Motor vehicle seat headrest
The headrest design with a reinforced mortise and optimized tenon arrangement addresses the lack of robustness in existing designs by enhancing impact force absorption and reducing sliding complications.
Patent Information
- Application Number
- FR2024001158
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-02-06
- Publication Date
- 2026-02-13
- Estimated Expiration
- 2044-02-06
AI Technical Summary
Existing motor vehicle seat headrest designs lack robustness in absorbing forces during a head impact, particularly when the volume is reduced, leading to potential torsional phenomena.
A headrest design with a reinforced mortise and optimized tenon arrangement, where at least one mortise is closed peripherally to enhance mechanical resistance, and the tenons are positioned within trapezoids with inclined sides, combined with a reinforcement piece and elastically retractable tabs for secure fitting.
Enhances the headrest's ability to absorb impact forces effectively, ensuring robustness and minimizing sliding issues while maintaining smooth operation.
Smart Images
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Abstract
Description
Title of the invention: Motor vehicle seat headrest
[0001] The invention relates to a motor vehicle seat headrest.
[0002] It is known, notably from document EP-4 100 281, to make a headrest of motor vehicle seat, said headrest comprising: • a mounting frame for attaching to the 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 integral with a passenger's head support wall, 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 fitting longitudinally into 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 with respect to the vertical,
[0003] said main body being provided with two mortises receiving respectively each of said tenons, said mortises being inscribed in longitudinal view in the corresponding trapezoid.
[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 smooth sliding of the secondary body relative to the main body, eliminating the phenomena of buttressing and / or impact of dimensional variations that impair 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 may not have the expected robustness to ensure good absorption of forces in the event of a head impact on a passenger, in particular to avoid torsional 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 for attaching to the 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 integral with a passenger's head support wall, 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 fitting longitudinally into 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 with respect to the vertical,
[0009] said main body being provided with two mortises receiving respectively each of said tenons, said mortises being inscribed in longitudinal view in the corresponding trapezoid, at least one of said mortises being closed on all of its 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 a head impact by a passenger.
[0011] In addition, the arrangement of the small base of the trapezoids towards the outside allows 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, ...) are taken with reference to the headrest arranged in the vehicle in a situation of 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 become apparent from the following description, made with reference to the accompanying figures, in which:
[0014] [Fig. 1] is a schematic partial perspective view of a headrest according to one embodiment,
[0015] [Fig.2] is a partial, semi-exploded representation of [Fig.1],
[0016] [Fig.3] is a partial view along a longitudinal direction of the headrest represented in [Fig.1].
[0017] With reference to the figures, a headrest 1 of a motor vehicle seat is described, said headrest comprising: • a mounting frame 2 for attaching to the back of said seat, • a main body 3 made of molded plastic material mounted at the top of said framework, • 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 integral with a support wall 16 of a passenger's head, 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 within a trapezoid (represented in dashed lines on [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 faces 8 with respect to the vertical,
[0018] said main body being provided with two mortises 9a,9b receiving respectively each of said tenons, said mortises being inscribed in longitudinal view in the corresponding trapezoid, at least one of said mortises being closed on the whole of its periphery so as to form a reinforced mortise 9a.
[0019] According to the embodiment shown, the frame 2 comprises two substantially vertical parallel tubular metal 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 opening from the molding of the main body 3 and opening towards the small base 7 of the trapezoid, said opening being closed along said small base by a transverse reinforcement crossbar 12 - in particular made of molded plastic material - fixed - in particular by interlocking - on said main body.
[0022] According to an unrepresented variant, the reinforced mortise 9a is defined by an orifice closed around its entire periphery, said orifice being formed by molding the main body 3.
[0023] According to the embodiment shown, the reinforced mortise 9a is located at the top of the main body 3, the location most mechanically stressed in the event of a passenger's head impact.
[0024] According to an embodiment not shown, both mortises 9a,9b are reinforced if it is desired to optimize 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 a minimum dimension of 40 mm, so as to allow good load transfer and limit the risks of blocking the sliding of the secondary body 4 by buttressing.
[0026] According to one embodiment, the small bases 7 of two respective trapezoids are separated from each other by at least 40 mm, so that the mortises 9a,9b are arranged as far to the periphery as possible to limit the risks of blocking the sliding of the secondary body 4 by buttressing.
[0027] According to the embodiment shown, the tenons 5 are hollowed out so as to present a housing receiving in fitting 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 analogous 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 trapezoid, by a fitted contact made between the corresponding reinforcement piece 13 and said mortise by rails 14 resulting from molding.
[0030] According to the embodiment shown, a lateral face - that is to say a face extending along an inclined plane 8 as defined above - of a mortise 9a,9b is provided with an elastically retractable tab 17, so as to ensure a tight contact with the corresponding tenon 5.
[0031] According to the embodiment shown, the leg 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 also laterally opposed, 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 catching up on play formed by the two legs 17 are used, which makes it possible to simplify the headrest 1.
[0034] Not shown, the headrest 1 may further include a locking device for 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 for the secondary body 4 may comprise: • a rack originating from said secondary body, said rack extending longitudinally, • a latch mounted movable relative to the main body 3 between a locking position, where it engages a notch of said rack, and a position of unlocking, where it is withdrawn from said notch in order to free the sliding of said secondary body.
[0036] According to an alternative not shown, the headrest 1 further includes a geared motor for actuation of the secondary body 4 in sliding motion, for example by means of pinions meshing with racks extending longitudinally.
[0037] Not shown, the main body 3 can be mounted to slide on the frame 2, and in particular on the arms 10, the headrest 1 comprising either a height locking device for said main body, so as to allow its locking in an adjustment position, or a geared motor for actuating said main body to slide towards the chosen adjustment position.
Claims
Demands
1. A motor vehicle seat headrest (1), said headrest comprising: • a frame (2) for mounting on a seat back, • a main body (3) of molded plastic material mounted on the upper part of said frame, • a secondary body (4) 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 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 within a trapezoid having a larger base (6) facing inwards and a smaller base (7) facing outwards,said bases extending horizontally and being connected to each other by two inclined surfaces (8) with respect to the vertical, said main body being provided with two mortises (9a, 9b) receiving respectively each of said tenons, said mortises being inscribed in longitudinal view within the corresponding trapezoid, said headrest being characterized in that at least one of said mortises is closed around 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 opening from the molding of the main body (3) and opening towards the small base (7) of the trapezoid, said opening being closed along said small base by a transverse reinforcing crossbar (12) fixed on said main body.
3. Headrest (1) according to claim 1, characterized in that the reinforced mortise (9a) is defined by an orifice closed around its entire periphery, said orifice being formed 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 disposed at the top of the main body (3).
5. Headrest (1) according to any one of the preceding claims, characterized in that the larger base (6) of a trapezoid has a minimum dimension of 50 mm and its smaller base (7) has 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 separated 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 a fit 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 trapezoid, by a fitted contact made between the corresponding reinforcing piece (13) and said mortise by rails (14) resulting from 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 a tight contact with the corresponding tenon (5).