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, a second locking device for said secondary body comprising a latch (8) mounted to slide on said main body, a common crosspiece (9) for unlocking said locking devices, said second locking device further comprising two racks (12a, 12b) integral with said tenon, said latch having two notching zones (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. Figure 2,

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 to produce a headrest for a motor vehicle seat, said headrest comprising: • a mounting frame on a back of said seat, said frame comprising two parallel rods extending vertically, • a main body made of molded plastic material slidably mounted on said rods so as to be able to adopt a plurality of vertical adjustment positions, • a first device for locking 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 secured to a wall supporting the head of a passenger, 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, • a second device for locking said secondary body in the chosen adjustment position, said second device comprising a latch slidably mounted on said main body in a transverse direction between a locking position and an unlocking position, • a common crosspiece for unlocking said devices, said crosspiece being mounted to slide transversely on said main body, said crosspiece having one end provided with an actuating means allowing it to be actuated in unlocking, said crosspiece having a support stop on said latch to bring it into the unlocking position when it is actuated in unlocking, • a spring means for returning said latch to the locking position.

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

[0004] However, the known arrangements have the disadvantage of offering moderate rigidity causing a risk of rotational movement of the secondary body, depending on a substantially vertical axis, which is detrimental in terms of quality perceived by a seat occupant.

[0005] The aim of the invention is to propose an arrangement making it possible 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 a back of said seat, said frame comprising two parallel rods extending vertically, • a main body made of molded plastic material slidably mounted on said rods so as to be able to adopt a plurality of vertical adjustment positions, • a first device for locking 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 secured to a wall supporting the head of a passenger, 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, • a second device for locking said secondary body in the chosen adjustment position, said second device comprising a latch slidably mounted on said main body in a transverse direction between a locking position and an unlocking position, • a common crosspiece for unlocking said locking devices, said crosspiece being mounted to slide transversely on said main body, said crosspiece having one end provided with an actuating means allowing it to be actuated in unlocking mode, said crosspiece having a support stop on said latch to bring it into the unlocking position when it is actuated in unlocking mode, • a spring means for returning said latch to the locking position,

[0007] said headrest further having the following characteristics: • said second locking device further comprises two racks secured to said tenon, said racks extending longitudinally, said racks being arranged on either side of said tenon in a transverse direction, • said latch has two notching zones 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.

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

[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 notching zones, makes it possible to ensure double locking on either side of the headrest, which makes it possible to avoid the above-mentioned risk of rotational movement of the secondary body.

[0010] Other features and advantages of the invention will appear in the following description, given with reference to the attached figures, in which:

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

[0012] [Fig.2] is a schematic view in partial perspective, from another angle of view, of the headrest shown in [Fig.l], 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 sectional views of the headrest shown in Figures 1 and 2, the latch of the second locking device being in the locking ([Fig.3a]) and unlocking ([Fig.3b]) positions,

[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.l].

[0017] With reference to the figures, a headrest 1 for a motor vehicle seat is described, said headrest comprising: • a mounting frame on a back of said seat, said frame comprising two parallel rods 2 extending vertically, • a main body 3 made of molded plastic material slidably mounted on said rods so as to be able to adopt a plurality of vertical adjustment positions, • a first device for locking 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 for 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 in sliding, • a second device for locking said secondary body in the chosen adjustment position, said second device comprising a latch 8 slidably mounted on said main body in a transverse direction between a locking position and an unlocking position, • a common crosspiece 9 for unlocking said locking devices, said crosspiece being mounted to slide transversely on said main body, said crosspiece having one end provided with an actuating means 10 - here in the form of a push button, or even a rotary button according to an embodiment not shown - allowing it to be actuated in unlocking, said crosspiece having a support stop on said latch to bring it into the unlocking position when it is actuated in unlocking, • a spring means for returning said latch to the locking position,

[0018] said headrest further having the following characteristics: • said second locking device further comprises two racks 12a, 12b secured to said tenon (in particular, as will be seen later, two racks 12a are secured to the tenon 6a and two racks 12b are secured to the tenon 6b), said racks extending longitudinally, said racks being arranged on either side of said tenon in a transverse direction, • said latch has two notching zones 13a, 13b cooperating with said racks (in particular, as will be seen later, two notching zones 13a cooperate with two racks 12a and two notching zones 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 produced by molding extending longitudinally, said tenons being arranged respectively along upper and lower edges of said secondary body, said upper tenon being secured to two upper racks 12a extending longitudinally on either side of said upper tenon and said lower tenon being secured to 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 mode and a lower mortise 7b for receiving said lower tenon in sliding mode, • the latch 8 in the locking position cooperates by two upper notching zones 13a with said upper racks and by two lower notching zones 13b with said lower racks, said latch moving away from said racks when it is brought into the unlocking 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 an occupant of the seat.

[0021] According to one embodiment, the overall distance 14 between two upper 13a and lower 13b notching zones 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 notching ends of two upper notching 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 movement along a substantially vertical axis.

[0023] According to the embodiment shown, the tenons 6a, 6b fit in longitudinal view into a trapezium (shown in dotted lines in [Fig.5]) having a large base 16 facing inwards and a small base 17 facing outwards, said bases extending horizontally and being connected to each other by two inclined sides 18 relative to the vertical, said mortises fitting in longitudinal view into the corresponding trapezium.

[0024] According to the embodiment shown, at least one of the mortises 7a - here the upper one - is closed over 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 so as to present a housing receiving in a nested manner a reinforcing piece 19 made of material molded plastic, the racks 12a, 12b being produced by molding said reinforcement part.

[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 affected by temperature differences.

[0028] Furthermore, such an arrangement makes it possible to reinforce 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 the two according to the embodiment shown - is guided in the corresponding mortise 7a, 7b, at least along the large base 16 of the trapezium, by an adjusted contact made between the corresponding reinforcing 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 adjusted 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 to move 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 release the sliding of said body.

Claims

1. Claims Headrest (1) for a motor vehicle seat, said headrest comprising: • a mounting frame on a back of said seat, said frame comprising two parallel rods (2) extending vertically, • a main body (3) made of molded plastic material slidably mounted on said rods so as to be able to adopt a plurality of vertical adjustment positions, • a first device for locking 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 in sliding, • a second device for locking said secondary body in the chosen adjustment position, said second device comprising a latch (8) slidably mounted on said main body in a transverse direction between a locking position and an unlocking position, • a common crosspiece (9) for unlocking said locking devices, said crosspiece being mounted to slide transversely on said main body, said crosspiece having one end provided with an actuating means (10) allowing it to be actuated in unlocking, said crosspiece having a support stop on said latch to bring it into the unlocking position when it is actuated in unlocking, • a spring means for returning said latch to the locking 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 notching zones (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 extending longitudinally, said tenons being arranged respectively along 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 and a lower mortise (7b) for receiving said lower tenon in sliding,• the latch (8) in the locking position cooperates by two upper notching zones (13a) with said upper racks and by two lower notching zones (13b) with said lower racks, said latch moving away from said racks when it is brought into the unlocking 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 notching ends of two upper notching 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 movement along a substantially vertical axis.

5. Headrest (1) according to any one of the preceding claims, characterized in that the tenons (6a, 6b) fit in longitudinal view into a trapezium having a large base (16) facing inwards and a small base (17) facing outwards, said bases extending horizontally and being connected to each other by two inclined sides (18) relative to the vertical, said mortises fitting in longitudinal view into the corresponding trapezium.

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 have a housing receiving a reinforcement piece (19) made of molded plastic material, the racks (12a, 12b) being produced by molding said reinforcement piece.

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