Assembly system for a cover piece with a support piece and resulting assembly of parts

Abstract

Assembly system of a trim piece with a support piece and resulting assembly of parts The invention relates to an assembly system of a trim piece (1) with a support piece (2), in which said support piece (2) has at least one through opening (3) in which is mounted with elastic retention a separate U-shaped element (4), forming a female receiving clip, and system in which the trim piece (1) has at least one male or protruding element, suitable and intended to engage, by insertion from the front face (2') of the support piece (2), in said U-shaped element (4), preferably with locking.Assembly system characterized in that it also comprises a stop means (7) substantially blocking any translational displacement, or at least any significant translational displacement, of the U-shaped element (4) beyond its mounting position in the through opening (3), in the direction from the front face (2') to the rear face (2'') of the support part (2), said stop means (7) being an integral part of the support part (2) or of a part adjacent to it. Figure to be published with the abbreviation: Fig. 9.

Description

Title of the invention: Assembly system for a covering part with a support part and assembly of resulting parts

[0001] The present invention relates to the field of interior or exterior vehicle equipment, more particularly the trimming of vehicle parts, such as doors, and has as its objects a system for assembling a trim piece with a support piece, a set of parts comprising such an assembly system, and intended to be installed in a vehicle and a method for assembling two such parts together.

[0002] Certain interior vehicle equipment components are assembled in two or more assembly stages, and in this case, a second part (or trim piece) is assembled with a first part (support piece) that has already been installed. The second part may partially or completely cover the first part. It is also possible for several second trim pieces to be mounted on a first support piece. The latter has a front face and a rear face, and the trim piece is mounted on the front face of this support piece.

[0003] To achieve this assembly, systems for assembling a covering piece with a support piece are known, in particular, in which said support piece has at least one through opening in which is mounted with elastic retention a separate U-shaped element, forming a female receiving clip, the two opposite walls of said U-shaped element coming directly into contact with opposite edges of said through opening and a part of this element including the bottom connecting the two walls extending beyond the rear face of said support piece.

[0004] Furthermore, in this type of system, the covering piece includes at least one male or protruding element, of the type male clip, shaft, lug, harpoon, tab, pin or tongue, suitable and intended to come into engagement, by insertion from the front face of the support element, in said U-shaped element, preferably with locking and possibly with elastic deformation.

[0005] Generally, such an assembly of the two parts by simple push is an assembly by multiple interlockings, with elastic locking or by notches of the interlockings.

[0006] However, it frequently happens that at least some of the female receiving clips are pushed through the through holes, the elastic grip of the hooks at the ends of the two walls not being strong enough to counter the pushing force exerted on the bottom of the U-shaped female clip element when The aforementioned male or protruding element comes to rest against it. The clip then detaches from the support piece, passes completely through the opening in which it was mounted, and falls to the rear of the support piece. The same result of clip loss can also occur if the trim piece is improperly handled during installation.

[0007] However, the support piece, which is also generally a major structural part, is normally pre-mounted on the part of the car concerned, before the installation of the added trim piece, it is necessary to remove it to retrieve this or these clips, for reasons of safety (loose element) and / or noise during rolling.

[0008] US patent 5533237 already discloses the possibility of installing a plastic part (shaped like a bathtub) that forms an enclosure around the U-shaped element and completely receives the latter, interposed between said element and the edges of the through-hole with which said plastic part is inserted for mounting. This solution thus requires the supply and installation of an additional part for each through-hole (additional part and mounting operation).

[0009] The present invention aims to overcome these drawbacks and to provide a simple, inexpensive solution, not requiring any additional parts and easily integrated into manufacturing and assembly processes, without modifying the assembly process and without significantly complicating the manufacture of parts.

[0010] To this end, it relates to a system for assembling a cover piece with a support piece, the support piece having a front face and a rear face and the cover piece being intended to be mounted on the front face of this support piece, a system in which said support piece has at least one through opening in which a separate U-shaped element, forming a female receiving clip, is mounted with elastic retention, the two opposite walls of said U-shaped element directly engaging with opposite edges of said through opening and a part of this element comprising the base which connects the two walls extending beyond the rear face of said support piece, and a system in which the cover piece has at least one male or protruding element, of the type male clip, shaft, lug, hook, tab, pin or tongue, suitable and intended to engage by insertion from the front face of the support piece,in said U-shaped element, preferably with locking, an assembly system characterized in that it also comprises a stopping means substantially blocking any translational movement, or at least any significant translational movement, of the U-shaped element beyond its mounting position in the through opening, in the front-to-rear-face direction, said stopping means being an integral part of the support piece or of a piece adjacent to the latter and assembled with it.

[0011] The invention will be better understood from the following description, which relates to preferred embodiments, given by way of non-limiting examples, and explained with reference to the accompanying schematic drawings, in which:

[0012] [Fig-1] is a partial perspective view of a part of a vehicle (here a door), equipped with a support piece (here a door panel or trim) on which a trim piece is being mounted, with implementation of the assembly system according to the invention, the support piece having several through holes equipped with female receiving clips;

[0013] [Fig.2A] is a detailed view and at another scale of a part of [Fig.1], centered on the dressing piece;

[0014] [Fig.2B] is a detail view, similar to that of [Fig.2B], but representing only the support piece;

[0015] [Fig.3] is a partial cross-sectional view, at the level of a through-hole (equipped with a female receiving clip), of the support piece and the cover piece shown in Figures 1 and 2a, during assembly;

[0016] [Fig.4] is a perspective view at a different scale of a female receiving clip equipping the support part of figures 1 to 3;

[0017] [Fig.5] is a partial view, from the rear face of the support piece shown [Fig.3] and along direction D, of the region of the through opening equipped with the clip;

[0018] [Fig.6] is a partial cross-sectional view similar to that of [Fig.3], illustrating an embodiment of the solution according to the invention;

[0019] [Fig.7] is a partial perspective view similar to that of [Fig.5], illustrating another embodiment of the solution according to the invention;

[0020] [Fig.8A] is a view at another scale of the object represented [Fig.7];

[0021] [Fig.8B] is a partial elevation view of an alternative embodiment of the mode of realization of [Fig.7] and 8A;

[0022] [Fig.9] is a cross-sectional view along AA of the object in [Fig.7], similar to those in Figures 3 and 6;

[0023] [Fig.1OA] and [Fig.1OB] are partial views at different scales illustrating two variants of another embodiment of the solution according to the invention;

[0024] [Fig. 11 A] is a perspective view along direction V of the object represented [Fig.lOA] ;

[0025] [Fig.llB] is a cross-sectional view along BB of [Fig.lOA] or [Fig.lOB], similar to those in Figures 3, 6 and 9;

[0026] [Fig.12A] and [Fig.12B] are partial views at different scales illustrating yet another embodiment of the solution according to the invention, [Fig.12A] being a view of the through orifice from the rear face of the support piece and [Fig.12B] being a view of this orifice from the front face (no clip being in place);

[0027] [Fig.13] is a view similar to that of [Fig.12A], at a different scale and with the clip in place in the through opening;

[0028] [Fig.14A] and [Fig.14B] are cross-sectional views along 1-1 and along 2-2 respectively of the object represented [Fig.13].

[0029] Figures 1 to 14 illustrate, in part, a system for assembling a cover piece (1) with a support piece (2), the support piece (2) having a front face (2') and a rear face (2”) and the cover piece (1) being intended to be mounted on the front face (2') of this support piece (2).

[0030] In this system, said support piece (2) comprises at least one through opening (3) in which a separate U-shaped element (4), forming a female receiving clip, is mounted with elastic retention. The two opposing walls (5, 5') of said U-shaped element (4) directly engage with opposite edges (3') of said through opening (3), and a portion (4') of this element (4) includes the base (4") which connects the two walls extending beyond the rear face (2") of said support piece (2). Also in this system, the cover piece (1) comprises at least one male or projecting element (6), of the type male clip, shaft, lug, barb, tab, pin, or tongue, adapted and intended to engage, by insertion from the front face (2') of the support piece (2), into said U-shaped element (4), preferably with locking, in particular elastic locking.

[0031] As shown by way of examples in figures 3, 6 and 11, the free edges of the walls (5 and 5') of the U-shaped clip-forming profile element (4) advantageously have hooks (5”) which engage under elastic or spring stress with the opposite elongated edges (3') of the through holes (3), in the form of oblong holes or slots.

[0032] In accordance with the invention, this assembly system also includes a stop means (7) substantially blocking any translational movement, or at least any significant translational movement, of the U-shaped element (4) beyond its mounting position in the through opening (3), in the direction of front face (2') to rear face (2”), said stop means (7) being an integral part of the support piece (2) or of a piece (8) adjacent to the latter and assembled with it.

[0033] Thanks to these provisions, the invention makes it possible to overcome the drawback mentioned in the introduction, the element (4) being prevented from passing through the opening (3) in which it is mounted, and also to provide a solution meeting the objective sought.

[0034] The expression "significant translational displacement" is to be understood herein as any displacement sufficient to disengage the two opposite walls (5, 5') of the U-shaped element (4) in question from their grip on the edges (3') of the relevant through opening (3), and thus ultimately cause it to fall to the rear of the support piece (2). Such a displacement can occur not only in case of excessive pressure of the male or protruding element (6) at the bottom (4”) of the U-shaped female element (4), but also in case of off-center insertion of said male or protruding element (6) in relation to the relevant through opening (3), likely to cause a disengagement of the grip of one of the two walls (5, 5') with the corresponding edge (3') of said opening.

[0035] As illustrated in Figures 1 and 2 by way of example, and within the framework of preferred applications of the invention, the support piece (2) comprises at least two, preferably several, through openings (3), each provided with a U-shaped element (4). Symmetrically and complementaryly, the cover piece (1) comprises as many male or projecting elements (6), of the type male clip, shaft, lug, hook, tab, pin, or tongue, each adapted and intended to engage, from the front face (2') of the support piece (2), in a corresponding U-shaped element (4). At least a majority of said male or projecting elements (6) are advantageously arranged by being distributed along the periphery of said cover piece (1), and at least some of said openings (3), possibly or preferably all of them, are provided with a locking stop (7).

[0036] As can be seen from the following description and the attached figures, the blocking stop means (7) can practically take different forms.

[0037] In accordance with a first embodiment illustrated in figures 7 to 9, resulting in a simple form limited to the function to be performed, the blocking stop means (7) consists of a rib formed on the rear face of the support piece (2) or of a piece (8) adjacent to the latter, this rib (7) being arranged opposite and at a distance from the relevant through opening (3) and bearing, or almost bearing, on the bottom (4”) of the U-shaped element (4) mounted in this opening (3), extending along said bottom (4”) or transversely with respect to the latter and being connected to said rear face (2”) by bosses or similar formations (9) formed around the relevant through opening (3).

[0038] The means (7) is thus limited to a simple transverse bar, arranged opposite the background (4”) and along the entire length of the latter.

[0039] The notion of "almost in support" is to be understood in the present as meaning that the stopping means (7) is at least sufficiently close to the bottom (4") of the U-shaped element (4), without necessarily being in contact with it, so as not to allow a movement of this element (4) which would cause the latter to detach or disengage from the edges (3') of the through opening (3) in which it is inserted, and therefore ultimately its fall to the rear of the support piece (2).

[0040] In order to ensure proper relative positioning between the means (7) and the U-shaped element (4), or even to ensure proper mounting of the latter in its opening (3), It may be provided, as shown for example in Figures 8B and 9, that the rib (7) has a lug (10) which engages with a complementary shape or cutout (11) present in the bottom (4”) of the U-shaped element (4) mounted in the through opening (3) opposite said rib (7).

[0041] Such a rib (7) can also consist of an extension of a neighboring part (8), in the form of a wing or a rod, connected to this part at only one end or at both ends.

[0042] In accordance with another embodiment, and as shown in Figures 10 to 14, the blocking stop means (7) consists of a profiled formation with a U-shaped cross-section, formed in one piece with the rear face (2”) of the support piece (2) around the through opening (3) considered and surrounding the part (4'), comprising the bottom (4”) connecting the two walls (5, 5') and extending beyond the rear face (2”) of said support piece (2), of the U-shaped element (4) mounted in this through opening (3), said formation (7) being supported against said bottom (4”) of the U-shaped element (4) concerned, and possibly at least partially against the two opposite walls (5 and 5') of said element (4). Thus, the part (4') of the element (4) protruding from the side of the rear face (2' ') is further limited in displacement, not only in translation along the direction of introduction (DI)-direction front face to rear face-, but also laterally.

[0043] According to a variant of this embodiment, illustrated in [Fig.6], the blocking stop means (7) consists of a profiled formation with a U or C cross-section, formed in one piece with the part (8) adjacent to the support part (2), arranged around the considered through opening (3) of this support part (2) and surrounding the part (4'), comprising the bottom (4”) connecting the two walls (5, 5') and extending beyond the rear face (2”) of said support part (2), of the U-shaped element (4) mounted in this through opening (3), said formation (7) being supported against said bottom (4”) of the U-shaped element (4) concerned, and possibly at least partially against the two opposite walls (5 and 5') of said element (4).

[0044] The blocking stopping means (7) consisting of a profiled formation with a U or C cross-section can have an open structure (figures 12 to 14), partially closed (figures 10A and 11A) or totally closed ([Fig.1OB]).

[0045] Thus, as shown in Figures 10 and 11 and in accordance with two variants of another embodiment of the invention, the blocking stop means (7) may consist of an encapsulating casing surrounding the part (4') of the U-shaped element (4) which includes the base (4”) connecting the two walls (5, 5') and which extends beyond the rear face (2”) of the support piece (2). This casing defines a partially or totally closed enclosure around the relevant through opening (3) and on said rear face (2”), this casing (7) being either formed in one piece with the rear face (2”) of the support piece (2) around the through opening (3) considered, or formed in one piece with a piece (8) adjacent to said support piece (2) and assembled with it.

[0046] When the blocking stop means (7) in the form of an encapsulating enclosure constitutes a totally closed enclosure, this can form a watertight barrier (water and / or air) around the through opening (3) on the side of the rear face (2”).

[0047] According to a preferred application of the invention, the opening or each through opening (3) has an elongated shape, of the oblong hole or slot type, and in that the element or each separate U-shaped element (4), forming a female receiving clip, has an elongated or profiled shape with a U-shaped section.

[0048] Furthermore, and favorably, the support piece (2) and at least the male or protruding elements (6) of the cover piece (1), and optionally also the adjacent piece (8), are made of a thermoplastic material, the U-shaped element or each separate element (4), forming a female receiving clip and inserted with hooking and locking by spring effect into a through opening (3) of the support piece (2), being made of metal, or of a plastic material of equivalent rigidity and strength. In addition, the U-shaped elements (4) advantageously have internal notches, slots, or spring blades (12) intended to retain the male or protruding element (6) received in this separate U-shaped element (4). This or these elastic retention means (12) may optionally consist of local deformations of the walls (5, 5).

[0049] When several retaining means (7) are present, they may all be of the same type mentioned above (rib, U-shaped profile, encapsulating casing), or of at least two different types. They may also all be present on the support part (2), all be present on the adjacent separate part (8), or be distributed between these two parts, as appropriate depending on assembly constraints, the installation environment, manufacturing constraints or ease of one or the other part, or similar circumstances.

[0050] In particular, the practical variants of the invention shown in figures 7 to 9 and 12 to 14 allow the stopping means (7) to be made in a single piece with the support piece (2), without complicating the manufacturing by molding of the latter.

[0051] The invention also relates, as illustrated at least partially in the attached figures, to a set of parts (1, 2), intended to cover a part (13) of a motor vehicle or to line the interior of such a part (13), in particular the interior of a door.

[0052] This assembly comprises, on the one hand, at least one support piece (2) having a front face (2') and a rear face (2”) and at least one through opening (3), and, on the other hand, at least one trim piece (1) mounted on the front face (2') of this support piece (2).

[0053] This assembly is characterized in that said at least one cladding piece (1) is assembled with said at least one support piece (2) by means of an assembly system as described above.

[0054] Optionally, this set of parts may further include at least one third part (8), adjacent to said support part (2) and assembled with it.

[0055] According to the invention, the support piece (2) is provided to include at least two, preferably several, through openings (3) each provided with a U-shaped element (4) and the cover piece (1) has as many tabs, pins and / or tongues (6) suitable and intended each to engage, from the front face (2') of the support piece (2), in a corresponding U-shaped element (4), at least a majority of said tabs, pins and / or tongues (6) being advantageously arranged by being distributed along the periphery of said cover piece (1).

[0056] In accordance with a possible advantageous feature, illustrated for example in Figures 10B and 1 IB, at least one of the stopping means (7) is configured to achieve air and / or liquid sealing at the relevant through opening (3), between the front (2') and rear (2") faces of the support part (2).

[0057] Furthermore, it may be provided that at least one of the stopping means (7) is formed in one piece with the support piece (2) and that at least one of the stopping means (7) is formed in one piece with a part (8) adjacent to the support piece (2), assembled with it and also forming part of the set of parts.

[0058] The invention also relates to a method of assembling a covering part (1) with a support part (2)

[0059] This method consists first of all in providing, on the one hand, a support piece (2) having a front face (2') and a rear face (2”) and having at least one through opening (3), preferably at least two through openings (3), and, on the other hand, a cover piece (1) having at least one, preferably at least two, male or projecting element(s) (6), of the type male clip, shaft, lug, harpoon, tab, pin or tongue, intended to be engaged in the opening or a through opening (3) of the support piece (2), as well as possibly a piece (8) adjacent to the latter and assembled with it.

[0060] This process also consists of:

[0061] -either to pre-mount the support part (2) on or in a part (13) of a motor vehicle, then to equip the opening or each opening (3) of this support part (2) with a separate U-shaped element (4), forming a female receiving clip for the male or protruding element (6) of the trim part (1),

[0062] -either to equip the or each opening (3) of the support part (2) with a separate U-shaped element (4), forming a female receiving clip for the element or a male or protruding element (6) of the trim part (1), and then to mount the support part (2) on or in a part (13) of a motor vehicle.

[0063] The two opposite walls (5, 5') of said or of each U-shaped element (4) then come directly into contact with opposite edges (3') of the through opening (3), ensuring its elastic retention in the latter, and a part (4') of this element (4), including the bottom (4”) which connects the two walls, extends beyond the rear face (2”) of said support piece (2).

[0064] The method then consists of engaging the male or each protruding element (6) in the U-shaped element or element (4), preferably until the assembly is locked, by introduction from the front face (2') of the support part (2), any translational movement of the element or of a U-shaped element (4) beyond its mounting position in the through opening (3), in the direction from front face (2') to rear face (2”), being blocked by a stopping means (7) forming an integral part of the support part (2) or of a part (8) adjacent to the latter and assembled with it.

[0065] Preferably, this method implements an assembly system as described above.

[0066] Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications remain possible, particularly with regard to the composition of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

1.

2. Demands Assembly system for a cover piece (1) with a support piece (2), the support piece (2) having a front face (2') and a rear face (2”) and the cover piece (1) being intended to be mounted on the front face (2') of this support piece (2), system in which said support piece (2) has at least one through opening (3) in which a separate U-shaped element (4), forming a female receiving clip, is elastically retained, the two opposite walls (5, 5') of said U-shaped element (4) directly engaging with opposite edges (3') of said through opening (3) and a portion (4') of this element (4) comprising the bottom (4”) which connects the two walls extending beyond the rear face (2”) of said support piece (2), and system in which the cover piece (1) has at least one male or projecting element (6), of the type male clip, shaft, lug, harpoon, leg, pin or tongue, suitable and intended to come into contact,by insertion from the front face (2') of the support piece (2), into said U-shaped element (4), preferably with locking, assembly system characterized in that it also comprises a stopping means (7) substantially blocking any translational movement, or at least any significant translational movement, of the U-shaped element (4) beyond its mounting position in the through opening (3), in the direction of front face (2') to rear face (2”), said stopping means (7) being an integral part of the support piece (2) or of a part (8) adjacent to the latter and assembled with it. An assembly system according to claim 1, characterized in that the support piece (2) comprises at least two, preferably several, through openings (3), each provided with a U-shaped element (4), and in that the cover piece (1) comprises as many male or projecting elements (6), of the type male clip, shaft, lug, hook, tab, pin, or tongue, each adapted and intended to engage, from the front face (2') of the support element, in a corresponding U-shaped element (4), at least a majority of said male or projecting elements (6) being advantageously arranged by being distributed along the periphery of said piece cladding (1) and said through openings (3) being provided with a blocking stop means (7).

3. Assembly system according to claim 1 or 2, characterized in that the locking stop means (7) consists of a rib formed on the rear face of the support piece (2) or of a piece (8) adjacent to the latter, this rib (7) being arranged opposite and at a distance from the relevant through opening (3) and bearing, or almost bearing, on the bottom (4”) of the U-shaped element (4) mounted in this opening (3), extending along said bottom (4”) or transversely with respect to the latter and being connected to said rear face (2”) by bosses or similar formations (9) formed around the relevant through opening (3).

4. Assembly system according to claim 3, characterized in that the rib (7) has a lug (10) engaging with a complementary shape or cutout (11) present in the bottom (4”) of the U-shaped element (4) mounted in the through opening (3) opposite said rib (7).

5. Assembly system according to claim 1 or 2, characterized in that the locking stop means (7) consists of a profiled formation with a U-shaped cross-section, formed in one piece with the rear face (2”) of the support piece (2) around the through opening (3) considered and surrounding the part (4') comprising the bottom (4”) connecting the two walls (5, 5') and extending beyond the rear face (2”) of said support piece (2), of the U-shaped element (4) mounted in this through opening (3), said formation (7) being in contact with said bottom (4”) of the U-shaped element (4) concerned, and possibly at least partially against the two opposite walls (5 and 5') of said element (4).

6. Assembly system according to claim 1 or 2, characterized in that the locking stop means (7) consists of a profiled formation with a U- or C-shaped cross-section, formed in one piece with the adjacent part (8) of the support part (2), arranged around the considered through opening (3) of this support part (2) and surrounding the portion (4'), comprising the base (4”) connecting the two walls (5, 5') and extending beyond the rear face (2”) of said support part (2), of the U-shaped element (4) mounted in this through opening (3), said formation (7) bearing against said base (4”) of the relevant U-shaped element (4), and optionally at less partially against the two opposite walls (5 and 5') of said element (4).

7. Assembly system according to claim 1, 2, 5 or 6, characterized in that the blocking stop means (7) consists of an encapsulating envelope, surrounding the part (4') of the U-shaped element (4) which includes the bottom (4”) connecting the two walls (5, 5') and which extends beyond the rear face (2”) of the support piece (2), and defining an enclosure, partially or totally closed, around the relevant through opening (3) and on said rear face (2”), this envelope (7) being either formed in one piece with the rear face (2”) of the support piece (2) around the relevant through opening (3), or formed in one piece with a part (8) adjacent to said support piece (2) and assembled with it.

8. Assembly system according to any one of claims 1 to 7, characterized in that the opening or each through opening (3) has an elongated shape, of the oblong hole or slot type, and in that the element or each separate U-shaped element (4), forming a female receiving clip, has an elongated or profiled shape with a U-shaped section.

9. Assembly system according to any one of claims 1 to 7, characterized in that the support piece (2) and at least the male or protruding elements (6) of the cover piece (1), and where appropriate also the adjacent piece (8), are made of a thermoplastic material, the element or each separate U-shaped element (4), forming a female receiving clip and inserted with hooking and locking by spring effect into a through opening (3) of the support piece (2), being made of metal, or of a plastic material of equivalent rigidity and resistance, and advantageously having internal notches, slots or spring blades (12) intended to retain the male or protruding element (6) received in this separate U-shaped element (4).

10. Assembly of parts, intended to cover a part (13) of a motor vehicle or to trim the interior of such a part (13), in particular the interior of a door, said assembly comprising, on the one hand, at least one support part (2) having a front face (2') and a rear face (2”) and at least one through opening (3), and, on the other hand, at least one trim part (1) mounted on the front face (2') of this support part (2), assembly characterized in that said at least one cladding piece (1) is assembled with said at least one support piece (2) by means of an assembly system according to any one of claims 1 to 9.

11. Assembly of parts according to claim 9, characterized in that it further comprises at least one third part (8), adjacent to said support part (2) and assembled with it.

12. Assembly of parts according to claim 9 or 10, characterized in that the support part (2) comprises at least two, preferably several, through openings (3) each provided with a U-shaped element (4) and in that the cover part (1) comprises as many male or protruding elements (6) each suitable and intended to engage, from the front face (2') of the support part (2), in a corresponding U-shaped element (4), at least a majority of said male or protruding elements (6) being advantageously arranged by being distributed along the periphery of said cover part (1).

13. Assembly of parts according to any one of claims 10 to 12, characterized in that at least one of the stopping means (7) is configured to achieve air and / or liquid sealing at the relevant through opening (3), between the front (2') and rear (2") faces of the support part (2).

14. Assembly of parts according to any one of claims 10 to 13, characterized in that at least one of the stopping means (7) is formed in one piece with the support part (2) and in that at least one of the stopping means (7) is formed in one piece with a part (8) adjacent to the support part (2), assembled with it and also forming part of the assembly of parts.

15. A method for assembling a cover piece (1) with a support piece (2), comprising, on the one hand, a support piece (2) having a front face (2') and a rear face (2”) and having at least one through opening (3), preferably at least two through openings (3), and, on the other hand, a cover piece (1) having at least one, preferably at least two, male or projecting element(s) (6), of the type male clip, shaft, lug, hook, tab, pin or tongue, intended to be engaged in the opening or a through opening (3) of the support piece

16. (2), and possibly a part (8) adjacent to and assembled with the latter, said process further consisting of: either to pre-mount the support piece (2) on or in a part (13) of a motor vehicle, then to equip the opening(s) (3) of this support piece (2) with a separate U-shaped element (4), forming a female receiving clip for the element or a male or protruding element (6) of the trim piece (1), or to equip the opening(s) (3) of the support piece (2) with a separate U-shaped element (4), forming a female receiving clip for the element or a male or protruding element (6) of the trim piece (1), then to mount the support piece (2) on or in a part (13) of a motor vehicle, the two opposing walls (5, 5') of said U-shaped element(s) (4) directly engaging with opposite edges (3') of the through opening (3), ensuring its elastic retention therein, and a portion (4') of this element (4), including the bottom (4”) which connects the two walls, extending beyond the rear face (2”) of said support piece (2),then to engage the male or protruding element (6) in the U-shaped element or element (4), preferably until the assembly is locked, by insertion from the front face (2') of the support part (2), any translational movement of the element or a U-shaped element (4) beyond its mounting position in the through opening (3), in the direction of the front face (2') to the rear face (2”), being blocked by a stop means (7) forming an integral part of the support part (2) or of a part (8) adjacent to the latter and assembled with it. Assembly method according to claim 13, characterized in that it implements an assembly system according to any one of claims 1 to 9.