Headrest for a motor vehicle seat

Abstract

The invention relates to a headrest (1) for a motor vehicle seat, said headrest comprising a main body (3) mounted slidably on rods (2) by means of a first locking device, a secondary body (4) mounted so as to slide longitudinally on said main body by means of a second locking device, a shared unlocking cross-member (5) of said devices, mounted so as to slide transversely by means of a push-button (7), a force-balancing part (9) mounted between said button and said cross-member and having an outer face on which the button rests and a track onto which bears a protrusion in a plurality of positions defined by the longitudinal adjustment position of said secondary body, and two rectifying springs (13) of the aforementioned part being mounted, at the front and rear ends of the part, between said part and said secondary body.

Description

[0001] DESCRIPTION

[0002] Title: Motor vehicle seat headrest

[0003] The invention relates to a headrest for a motor vehicle seat.

[0004] It is known to produce a headrest for a motor vehicle seat, said headrest comprising:

[0005] • a mounting frame on a back of said seat, said frame comprising two parallel rods extending vertically,

[0006] • 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,

[0007] • a first device for locking said main body in the chosen adjustment position,

[0008] • 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 longitudinal adjustment positions,

[0009] • a second device for locking said secondary body in the chosen adjustment position,

[0010] • a common crosspiece for unlocking said devices, said crosspiece being mounted to slide transversely on said main body, said crosspiece having an end part cooperating with a push button, mounted to slide transversely on said secondary body, allowing it to be actuation in unlocking, so as to release the sliding of said main and secondary bodies,

[0011] • a spring for returning said crosspiece to the locking position.

[0012] In such an arrangement, it is known to press the button against the end part of the crosspiece, the actuation of said pressure button making it possible to slide said crosspiece towards its unlocking position. And, depending on the adjustment position chosen for the secondary body, the button can adopt a plurality of longitudinal positions relative to the crosspiece.

[0013] When the crossbar is not in line with the button, this causes said crossbar to be actuated by said overhanging button, which may cause additional force to be applied to said button to achieve unlocking actuation.

[0014] The invention aims to overcome this drawback.

[0015] To this end, the invention proposes a headrest for a motor vehicle seat, said headrest comprising:

[0016] • a mounting frame on a back of said seat, said frame comprising two parallel rods extending vertically,

[0017] • 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,

[0018] • a first device for locking said main body in the chosen adjustment position,

[0019] • 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 longitudinal adjustment positions,

[0020] • a second device for locking said secondary body in the chosen adjustment position,

[0021] • a common crosspiece for unlocking said devices, said crosspiece being mounted to slide transversely on said main body, said crosspiece having an end part cooperating with a push button, mounted to slide transversely on said secondary body, allowing it to be actuation in unlocking, so as to release the sliding of said main and secondary bodies,

[0022] • a spring for returning said crosspiece to the locking position, said headrest further comprising:

[0023] • a force balancing part interposed between said button and said crosspiece, said part extending longitudinally, said part having an external face on which said button rests and an internal face in the form of a track extending longitudinally, said track receiving a projection, located on said end part, in a plurality of positions defined by the longitudinal adjustment position of said secondary body,

[0024] • two springs for straightening said part when said projection rests in the non-median longitudinal zone of said track, said springs being interposed at the front and rear ends of said part between said part and said secondary body.

[0025] In this description, the terms of positioning in space (longitudinal, transverse, vertical, horizontal, front, rear, etc.) are taken in reference to the headrest placed in the vehicle in use.

[0026] With the proposed arrangement, implementing a force balancing part rebalanced by two straightening springs, the risk of additional force to be applied to the button to achieve unlocking actuation is minimized.

[0027] Other features and advantages of the invention will appear in the following description, given with reference to the attached figures, in which: [Fig.1] is a partial schematic perspective view of a headrest according to one embodiment,

[0028] [Fig.2] is a schematic exploded partial perspective view of the headrest of Figure 1,

[0029] [Fig.3] is a schematic view of a partial perspective detail of the headrest of the preceding figures,

[0030] [Fig. 4] is a schematic horizontal sectional view of the headrest of the preceding figures, the secondary body being in the intermediate adjustment position and the crosspiece not being actuated in unlocking,

[0031] [Fig.5a] and [Fig.5b] are schematic horizontal sectional views of the headrest of the preceding figures, the secondary body being in two extreme adjustment positions and the crosspiece being actuated in unlocking,

[0032] [Fig.6] is a partial schematic perspective view of the headrest of the preceding figures provided with a secondary body locking device according to one embodiment.

[0033] With reference to the figures, a headrest 1 for a motor vehicle seat is described, said headrest comprising:

[0034] • a mounting frame on a back of said seat, said frame comprising two parallel rods 2 extending vertically,

[0035] • 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,

[0036] • a first device for locking said main body in the chosen adjustment position,

[0037] • 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 longitudinal adjustment positions, said secondary body being provided with a support wall 17 for the head of an occupant of said seat,

[0038] • a second device for locking said secondary body in the chosen adjustment position,

[0039] • a common crosspiece 5 for unlocking said devices, said crosspiece being mounted to slide transversely on said main body, said crosspiece having an end part 6 cooperating with a push button 7, mounted to slide transversely on said secondary body, allowing it to be actuation in unlocking, so as to release the sliding of said main and secondary bodies,

[0040] • a return spring 8 of said crosspiece in the locking position, said headrest further comprising: • a force balancing part 9 interposed between said button and said crosspiece, said part extending longitudinally, said part having an external face 10 on which said button bears and an internal face 11 in the form of a track extending longitudinally, said track receiving a projection 12, located on said end part, in a plurality of positions defined by the longitudinal adjustment position of said secondary body,

[0041] • two straightening springs 13 of said part when said projection bears in the non-median longitudinal zone of said track, said springs being interposed at the front and rear ends of said part between said part and said secondary body.

[0042] According to the embodiment shown, the return spring 8 is in the form of an elastically compressible foam washer, said washer being interposed between the secondary body 4 and the button 7.

[0043] In a variant not shown, the return spring 8 is based on spring metal.

[0044] According to the embodiment shown, the straightening springs 13 are in the form of blocks of elastically compressible foam.

[0045] In a variant not shown, the straightening springs 13 are based on spring metal.

[0046] According to the embodiment shown, the end part 6 is generally U-shaped, a first branch 14 of the U being in the extension of the rest of the crosspiece 5 and the second branch 15 of the U sliding in a guide means 16 provided in the secondary body 4.

[0047] Such an arrangement makes it possible to ensure optimized guidance of the crosspiece 5 to limit its deformation when it is actuated in unlocking mode.

[0048] According to the embodiment shown, the projection 12 is located in the middle part of the U. According to the embodiment shown, the projection 12 has a curved shape, so as to limit the contact surface between the crosspiece 5 and the balancing part 9, and thus to limit the friction between the two when adjusting the secondary body 4.

[0049] According to the embodiment shown, the secondary body 4 is mounted on the main body 3 by two tenons 23 arranged on its periphery, said tenons having in longitudinal view a shape inscribed in a trapezium having a large base facing inwards and a small base facing outwards, said tenons sliding in two respective mortises 24 of complementary shape, opening outwards through said small base, provided in said main body, so as to form “dovetail” type fixings.

[0050] According to the embodiment shown, the locking device of the main body 3 comprises:

[0051] • at least one notched rod 2 provided with adjustment notches 18 arranged axially, that is to say along the extension axis of said rod,

[0052] • at least one locking projection 19 mounted to move relative to the main body 3 - said projection being here formed by a zone of a deformable spring metal wire - between a locking position, where said projection is inserted into one of said notches (see figure 4), and an unlocking position, where said projection is withdrawn from said notch (see figures 5) - here by bending of said wire when the crosspiece 5 is actuated in unlocking - in order to release the sliding of said main body.

[0053] According to the embodiment shown in Figure 6, the locking device of the secondary body 4, in the chosen adjustment position, comprises:

[0054] • a rack 20 secured to said secondary body, said rack extending longitudinally,

[0055] • a latch 21 mounted to move relative to the main body 3 between a locking position, where it engages a notch of said rack, and an unlocking position, where it withdraws from said notch in order to release the sliding of said secondary body, said latch being returned to the locking position by a return spring means 22. According to the embodiment shown, the locking device of the secondary body 4 comprises two latches 21 each cooperating with a respective rack 20, in order to ensure reinforced locking.

[0056] According to the embodiment shown, the racks 20 are arranged on the tenons 23.

[0057] According to various embodiments, the secondary body 4 can be molded in one piece with the support wall 17 or constitute a separate part which is mounted on said wall.

Claims

CLAIMS 1. 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 that said secondary body can adopt a plurality of longitudinal adjustment positions, said secondary body being provided with a support wall (17) for the head of an occupant of said seat, • a second device for locking said secondary body in the chosen adjustment position, • a common crosspiece (5) for unlocking said devices, said crosspiece being mounted to slide transversely on said main body, said crosspiece having an end part cooperating with a push button (7), mounted to slide transversely on said secondary body, allowing it to be actuation in unlocking, so as to release the sliding of said main and secondary bodies, • a return spring (8) of said crosspiece in the locking position, said headrest being characterized in that it further comprises: • a force balancing part (9) interposed between said button and said crosspiece, said part extending longitudinally, said part having an external face (10) on which said button rests and an internal face (11) in the form of a track extending longitudinally, said track receiving a projection (12) located on said end part, in a plurality of positions defined by the longitudinal adjustment position of said secondary body, • two straightening springs (13) of said part when said projection bears in the non-median longitudinal zone of said track, said springs being interposed at the front and rear ends of said part between said part and said secondary body.

2. Headrest according to claim 1, characterized in that the return spring (8) is in the form of an elastically compressible foam washer, said washer being interposed between the secondary body (4) and the button (7).

3. Headrest according to one of the preceding claims, characterized in that the straightening springs (13) are in the form of blocks of elastically compressible foam.

4. Headrest according to any one of the preceding claims, characterized in that the end part (6) is generally U-shaped, a first branch (14) of the U extending from the rest of the crosspiece (5) and the second branch (15) of the U sliding in a guide means (16) provided in the secondary body (4).

5. Headrest according to any one of the preceding claims, characterized in that the projection (12) has a curved shape, so as to limit the contact surface between the crosspiece (5) and the balancing piece (9).

Images