Motor vehicle seat headrest

Abstract

The invention relates to a headrest (1) for a motor vehicle seat, said headrest comprising a main body (3) provided with a first locking device and a secondary body (4) mounted to slide longitudinally on said main body and being provided with at least one tenon (6a,6b), said main body being provided with a mortise (7a,7b) receiving said tenon in sliding motion, a second locking device for said secondary body comprising a latch (8) mounted to slide on said main body, a common crossbar (9) for unlocking said locking devices, said second locking device further comprising two racks (12a,12b) integral with said tenon, said latch having two notched areas (13a,13b) cooperating with said racks when said latch is in the locked position,said latch moves away from said racks when actuated in the unlocked position in order to free the sliding of said secondary body. Figure 2,

Description

Title of the invention: Motor vehicle seat headrest

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

[0002] It is known to produce a motor vehicle seat headrest, said headrest comprising: • a mounting frame on the back of said seat, said frame comprising two parallel rods extending vertically, • a main body made of molded plastic material mounted to slide on said rods so as to be able to adopt a plurality of vertical adjustment positions, • a first locking device for said main body in the chosen adjustment position, • a secondary body made of molded plastic material mounted to slide longitudinally on said main body so as to be able to adopt a plurality of longitudinal adjustment positions, said secondary body being integral with a passenger head support wall, said secondary body being provided with at least one molded tenon extending longitudinally, said main body being provided with a mortise receiving said tenon in sliding motion, • a second locking device for said secondary body in the chosen adjustment position, said second device comprising a latch mounted to slide on said main body in a transverse direction between a locking position and an unlocking position, • a common unlocking crossbar for said devices, said crossbar being mounted for transverse sliding on said main body, said crossbar having an end provided with an actuating means allowing its unlocking action, said crossbar having a support stop on said latch to bring it into the unlocking position when it is actuated for unlocking, • a spring means for returning said latch to the locked position.

[0003] Such an arrangement, in which the latch is mounted to slide along a transverse direction, makes it easier to install the second locking device in headrests with reduced vertical dimensions.

[0004] However, the known arrangements have the disadvantage of offering moderate rigidity, causing a risk of rotational deflection of the secondary body, according to a roughly vertical axis, which is detrimental in terms of perceived quality for a seat occupant.

[0005] The invention aims to provide an arrangement to overcome this drawback.

[0006] To this end, the invention proposes a headrest for a motor vehicle seat, said headrest comprising: • a mounting frame on the back of said seat, said frame comprising two parallel rods extending vertically, • a main body made of molded plastic material mounted to slide on said rods so as to be able to adopt a plurality of vertical adjustment positions, • a first locking device for said main body in the chosen adjustment position, • a secondary body made of molded plastic material mounted to slide longitudinally on said main body so as to be able to adopt a plurality of longitudinal adjustment positions, said secondary body being integral with a passenger head support wall, said secondary body being provided with at least one molded tenon extending longitudinally, said main body being provided with a mortise receiving said tenon in sliding motion, • a second locking device for said secondary body in the chosen adjustment position, said second device comprising a latch mounted to slide on said main body in a transverse direction between a locking position and an unlocking position, • a common unlocking crossbar for said locking devices, said crossbar being mounted to slide transversely on said main body, said crossbar having an end provided with an actuating means allowing its unlocking action, said crossbar having a support stop on said latch to bring it into the unlocking position when it is actuated for unlocking, • a spring means for returning said latch to the locked position,

[0007] said headrest further having the following characteristics: • said second locking device further comprises two racks integral with said tenon, said racks extending longitudinally, said racks being arranged on either side of said tenon in a transverse direction, • said latch has two notched areas cooperating with said racks when said latch is in the locked position, said latch moving away from said racks when it is actuated in the unlocked position in order to release the sliding of said secondary body.

[0008] In this description, the terms of positioning in space (longitudinal, transverse, vertical, horizontal, superior, inferior, ...) 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).

[0009] With the proposed arrangement, the presence of the two racks arranged on either side of the tenon in a transverse direction, and engaging with the latch by its two notched areas, makes it possible to ensure a double locking on either side of the headrest, which makes it possible to avoid the aforementioned risk of rotational movement of the secondary body.

[0010] Other features and advantages of the invention will become apparent from the following description, made with reference to the accompanying figures, in which:

[0011] [Fig-1] is a schematic partial perspective view of a headrest according to one embodiment,

[0012] [Fig.2] is a schematic partial perspective view, from another viewpoint, of the headrest shown in [Fig. 1], representing the second locking device for locking the secondary body, said secondary body being locked,

[0013] [Fig. 3a] and

[0014] [Fig.3b] are schematic horizontal cross-sectional views of the headrest shown in figures 1 and 2, with the latch of the second locking device in the locked position ([Fig.3a]) and unlocked position ([Fig.3b]),

[0015] [Fig.4] is a schematic view along a longitudinal direction of the latch of the headrest shown in figures 1 to 3,

[0016] [Fig.5] is a detailed enlargement of [Fig.1].

[0017] With reference to the figures, a headrest 1 of a motor vehicle seat is described, said headrest comprising: • a mounting frame on the back of said seat, said frame comprising two parallel rods extending vertically, • a main body 3 made of molded plastic material mounted to slide on said rods so as to be able to adopt a plurality of vertical adjustment positions, • a first locking device for said main body in the chosen adjustment position, • a secondary body 4 made of molded plastic material mounted to slide longitudinally on said main body so as to be able to adopt a plurality of longitudinal adjustment positions, said secondary body being integral with a support wall 5 of the head of a passenger, said secondary body being provided with at least one tenon 6a,6b resulting from molding extending longitudinally, said main body being provided with a mortise 7a,7b receiving said tenon by sliding, • a second locking device for said secondary body in the chosen adjustment position, said second device comprising a latch 8 mounted to slide on said main body in a transverse direction between a locking position and an unlocking position, • a common crossbar 9 for unlocking said locking devices, said crossbar being mounted to slide transversely on said main body, said crossbar having an end provided with an actuating means 10 - here in the form of a push button, or a rotary button according to an embodiment not shown - allowing its actuation in unlocking, said crossbar having a stop against said latch to bring it into the unlocking position when it is actuated in unlocking, • a spring means for returning said latch to the locked position,

[0018] said headrest further having the following characteristics: • said second locking device further comprises two racks 12a, 12b integral with said tenon (in particular, as will be seen later, two racks 12a are integral with tenon 6a and two racks 12b are integral with tenon 6b), said racks extending longitudinally, said racks being arranged on either side of said tenon in a transverse direction, • said latch has two notched areas 13a, 13b cooperating with said racks (in particular, as will be seen later, two notched areas 13a cooperate with two racks 12a and two notched areas 13b cooperate with two racks 12b) when said latch is in the locking position, said latch moving away from said racks when it is actuated in the unlocking position in order to release the sliding of said secondary body.

[0019] In particular, according to the embodiment shown: • the secondary body 4 is provided with an upper tenon 6a and a lower tenon 6b resulting from a longitudinally extending molding, said tenons being arranged respectively along the upper and lower edges of said secondary body, said upper tenon being integral with two upper racks 12a extending longitudinally on either side of said upper tenon and said lower tenon being integral with two lower racks 12b extending longitudinally on either side of said lower tenon, • the main body 3 is provided with an upper mortise 7a for receiving said upper tenon in sliding motion and a lower mortise 7b for receiving said lower tenon in sliding motion, • the latch 8 in the locked position cooperates by two upper notched areas 13a with said upper racks and by two lower notched areas 13b with said lower racks, said latch moving away from said racks when it is brought into the unlocked position in order to release the sliding of said secondary body.

[0020] Such an arrangement also makes it possible to prevent rotational movement of the secondary body 4 along a transverse axis, which makes it possible to optimize the quality perceived by a seat occupant.

[0021] According to one embodiment, the overall distance 14 between two upper notching zones 13a and lower 13b arranged on the same side of the latch 8 is greater than 25 mm, so as to optimize the holding of the secondary body 4 in movement along a transverse axis.

[0022] According to one embodiment, the distance 15 between the serration ends of two upper serration zones 13a - respectively or lower 13b - intended to cooperate with the upper racks 12a - respectively or lower 12b - of a given upper tenon 6a - respectively or lower 6b - is greater than 35 mm, so as to optimize the holding of the secondary body 4 in deflection along a substantially vertical axis.

[0023] According to the embodiment shown, the tenons 6a,6b are in longitudinal view within a trapezoid (shown in dotted lines on [Fig.5]) having a large base 16 turned inwards and a small base 17 turned outwards, said bases extending horizontally and being connected to each other by two inclined faces 18 with respect to the vertical, said mortises being in longitudinal view within the corresponding trapezoid.

[0024] According to the embodiment shown, at least one of the mortises 7a - here the upper one - is closed on its entire periphery so as to form a reinforced mortise.

[0025] According to the embodiment shown, at least one tenon 6a,6b is hollowed out to provide a housing for a reinforcing piece 19 made of material molded plastic, the racks 12a, 12b being made from molding of said reinforcement piece.

[0026] In particular, the material of the reinforcing piece 19 is less sensitive to deformation as a function of temperature than the material constituting the corresponding tenon 6a,6b and said material is of the same nature as the material constituting the main body 3.

[0027] With such an arrangement, the dimensional clearances between the tenons 6a,6b and mortises 7a,7b are little impacted by temperature variations.

[0028] In addition, such an arrangement makes it possible to strengthen the locking of the secondary body 4.

[0029] According to the embodiment shown, the two tenons 6a,6b are hollowed out and each provided with a reinforcing piece 19 supporting the racks 12a, 12b.

[0030] According to one embodiment, a tenon 6a,6b - in particular both according to the embodiment shown - is guided in the corresponding mortise 7a,7b, at least along the large base 16 of the trapezoid, by a fitted contact made between the corresponding reinforcement piece 19 and said mortise by rails 20 resulting from molding.

[0031] According to the embodiment shown, a lateral face of a mortise 7a,7b is provided with an elastically retractable tab 21 - in particular made of spring metal - so as to ensure a tight contact with the corresponding tenon 6a,6b.

[0032] According to one embodiment, the first locking device comprises: • a plurality of locking notches 22 arranged vertically on at least one of the rods 2 - both according to the embodiment shown - so as to define a notched rod, • at least one locking projection mounted movable relative to the main body 3 between a locking position, where said projection is inserted into one of said notches, and an unlocking position, where said projection is withdrawn from said notch in order to free the sliding of said body.

Claims

1. Demands Headrest (1) of a motor vehicle seat, said headrest comprising: • a mounting frame on a backrest of said seat, said frame comprising two parallel rods (2) extending vertically, • a main body (3) made of molded plastic material mounted to slide on said rods so as to be able to adopt a plurality of vertical adjustment positions, • a first locking device for said main body in the chosen adjustment position, • a secondary body (4) made of molded plastic material mounted to slide longitudinally on said main body so as to be able to adopt a plurality of longitudinal adjustment positions, said secondary body being integral with a support wall (5) of the head of a passenger, said secondary body being provided with at least one tenon (6a,6b) resulting from a molding extending longitudinally, said main body being provided with a mortise (7a,7b) receiving said tenon by sliding, • a second locking device for said secondary body in the chosen adjustment position, said second device comprising a latch (8) mounted to slide on said main body in a transverse direction between a locking position and an unlocking position, • a common unlocking crossbar (9) for said locking devices, said crossbar being mounted to slide transversely on said main body, said crossbar having an end provided with an actuating means (10) allowing its unlocking action, said crossbar having a support stop on said latch to bring it into the unlocking position when it is actuated for unlocking, • a spring means for returning said latch to the locked position, said headrest being characterized in that: • said second locking device further comprises two racks (12a, 12b) integral with said tenon, said racks extending longitudinally, said racks being arranged on either side of said tenon in a transverse direction, • said latch has two notched areas (13a, 13b) cooperating with said racks when said latch is in the locking position, said latch moving away from said racks when it is actuated in the unlocking position in order to release the sliding of said secondary body.

2. Headrest (1) according to claim 1, characterized in that: • the secondary body (4) is provided with an upper tenon (6a) and a lower tenon (6b) formed by molding and extending longitudinally, said tenons being arranged respectively along the upper and lower edges of said secondary body, said upper tenon being integral with two upper racks (12a) extending longitudinally on either side of said upper tenon and said lower tenon being integral with two lower racks (12b) extending longitudinally on either side of said lower tenon, • the main body (3) is provided with an upper mortise (7a) for receiving said upper tenon in sliding motion and a lower mortise (7b) for receiving said lower tenon in sliding motion,• the latch (8) in the locked position cooperates via two upper serrated zones (13a) with said upper racks and via two lower serrated zones (13b) with said lower racks, said latch moving away from said racks when brought to the unlocked position in order to release the sliding of said secondary body.

3. Headrest (1) according to claim 2, characterized in that the overall distance (14) between two upper notching zones (13a) and lower (13b) arranged on the same side of the latch (8) is greater than 25 mm.

4. Headrest (1) according to any one of the preceding claims, characterized in that the distance (15) between the serration ends of two upper serration zones (13a) - respectively or lower (13b) - intended to cooperate with the upper racks (12a) - respectively or lower (12b) - of an upper tenon (6a) - respectively or lower (6b) - given is greater than 35 mm, so as to optimize the holding of the secondary body (4) in deflection about a substantially vertical axis.

5. Headrest (1) according to any one of the preceding claims, characterized in that the tenons (6a,6b) are inscribed in longitudinal view in a trapezoid having a large base (16) turned inwards and a small base (17) turned outwards, said bases extending horizontally and being connected to each other by two inclined faces (18) with respect to the vertical, said mortises being inscribed in longitudinal view in the corresponding trapezoid.

6. Headrest (1) according to any one of the preceding claims, characterized in that at least one tenon (6a,6b) is hollowed out so as to present a housing receiving in a fit a reinforcing piece (19) of molded plastic material, the racks (12a,12b) being made from molding of said reinforcing piece.