Seat portion manufactured by 3D printing

Abstract

The invention relates to a seat portion (100) comprising a first extended mesh (101) intended to provide the seat portion with a degree of flexibility for the purposes of comfort and a second mesh (102) located in a front half of the seat portion (100) and extending over an entire width of the seat portion (100), the second mesh (102) being intended to provide the seat portion (100) with a degree of stiffness in order for the seat portion to serve as an anti-submarining bar, the cells of the first mesh (101) being different from the cells of the second mesh (102).

Description

[0001] Title of the invention: seat base manufactured by 3D printing

[0002] The present invention relates to a seat base manufactured by 3D printing.

[0003] In order to understand how the structure of a seat according to the invention is arranged, the detailed description of said seat is carried out with reference to a direct orthonormal reference frame XYZ linked to a vehicle in which said seat would be placed in a functional horizontal position, and in which X is a front-rear longitudinal axis of the vehicle facing rearward, Y is a transverse axis facing towards the right of the vehicle and Z is a vertical axis facing upwards.

[0004] As a reminder, an object resulting from 3D printing is presented in the form of hollow three-dimensional meshes, which can be connected to each other by arms, each mesh having its own shape and dimensions. One of the advantages of 3D printing is that it is possible to vary the characteristics of the object to be manufactured very quickly and very easily, for example in terms of shape, dimension and rigidity, by means of an appropriate choice of input parameters of software associated with a 3D printer.

[0005] Currently, some vehicle seat bases include an anti-submarining bar, in the form of a sheet metal bar, incorporated into said bases, and intended to dissipate the energy from the pelvis of the occupants who would be sitting on the seats, during a sudden deceleration caused by a frontal impact of the vehicle. However, such an anti-submarining bar appearing in the form of an added part has at least two disadvantages:

[0006] -it has a marked rigidity that an occupant sitting on the seat including this anti-submarining bar may feel somewhat unpleasant during routine use of the vehicle. Indeed, when the occupant adopts certain postures on the seat, his legs may come directly into contact with the anti-submarining bar, and said occupant may then feel a certain discomfort.

[0007] -it can deform plastically under the effect of the body of the occupant who would be sitting on the seat and who would suddenly impact it, during a frontal collision of said vehicle against an external obstacle. Such plastic deformation is not desirable because it is absolutely not controlled. An anti-submarining bar could then cause other more significant damage.

[0008] A seat of a chair according to the invention is manufactured by 3D printing and has an additional functionality obtained by simply varying the characteristics of certain meshes constituting it.

[0009] The invention relates to a vehicle seat base obtained by 3D printing.

[0010] According to the invention, the seat comprises a first extended network of meshes intended to provide the seat with a certain flexibility of comfort, and a second localized network of meshes located in a front half of the seat and extending over an entire width of said seat, said second network of meshes being intended to provide the seat with a certain rigidity to fulfill the function of an anti-submarining bar, the first network of meshes being less rigid than the second network of meshes. The principle of the invention consists in taking advantage of manufacturing by 3D printing of a seat of a vehicle seat, to give it an additional function through the presence of an anti-submarining bar. It is obvious that this anti-submarining bar is manufactured by 3D printing at the same time as the rest of the seat.This anti-submarining bar is therefore made up of a second network of meshes, which is more rigid than the first network of meshes constituting the rest of the seat, said anti-submarining bar being however made of the same material as that of the rest of the seat. It is therefore sufficient to vary the input parameters in the 3D printer to obtain an anti-submarining bar within the seat:.

[0011] -more or less voluminous,

[0012] -having the desired shape,

[0013] -having the desired dimensions,

[0014] -possessing zones of different rigidities, -oriented in a given direction,

[0015] In the context of the invention, 3D printing makes it possible to obtain a seat base having an anti-submarining bar having a plurality of structural and dimensional characteristics, without ever having to modify, readjust or rethink the seat manufacturing tools. A seat according to the invention can indifferently be a seat of an individual seat or a seat of a bench seat having at least two places. The term "front half" must be interpreted as if the seat were positioned in a vehicle. In this way, the front half must be considered relative to a longitudinal axis X of the vehicle. The fact that the anti-submarining bar is manufactured by 3D printing at the same time as the rest of the seat does not change its position within the seat, compared to the position of current anti-submarining bars which are added sheet metal parts.

[0016] According to a possible characteristic of the invention, the first mesh network and the second mesh network differ from each other by at least one parameter to be chosen from the geometry of the meshes, the dimensions of the meshes and the characteristics of the arms connecting the meshes together. Indeed, the main parameters governing the rigidity of a mesh network are: - either the geometry of the meshes constituting it, - or their dimension,

[0017] -either the characteristics of the arms connecting the meshes together, -or a combination of the previous parameters.

[0018] According to a possible characteristic of the invention, the front half is to be considered in relation to a length of the seat, the second network extending over the entire width of said seat while being perpendicular to said length. In this way, and without surprise, the anti-submarining bar is elongated and extends along a transverse axis Y of a vehicle in which the seat would be mounted, being placed in a front half of said seat considered along a longitudinal axis X of said vehicle.

[0019] According to a possible characteristic of the invention, the second mesh network representing the anti-submarining bar originates on a lower surface of the seat and extends over a height which is less than the total height of the seat. The lower surface represents the lowest part of the seat if it were mounted in a vehicle in a substantially horizontal plane. The height is the dimension of the seat considered along a vertical axis Z if said seat were mounted in a vehicle.

[0020] According to a possible characteristic of the invention, the second network of meshes representing the anti-submarining bar has a first lower end comprising at least one layer of rigid meshes originating on the lower surface of the base and extending parallel to said surface, said second network of meshes having a second upper end materializing the height of said anti-submarining bar and comprising at least one layer of meshes less rigid than the meshes of the first end and extending parallel to said at least one layer of rigid meshes of the first lower end. For this configuration, the base of the anti-submarining bar represented by the first end is rigid, while the top of said anti-submarining bar materialized by the second end is less rigid than the base.Indeed, for the anti-submarining bar to be effective in the event of a frontal impact of the vehicle against an external obstacle, it is not necessary for the entire bar to be rigid. Currently, anti-submarining bars are made of sheet metal and are therefore uniformly rigid. Manufacturing the anti-submarining bar by 3D printing makes it possible, in particular, to obtain an anti-submarining bar whose upper part is less rigid, so that a person sitting on said seat could not unpleasantly feel the presence of this bar during a routine phase of use of the vehicle. For this configuration, the anti-submarining bar remains effective against a frontal impact of the vehicle, while remaining pleasant to the touch during a normal rolling phase of the vehicle.The first end and the second end of the anti-submarining bar may each comprise a single layer, or several superimposed layers having the same rigidity. According to a possible characteristic of the invention, the second mesh network representing the anti-submarining bar comprises several intermediate layers of meshes, which are parallel to the layer of meshes of the first lower end and to the layer of meshes of the second upper end, the meshes of these intermediate layers having a rigidity which is between that of the meshes of the layer of the first lower end and that of the meshes of the layer of the second upper end. These intermediate layers of meshes may all have meshes of the same rigidity, or have meshes of different rigidity.

[0021] According to a possible characteristic of the invention, the rigidity of the cells of the intermediate layers varies progressively and monotonically between that of the cells of the first lower end and that of the cells of the second upper end, the rigidity of the cells of the intermediate layers varying gradually between said first lower end and said second upper end. In other words, along its height, the anti-submarining bar has a rigidity gradient, allowing said bar to be efficient in its anti-submarining function while being pleasant to contact during a normal rolling phase of the vehicle.

[0022] According to a possible characteristic of the invention, an upper zone of the second mesh network representing the anti-submarining bar, including the second upper end, has a softened contour, so that a person sitting on said seat does not feel the presence of the anti-submarining bar during a routine use phase of the vehicle. It is sufficient to enter the correct parameters into the 3D printer to obtain this softened contour, without having to modify the structure of an already existing anti-submarining bar. The term "softened" means "without having angles or edges" which would be likely to make the contact between the legs of the occupant sitting on the seat and the anti-submarining bar unpleasant.

[0023] According to a possible characteristic of the invention, a product is incorporated outside of 3D printing, in all the meshes making up the seat, said product comprising a rheology meeting the need for rigidity under rapid stress while remaining flexible under slow stress.

[0024] According to a possible characteristic of the invention, the product is a silicone gel. A seat according to the invention has the advantage of being able to have an additional functionality, through the presence of the anti-submarining bar which is an integral part of said seat, without having been structurally modified and without having undergone the slightest treatment. It is sufficient to program the 3D printer with the right parameters to obtain simply, quickly and in a safe and reliable manner, a seat base with an effective and pleasant anti-submarining bar.

[0025] A detailed description of a preferred embodiment of a seat according to the invention is given below with reference to the following figures:

[0026] [Fig. 1] Figure 1 is a sectional view of a seat base of a vehicle according to the state of the art showing the location of an anti-submarining bar as well as said anti-submarining bar. [Fig. 2] Figure 2 is a sectional view of a seat base of a vehicle according to the invention, incorporating an anti-submarining bar.

[0027] The detailed description of the seats 1, 100 which follows is carried out assuming that said seats 1, 100 are mounted in a vehicle, in a functional position for which it extends in a substantially horizontal plane, assuming that the seat in which it is incorporated is conventionally placed facing the road.

[0028] Referring to Figure 1, a seat base 1 of the state of the art is in the form of a polyurethane cushion extending in a substantially horizontal plane XY. The term "substantially" is due to the fact that a front part 2 of said seat base 1 considered along a longitudinal axis X of the vehicle, is slightly raised relative to the rest of the seat base 1 and therefore that said seat base 1 does not extend in a strictly horizontal plane. A front half of the seat base 1 considered along a longitudinal axis X of the vehicle, comprises an elongated groove 3 extending along a transverse axis Y of the vehicle, said groove 3 being made in a horizontal and lower surface 4 of the seat base 1. The groove 3 has a trapezoidal cross-section, delimited by a vertical front edge 5, by a rear edge 6 inclined relative to a vertical axis Z, and by an upper and horizontal connecting edge 7.The connecting edge 7 connects upper ends of the front edge 5 and the rear edge 6, the inclination of said rear edge 6 being such that the width of the groove 3 at the level of the lower and horizontal surface 4 of the seat 1, is greater than the width of the connecting edge 7. The width represents the dimension of the groove 3 considered along a longitudinal axis X of the vehicle. The presence of such a groove 3 in the seat 2 is justified insofar as it is intended to receive an anti-submarining bar 8 made of sheet metal, such a bar 8 making it possible to retain the pelvis of an occupant who would be seated on the seat 1 in the event of an accidental frontal impact of the vehicle against an external obstacle.The presence of the inclined rear edge 6 of the groove 3 will make it possible to accommodate an inclined rear wall of the anti-submarining bar 8, designed to soften the contact conditions between the legs of an occupant who would be seated on the seat 1 and said anti-submarining bar 8 during a phase of normal use of the vehicle. Generally, this anti-submarining bar 8 is obtained by stamping. However, this anti-submarining bar 8 has at least two major drawbacks: - it remains impossible to modify its structural characteristics without changing the equipment and other devices necessary for its manufacture. Indeed, a simple modification of shape and / or dimension requires the use of suitable equipment and / or device which must be redesigned;

[0029] -it has plastic deformation properties which can make it dangerous in the event of an accidental frontal impact of the vehicle against an external obstacle.

[0030] A seat 100 of a seat according to the invention makes it possible to overcome the drawbacks encountered with the seats 1 of seats according to the state of the art.

[0031] Referring to Figure 2, a seat 100 of a seat according to the invention is manufactured by 3D printing and is therefore in the form of a network of hollow meshes, connected to each other by deformable connecting arms. In addition to their manufacturing method, the main difference between the seat 1 of the prior art previously described and the seat 100 according to the invention is that in the seat 100 according to the invention the anti-submarining bar 102 is an integral part of said seat 100. This anti-submarining bar 102 is manufactured simultaneously with the seat 100, during the same 3D printing process and cannot therefore be dissociated from said seat 100.

[0032] The seat 100 according to the invention essentially comprises a first network 101 of meshes having a certain flexibility, and a second network 102 of more rigid meshes, materializing the anti-submarining bar 102. The anti-submarining bar 102 occupies the same place within the seat 100 as that of the anti-submarining bars 8 of the seats 1 of the prior art, because it has exactly the same function as the latter. The anti-submarining bar 102 of a seat 100 according to the invention has a trapezoidal cross-section, delimited by a vertical front edge 105, by a rear edge 106 inclined relative to a vertical axis Z, by a horizontal upper connecting edge 107 and by a horizontal lower connecting edge 108.The upper connecting edge 107 connects upper ends of the front edge 105 and the rear edge 106, and the lower connecting edge 108 connects lower ends of said front edge 105 and said rear edge 106. The inclination of said rear edge 106 is such that the width of the upper connecting edge 107 is less than the width of the horizontal lower connecting edge 108, the width representing the dimension of the anti-submarining bar 102 considered along a longitudinal axis X of the vehicle. The lower connecting edge 108 of the anti-submarining bar is flush with a lower surface 104 of the seat 100. The height of the anti-submarining bar 102 is less than that of the seat 100, so that said anti-submarining bar 102 is not visible from above the seat 102, the height representing the dimension of the anti-submarining bar 102 considered along a vertical axis Z.

[0033] Preferably, the anti-submarining bar 102 has a rigidity which decreases progressively between the lower connecting edge 108 and the upper connecting edge 107, so that a base 109 of this anti-submarining bar 102 is very rigid and an upper zone 110 thereof is flexible. This decrease in rigidity can be:

[0034] -either continuous and monotonous over the entire height of the anti-submarining bar 102,

[0035] -either carried out in stages, and in this case, the decrease in rigidity occurs zone by zone, each zone comprising several superimposed layers of hollow meshes having a constant rigidity.

[0036] The anti-submarining bar 102 of a seat base 100 according to the invention has two major advantages:

[0037] -when the vehicle is in the normal driving phase, an occupant sitting on the seat 100 would not feel or would hardly feel the presence of said anti-submarining bar 102, due to the flexibility of the upper zone 110 thereof which softens the conditions of contact with this bar 102,

[0038] -it has elastic deformation properties due in particular to the presence of the hollow meshes constituting the second network 102. In the event of an accidental frontal impact of the vehicle, the anti-submarining bar 102 will first deform under the effect of contact with the pelvis of the person sitting on said seat 100, before returning to its initial shape, thus not risking causing additional damage due to its permanent deformation.

[0039] The first network 101 of meshes which gives a certain flexibility to the seat 100 and which constitutes the entire seat 100 with the exception of the anti-submarining bar 102, has a front zone 111 constituted by a third network of meshes having a more marked rigidity than the rest of the first network 101. This front zone 111 has the same height as that of the anti-submarining bar 102 and is placed just in front of said bar 102 while being in the continuity of the latter.

[0040] It should be noted that since the seat 100 and the anti-submarining bar 102 are made of open three-dimensional meshes, a material whose rheology meets the need for rigidity under rapid stress, while remaining flexible under slow stress, can be incorporated into said meshes. This incorporation is carried out outside the 3D printing process. Such a material can for example be a silicone gel. The difference in rigidity between the first network 101 and the second network 102 can be obtained by adjusting at least one of the following parameters: - the geometry of the meshes, - the shape of the meshes,

[0041] -the characteristics of arms connecting the meshes of the same network 101, 102 between them.

[0042] For example, for a given mesh geometry, larger meshes will be more flexible than smaller meshes.

Claims

Claims

1. Seat (1, 100) of a vehicle seat obtained by 3D printing, characterized in that it comprises a first extended network (101) of meshes and intended to provide the seat with a certain flexibility of comfort, and a second localized network (102) of meshes located in a front half of the seat (100) and extending over an entire width of said seat (100), and in that the second network of meshes (102) is intended to provide the seat (100) with a certain rigidity to fulfill the function of an anti-submarining bar, the first network (101) of meshes being less rigid than the second network (102) of meshes.

2. Seat according to claim 1, characterized in that the first mesh network (101) and the second mesh network (102) differ from each other by at least one parameter to be chosen from the geometry of the meshes, the dimensions of the meshes and the characteristics of arms connecting the meshes together.

3. Seat according to any one of claims 1 or 2, characterized in that the front half is to be considered in relation to a length of the seat (100), and in that the second network (102) extends over the entire width of said seat (100) while being perpendicular to said length.

4. Seat according to any one of claims 1 to 3, characterized in that the second network (102) of meshes materializing the anti-submarining bar originates on a lower surface (104) of the seat (100) and extends over a height which is less than the total height of the seat (100).

5. Seat according to claim 4, characterized in that the second network (102) of meshes representing the anti-submarining bar has a first lower end (109) comprising at least one layer of very rigid meshes originating on the lower surface (104) of the seat (100) and extending parallel to said surface (104), and in that said second network (102) of meshes has a second upper end (110) materializing the height of said anti-submarining bar (102) and comprising at least one layer of meshes less rigid than the meshes of the first end (109) and extending parallel to said at least one layer of very rigid meshes of the first lower end (109).

6. Seat according to claim 5, characterized in that the second network (102) of meshes representing the anti-submarining bar comprises several intermediate layers of meshes, which are parallel to the layer of meshes of the first lower end (109) and to the layer of meshes of the second upper end (110), and in that the meshes of these intermediate layers have a rigidity which is between that of the meshes of the layer of the first lower end (109) and that of the meshes of the layer of the second upper end (110).

7. Seat according to claim 6, characterized in that the rigidity of the cells of the intermediate layers varies progressively and monotonically between that of the cells of the first lower end (109) and that of the cells of the second upper end (110), and in that the rigidity of the cells of the intermediate layers varies gradually between said first lower end (109) and said second upper end (110).

8. Seat according to any one of claims 6 or 7, characterized in that an upper zone of the second network (102) of meshes representing the anti-submarining bar, comprising the second upper end (110) has a softened contour, so that a person sitting on said seat (100) does not feel the presence of the anti-submarining bar (102) during a phase of routine use of the vehicle.

9. Seat according to any one of claims 1 to 8, characterized in that a product is incorporated outside of 3D printing, in all the meshes making up the seat (100), and in that said product has a rheology meeting the need for rigidity under rapid stress while remaining flexible under slow stress.

10. Seat according to claim 9, characterized in that the product is a silicone gel.

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