Motor vehicle seat headrest

Abstract

The invention relates to a headrest (1) for a motor vehicle seat, said headrest comprising a first structural element (2a), a second structural element (3a) supporting a cushion which is slidably mounted relative to said first element by means of an actuation device comprising a geared motor (4) fixed to one of said elements, said device comprising an internal worm screw (5) rotated by said geared motor, an external worm screw (6) having an external thread (7), said screw being tubular and having an internal thread (8) extending over a portion of its length, said external screw receiving said internal screw by screwing into said internal thread, said internal thread being disposed at the end (9) of said external screw closest to said geared motor, and a nut (10) receiving said external thread, said nut being fixed to the other of said elements. 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 first structural element, • a second structural element supporting a headrest cushion for an occupant of said seat, said second element being mounted to slide relative to said first element, so as to allow adjustment of the position of said cushion, • a motorized actuation device for said second sliding element, said device comprising a geared motor fixed to one of said elements.

[0003] With such an arrangement, it may prove difficult to fit within the volume of the headrest, particularly when it has a certain compactness, an actuation device allowing sufficient travel of the second sliding element.

[0004] The invention aims to provide an arrangement that meets this expectation.

[0005] To this end, the invention proposes a headrest for a motor vehicle seat, said headrest comprising: • a first structural element, • a second structural element supporting a headrest cushion for an occupant of said seat, said second element being mounted to slide relative to said first element, so as to allow adjustment of the position of said cushion, • a motorized actuation device for said second sliding element, said device comprising a geared motor fixed to one of said elements,

[0006] said device further comprising: • an internal worm gear driven in rotation by said geared motor, • an external worm screw having an external thread, said screw being tubular and having an internal thread extending over a portion of its length, said external screw receiving said internal screw by screwing into said internal thread, said internal thread being disposed at the end of said external screw closest to said geared motor, • a nut receiving said external thread, said nut being fixed to the other of said elements,

[0007] so that said elements are connected to each other by a double screw in order to maximize the sliding range of said second element.

[0008] It is specified here that, when it is noted that the second element supports a cushion, it should be taken into account that the cushion can be directly associated with said second element, or indirectly through an intermediate block mounted to slide on said second element, as will be seen later.

[0009] In this description, the terms of positioning in space (high, longitudinal, transverse, vertical, ...) are taken with reference to the headrest in place in the vehicle, said vehicle extending longitudinally along its length (X), transversely along its width (Y) and vertically along its height (Z).

[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 cross-sectional view of a motorized actuation device, according to one embodiment, the double screw being deployed in a maximal (A), intermediate (B) and minimal (C) manner,

[0012] [Fig.2] is a partial general view of a headrest according to an embodiment receiving the actuation device shown in [Fig.1] for height adjustment of the second element relative to the first, the double screw being deployed in a maximum (A), intermediate (B) and minimum (C) position,

[0013] [Fig.3] is a schematic partial perspective view of a headrest according to one embodiment, said headrest being provided with two actuation devices to allow adjustment of the cushion both in height and in a longitudinal direction.

[0014] With reference to the figures, a headrest 1 of a motor vehicle seat is described, said headrest comprising: • a first structural element 2a,2b, • a second structural element 3a,3b supporting a cushion, not shown, for the head support of an occupant of said seat, said second element being mounted to slide relative to said first element, so as to allow adjustment of the position of said cushion, • a motorized actuation device for said second sliding element, said device comprising a geared motor 4 fixed to one of said elements,

[0015] said device further comprising: • an internal worm gear 5 driven in rotation by said geared motor, • an external worm screw 6 having an external thread 7, said screw being tubular and having an internal thread 8 extending over a portion of its length, said external screw receiving said internal screw by screwing into said internal thread, said internal thread being disposed at the end 9 of said external screw closest to said geared motor, • a nut 10 receiving said external thread, said nut being fixed to the other of said elements,

[0016] so that said elements are connected to each other by a double screw 11 in order to maximize the sliding range of said second element.

[0017] To facilitate understanding of the description, it is specified here that, in the embodiments presented later, a first element 2a is connected - by a double screw 11 - to a second element 3a and a first element 2b is connected - by a double screw 11 - to a second element 3b.

[0018] According to the embodiment shown in [Fig.2]: • the first element 2a is in the form of a frame 12 intended to be mounted to a seat back, • the second element 3a is in the form of a main block 16 mounted to slide vertically on said frame, the cushion being supported by said block.

[0019] According to the embodiment shown in [Fig.2], the geared motor 4 is fixed to the first element 2a and the nut 10 is fixed to the second element 3a.

[0020] In an alternative not shown, the geared motor 4 is fixed to the second element 3a and the nut 10 is fixed to the first element 2a.

[0021] Such an arrangement applies in particular to a headrest 1 whose cushion is only adjustable in height.

[0022] According to the embodiment shown in [Fig.3], the headrest 1 comprises a frame 12 intended to be mounted to a seat back, given that: • a first element 2a is formed by said reinforcement, • a second element 3a is formed by a main block 16 mounted to slide vertically on said frame, • an intermediate block 13 is mounted in longitudinal sliding on said main block, the cushion being integral with said intermediate block.

[0023] Such an arrangement allows vertical adjustment of the second element 3a and longitudinal adjustment of the intermediate block 13, the cushion being indirectly supported by said second element, through said intermediate block, the adjustment of said intermediate block being made by means of a double screw 11 according to the embodiment shown but being able to be made by another means according to a variant not shown.

[0024] According to the embodiment shown in [Fig.3], the headrest 1 comprises a frame 12 intended to be mounted to a seat back, given that: • a first element 2b is formed by a main block 16 mounted to slide vertically on said frame, • a second element 3b is formed by an intermediate block 13 mounted in longitudinal sliding on said main block, the cushion being integral with said intermediate block.

[0025] Such an arrangement allows longitudinal adjustment of the second element 3b and vertical adjustment of the main block 16, the cushion being directly supported by said second element, the adjustment of said main block forming the first element 2b being done by means of a double screw 11 according to the embodiment shown but being able to be done by another means according to a variant not shown.

[0026] According to the embodiment shown in [Fig.3], the vertical and longitudinal adjustments of the cushion are each made by means of a respective double screw 11, the headrest 1 comprising a frame 12 intended to be mounted to a seat back, said headrest further comprising a main block 16 mounted to slide vertically on said frame and an intermediate block 13 mounted to slide longitudinally on said main block, the cushion being integral with said intermediate block, given that: • For the vertical adjustment of said cushion, a first element 2a is formed by said frame and a second element 3a by said main block, • for the longitudinal adjustment of said cushion, a first element 2b is formed by said main block and a second element 3b by said intermediate block.

[0027] In other words, the main block 16 forms either a second element 3a or a first element 2b depending on the arrangement envisaged.

[0028] According to the embodiment shown in [Fig.3]: • The geared motor 4 used for vertical adjustment is fixed to the frame 12, on the spacer 15, the nut 10 being fixed to the main block 16, • The geared motor 4 used in longitudinal adjustment is fixed to the intermediate block 13, the nut 10 being fixed to said main block.

[0029] In variants not shown, it would be possible to consider interchanging the positions of a geared motor 4 and the corresponding nut 10: for example, as envisaged in the embodiment shown in [Fig.2], the geared motor 4 used in vertical adjustment could be fixed to the main block 16, the nut 10 being fixed to the spacer 15.

[0030] Similarly for the longitudinal adjustment, it could be envisaged that the geared motor 4 be fixed to the main block 16 and the nut 10 to the intermediate block 13.

[0031] According to an embodiment not shown, in the case of the presence of an intermediate block 13, said block may be provided with two lateral head support wings of a passenger, said wings being mounted laterally on either side of said block and rotated so as to be able to be adjusted angularly.

[0032] According to an embodiment not shown, the first element 2a is in the form of a frame 12 intended to be fixed to the seat back, the second element 3a being in the form of a block mounted to slide longitudinally relative to said frame, the cushion being attached to said block.

[0033] Such an arrangement applies in particular to a headrest 1 whose cushion is only adjustable in a longitudinal direction.

[0034] According to the embodiments illustrated in figures 2 and 3, the frame 12 comprises two parallel metal rods 14 - in particular tubular - extending vertically, said rods having two upper ends connected to each other by a transverse spacer 15 - in particular made of molded plastic material - fixed on said upper ends - in particular by interlocking.

[0035] According to an unrepresented variant, the armature 12 could be based on a metal tube folded to present in longitudinal view a general shape of an inverted U, so as to present two parallel metal rods 14 extending vertically, said rods being formed by the arms of the U, and a transverse spacer 15 formed by the middle part of the U.

[0036] According to one embodiment, the blocks 13,16 described above are based on molded plastic material.

[0037] According to the embodiment shown in [Fig.3], the intermediate block 13 is mounted on the main block 16 by means of "dovetails" using tenons 17 provided on said intermediate block cooperating with mortises 18 provided on said main block.

Claims

Demands

1. Headrest (1) for a motor vehicle seat, said headrest comprising: • a first structural element (2a, 2b), • a second structural element (3a, 3b) supporting a headrest cushion for an occupant of said seat, said second element being slidably mounted relative to said first element, so as to allow adjustment of the position of said cushion, • a motorized actuating device for said sliding second element, said device comprising a geared motor (4) fixed to one of said elements, said headrest being characterized in that the device further comprises: • an internal worm screw (5) actuated in rotation by said geared motor, • an external worm screw (6) having an external thread (7), said screw being tubular and having an internal thread (8) extending over a portion of its length,said external screw receiving said internal screw by screwing into said internal thread, said internal thread being disposed at the end (9) of said external screw closest to said geared motor, • a nut (10) receiving said external thread, said nut being fixed to the other of said elements, so that said elements are connected to each other by a double screw (11) in order to maximize the sliding range of said second element.

2. Headrest (1) according to claim 1, characterized in that: • the first element (2a) is in the form of a frame (12) intended to be mounted to a seat back, • the second element (3a) is in the form of a main block (16) mounted to slide vertically on said frame, the cushion being supported by said block.

3. Headrest (1) according to claim 1, said headrest comprising a frame (12) intended to be mounted to a seat back, said headrest being characterized in that: • a first element (2a) is formed by said frame, • a second element (3a) is formed by a main block (16) mounted to slide vertically on said frame, • an intermediate block (13) is mounted to slide longitudinally on said main block, the cushion being integral with said intermediate block.

4. Headrest (1) according to claim 1, said headrest comprising a frame (12) intended to be mounted to a seat back, said headrest being characterized in that: • a first element (2b) is formed by a main block mounted to slide vertically on said frame, • a second element (3b) is formed by an intermediate block (13) mounted to slide longitudinally on said main block, the cushion being integral with said intermediate block.

5. Headrest (1) according to claim 1, said headrest comprising a frame (12) intended to be mounted to a seat back, said headrest further comprising a main block (16) mounted to slide vertically on said frame and an intermediate block (13) mounted to slide longitudinally on said main block, the cushion being integral with said intermediate block, said headrest being characterized in that: • for the vertical adjustment of said cushion, a first element (2a) is formed by said frame and a second element (3a) by said main block, • for the longitudinal adjustment of said cushion, a first element (2b) is formed by said main block and a second element (3b) by said intermediate block.

6. Headrest (1) according to any one of claims 3 to 5, characterized in that the intermediate block (13) is provided with two lateral head support wings for a passenger, said wings being mounted laterally on either side of said block and rotated so as to be able to be angularly adjusted.

7. Headrest (1) according to claim 1, characterized in that the first element (2a) is in the form of a frame (12) intended to be fixed to the seat back, the second element (3a) being in the form of a block mounted to slide longitudinally relative to said frame, the cushion being integral with said block.

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