Motor vehicle seat headrest

Abstract

The invention relates to a headrest (1) for a motor vehicle seat, said headrest comprising a main body (3) and a secondary body (4) mounted to slide longitudinally on said main body and being provided with two tenons (5) arranged along two upper and lower edges of said secondary body, said tenons fitting in longitudinal view into a trapezium, said main body being provided with two mortises (9a, 9b) respectively receiving each of said tenons, said mortises fitting in longitudinal view into the corresponding trapezium, at least one of said mortises being closed over its entire periphery so as to form a reinforced mortise (9a). Figure 1

Description

Title of the invention: Headrest for a motor vehicle seat

[0001] The invention relates to a headrest for a motor vehicle seat.

[0002] It is known, in particular from document EP-4 100 281, to produce a headrest of motor vehicle seat, said headrest comprising: • a mounting frame on a back of said seat, • a main body made of molded plastic material mounted in the upper part of said frame, • a secondary body made of molded plastic material mounted to slide longitudinally on said main body, so that said secondary body can adopt a plurality of positions, said secondary body being secured to a wall supporting the head of a passenger, said secondary body being provided with two molded tenons extending longitudinally, said tenons being arranged along two upper and lower edges of said secondary body, said tenons being inscribed in longitudinal view in a trapezoid having a large base facing inwards and a small base facing outwards, said bases extending horizontally and being connected to each other by two sides inclined relative to the vertical,

[0003] said main body being provided with two mortises respectively receiving each of said tenons, said mortises being inscribed in longitudinal view in the corresponding trapezium.

[0004] According to the known arrangement, the mortises open outwards along the small bases of the trapezoids.

[0005] The known arrangement makes it possible to ensure guidance of the secondary body in the peripheral zone of the headrest, which allows: • to best control the correct sliding of the secondary body in relation to the main body, with elimination of the phenomena of buttressing and / or impact of dimensional dispersions which harm said sliding and the rigidity of the assembly, • to reduce the number of ways to catch up on games.

[0006] However, when the volume of the headrest is reduced, such an arrangement risks not having the expected robustness to ensure good absorption of forces in the event of impact of a passenger's head, in particular to avoid torsion phenomena.

[0007] The invention aims to overcome this drawback.

[0008] To this end, the invention proposes a headrest for a motor vehicle seat, said headrest comprising: • a mounting frame on a back of said seat, • a main body made of molded plastic material mounted in the upper part of said frame, • a secondary body made of molded plastic material mounted to slide longitudinally on said main body, so that said secondary body can adopt a plurality of positions, said secondary body being secured to a wall supporting the head of a passenger, said secondary body being provided with two molded tenons extending longitudinally, said tenons being arranged along two upper and lower edges of said secondary body, said tenons being inscribed in longitudinal view in a trapezoid having a large base facing inwards and a small base facing outwards, said bases extending horizontally and being connected to each other by two sides inclined relative to the vertical,

[0009] said main body being provided with two mortises respectively receiving each of said tenons, said mortises being inscribed in longitudinal view in the corresponding trapezium, at least one of said mortises being closed over its entire periphery so as to form a reinforced mortise.

[0010] With such an arrangement, the fact that at least one of the mortises is closed around its entire periphery makes it possible to reinforce it in the event of an impact to the head of a passenger.

[0011] In addition, the arrangement of the small base of the trapeziums towards the outside makes it possible to optimize the holding of the tenons in the mortises.

[0012] In this description, the terms of positioning in space (top, bottom, upper, lower, longitudinal, transverse, lateral, vertical, etc.) are taken with reference to the headrest arranged in the vehicle in use, said vehicle extending longitudinally along its length (X axis), transversely along its width (Y axis) and vertically along its height (Z axis).

[0013] Other features and advantages of the invention will appear in the following description, given with reference to the attached figures, in which:

[0014] [Fig.l] is a partial schematic perspective view of a headrest according to one embodiment,

[0015] [Fig.2] is a partial semi-exploded representation of [Fig.l],

[0016] [Fig.3] is a partial view along a longitudinal direction of the headrest represented in [Fig.l].

[0017] With reference to the figures, a headrest 1 for a motor vehicle seat is described, said headrest comprising: • a frame 2 for mounting on a back of said seat, • a main body 3 made of molded plastic material mounted in the upper part of said frame, • a secondary body 4 made of molded plastic material mounted to slide longitudinally on said main body, so that said secondary body can adopt a plurality of positions, said secondary body being secured to a support wall 16 for the head of a passenger, said secondary body being provided with two molded tenons 5 extending longitudinally, said tenons being arranged along two upper and lower edges of said secondary body, said tenons being inscribed in longitudinal view in a trapezium (shown in dotted lines in [Fig. 3]) having a large base 6 facing inwards and a small base 7 facing outwards, said bases extending horizontally and being connected to each other by two inclined sides 8 relative to the vertical,

[0018] said main body being provided with two mortises 9a, 9b respectively receiving each of said tenons, said mortises being inscribed in longitudinal view in the corresponding trapezium, at least one of said mortises being closed over its entire periphery so as to form a reinforced mortise 9a.

[0019] According to the embodiment shown, the frame 2 comprises two substantially vertical parallel metal tubular branches 10.

[0020] According to the embodiment shown, the branches 10 are connected to each other by a spacer 11, for example made of molded plastic material, extending between their upper ends.

[0021] According to the embodiment shown, the reinforced mortise 9a is defined by an orifice resulting from molding of the main body 3 and opening towards the small base 7 of the trapezium, said orifice being closed along said small base by a transverse reinforcing crosspiece 12 - in particular made of molded plastic material - fixed - in particular by fitting - on said main body.

[0022] According to a variant not shown, the reinforced mortise 9a is defined by an orifice closed over its entire periphery, said orifice being produced by molding the main body 3.

[0023] According to the embodiment shown, the reinforced mortise 9a is arranged at the top of the main body 3, the location most mechanically stressed in the event of an impact to the head of a passenger.

[0024] According to an embodiment not shown, the two mortises 9a, 9b are both reinforced if it is desired to optimize the mechanical resistance.

[0025] According to one embodiment, the large base 6 of a trapezoid has a minimum dimension of 50 mm and its small base 7 has a minimum dimension of 40 mm, so as to allow good absorption of forces and limit the risks of blocking the sliding of the secondary body 4 by bracing.

[0026] According to one embodiment, the small bases 7 of two respective trapezoids are spaced apart from each other by at least 40 mm, so that the mortises 9a, 9b are arranged as far out as possible to limit the risks of blocking the sliding of the secondary body 4 by bracing.

[0027] According to the embodiment shown, the tenons 5 are hollowed out so as to present a housing receiving in a nested manner a reinforcement piece 13 based on a material of the same thermoplastic nature as the material constituting the main body 3 - said material being for example polyamide, which is dimensionally insensitive to temperature variations.

[0028] Such an embodiment makes it possible, in the case of a secondary body 4 based on a material dimensionally sensitive to temperature variations - such as high density polyethylene (HDPE) - to obtain similar dimensional variations between the tenons 5 and mortises 9a, 9b and to have constant dimensional clearances between them.

[0029] According to the embodiment shown, a tenon 5 is guided in the corresponding mortise 9a, 9b, at least along the large base 6 of the trapezium, by an adjusted contact made between the corresponding reinforcing piece 13 and said mortise by rails 14 produced by molding.

[0030] According to the embodiment shown, a lateral face - that is to say a face extending along an inclined face 8 as defined above - of a mortise 9a, 9b is provided with an elastically retractable tab 17, so as to ensure adjusted contact with the corresponding tenon 5.

[0031] According to the embodiment shown, the tab 17 is in the form of a spring-loaded metal blade.

[0032] According to the embodiment shown, the clamping contact is ensured by two tabs 17 arranged respectively at the top and bottom of the bodies 3, 4, said tabs being moreover laterally opposite, which makes it possible to ensure both vertical and transverse centering of the secondary body 4 while minimizing the number of said tabs.

[0033] With such an arrangement, only two means of compensating for the play formed by the two legs 17 are used, which makes it possible to simplify the headrest 1.

[0034] In a manner not shown, the headrest 1 may further comprise a device for locking the secondary body 4 in a plurality of positions, so that the support wall 16 can have a plurality of adjustment positions.

[0035] According to an embodiment not shown, the locking device of the secondary body 4 may comprise: • a rack originating from said secondary body, said rack extending longitudinally, • a latch mounted to move relative to the main body 3 between a locking position, where a notch of said rack is inserted, and a position of unlocking, where it withdraws from said notch in order to release the sliding of said secondary body.

[0036] According to an alternative not shown, the headrest 1 further comprises a geared motor for actuating the secondary body 4 in sliding, for example by means of pinions meshing with racks extending longitudinally.

[0037] In a manner not shown, the main body 3 can be slidably mounted on the frame 2, and in particular on the branches 10, the headrest 1 comprising either a device for locking the height of said main body, so as to allow it to be locked in an adjustment position, or a geared motor for actuating said main body to slide towards the chosen adjustment position.

Claims

Claims

1. Headrest (1) for a motor vehicle seat, said headrest comprising: • a frame (2) for mounting on a back of said seat, • a main body (3) made of molded plastic material mounted in the upper part of said frame, • a secondary body (4) made of molded plastic material mounted in longitudinal sliding on said main body, so that said secondary body can adopt a plurality of positions, said secondary body being integral with a support wall (16) for the head of a passenger, said secondary body being provided with two molded tenons (5) extending longitudinally, said tenons being arranged along two upper and lower edges of said secondary body, said tenons being inscribed in longitudinal view in a trapezoid having a large base (6) facing inwards and a small base (7) facing outwards,said bases extending horizontally and being connected to each other by two inclined sides (8) relative to the vertical, said main body being provided with two mortises (9a, 9b) respectively receiving each of said tenons, said mortises being inscribed in longitudinal view in the corresponding trapezium, said headrest being characterized in that at least one of said mortises is closed over its entire periphery so as to form a reinforced mortise (9a).,

2. Headrest (1) according to claim 1, characterized in that the reinforced mortise (9a) is defined by an orifice resulting from molding of the main body (3) and opening towards the small base (7) of the trapezium, said orifice being closed along said small base by a transverse reinforcing crosspiece (12) fixed to said main body.

3. Headrest (1) according to claim 1, characterized in that the reinforced mortise (9a) is defined by an orifice closed over its entire periphery, said orifice being produced by molding the main body (3).

4. Headrest (1) according to any one of the preceding claims, characterized in that the reinforced mortise (9a) is arranged at the top of the main body (3).

5. Headrest (1) according to any one of the preceding claims, characterized in that the large base (6) of a trapezoid has a minimum dimension of 50 mm and its small base (7) a minimum dimension of 40 mm.

6. Headrest (1) according to any one of the preceding claims, characterized in that the small bases (7) of two respective trapezoids are spaced from each other by at least 40 mm.

7. Headrest (1) according to any one of the preceding claims, characterized in that the tenons (5) are hollowed out so as to present a housing receiving in nesting a reinforcing piece (13) based on a material of the same thermoplastic nature as the material constituting the main body (3).

8. Headrest (1) according to the preceding claim, characterized in that a tenon (5) is guided in the corresponding mortise (9a, 9b), at least along the large base (6) of the trapezium, by an adjusted contact made between the corresponding reinforcing piece (13) and said mortise by rails (14) produced by molding.

9. Headrest (1) according to any one of the preceding claims, characterized in that a lateral face of a mortise (9a, 9b) is provided with an elastically retractable tab (17), so as to ensure adjusted contact with the corresponding tenon (5).

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