Monolithic cushion

Abstract

The invention relates to a monolithic cushion (10) comprising: - a cushion main part (100) providing comfort on contact, said main part comprising at least one deformable comfort layer (106) having a plurality of open cells (107), - a retention sheet (112) that is separate from the cushion main part (100) and at least partially surrounds same so as to at least partially delimit the peripheral open cells (107) of the comfort layer (106), the retention sheet comprising a plurality of meshes (130).

Description

Description Title of the invention: Monolithic cushion Technical field

[0001] The present invention relates to a monolithic cushion, in particular produced by 3D printing.

[0002] The invention relates more particularly to cushions adapted to a vehicle seat. Technological background

[0003] Generally speaking, a vehicle seat has a seat and a backrest.

[0004] In some cases, particularly in racing vehicles intended to run on a circuit, the geometry of the seat and / or backrest may have complex shapes, including different inclined walls intended to keep the driver's body in the most stable position possible on the seat. In order to improve the comfort and support of these drivers, soft cushions are placed on the different walls making up the seat.

[0005] Traditional manufacturing techniques generally involve manufacturing the various components of the cushion and then assembling them in the desired manner. These techniques are not entirely satisfactory. They are generally designed for a specific type of seat and user profile. Consequently, a change in shape and / or dimensions requires modifications to the various equipment used in these techniques to obtain the desired product, to adapt to the new geometry and dimensions. These equipment modifications are cumbersome to carry out and require modifications or creation of specific tooling. In addition, they are time-consuming and therefore generate additional costs and delays.

[0006] To overcome these drawbacks, another solution is to manufacture these cushions using 3D printing. This is a simple, automated, and fast manufacturing technique. In fact, all you have to do is program the characteristics of the different layers to be placed in the cushion into the 3D printer to obtain a cushion with the desired properties. 3D printing allows the cushion to be produced continuously and in one go from one end to the other, without having to manufacture the different elements of the cushion separately.

[0007] There is a need to further improve 3D printed cushions, particularly for vehicle seats, in order to improve their quality, including comfort, rigidity and durability. Summary of the invention

[0008] The invention aims to meet this objective and has as its subject, according to one of its aspects, a monolithic cushion, in particular produced by 3D printing, said cushion comprising: - A cushion body providing contact comfort, said body comprising at least one comfort layer constituting the core of the cushion and comprising at least one layer of openwork cells, - A support sheet separate from the cushion body and at least partially surrounding the latter so as to at least partially delimit the peripheral cells of the comfort layer, the support sheet comprising a plurality of meshes.

[0009] By "monolithic" we mean that the cushion is in the form of a single block. The cushion is made of a single material, that is, from material.

[0010] The support sheet according to the invention has several advantages.

[0011] First of all, due to the cellular structure of the comfort layer, said layer has cell strands at its lateral ends. These cell strands can be free or joined. The comfort layer can thus have protruding and / or floating shapes at its lateral faces, making them less pleasant to the touch. The support layer makes it possible to retain these cell strands in order to make the cushion softer to the touch. This avoids any possible discomfort and / or aggression for the user.

[0012] Furthermore, depending on the intended use of the cushion, particularly in the case of a seat cushion, it may be subjected to repeated friction and shear stresses that are detrimental to the durability of the cellular comfort layer. The support sheet thus improves the durability of the cushion by creating a protective interface with the comfort layer. This reduces the risk of the cell strands being torn off and / or snagged at the periphery of the comfort layer.

[0013] The support layer also helps to stiffen the cushion structure by compensating for the weakness of the openwork cells present at the periphery of the comfort layer. This thus helps to minimize, or even eliminate, the collapse effect at the periphery of the layer.

[0014] Furthermore, the support sheet also serves an aesthetic purpose. It helps give the cushion an overall shape by delineating its boundaries and connecting the cell strands at the periphery. This can allow, if desired, to stretch a fabric around the cushion without the appearance of unwanted ridges or curves. It also offers the possibility of adding a graphic pattern.

[0015] Finally, the hollow structure of the support sheet makes it possible to lighten the cushion as much as possible and to facilitate the dust removal of said cushion at the end of its manufacturing process, in particular by 3D printing. Indeed, at the end of the process, dust remains stored in the cushion and it is necessary to be able to evacuate it simply and quickly. quickly. The hollow structure of the sheet can also facilitate other post-manufacturing treatments such as the application of coatings for example.

[0016] Preferably, the cushion is obtained by 3D printing.

[0017] Preferably, the support sheet is in contact with the comfort layer, in particular in contact with the peripheral cell strands.

[0018] In embodiments, the cushion body has two opposing faces and the support sheet extends along a peripheral edge joining the two faces.

[0019] Preferably, the retaining sheet has a width substantially identical to the thickness of the cushion body, in particular at the height of the peripheral edge of the cushion body.

[0020] Preferably, the support sheet has a thickness of less than 20 mm, better still less than 10 mm, even better still less than 5 mm.

[0021] In embodiments, the meshes of the retaining web are designed to promote deformation of the web along a single deformation axis. This allows for better control of the deformation of the web along a predetermined direction and makes it possible to minimize or even avoid any other unwanted movement.

[0022] Preferably, these meshes each have a diamond shape.

[0023] The meshes of the support sheet can be identical.

[0024] Alternatively, the meshes of the support sheet have different shapes and / or different dimensions.

[0025] The support sheet may be single-layer or multi-layer. In particular, it may comprise at least two layers at least partially superimposed on each other.

[0026] Depending on the intended application, the support sheet may be continuous or discontinuous. When discontinuous, it may comprise at least two separate segments arranged at predefined locations on the periphery of the cushion body.

[0027] The support sheet may have substantially flat faces. Alternatively, at least one of the faces of the support sheet has one or more reliefs. These reliefs may be intended to receive interfaces specific to the functional environment of the cushion. For example, in the case of a car seat, the reliefs may be used to accommodate interfaces related to the safety of the vehicle such as airbags, or interfaces related to function controls or sensors, such as switches, dimmers, thermal sensors, presence sensors. The reliefs may also receive interfaces for protecting the comfort layer, interfaces with other elements of the interior furnishings of the vehicle, such as a central console, interior trim, or interfaces for decorative elements, such as a snap-on surface or embroidery areas.

[0028] The number of layers constituting the comfort layer depends on the thickness and desired deformation properties for the cushion.

[0029] The comfort layer may be flat or not. When it is not flat, the comfort layer may have at least one fold so as to present two consecutive sections inclined relative to each other.

[0030] Preferably, the comfort layer comprises openwork cells in the shape of a truncated octahedron. This gives the comfort layer good deformation capacity, thus increasing the comfort of the cushion. This also makes it easier to dust the cushion, as mentioned above. Other shapes of openwork cells can be used depending on the desired mechanical behavior.

[0031] The invention also relates to a method of manufacturing a cushion according to the invention, comprising the steps consisting of: - Provide a digital model of the cushion, - Create the cushion in successive layers from the digital model.

[0032] Preferably, the digital model comprises a plurality of voxels. A voxel is a volumetric unit of a digital 3D space, preferably cubic in shape. This unit can be assembled into several units by mathematical operations to create objects of different shapes. The voxel can be solid or empty, which corresponds to the presence or absence of matter.

[0033] Taking the support layer into account when designing the digital model makes it possible to add a continuous overlay at the limit of the voxels representative of the comfort layer.

[0034] The invention also relates to a vehicle seat comprising at least one cushion according to the invention.

[0035] The vehicle seat may comprise a seat and a backrest, F at least one cushion according to the invention may be fixed to at least one of the two elements constituted by said backrest and said seat.

[0036] The invention also relates to a vehicle comprising a seat according to the invention. Brief description of the figures

[0037] The invention may be better understood by reading the detailed description which follows, by examining the non-limiting example of its implementation, and by examining the attached drawing in which

[0038] [Fig.1] [Fig.1] is a schematic and partial view of a cushion according to the invention;

[0039] [Fig.2] [Fig.2] is an exploded view of the cushion according to the invention,

[0040] [Fig.3] [Fig.3] is a longitudinal section of the cushion of [Fig.l] according to the plan HAS;

[0041] [Fig.4] [Fig.4] represents a side view of an example of a retaining sheet according to the invention;

[0042] [Fig.5] [Fig.5] is a detail of [Fig.3] illustrating the deformation of the meshes of the support sheet, and

[0043] [Fig.6] [Fig.6] is a perspective view of the retaining sheet according to the invention. Description of embodiment(s)

[0044] As illustrated in [Fig.l], the cushion 10 comprises a cushion body 100. This cushion body 100 comprises a first face 120 intended to come into contact with the user, a second face 124 parallel to the first face 120 and opposite thereto and a peripheral edge 122 joining the first and second faces 120 and 124.

[0045] In the illustrated example, the first and second faces 120 and 124 are flat, but it does not depart from the scope of the invention if they have different shapes, in particular protrusions of material.

[0046] As illustrated in [Fig.2], the cushion body 100 comprises the following distinct layers: - A front contact layer 101 comprising a single layer materializing a grid of several solid unit cells 102, connected to each other by arms revealing free spaces between said solid unit cells 102. These solid unit cells 102 have the same dimensions within said front layer 101, and each have a rectangular shape. Each of these solid unit cells 102 has a central opening 103. Advantageously, the thickness of this front layer 101 is less than or equal to 5mm, referring to [Fig.l], the solid unit cells 102 of the front layer 101 are connected to each other by non-rectilinear arms 150, which may for example have a curvature or at least a fold. In this way, when the front layer 101 deforms, for example under the effect of a person sitting on the cushion 100, these arms 150 can easily accompany this deformation by deploying. When the arms 150 are going to deploy, they will have a tendency to adopt an elongated rectilinear profile, - a soft intermediate layer 104 comprising a single layer materializing a grid of several hollow unit cells 105, connected to each other by arms revealing free spaces between said hollow unit cells 105, said intermediate layer 104 being in contact with the front layer 101 such that each solid unit cell 102 comes into correspondence and abuts against a hollow unit cell 105. The hollow unit cells 105 of the intermediate layer 104 are of elliptical, trapezoidal or other shape, and have dimensions less than or equal to those of the solid unit cells 102 of the front layer 101 of contact. Preferably, the thickness of this intermediate layer 104 is less than or equal to 5 mm, and - a rear comfort layer 106 constituting the core of the cushion 100 and comprising a superposition of at least two layers of openwork cells 107, said rear layer 106 being in contact with the intermediate layer 104 so that said intermediate layer 104 is between the front contact layer 101 and the rear layer 106. Each of the openwork cells 107 has the shape of a truncated octahedron.

[0047] The cushion 10 further comprises a retaining sheet 112 separate from the cushion body 100, and extending over the periphery of this cushion body 100.

[0048] As illustrated in Figures 1 and 2, the support sheet 112 is in the form of a strip surrounding the lateral edge of the cushion body 110. The support sheet 112 comes into contact with the comfort layer 106 and is connected to the openwork cells 107 thereof by connecting strands 117, as can be seen in [Fig. 3].

[0049] In the example illustrated, the retaining sheet 112 is continuous and extends over the entire length of the lateral edge 122 of the body of the cushion 100. The retaining sheet 112 has a width L substantially identical to the thickness of the body of the cushion 100.

[0050] The retaining layer 112 may have a rim 140 at its junction with the first and second faces 120 and 124.

[0051] As illustrated in Figures 1, 2, 4 and 6, the support sheet 20 comprises a plurality of meshes 130. In the example considered, the meshes 130 each have a general diamond shape. These meshes 130 are designed so as to promote the deformation of the support sheet 112 in the width direction, along a single deformation axis XI, to accompany the deformation of the body of the cushion 100, when, for example, the user sits on the body of the cushion 100, as can be seen in [Fig. 5].As can be seen in this figure, the meshes 130 undergo compression along the deformation axis XI, which results in a narrowing of the width of the meshes 130 in the direction of the arrows FL. It is noted that the meshes 130 can undergo a non-significant or even zero displacement along an axis perpendicular to XL. Also, thanks to the shape and arrangement of the meshes, it is possible to control the displacement of the support sheet and thus avoid any unwanted displacement during stresses on the cushion.

[0052] Of course, the invention is not limited to the example just described.

[0053] The mesh of the tablecloth may have a shape other than that of a diamond.

[0054] The support sheet may have one or more discontinuities of material and / or extend partially over a shorter length of the edge of the body of the cushion.

Claims

Claims

1. Monolithic cushion (10), comprising: - A cushion body (100) providing contact comfort, said body comprising at least one deformable comfort layer (106) comprising a plurality of openwork cells (107), - A support sheet (112) separate from the cushion body (100) and at least partially surrounding the latter so as to at least partially delimit the peripheral openwork cells (107) of the comfort layer (106), the support sheet comprising a plurality of meshes (130).

2. Cushion according to claim 1, the cushion body (100) having two opposite faces (120; 124) and a peripheral edge (122) joining the two faces (120; 124), the retaining sheet at least partially surrounding the peripheral edge (122).

3. Cushion according to claim 1 or 2, the meshes (130) of the retaining sheet (112) being designed to promote the deformation of the retaining sheet (112) along a single deformation axis (XI).

4. Cushion according to any one of the preceding claims, the support sheet (112) being single-layer.

5. Cushion according to any one of claims 1 to 3, the support sheet (112) comprising at least two layers at least partially superimposed on each other.

6. Cushion according to any one of the preceding claims, the retaining sheet (112) having a width (L) substantially identical to the thickness of the cushion body (100).

7. Cushion according to any one of the preceding claims, the retaining sheet (112) being continuous.

8. Cushion according to any one of claims 1 to 6, the retaining sheet (112) being discontinuous by being constituted by at least two separate segments arranged at predefined locations on the periphery of the cushion body (100).

9. Vehicle seat comprising a seat and a backrest, at least one cushion (10) according to any one of claims 1 to 8, is fixed to at least one of the two elements constituted by said backrest and said seat.

10. Vehicle comprising at least one seat according to claim 9.

11. A method of manufacturing a cushion (10) according to any one of claims 1 to 8, comprising the steps of: - Provide a digital model of the cushion, - Create the cushion (10) in successive layers from the digital model.

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