Cushion obtained through 3D printing

Abstract

The invention relates to a monolithic cushion (100). According to the invention, the cushion comprises at least three distinct layers (101, 104, 106): - a front contact layer (101) comprising a single layer forming a grid of several solid unit cells (102), connected to each other by front arms (140), and - an intermediate layer (104) comprising a single layer having 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), 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). Figure for the abbreviation: Figure 2

Description

Title of the invention: Cushion obtained by 3D printing

[0001] The present invention relates to a cushion obtained by 3D printing

[0002] Such a cushion is particularly, but not exclusively, suited to a vehicle seat. Generally, a vehicle seat comprises a seat and a backrest. In some cases, such as in racing vehicles designed for track use, the geometry of this seat and backrest can be complex, featuring various inclined surfaces designed to maintain the driver's body in the most stable position possible. To improve the comfort and support of these drivers, soft cushions made, for example, of foam and covered with a fabric envelope are attached to the various surfaces constituting the backrest and seat.

[0003] However, current manufacturing techniques for these cushions are severely lacking in flexibility, as they are time-consuming to develop and difficult to customize (they are designed for only one type of seat and one user profile). Indeed, even a slight change in the seat's shape and / or dimensions renders these techniques unsuitable. It then becomes necessary to modify the various pieces of equipment used in these techniques to obtain the desired product, with the correct geometry and dimensions. These equipment modifications, which are complex to implement, require modifications or the creation of specific tooling, are time-consuming, and therefore generate additional costs and delays.

[0004] To overcome all these drawbacks, a current trend is to manufacture these cushions using 3D printing, which is a simple, automated, and rapid manufacturing technique. Indeed, it is simply a matter of designing the product and programming the characteristics of the different layers to be placed in the cushion into the 3D printer to obtain a cushion with the desired properties. It is important to remember that a major advantage of parametric design for 3D printing is that the object to be manufactured, in this case a cushion, is produced continuously and in a single step from one end to the other, without having to manufacture the different constituent elements of this object separately and then assemble them as required. With 3D printing, depending on the volumes and quantities produced, the assembly time and costs of an equivalent product manufactured using conventional methods are therefore considerably reduced.

[0005] A cushion according to the invention is obtained by means of 3D printing, while exhibiting comfort and support qualities at least equivalent to those of cushions obtained with traditional manufacturing techniques.

[0006] The invention relates to a monolithic cushion.

[0007] According to the invention, the cushion comprises at least three distinct layers: -a front contact layer comprising a single layer materializing a grid of several solid unit cells, connected to each other by arms leaving free spaces between said solid unit cells, and -a soft intermediate layer comprising a single layer having a grid of several hollow unit cells, connected to each other by arms leaving free spaces between said hollow unit cells, said intermediate layer being in contact with the front layer such that each solid unit cell corresponds to and rests against a hollow unit cell, and -a back comfort layer constituting the core of the cushion and comprising an overlap of at least two layers of openwork cells, said back layer being in contact with the intermediate layer so that said intermediate layer is included between the front layer and the back layer.

[0008] Schematically, the front contact layer is designed to come into contact with a person, replacing the usual textile, and the intermediate and back layers ensure the overall mechanical behavior (including comfort) of the cushion, with the intermediate layer acting as an adhesion layer for the front layer. The presence of solid unit cells in the front layer is justified because these are the cells that will come into contact with a part of an individual's body. They must therefore offer a certain softness to the touch, unlike hollow cells which are less pleasant to the touch. Advantageously, the grid of the front layer is substantially flat. The cushion's softness is provided by the intermediate and back layers, with the intermediate layer ensuring the transition between the front and back layers.The fact that a hollow cell in the intermediate layer corresponds to and is in contact with a solid cell in the front layer ensures stable contact between these two layers, thus preventing relative slippage between them as soon as a part of an individual's body comes into contact with the front layer. The number of layers constituting the back layer depends on the desired thickness and deformation properties of the cushion. The three constituent layers of the cushion can be flat or have at least one fold, presenting two consecutive sections inclined relative to each other. Preferably, the thicknesses of the front and intermediate layers are less than 1 cm, and even more advantageously, less than 0.5 cm. The back layer can be several centimeters thick. Advantageously, the three constituent layers of the cushion have contours of the same dimensions.The three constituent layers of the cushion each have a maximum of passages and openings to lighten the said cushion, and to ensure dust removal of the said cushion at the end of manufacture and. to ensure a final color or other finishing treatment. The openings between the layers offer superior passive ventilation compared to a typical car seat. The term "monolithic," applied to the cushion, means that the cushion is made from a single material using a single process.

[0009] According to a possible feature of the invention, the solid unit cells of the front layer have a quadrilateral shape.

[0010] According to one possible feature of the invention, the solid unit cells of the front layer each have a central opening. The central openings contribute to further lightening the cushion and facilitating dust removal at the end of the cushion manufacturing process.

[0011] According to one possible feature of the invention, the hollow unit cells of the intermediate layer are elliptical in shape and have dimensions less than or equal to those of the solid unit cells of the front layer. Such cell interaction ensures good continuity between the front and intermediate layers without risk of causing relative slippage between the two layers when a part of an individual's body comes into contact with the cushion.

[0012] According to one possible feature of the invention, the back comfort layer comprises perforated cells in the shape of a truncated octahedron, or corresponding to the desired mechanical behavior. This type of cell gives the back layer good deformation capacity, thus increasing the comfort of the cushion.

[0013] According to one possible feature of the invention, the comfort back layer comprises a first face that is in contact with the soft intermediate layer and a second face that is substantially parallel to said first face and is intended to come into contact with an external surface, said second face having material protrusions to increase the contact area between the cushion and said external surface. The sole purpose of these material protrusions is to increase the contact area between the cushion and an external surface to which said cushion is intended to be attached. This external surface may, for example, be a seat or backrest surface of a car seat. These material protrusions emerge only very slightly from the second face of the cushion's back layer so as not to enlarge, or to enlarge by less than 1%, the dimensions of the cushion.These protrusions can be replaced by a solid, continuous surface. These protrusions, however, offer a significantly lighter construction than this solid surface solution and allow for better dust removal from the cushion after installation.

[0014] According to a possible feature of the invention, the second face has a hollow groove delimited by a continuous wall and intended for the insertion of a material The attachment material can, for example, be an adhesive or a Velcro-type material. Advantageously, this groove forms a closed loop, and even more advantageously, a rectangular loop. This groove extends into a peripheral region of the cushion. According to one embodiment of the invention, the groove can be designed discontinuously, in relation to the desired attachment zones.

[0015] According to one possible feature of the invention, the front contact layer, the soft intermediate layer, and the back comfort layer have contours of the same dimensions. The cushion includes a support layer in the form of a lateral band surrounding the three superimposed layers constituting the cushion, the width of said band corresponding to the overlap height of said three layers constituting said cushion. This support layer helps to give the cushion good overall shape and to contain potential accidental extensions of the three layers constituting the cushion within said cushion 100. These extensions are inherent to the manufacture of the cushion and are not desirable. The support layer retains these extensions in order to make the cushion softer to the touch.

[0016] According to one possible feature of the invention, the support layer is made up of multiple meshes. Preferably, these meshes are diamond-shaped or elliptical. These meshes create openings and contribute to making the cushion lighter compared to a solid, continuous support layer. These openings also help to improve dust removal from the assembly after manufacturing.

[0017] Finally, manufacturing all these layers using the same process without assembly makes it more environmentally advantageous, particularly for recycling the overall cushion.

[0018] According to one possible feature of the invention, the front arms connecting the solid unit cells of the front layer are not straight and have a curve or at least a fold, so as to be able to unfold when said front layer is deformed. In this way, when the front layer deforms, for example, when a person sits on the cushion, the arms can follow this deformation by unfolding. When the arms unfold, they tend to adopt a straight profile. These front arms provide flexibility to the front layer, particularly in the plane containing the solid unit cells.

[0019] The invention also relates to a vehicle seat comprising a seat and a backrest.

[0020] According to the invention, at least one cushion according to the invention is attached to said seat and said backrest. The cushions according to the invention have been developed to be advantageous securely attached to a vehicle seat, particularly to a sports car bucket seat

[0021] The invention also relates to a vehicle comprising at least one seat conforming to the invention.

[0022] A cushion according to the invention has the advantage of being able to be manufactured quickly, automatically, and precisely, while possessing the properties required to ensure good comfort and support for an individual, who might, for example, be seated on a vehicle seat to which said cushion has been previously attached. Furthermore, it has the advantage of being able to be manufactured with a wide range of materials, or even be multi-material, thanks to 3D printing, and therefore to exhibit varied or even novel structural characteristics adapted to the materials used. Such a cushion also has the advantage of being able to appear with various patterns and colors, depending on the materials used in the 3D printing, making it possible, for example, to improve the visual appearance of a vehicle's interior if said cushion were attached to a seat of said vehicle.

[0023] A detailed description of a preferred embodiment of a cushion according to the invention is given below with reference to the following figures, in which:

[0024] [Fig-1] Fig. 1 is a perspective view of a vehicle seat comprising several cushions according to the invention,

[0025] [Fig.2] Fig.2 is an exploded view of a first embodiment of a cushion according to the invention,

[0026] [Fig.3] Fig.3 is a perspective view of a back layer of the first mode for the production of a cushion according to the invention,

[0027] [Fig.4] Fig.4 is a perspective view of a second embodiment of a cushion according to the invention.

[0028] [Fig. 5] Fig. 5 is a perspective view of an area of ​​a cushion according to the invention, showing the structural characteristics of the front layer and the support layer.

[0029] With reference to [Fig. 1], a vehicle seat 1 according to the invention is a racing vehicle seat comprising a seat 2 and a backrest 3. This seat 2 has a flat central section 4, substantially rectangular in shape, and two raised lateral sections 5, 6 originating from two parallel edges of the central section 4, said central section 4 having a front notch 7. The two raised lateral sections 5, 6 prevent a driver seated on the central section 4 of the seat 2 from inadvertently sliding to the sides of said seat 2, for example when the vehicle is going around a curve. The front notch 7 allows for the attachment of a seat belt, and the two portions 8, 9 of the central section 4 located on either side of the notch 7 serve as leg supports for said driver. The backrest 3 has a main section 10 against which the driver's back is intended to rest, a headrest 11 placed above said main section 10, and a connecting wall 12 located between the main section 10 of the backrest 3 and the central section 4 of the seat 2. The connecting wall 12 is delimited by two inclined lateral edges 13, 14, each of said two inclined lateral edges 13, 14 being located in the extension of a lateral section 5, 6 raised from the seat 2. In the same way as said two lateral sections 5, 6, the two inclined lateral edges 13, 14 prevent a driver who is seated on the seat 1 leaning against the backrest 3 from inadvertently sliding on the sides of said backrest 3, for example when the vehicle is going around a curve.

[0030] The particularity of the seat 1 described above is that it comprises several cushions 100 manufactured by 3D printing, also called simultaneous additive manufacturing, said cushions 100 replacing the foam, the fabric cover surrounding said foam of traditionally manufactured cushions, as well as the means for assembling or reinforcing said foam and said fabric cover.

[0031] With reference to Figures 2, 3, 5, a first embodiment of a cushion 100 according to the invention, which is manufactured by 3D printing, is intended to be attached to the headrest 11 of the seat 1. This cushion 100 comprises four distinct layers: -a front contact layer 101 comprising a single layer forming a substantially flat grid of several solid unit cells 102, connected to each other by arms leaving free spaces between said solid unit cells 102. These solid unit cells 102 have the same dimensions within said front layer 101, and each has a rectangular shape. Each of these solid unit cells 102 may have a central opening 103. Advantageously, the thickness of this front layer 101 is less than or equal to 5 mm. Referring to [Fig. 5], the solid unit cells 102 of the front layer 101 are connected to each other by non-straight front arms 140, which may, for example, have a curvature or at least a fold.In this way, when the front layer 101 deforms, for example due to a person sitting on the cushion 100, these front arms 140 can easily accommodate this deformation by unfolding. When the front arms 140 unfold, they tend to adopt an elongated, rectilinear profile and provide flexibility, particularly in the plane containing the solid unit cells, and a soft intermediate layer 104 comprising a single layer forming a grid of several hollow unit cells 105, connected to each other by arms that leave free spaces between said hollow unit cells 105, said intermediate layer 104 being in contact with the front layer 101 in such a way that each solid unit cell 102 corresponds to and rests against a hollow unit cell 105.The hollow unit cells 105 of the intermediate layer 104 are elliptical or trapezoidal in shape and have dimensions less than or equal to those of the . solid unit cells 102 of the front contact layer 101. 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 such that said intermediate layer 104 is situated between the front contact layer 101 and the rear layer 106. Each of the openwork cells 107 has the shape of a truncated octahedron or corresponding to the desired mechanical behavior. Referring to [Fig.[3] The rear comfort layer 106 comprises a first face that is in contact with the soft intermediate layer 104 and a second face 108 that is substantially parallel to said first face and is intended to come into contact with a surface of the headrest 11 of the seat 1. This second face 108 has protrusions 109 of material so as to increase the contact area between the cushion 100 and the surface of said headrest 11. It is important that this second face 108 exhibits consistent mechanical strength so that the cushion 100 does not deform uncontrollably and wear prematurely. These protrusions 109, which can take on a variety of shapes, have the sole purpose of increasing the contact area between the second face 108 of the cushion 100 and the surface of the headrest 11.This second face 108 may have a hollow groove 110, delimited by a continuous wall 111 of substantially hemispherical or rectangular shape, intended to house an attachment material, such as, for example, a Velcro strip. This hollow groove 110 is obtained by 3D printing, preferably using the same embodiment as the rest of the cushion 100 and therefore produced simultaneously, and thus does not result from the insertion of a wall added to the back layer 106. This groove 111 is closed and forms a frame of substantially rectangular shape which is close to the peripheral edge of said back layer 106, and . - a support layer 112 of the front contact layer 101, the intermediate soft layer 104 and the rear comfort layer 106. Indeed, these three layers 101, 104, 106 constituting the cushion 100 have contours of the same dimensions, the said retaining layer 112 appearing in the form of a band surrounding the said three superimposed layers 101, 104, 106. The width of this band constituting the retaining layer 112 corresponds to the height of the overlap of the three layers 101, 104, 106 constituting the cushion 100. This retaining layer 112 contributes to giving the cushion 100 good overall stability, and to containing potential accidental extensions of the three layers 101, 104, 106 constituting the cushion 100 within said cushion 100. These extensions are inherent to the manufacture of the cushion 100 and are not intended. The 112 support layer holds these extensions in place to make the cushion softer to the touch.Preferably, this one. The support layer 112 consists of a multiplicity of meshes 130, each advantageously having a diamond shape.

[0032] The various layers 101, 104, 106, 112 of the cushion obtained by 3D printing each have openings, passages, orifices, and free spaces in order to lighten the cushion 100 as much as possible and to facilitate the removal of dust from said cushion 100 at the end of its 3D printing manufacturing process. Indeed, at the end of said process, dust remains stored in the cushion 100, and it is essential to be able to remove it simply and quickly.

[0033] Referring to [Fig. 4], a second embodiment of a cushion 100 according to the invention is intended to be attached to the seat 2 of the seat 1. The structural characteristics of this second embodiment are similar to those of the first embodiment described above; only the general shape of the cushion 100 changes. This second embodiment illustrates that a parametric design for 3D printing allows any type of shape to be given to said cushion 100. This second embodiment comprises a central, flat section 113, substantially rectangular in shape, and two raised lateral sections 114, 115 originating from two parallel edges of the central section 113, said central section 113 having a front notch 116. This second embodiment of a cushion 100 according to the invention is intended to be attached to the seat 2 of the seat 1 described above.

[0034] At least one cushion 100 according to the invention is attached to each constituent element of the seat 2 and the backrest 3 and intended to come into contact with a part of the body of a pilot who would be seated on said seat 1. A parametric design for 3D printing makes it possible to give each cushion 100 a shape adapted to the shape of the seat element against which said cushion is intended to be attached.

[0035] A parametric design for 3D printing makes it possible to give each cushion 100 a morphology and an overall mechanical response adapted to the morphology of the user.

Claims

Claims

1. Monolithic cushion (100), characterized in that it comprises at least three distinct layers (101, 104, 106): - a front contact layer (101) comprising a single layer materializing a grid of several solid unit cells (102), connected to each other by front arms (140) revealing free spaces between said solid unit cells (102), and - an intermediate layer (104) comprising a single layer having 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) and connected to the front layer by arms such that each solid unit cell (102) comes into correspondence and bears against a hollow unit cell (105),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 layer (101) and the rear layer (106).,

2. Cushion according to claim 1, characterized in that the solid unit cells (102) of the front layer (101) have a quadrilateral shape.

3. Cushion according to claim 2, characterized in that the solid unit cells (102) of the front layer (101) each have a central opening (103).

4. Cushion according to any one of claims 2 or 3, characterized in that the hollow unit cells (105) of the intermediate layer (104) are elliptical in shape and have dimensions less than or equal to those of the solid unit cells (102) of the front layer (101).

5. Cushion according to any one of the claims of claims 1 to 4, characterized in that the rear comfort layer (106) comprises openwork cells (107) in the shape of a truncated octahedron.

6. Cushion according to any one of claims 1 to 5, characterized in that the rear comfort layer (106) comprises a first face which is in contact with the soft intermediate layer (104) and a second face (108) which is substantially parallel to said first face and which is intended to come into contact with an exterior surface, said second face (108) having protrusions (109) of material to increase the contact surface between the cushion (100) and said exterior surface.

7. Cushion according to claim 6, characterized in that the second face (108) has a hollow groove (110) delimited by a continuous wall (111) and intended for the insertion of a bonding material.

8. Cushion according to any one of claims 1 to 7, characterized in that the front contact layer (101), the soft intermediate layer (104) and the rear comfort layer (106) have contours of the same dimension, and in that the cushion (100) comprises a support layer (112) in the form of a lateral band surrounding the three superimposed layers (101, 104, 106) constituting the cushion (100), the width of said band corresponding to the height of superposition of said three constituent layers (101, 104, 106) of said cushion (100).

9. Cushion according to claim 8, characterized in that the holding layer (112) consists of a multiplicity of meshes (130).

10. Cushion according to any one of claims 1 to 9, characterized in that the front arms (140) connecting the solid unit cells (102) of the front layer (101) have a curvature or at least a fold, so as to be able to deploy when said front layer (101) is deformed.

11. Vehicle seat comprising a seat (2) and a backrest (3), characterized in that at least one cushion (100) according to any one of claims 1 to 9 is fixed to said seat (2) and to said backrest (3).

12. Vehicle comprising at least one seat according to claim 11.

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