The guide means may consist of a single thick grid or, preferably and as illustrated, of two thin grids 50 and 50 'placed at a distance from each other to ensure satisfactory guidance.

As can be seen in FIG. 3, each of the rods 40 has a lower end 41 in the form of a ball coming into non-integral contact with the flexible membrane 10, and an upper end 42 in the form of a disc in contact with the surface skin 1. The contact between the disk 42 and the surface skin 1 is preferably an integral contact (the bonding resulting for example from bonding), but can also be non-integral, the surface skin then being simply placed on the disks 42.

It will be noted that no obstacle other than the rods 40, bearing on the flexible membrane 10, is interposed between the surface skin 1 and the guide means formed by grids 50, 50 'to oppose the deformation of the surface skin towards these guide means under the effect of the weight of a person lying or sitting on the mattress.

To give the lying or sitting person a feeling of continuous contact, the rods 40 must be very numerous, typically with a density of 1 rod / cm ² , the rods being regularly distributed in a two-dimensional network with a pitch of 10 mm.

As regards the dimensions of the rods, it is possible, for example, to choose rods of 2 mm in diameter with a ball-shaped end 41 of 8 mm in diameter and a disc 42 with a surface area of 0.5 cm ² . The length of rods may be of the order of 200 to 220 mm, the grid 50 being arranged approximately 20 mm above the flexible membrane 10.

The material of the surface skin 1 will be chosen to be very extensible, but without hysteresis (in order to be able to return to its initial shape after removal of the stresses) and without notable own elasticity (that is to say that its stiffness will be much less than that of the membrane 10 so as not to counteract the effect produced by it.

The second elastically deformable element 20 is another membrane, but of stiffness greater than that of the flexible membrane 10 (for this reason, this second membrane will be called "hard membrane"). It is arranged parallel to the flexible membrane 10 and at a predetermined distance d ₁ (FIG. 5) from the latter, so that it will only be stressed after the deflection of the flexible membrane 10 has exceeded this value d ₁ , as can be seen in the central part of FIG. 5. The two membranes 10 and 20 are stretched over the frame 2 in order to give them the desired stiffness. Optionally, means are provided for adjusting or readjusting the tension of the membranes, for example in the form of tension rollers (not shown).

Finally, the third elastically deformable element 30 consists of a block of foam of stiffness much greater than that of the hard membrane 20, a block which will be called in the following "very hard foam". This very hard foam 30 is placed at a distance d ₂ (FIG. 5) from the hard membrane 20, and its thickness is d ₃ . As can be seen on the right-hand side of FIG. 5, the foam 30 will only be stressed when the clearance of the second membrane has exceeded the value d ₂ .

Not shown, the third elastically deformable element 30 could also consist of a third membrane, of stiffness greater than that of the hard membrane 20 and placed at the distance d ₃ from the bottom. To allow such operation of the mattress, the guide means constituted in the example illustrated by the thin grids 50 and 50 'are placed at a distance at least equal to the sum of the values d ₁ , d ₂ , d ₃ of the skin surface 1 assumed to be at rest, under this surface skin 1; this distance could be reduced to a value at least equal to the sum of the values d ₁ and d ₂ in the case of a mattress not comprising the third element 30, for example replaced by the bottom 3, or to the value d ₁ in the case of a mattress comprising neither this third element 30, nor the second element 20, for which the bottom 3 could then be substituted; the length of the rods 40 is naturally chosen accordingly.

Naturally, in what precedes as in what follows, the term "membrane" is understood to mean both a single membrane and a superposition of membranes.

Furthermore, the membranes 10 and 20 (and the membrane possibly replacing the foam 30) can be divided, in particular when they are of large extent, by providing intermediate anchoring and support points represented in the form of partitions 60 in dashed in Figure 1.

The partitions 60 are of course flexible partitions, in fabric for example, so as not to be perceived by the person lying or sitting on the mattress. They can be replaced by any other means capable of subdividing at least functionally the or each membrane 10, 20 into membranes of lesser extent, that is to say corresponding to less than all of the rods 40, and for example by a underlying net, substantially inextensible, stretched over the peripheral frame 2 so as to offer the respective membrane downward support, in an integral or free manner, while however presenting facing the rods 40 meshes corresponding to a single rod 40 or with several rods 40 and allowing a free punctual deformation of the respective membrane under the action of the rods; such a net has not been illustrated, but its positioning and its mode of cooperation with the respective membrane can easily be deduced from an embodiment of the invention described later, with reference to FIG. 10. This division of the membranes makes it possible to better distribute the tension of these and to avoid a central curving effect, which would appear with single membranes of too large extent.

In addition, in the event of a tear in a membrane, the mattress may nevertheless continue to be used, the consequences of an isolated tear being all the less noticeable as the structure is sharply divided.

The mattress can thus be produced in modular form, as illustrated in FIG. 7, from a plurality of boxes, the respective grids 50a, 50b, 50c, 50d, etc. are juxtaposed and assembled by an appropriate means, known per se (tongue and groove assembly, by hooks, etc.); the position of the openings on each respective grid 50a, 50b, 50c, 50d, etc. is of course determined so as to keep in the two directions X and Y a constant pitch p (for example 1 cm) from one well to another.

Furthermore, the division of the membranes also makes it possible, if desired, to produce a mattress comprising the particular structure of the invention only on a particular zone, or several particular zones, of its surface. In the case of a plurality of such particular zones, it is also possible to give them possibly different characteristics. It will be noted that, in the case of such a composite mattress, the part of traditional structure will be produced so as to harmonize as well as possible with the rest of the mattress, so that the user feels the transition between the two different structures as little as possible. of the composite mattress.

As illustrated in FIG. 2, it is thus possible to entirely produce the mattress with the structure of FIG. 1, with the exception of a peripheral zone of the order of 10 to 20 cm wide (perimeter referenced 4) but , in this case, by dividing it into a plurality of independent, juxtaposed compartments, all made on the same principle.

It is also possible to provide the structure illustrated diagrammatically in FIG. 1 only in certain regions. determined of the mattress, for example the lumbar region 5 and / or the cervical region 6, the rest of the mattress being produced by traditional bedding techniques and the assembly being enclosed in a common envelope.

As can be seen, the mattress of the invention plays the role of both a traditional box spring and a traditional mattress proper; it is then useful to provide approximately at mid-height of the frame 2 a "pseudo-separation" 7 formed of a narrow and deep peripheral groove in which the sheet will be pinched, so as to be able to border the bed as with a mattress / traditional box spring. The material and / or the structure of the frame are then preferably chosen so as to present a certain flexibility at the location of this pseudo-separation, in order to be able to achieve this pinching effect there.

As regards the respective stiffnesses of the various elastically deformable elements, it is possible, for example, to take values d ₁ = 30 mm, d ₂ = 100 mm and d ₃ = 20 mm. The respective stiffnesses of the membranes 10 and 20 and of the foam 30 (or of the membrane possibly replacing this) will then be chosen so that:

- in the supine position, only the flexible membrane 10 is stressed (case illustrated in the left part of FIG. 5, that is to say for a depression less than d ₁ ), - in the seated position, the hard membrane 20 is also requested (case illustrated in the central part of FIG. 5, that is to say for a total depression greater than d ₁ and less than d ₁ + d ₂ ) and that

- in the upright position, the very hard foam 30 (or the membrane possibly replacing it) is also stressed upon sinking, however on a value not exceeding d. (case illustrated in the right part of FIG. 5, that is to say for a total depression greater than d ₁ + d ₂ ).

This gives the following choices of stiffnesses of materials: - for the flexible membrane 10, a material whose stiffness gives a clearance of 30 mm for a local pressure of

0.1 N / cm ² (approximately corresponding to the case of a 70 kg person in a lying position), therefore a coefficient elongation of 300 mm / N / cm ² ;

- for the hard membrane 20, a material whose stiffness gives a travel of 100 mm for a local pressure of 8 N / cm ² (corresponding approximately to the case of a person of 70 kg in a seated position), therefore a coefficient of elongation of 12.5 mm / N / cm ² , a degree of firmness 24 times greater;

- for very hard foam 30 (or the membrane possibly replacing this), a material whose stiffness gives a clearance of 20 mm for a local pressure of 1.6 N / cm ² (corresponding approximately to the case of a person 70 kg in standing position), therefore an elongation coefficient of 0.8 mm / N / cm ² , a degree of firmness 375 times greater than the first value.

This gives the total driving-in characteristic d as a function of the local pressure applied P as illustrated in FIG. 4, the arc I corresponding to the lying position (left part of FIG. 5), the arc II corresponding to the sitting position (central part of Figure 5) and the arc III corresponding to a standing position (right part of Figure 5).

As can be seen, the degree of firmness of the mattress varies depending on the pressure applied; in other words, the degree of firmness adapts to the person's position on the mattress (lying, sitting, or standing).

FIG. 6 illustrates a second embodiment, in which the mattress is a reversible mattress (that is to say comprising a summer face and a winter face).

Two symmetrical structures similar to those of FIG. 1 are then provided on either side of the foam 30, which is now in the central position. It will be noted that, in this embodiment, it is no longer necessary to provide a rigid bottom, the role of this being able to be assigned to the central foam 30 (or the membrane possibly replacing this).

Note that, in the case of this symmetrical structure, it is possible to replace the common central foam layer with a common membrane if it is planned to offset in the transverse direction of a half-step p / 2 the respective rods of the lower structure and those of the lower structure, with respect to each other.

FIGS. 8 to 11 illustrate details of an embodiment in which a counter-grid 51 is provided attached to the first membrane and having, at the level of each rod 40, an orifice 52 housing the homologous end 41 of the rod in the absence of external solicitation on it.

The membrane can advantageously be produced no longer in the form of a common element from a continuous surface, but, as illustrated, in the form of a plurality of individual elastic discs 11, in a number equal to that of the rods, coaxial with orifices 52 and secured at their periphery (dashed outline of Figure 9) to the counter-grid.

It should be noted, however, that it is equally possible, with this embodiment comprising a counter-grid, to use a continuous common membrane secured locally to the counter-grid along circular contours coaxial with the orifices, a structure which would be functionally equivalent.

Against the grid 51 may be constituted by a separate element from the guide grids 50 and / or 50 ′, or else by the lower grid 50 of FIG. 1.

In the latter case, it will be essential to provide a second guide grid 50 ′ because the orifices 52 which house the ends 41 have a diameter greater than that of the body of the rod 40 and could not in themselves provide suitable guidance (we could however overcome this drawback by taking for the lower grid 50 forming the counter-grid 51 a thick grid with a thinned opening, with a large diameter portion in the vicinity of the outlet to form a countersink for housing the end of the rod 41 , followed by a part of smaller diameter used for guiding the body of the rod 40).

In FIG. 8, the membrane 11 (individual disks or common membrane) is placed under the counter-grid 51, and stuck to it; it is also possible, as illustrated in FIG. 10, to glue or place the membrane 11 (here again, whether it is in the form of individual disks or a common membrane) on the counter-grid 51, or also, as illustrated in FIG 11, to pinch the membrane 11 (individual disks or common membrane) between two plates 53, 54 together constituting the counter-grid 51.

Claims

1. A mattress, characterized in that it comprises, at least over part of its surface, a structure having successively:

- an extensible, essentially horizontal surface skin (1), and

- At least one first elastically deformable element (10) extending parallel to the surface skin and connected thereto by a series of vertical movable rods (40), guided in vertical sliding, directly transmitting the forces applied to it surface skin,

so as to transform the distributed pressures applied to the surface skin into point pressures applied, in line with each of the respective rods, to the first elastically deformable element.

2. The mattress of claim 1, wherein the first elastically deformable element (10) is a block of foam.

3. The mattress of claim 1, wherein the first elastically deformable element (10) is a membrane.

4. The mattress of claim 3, further comprising: - at least one second elastically deformable element (20), of stiffness greater than that of the first element and extending parallel to the latter at a first distance (d ₁ ) , this second element receiving the forces applied punctually to the surface skin at the level of each of the respective rods only after the deflection of the first element has exceeded the value of said first distance, so that the characteristic deflection / punctual force of said structure has at least two sections of respective increasing stiffnesses, each corresponding to the successive deformation of each of the two elastically deformable elements.

5. The mattress of claim 4, in which:

- The stiffness of the first elastically deformable element (10) is chosen so as to obtain a clearance substantially equal to said first distance (d ₁ ) for a punctual force corresponding approximately to that exerted punctually by a person lying on the mattress.

6. The mattress of claim 4, wherein the second elastically deformable element (20) is a block of foam.

7. The mattress of claim 4, wherein the second elastically deformable element (20) is a membrane.

8. The mattress of claim 7, further comprising:

- A third elastically deformable element (30), of stiffness greater than that of the second element, placed at a second distance (d ₂ ) from the latter, this third elastically deformable element receiving the forces applied punctually to the surface skin at right of each of the respective rods only after the deflection of the second element has exceeded the value of said second distance, so that the characteristic deflection / punctual force of said structure has three sections of respective increasing stiffnesses, each corresponding to the setting in successive deformation of each of the three elastically deformable elements.

9. The mattress of claim 8, characterized in that the stiffness of the second elastically deformable element (20) is chosen so as to obtain a clearance close to said second distance (d ₂ ) for a punctual force corresponding substantially to that exerted by a person sitting on the mattress.

10. The mattress of claim 8, wherein the stiffness of the third elastically deformable element is chosen so as to obtain a determined maximum clearance (d ₃ ) for a punctual effort corresponding substantially to that exerted by a person standing on the mattress.

11. The mattress of claim 8, in which the third elastically deformable element (30) is a block of foam.

12. The mattress of claim 8, in which the third elastically deformable element (30) is a membrane.

13. The mattress of claim 1, wherein said structure is formed on almost the entire surface of the mattress.

14. The mattress of claim 1, wherein said structure is produced only on localized areas of the mattress.

15. The mattress of claim 14, wherein said structure is produced only on the areas of the mattress corresponding to the position of the lumbar (5) and / or cervical (6) regions of a person lying on the mattress.

16. The mattress of one of claims 13 and 14, wherein said structure is formed of similar substructures, of smaller dimensions, juxtaposed on either side of common intermediate points (60) for anchoring and 'support of membranes.

17. The mattress of claim 1, in which the density of rods per unit area of the mattress is of the order of 1 rod / cm ² .

18. The mattress of claim 1, wherein the ends (41) of the rods in contact with the first elastically deformable element (10) are in non-integral contact with the latter.

19. The mattress of claim 1, in which the ends (42) of the rods in contact with the surface skin are in integral contact with the latter.

20. The mattress of one of claims 3, 7 and 12, further comprising means for adjusting the tension of the membrane or membranes.

21. The mattress of claim 3, further comprising at least one counter-grid (51) attached to the membrane (10) and having, at the level of each rod, an orifice

(52) receiving the homologous end of the rod.

22. The mattress of claim 21, in which the membrane (10) is formed of a plurality of individual elastic discs (11), in a number equal to that of the rods, coaxial with the orifices and secured at their periphery to the counter wire rack.

23. The mattress of claim 21, in which the membrane is formed from an element common to a plurality of rods and secured locally to the counter-grid along circular contours coaxial with the orifices.

24. The mattress of claim 1, wherein said structure is a reversible structure formed of two substantially symmetrical similar substructures extending on either side of a median plane.

25. The mattress of claim 24, wherein the respective rods of the first and second substructures are mutually offset in the transverse direction by half a step.