FR3137029A1 - Vehicle seat back, vehicle seat and assembly method thereof - Google Patents

Abstract

Vehicle seat back, vehicle seat and associated assembly method The invention relates to a vehicle seat back (12) comprising a frame (28), at least three trim modules (30) formed by a central module of trim (32) and two side trim modules (34). Each of the trim modules (30) is assembled on the frame (28) independently of the other trim modules (30). Each upholstery module (30) comprises a support (70), a padding (60, 72) assembled on the support (70) and a cap (62, 74) covering at least partially the padding (60, 72). The backrest (12) further comprises at least two reversible fixing devices (114, 116), each of the caps (62) of the side trim modules (34) being connected to the cap (74) of the central trim module (32). ) by one of the reversible fixing devices (114, 116). Figure for abstract: Figure 2

Description

Vehicle seat back, vehicle seat and assembly method thereof

The present invention relates, according to a first aspect, to a vehicle seat back, in particular a motor vehicle.

According to a second aspect, the invention relates to a vehicle seat comprising such a backrest.

According to a third aspect, the invention also relates to a method of assembling such a file.

In the automotive field, it is known to produce a vehicle seat back integrating numerous comfort and/or safety functions. To do this, it is known to attach a support to the backrest frame, to mount the various elements necessary for carrying out the comfort and/or safety functions on the support or to the backrest frame, then to cover the resulting set of foam forming the padding. The headdress then wraps the whole thing.

Depending on the number and complexity of the functions to be integrated into the back of a seat, the assembly of a back can be very different on an assembly line. In addition, the assembly operations are long and tedious and require a certain dexterity on the part of the operator, in particular to assemble the cover on the padding. The structure of this type of file also does not allow easy customization of the file, nor the replacement of one or more defective or damaged parts. The operations for dismantling the seat elements at the end of their life are also complex and tedious, which does not facilitate the recycling of the seat.

One of the aims of the invention is to overcome these drawbacks by proposing a seat back that is simple and quick to assemble, easily customizable and presenting a good level of repairability, while maintaining a satisfactory aesthetic appearance.

For this purpose, the invention relates to a vehicle seat back, said back comprising a frame, at least three trim modules formed by at least one central trim module and at least two side trim modules, the side trim modules being arranged on either side of the central trim module in a transverse direction, each of the trim modules being assembled on the frame independently of the other trim modules, each trim module comprising a support, a padding assembled on the support and a cap covering at least partly the padding, the backrest further comprising at least two reversible fixing devices, each of the caps of the side trim modules being connected to the cap of the central trim module by one of the reversible fixing devices.

Thus, the upholstery of such a backrest can easily and quickly be mounted on the backrest frame. In addition, by adapting the components and the cover of the central trim module and/or the side trim modules, it is possible, while always retaining the same general configuration of the backrest with three independent trim modules, to mount seat backs of vehicle having variable functionalities and exterior appearance, improving the customization of the seat. Seat repairability is improved since the trim modules can be replaced independently of each other. Reversible fasteners make it easier to assemble and disassemble the trim modules together and reduce the time required to assemble and disassemble a seat back.

The file according to the invention may also include one or more of the following characteristics, taken individually or in any technically conceivable combination:

- the frame defines a front face and a rear face opposite the front face in a longitudinal direction substantially perpendicular to the transverse direction, the cover of the central trim module comprising a front cover element extending on the side of the front face of the frame between an upper end and a lower end in a direction of elevation substantially perpendicular to the longitudinal direction and the transverse direction, and a rear cap element extending on the side of the rear face between a upper end and a lower end according to the direction of elevation;

- at least the rear cap element is connected to the caps of the side trim modules by the reversible fixing devices, each reversible fixing device extending from the lower end of the rear cap element to the upper end of the rear cover element;

- the front cover element is connected to the frame and/or is fixed to the padding of the central trim module;

- the front cover element is connected to the covers of the side trim modules by said reversible fixing devices, each reversible fixing device extending from the lower end of the front cover element to the lower end of the rear cover element;

- each reversible fixing device is a zipper comprising a first toothed strip fixed on the cap of the central trim module, a second toothed strip fixed on the cap of the corresponding lateral trim module, and a slider adapted to assemble or disassemble the first toothed band and the second toothed band;

- the cover of the central trim module is fixed to an upper end of the padding at a fixing region; And

- the cover of the central trim module is removable.

According to another aspect, the invention also relates to a vehicle seat comprising such a backrest.

According to another aspect, the invention relates to a method of assembling a file as defined above, the method comprising the following steps:

- mount the trim modules on the frame,

- connect the covers of the side trim modules to the cover of the central trim module using the reversible fixing devices.

The description also relates to a method of assembling a vehicle seat back, the back comprising a frame, at least three trim modules formed by at least one central trim module and at least two side trim modules, the modules side trim modules being arranged on either side of the central trim module in a transverse direction, each of the trim modules being assembled on the frame independently of the other trim modules, each trim module comprising a support, an assembled padding on the support and a cap covering at least partly the padding,

the frame defining a front face and a rear face opposite the front face in a longitudinal direction substantially perpendicular to the transverse direction, the cover of the central trim module comprising a front cover element extending on the side of the front face of the frame and a rear cover element extending from the side of the rear face, the method comprising the following steps:

- mount the trim modules on the frame,

- fix the front cover element and the rear cover element between them to form a central cover assembly,

- place the central cover assembly on the padding of the central trim module,

- connect the central cover assembly to the covers of the side modules.

The method may also include one or more of the following characteristics, taken individually or in any technically conceivable combination:

- the front cover element and the rear cover element are fixed together by at least one seam,

- the front cap element extends on the side of the front face of the frame between an upper end and a lower end in a direction of elevation substantially perpendicular to the longitudinal direction and to the transverse direction, and an element of rear cap extending on the side of the rear face between an upper end and a lower end in the direction of elevation, the front cap element and the rear cap element being fixed together by the upper ends of said elements of cap,

- the central cover assembly and the covers of the side trim modules are connected by reversible fixing devices.

Other aspects and advantages will appear on reading the description which follows, given by way of example and made with reference to the appended drawings including:

there is a schematic view of a seat according to a first embodiment of the invention,

there is an exploded view of the seat back of the ,

Figures 3 and 4 are respectively views of the front and rear of the backrest of the .

In the remainder of the description, the terms "front", "rear" are used with reference to a longitudinal direction L which corresponds to the longitudinal direction of extension of the seat, which is the normal direction of advancement of the vehicle in which the seat is mounted. The terms “left” and “right” are used with reference to a transverse direction T substantially perpendicular to the longitudinal direction L. The terms “top”, “bottom”, “lower” and “upper” are used with reference to a direction of elevation Z substantially perpendicular to the longitudinal direction L and the transverse direction T.

In reference to the , a vehicle seat 10 is described, such as a motor vehicle seat, comprising a backrest 12. The seat 10 further comprises a seat 14 connected to the backrest 12 and a headrest 16 assembled on the backrest 12. For example , in known manner, the backrest 12 is pivotally mounted relative to the seat 14 around a transverse axis 18.

As visible in more detail on the , the backrest 12 comprises a frame 28 and at least three trim modules 30 mounted on the frame 28. In particular, in the example illustrated, the backrest 12 comprises a central trim module 32 and two side trim modules 34 arranged on either side of the central trim module 32 in the transverse direction T, forming a right side trim module 36 and a left side trim module 38.

In the example illustrated, the frame 28 forms a frame comprising two flanges 42 spaced from one another in the transverse direction T. The flanges 42 are connected to each other by a lower crosspiece 48 and a upper crosspiece 50 extending in the transverse direction T to the lower and upper ends of the flanges 42 and spaced apart from each other in the direction of elevation Z.

The frame 28 defines a front face 52 and a rear face 54 extending on either side of the support frame 40 in the longitudinal direction L. The rear face 54 corresponds for example to the back of the backrest 12, facing towards the rear of the vehicle when the seat 10 faces the front of the vehicle. The front face 52 extends for example on the side of the passenger receiving surface, on which the passenger's back rests when seated on the seat 10.

The frame 28 comprises, for example, metal elements mounted between the flanges 42 on the side of the front face 52 of the frame 28 and forming a deflection sheet 59.

In the example illustrated, the central trim module 32 defines a support surface 56 intended to support the passenger, and in particular the back of the passenger. The lateral trim modules 34 are arranged projecting relative to the support surface 56 of the central trim module 32. Each lateral trim module 34 defines a support surface 58 intended to receive in support at least one lateral part of the back of the passenger. The central trim module 32 and the side trim modules 34 delimit between them a passenger reception cradle.

Each of the trim modules 30 is assembled on the frame independently of the other trim modules 30. In other words, the trim modules 30 pre-exist their assembly on the frame 28 of the backrest 12. Thus, the trim modules 30 are not not made by overmolding on the frame 28 of the backrest 12 and/or structural elements already secured to the frame 28 of the backrest 12. This does not prevent each of the trim modules 30 from being able to be made in part by overmolding of a support. However, in this case, the overmolding is carried out prior to the assembly of the trim modules 30 on the frame 28. In other words, each trim module 30 can be assembled on the frame 28 while the other modules of fittings 30 are not yet mounted on the frame 28.

Each lateral trim module 34 may include a support, for example in the form of a plate, a padding 60 fixed on the support and a cap 62 surrounding at least part of the padding 60. Each lateral trim module 34 extends mainly along the direction of elevation Z between an upper end 64 and a lower end 66.

Each lateral trim module 34 is mounted on the frame 28. In particular, the support of each lateral trim module 34 is mounted on a corresponding flange 42 of the frame 28, for example by elastic fitting and/or screwing, and /or by force fixing.

The padding 60 is for example a foam body, such as polyurethane foam or the like. The padding 60 gives the lateral trim module 34 its comfort qualities. The padding 60 is preferably one-piece. For example, the padding 60 is obtained by cutting from a panel. The padding 60 is glued or elastically fitted onto the support. The padding 60 then preferably comprises inserts forming elastic nesting reliefs on the support. Alternatively, the padding 60 is overmolded on the support.

The cap 62 covers at least partially the padding 60 of the lateral trim module 34 so as to form the exterior surface 68 of the lateral trim module 34, that is to say the visible part of the lateral trim module 34 from the vehicle interior. The cover 62 gives its appearance and feel to the side trim module 34. The cover 62 is for example made of fabric or leather, natural or synthetic material.

According to various embodiments, each lateral trim module 34 comprises for example one or more elements each associated with one or more passenger comfort or safety functions. For example, each side trim module 34 comprises at least one inflatable pocket of a device for adjusting the lateral support of the passenger's back fixed on the support of each side trim module, and/or at least inflatable massage cushion and/or or a side airbag system. Generally speaking, each of the side trim modules 34 and/or the central trim module 32 can be equipped with one or more comfort and/or safety system(s).

The central trim module 32 preferably comprises a support 70, for example in the form of a plate, a padding 72 fixed on the support 70 and a cap 74 covering at least partly the padding 72.

The support 70 extends in the direction of elevation Z between a lower end 76 and an upper end 78, preferably curved. The upper end 78 rests on the upper crosspiece 50 of the frame 28. The support 70 is assembled on the frame 28 on the side of the front face 52 of the frame 28. In particular, the lower end 76 of the support 70 is assembled on the lower crosspiece 48 of the frame 28. To do this, the upper 78 and lower 76 ends of the support 70 and the upper 50 and lower crosspieces 48 of the frame 28 respectively, cooperate with each other by means of devices of fixation. For example, the fixing devices include complementary reliefs for forceful fixing of the central trim module 32 and/or complementary elastic interlocking reliefs, such as clips, for fixing by elastic interlocking.

The padding 72 is for example assembled on the support 70. The padding 72 extends in the direction of elevation Z between an upper end 73 and a lower end 75. The padding extends only on the side of the front face of the frame 28. The padding 72 is for example a foam body, such as polyurethane foam. When the passenger uses the seat, he leans on the padding 72. The padding 72 gives the central trim module 32 its comfort qualities. The padding 72 is preferably one-piece. For example, the padding 72 is obtained by cutting from a panel. The padding 72 is glued or fitted elastically onto the support 70. The padding 72 then preferably comprises inserts forming elastic nesting reliefs on the support 70. Alternatively, the padding 72 is overmolded onto the support 70.

The cap 74 covers the frame 28 and the padding 72 so as to form the exterior surface 82 of the central trim module 32, that is to say the visible part of the central trim module 32 from the passenger compartment of the vehicle. In particular, the cap 74 extends facing the frame 28 on the side of the rear face 54 of the frame 28. The cap 74 gives its appearance and its touch to the central trim module 32. The cap 74 is for example in fabric or leather, in natural or synthetic material.

In the example illustrated, the cover 74 comprises a front cover element 86 extending on the side of the front face 52 of the frame 28 and a rear cover element 88 extending on the side of the rear face 54 of the frame 28. frame 28. In the example illustrated, the front cover element 86 and the rear cover element 88 are located on either side of the fixing region 84 in the longitudinal direction L.

The front cap element 86 extends mainly in the direction of elevation Z between a lower end 90 and an upper end 92. The front cap element 86 further extends in the transverse direction T between a side edge right 94 and a left side edge 96. The front cover element 86 covers the padding 72. In the example illustrated, the front cover element 86 is fixed on the padding 72, for example by gluing. Preferably, the entire surface of the front cover element 86 is fixed on the padding 72.

The rear cap element 88 extends mainly in the direction of elevation Z between a lower end 98 and an upper end 100. The lower end 98 preferably forms a free edge. The rear cap element 88 further extends in the transverse direction T between a right side edge 102 and a left side edge 104. The rear cap element 88 covers the frame 28 and more particularly the rear face 54 of the frame 28. Preferably, the rear cap element 88, the frame 28 and the support 70 of the central trim element 32 delimit between them an empty interstitial space, that is to say that the interstitial space is devoid of elements arranged in the interstitial space between the support 70 and the rear cap element 88.

According to the invention, the backrest 12 further comprises at least two reversible fixing devices 106. Each of the caps 62 of the side trim modules 34 is connected to the cap 74 of the central trim module 32 by at least one reversible fixing device 106.

By “reversible fixing device” is meant a fixing device which makes it possible to assemble and disassemble the cap 62 of the side trim modules 34 and the cap 74 of the central trim module 32 without affecting the physical integrity of the caps 62 , 74. Advantageously, each reversible fixing device 106 is a zipper comprising a first toothed strip 108 fixed on the cap 74 of the central trim module 32, a second toothed strip 110 fixed on the cap 62 of the lateral trim module 34 corresponding, and a slider 112 adapted to assemble or disassemble the first toothed band 108 and the second toothed band 110.

Preferably, the slider 112 comprises a gripping member allowing a user to move the slider 112 along the first toothed strip 108 and the second toothed strip 110 during assembly and disassembly.

It is understood that, according to certain embodiments, the gripping member is intended to remain integral with the slider 112, once the cap 62 of the side trim modules 34 and the cap 74 of the central trim module 32 assembled together. According to other embodiments, the gripping member is separated from the slider 112 once the cap 62 of the side trim modules 34 and the cap 74 of the central trim module 32 assembled together. It nevertheless remains that the cap 62 of the side trim modules 34 and the cap 74 of the central trim module 32 can be disassembled by repositioning the gripping member on the slider 112 or by using a tool adapted to be fixed on the cursor 112 and allow the cursor 112 to move along the first toothed strip 108 and the second toothed strip 110.

Alternatively, the slider 112 does not have a gripping member. The movement of the cursor 112 along the first toothed strip 108 and the second toothed strip 110 is carried out using a tool removably fixed on the cursor 112.

As a variant (not shown), the reversible fixing device 106 is a self-gripping fixing device comprising a first textile strip comprising hooks fixed on one of the cap 74 of the central trim module 32 and the cap 62 of the lateral trim module 34, a second textile strip comprising loops fixed on the other of the cap 74 of the central trim module 32 and the cap 62 of the lateral trim module 34, the loops cooperating with the hooks of the first strip .

In the example illustrated, the backrest 12 comprises a first reversible fixing device 114 and a second reversible fixing device 116. The first reversible fixing device 114 connects the right lateral edge 94 of the front cover element 86 and the edge right side 102 of the rear cover element 88 to the cover 62 of the side trim module 34, and in particular to the cap 62 of the right side trim module 36. The second reversible fixing device 116 connects the left side edge 96 of the front cover element 86 and the left side edge 104 of the rear cover element 88 to the cover 62 of the side trim module 34, and in particular to the cap 62 of the left side trim module 38. Each of the fixing devices 114, 116 extend from the lower end 90 of the front cap element 86 to the lower end 98 of the rear cap element 88. The first device 114 extends along the right side edge 94 of the front cover element 86 and along the right side edge 102 of the rear cover element 88. The second device 116 extends along the left side edge 96 of the front cover element 86 and along the left lateral edge 104 of the rear cover element 88. Thus, each of the reversible fixing devices 114, 116 extends on either side of the frame 28, on the side of the front face 52 and on the side of the rear face 54. Preferably, the first toothed strip 108 and the second toothed strip 110 are engaged with one another on the side of the front face 52 and the cursor 112 is moved from the side of the front face 52 towards the side of the rear face 54. Alternatively, the first toothed strip 108 and the second toothed strip 110 are engaged with each other on the side of the rear face 54 and the cursor 112 is moved from the side of the rear face 54 towards the side of the front face 52.

Preferably, the reversible fixing devices 114, 116 are symmetrical with respect to the median elevation plane P of the backrest 12. The median elevation plane P is a plane substantially perpendicular to the transverse direction T which divides the backrest 12 in two left and right parts substantially identical to each other.

According to various embodiments, the central trim module 32 comprises one or more elements each associated with one or more passenger comfort and/or safety functions. For example, the central trim module 32 comprises a backrest ventilation device, and/or a device for massaging and supporting the passenger's back and/or a heating device and/or at least one speaker.

A method of assembling a file 12 as described above is now described.

First of all, the method includes a step consisting of providing a frame 28 of backrest 12 and the three upholstery modules 30. At this step, the frame 28 of the backrest 12 can possibly already be fixed on the seat 14.

The trim modules 30 are then mounted on the frame 28. The order of assembly of the trim modules 30 may depend on the geometry of the supports of the different trim modules 30 and on the nature of the fixing on the frame 28 in particular. . We can for example start by mounting each of the side trim modules 34 on the frame 12, then then place the central trim module 32 between the two side trim modules 34. Alternatively, we first start by mounting the module central trim 32 on the frame 12, then each of the side trim modules 34 is placed on the frame 12.

Each of the trim modules 30 is assembled on the frame 28 using one or more of the fixing devices mentioned above.

The caps 62 of the side trim modules 34 are then connected to the cap 74 of the central trim module 32 using the reversible fixing devices 114, 116.

In particular in the example illustrated, for the first reversible fixing device 114, the first toothed strip 108 of the cap 74 of the central trim module 32 is engaged with the second toothed strip 110 of the cap 62 of the right side trim module 36 at the level of the slider 112. The slider 112 is then slid, from the lower end 90 of the front cover element 86, along the right lateral edge 94 of the front cover element 86 to assemble the element front cover 86 to the cover 62 of the right side trim module 36 on the side of the front face 52 of the frame 28, then along the right side edge 102 of the rear cover element 88 to assemble the cover element rear cover 88 to the cover 62 of the right side trim module 36 on the side of the rear face 54 of the frame 28. The same operation is repeated for the second reversible closing device 116 to assemble the left side edge 96 of the front cover element 86 and the left side edge 104 of the rear cover element 88 to the cover 62 of the left side trim module 38.

Alternatively, for the first reversible fixing device 114, the first toothed strip 108 of the cap 74 of the central trim module 32 is engaged with the second toothed strip 110 of the cap 62 of the right side trim module 36 at the level of the slider 112. The slider 112 is then slid, from the lower end 98 of the rear cap element 88, along the right lateral edge 102 of the rear cap element 88 to assemble the rear cap element 88 to the cover 62 of the right side trim module 36 on the side of the rear face 54 of the frame 28, then along the right side edge 94 of the front cover element 86 to assemble the front cover element 86 to the cover 62 of the right side trim module 36 on the side of the front face 52 of the frame 28. The same operation is repeated for the second reversible closing device 116 to assemble the left side edge 96 of the front cover element 86 and the left side edge 104 of the rear cover element 88 to the cover 62 of the left side trim module 38.

A second embodiment (not shown) is described in terms of differences from the first embodiment.

In this embodiment, the cover 74 is only fixed on the padding 72 at the level of the upper end of the padding 72 along at least one fixing region. For example, the cap 74 is sewn or glued to the padding 72 along at least one fixing region formed by at least one sewing or gluing line extending along an axis substantially parallel to the transverse direction T.

The method of assembling the backrest 12 is identical to that described in the first embodiment.

A third embodiment (not shown) is described in differences with respect to the first embodiment.

In this embodiment, the cap 74 of the central trim module 32 is not fixed to the padding 72 of the central trim module 32. Thus, the cap 74 of the central trim module 32 is removable. By “removable” we mean that the cap 74 of the central trim module 74 is configurable between a detached configuration in which the cap 74 is arranged away from the side trim modules 34 and the padding 72 of the central trim module. 32, and an assembled configuration in which the cap 74 of the central trim module 32 is at least partly assembled to one of the caps 62 of the side trim modules 34. It is understood that the change in configuration is carried out without affecting the physical integrity of the caps 74, 62 of the trim modules 30 and of the padding 72 of the central trim module 32.

The method of assembling a file 12 according to the second embodiment is identical to the method of assembling a file 12 according to the first embodiment.

The customization and reparability of the backrest 12 are improved since the cover 74 of the central trim module 32 can be easily changed without it being necessary to dismantle the trim modules 30 of the frame 28 of the backrest 12.

A fourth embodiment (not shown) is now described with differences from the first embodiment.

In this embodiment, the reversible fixing devices 114, 116 only connect the rear cover element 88 to the side trim modules 34. In particular, the first reversible fixing device 114 connects the right side edge 102 of the element of rear cap 88 to the cap 62 of the side trim module 34, and in particular to the cap 62 of the right side trim module 36. The second reversible fixing device 116 connects the left side edge 104 of the rear cap element 88 to the cap 62 of the side trim module 34, and in particular to the cap 62 of the left side trim module 38. In this embodiment, each reversible fixing device 114, 116 extends from the lower end 98 of the rear cap element 88 to the upper end 100 of the rear cap element 88. Thus, each of the reversible fixing devices 114, 116 extends only on the side of the rear face 54 of the frame 28.

Preferably, during assembly, the first toothed strip 108 and the second toothed strip 110 are engaged with one another at the upper end 100 of the rear cap element 88 and the slider 112 is moved from the upper end 100 towards the lower end 98 of the rear cap element 88.

In this embodiment, the front cover element 86 is for example fixed on the frame 28 on the side of the front face 52. Preferably, each side edge 94, 96 of the front cover element 86 comprises a plurality of fixing members cooperating with a part of the frame 28 and in particular with the flanges 42 of the frame 28.

When assembling the backrest 12, preferably, the front cover element 86 is first assembled on the frame 28 before the rear cover element 88 is connected to the covers 62 of the side trim modules 34.

Thus, the backrest 12 according to the invention is particularly advantageous. Indeed, the upholstery of such a backrest 12 can easily and quickly be mounted on the frame 28 of the backrest 12. In addition, by adapting the components and the cover 74 of the central upholstery module 32 and/or the side modules of trim 34, it is possible, while always retaining the same general configuration of the backrest 12 with three independent trim modules 30, to mount vehicle seat backs 12 having variable functionalities and exterior appearance, improving the personalization of the seat 10 The repairability of the seat 10 is improved since the trim modules 30 can be replaced independently of each other. The reversible fixing devices 112, 114 facilitate the assembly of the trim modules 30 together and reduce the time necessary for assembling a seat back 12 10. The rear cover element 88 makes it possible to obtain a backrest presenting a satisfactory aesthetic appearance without the need to use an expensive shell which weighs down the backrest 12.

Claims (10)

Backrest (12) of vehicle seat (10), said backrest (12) comprising a frame (28), at least three trim modules (30) formed by at least one central trim module (32) and at least two modules lateral trim modules (34), the lateral trim modules (34) being arranged on either side of the central trim module (32) in a transverse direction (T), each of the trim modules (30) being assembled on the frame (28) independently of the other trim modules (30), each trim module (30) comprising a support (70), a padding (60, 72) assembled on the support (70) and a cover (62, 74) covering at least partly the padding (60, 72), the backrest (12) further comprising at least two reversible fixing devices (114, 116), each of the caps (62) of the side trim modules (34) being connected to the cover (74) of the central trim module (32) by one of the reversible fixing devices (114, 116). Backrest (12) according to claim 1, in which the frame (28) defines a front face (52) and a rear face (54) opposite the front face (52) in a longitudinal direction (L) substantially perpendicular to the transverse direction (T), the cap (74) of the central trim module (32) comprising a front cap element (86) extending on the side of the front face (52) of the frame (28) between an upper end (92) and a lower end (90) in a direction of elevation (Z) substantially perpendicular to the longitudinal direction (L) and the transverse direction (T), and a rear cap element (88) extending on the side of the rear face (54) between an upper end (100) and a lower end (98) in the direction of elevation (Z). Backrest (12) according to claim 2, in which at least the rear cover element (88) is connected to the covers (62) of the side trim modules (34) by the reversible fixing devices (114, 116), each reversible fastener (114, 116) extending from the lower end (98) of the rear cowl member (88) to the upper end (100) of the rear cowl member (88) . Backrest (12) according to claim 3, in which the front cover element (86) is connected to the frame (28) and/or is fixed to the padding (72) of the central trim module (32). Backrest (12) according to claim 3 or 4, in which the front cover element (86) is connected to the covers (62) of the side trim modules (34) by said reversible fixing devices (114, 116), each reversible fastener (114, 116) extending from the lower end (98) of the front cowl member (86) to the lower end (98) of the rear cowl member (88) . Backrest (12) according to any one of claims 1 to 5, in which each reversible fixing device (114, 116) is a zipper comprising a first toothed strip (108) fixed to the cover (74) of the central module trim (32), a second toothed strip (110) fixed on the cap (62) of the corresponding lateral trim module (34), and a slider (112) adapted to assemble or disassemble the first toothed strip (108) and the second toothed band (110). Backrest (12) according to any one of claims 1 to 6, in the cap (74) of the central upholstery module (32) is fixed to an upper end (73) of the padding (72) at a region of fixation. Backrest (12) according to any one of claims 1 to 6, in which the cover (74) of the central trim module (32) is removable. Vehicle seat (10) comprising a backrest (12) according to any one of claims 1 to 8. Method of assembling a file (12) according to any one of claims 1 to 8, the method comprising the following steps:
- mount the trim modules (30) on the frame (28),
- connect the caps (62) of the side trim modules (34) to the cap (74) of the central trim module (32) using the reversible fixing devices (114, 116).