Motor vehicle seat headrest

Abstract

The invention relates to a headrest for a motor vehicle seat, said headrest comprising a motorized actuation device (7) for a second structural element sliding relative to a first structural element, said device comprising a geared motor (4a, 4b) comprising a pair of toothed wheels (8) and worm screws (9), an angle transmission means, a transverse shaft (11) mounted in rotation about a second axis (12) parallel to the first axis (6), two pinions (13) respectively secured to the two lateral ends of said shaft, two racks (14a, 14b), each of said racks cooperating respectively with one of said pinions. Figure 1

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 first structural element, • a second structural element supporting a head support 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 actuation device for said second sliding element, said device comprising a geared motor fixed to one of said elements, said geared motor comprising an electric motor operable in rotation along a first transverse axis.

[0003] Usually, the installation of the actuating device, involving - in particular with wheels and worm screws - several stages of speed reduction relative to the rotation speed along the first axis, requires providing a significant dimension for the headrest along the sliding axis of the second element.

[0004] This prevents having a compact geared motor along the sliding axis, said headrest then being able to have an excessive dimension along said axis.

[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 first structural element, • a second structural element supporting a head support 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 actuation device for said second sliding element, said device comprising a geared motor fixed to one of said elements, said geared motor comprising an electric motor operable in rotation along a first transverse axis,

[0007] in which: • said geared motor further comprises a pair of toothed wheels and worm screws, an angle transmission means and a transverse shaft mounted for rotation along a second axis parallel to said first axis, said shaft being actuated in rotation by said angle transmission means,

[0008] said actuating device further comprising: • two pinions respectively secured to the two lateral ends of said shaft, • two racks integral with the other of said elements, each of said racks cooperating respectively with one of said pinions.

[0009] 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 by means of an intermediate block slidably mounted on said second element, as will be seen later.

[0010] Furthermore, in this description, the terms of positioning in space (longitudinal, transverse, vertical, lateral, upper, etc.) 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).

[0011] With the proposed arrangement, in particular due to the parallelism between the first and second axes, there is a headrest which can have an optimized compactness along the sliding axis of the second element.

[0012] Other features and advantages of the invention will appear in the following description, given with reference to the attached figures, in which:

[0013] [Fig. 1] is a partial schematic perspective view of a motorized actuating device according to one embodiment,

[0014] [Fig.2] is a partial schematic perspective view of a headrest provided with the device illustrated in [Fig.l].

[0015] To facilitate understanding of the rest of the description, it is specified here that, in the embodiments presented below: • a second element 3a is mounted in vertical sliding on a first element 2a by means of a primary geared motor 4a cooperating with primary racks 14a, • a second element 3b is mounted in longitudinal sliding on a first element 2b by means of a secondary geared motor 4b cooperating with secondary racks 14b.

[0016] In other words, in the references used, the suffix "a" is partially used to designate elements involved in a vertical sliding, the suffix "b" being partially used to designate elements involved in a longitudinal sliding.

[0017] With reference to the figures, a headrest 1 for a motor vehicle seat is described, said headrest comprising: • a first structural element 2a,2b, • a second structural element 3a, 3b supporting a cushion for supporting the head 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 7 for said second sliding element, said device comprising a geared motor 4a, 4b fixed to one of said elements, said geared motor comprising an electric motor 5 operable in rotation along a first transverse axis 6,

[0018] in which: • said geared motor further comprises a pair of toothed wheels 8 and worm screws 9, an angle transmission means and a transverse shaft 11 mounted in rotation along a second axis 12 parallel to said first axis, said shaft being actuated in rotation by said angle transmission means,

[0019] said actuating device further comprising: • two pinions 13 respectively secured to the two lateral ends of said shaft, • two racks 14a, 14b secured to the other of said elements, each of said racks cooperating respectively with one of said pinions.

[0020] According to the embodiment shown in [Fig.l], the geared motor 4a, 4b further comprises at least two toothed wheels 15 without angle transmission.

[0021] According to the embodiment shown in [Fig.l], the angle transmission means comprises: • a first angle gear wheel 16 mounted on the shaft 11 so as to be able to rotate along the second axis 12, • a second right-angle gear wheel 17 mounted in the geared motor 4a, 4b so as to be able to rotate along a third axis 18 perpendicular to said second axis.

[0022] According to the embodiment shown in [Fig.l], the worm screw 9 is mounted on the motor 5 so as to be able to rotate along the first axis 6.

[0023] In a partially represented manner, the shaft 11 is axially - that is to say along the second axis 12 - hollowed out so as to define a conduit, not visible in the figures, of non-circular section - for example square -, a rod 19 of complementary section being fitted into said conduit, said rod projecting laterally on either side of said shaft and being provided at each of its ends with a pinion 13 cooperating with a respective rack 14a, 14b.

[0024] In other words, the pinions 13 are integral with the lateral ends of the shaft 11 by means of the rod 19.

[0025] According to an embodiment not shown concerning a headrest 1 whose cushion is only adjustable in height: • the first element 2a is in the form of a frame 20 intended to be mounted on a back of the seat, said frame comprising two parallel metal rods 21 extending vertically, two primary racks 14a extending respectively along each of said rods, • the second element 3a is in the form of a main block 22 mounted in vertical sliding on said frame, the cushion being supported by said block, a primary geared motor 4a being fixed to said second element.

[0026] According to the embodiment shown in [Fig.2]: • a first element 2a is in the form of a frame 20 intended to be mounted on a back of the seat, said frame comprising two parallel metal rods 21 extending vertically, two primary racks 14a extending respectively along each of said rods, • a second element 3a is in the form of a main block 22 mounted in vertical sliding on said frame, a primary geared motor 4a being fixed to said second element, • an intermediate block 23 is mounted to slide longitudinally on said main block, the cushion being integral with said intermediate block.

[0027] Such an arrangement allows vertical adjustment of the second element 3a and longitudinal adjustment of the intermediate block 23, the cushion being indirectly supported by said second element, by means of said intermediate block, the adjustment of said intermediate block being carried out by an actuating device such as illustrated in [Fig.l] according to the embodiment shown, but which can be carried out by another means according to a variant not shown.

[0028] According to the embodiment shown in [Fig.2], the headrest 1 comprises a frame 20 intended to be mounted on a back of the seat, knowing that: • a first element 2b is formed by a main block 22 mounted in vertical sliding on said frame, secondary racks 14b being integral with said first element, • a second element 3b is formed by an intermediate block 23 mounted in longitudinal sliding on said main block, the cushion being integral with said intermediate block, a secondary geared motor 4b being fixed to said intermediate block.

[0029] Such an arrangement allows longitudinal adjustment of the second element 3b and vertical adjustment of the main block 22, the cushion being directly supported by said second element, the adjustment of said main block being carried out by an actuating device as illustrated in [Fig.l] according to the embodiment shown, but which can be carried out by another means according to a variant not shown.

[0030] According to the embodiment shown in [Fig.2], the headrest 1 comprises a frame 20 intended to be mounted on a back of the seat, said frame comprising two parallel metal rods 21 extending vertically, said headrest further comprising a main block 22 mounted to slide vertically on said frame and an intermediate block 23 mounted to slide longitudinally on said main block, the cushion being integral with said intermediate block, in which: • 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, a primary geared motor 4a being fixed to said second element, two primary racks 14a extending respectively along each of said rods, • 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, a secondary geared motor 4b being fixed to said intermediate block and secondary racks 14b being integral with said main block and extending longitudinally.

[0031] In other words, the main block 22 forms either a second element 3a or a first element 2b depending on the adjustment envisaged.

[0032] According to an embodiment not shown, in the case of the presence of an intermediate block 23, said block can be provided with two wings for lateral support of the head of a passenger, said wings being mounted laterally on either side of said block and rotating so as to be able to be adjusted angularly.

[0033] According to an embodiment not shown concerning a headrest 1 whose cushion is only longitudinally adjustable, the first element 2b is in the form of a frame 20 intended to be fixed to the back of the seat, the second element 3b being in the form of an intermediate block 23 mounted to slide longitudinally relative to said frame, the cushion being integral with said block, a secondary geared motor 4b being fixed to said block and secondary racks 14b being integral with said frame.

[0034] According to the embodiment of [Fig.2], the frame 20 comprises two parallel metal rods 21 - in particular tubular - extending vertically, said rods having two upper ends connected to each other by a transverse spacer 24 - in particular based on molded plastic material - fixed on said upper ends - in particular by interlocking.

[0035] According to one embodiment, the blocks 22, 23 previously described are based on molded plastic material.

[0036] According to an embodiment not shown, the primary racks 14a are made from molded plastic material, said racks being associated by fitting to the rods 21.

[0037] Finally, according to variants not shown, the respective positions of the secondary geared motor 4b and the secondary racks 14b could be swapped, said geared motor being able to be fixed to a first element 2b and said racks being integral with the second element 3b.

Claims

Claims

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 cushion for supporting the head of an occupant of said seat, said second element being mounted so as to slide relative to said first element, so as to allow adjustment of the position of said cushion, • a motorized actuating device (7) for said second sliding element, said device comprising a reduction motor (4a, 4b) fixed to one of said elements, said reduction motor comprising an electric motor (5) rotatable about a first transverse axis (6), said headrest being characterized in that: • said reduction motor further comprises a pair of toothed wheels (8) and worm screws (9), an angle transmission means and a transverse shaft (11) rotatably mounted about a second axis (12) parallel to said first axis,said shaft being actuated in rotation by said angle transmission means, and in that said actuating device further comprises: • two pinions (13) respectively secured to the two lateral ends of said shaft, • two racks (14a, 14b) secured to the other of said elements, each of said racks cooperating respectively with one of said pinions.,

2. Headrest (1) according to claim 1, characterized in that the geared motor (4a, 4b) further comprises at least two toothed wheels (15) without angle transmission.

3. Headrest (1) according to one of the preceding claims, characterized in that the angle transmission means comprises: • a first angle transmission toothed wheel (16) mounted on the shaft (11) so as to be able to rotate along the second axis (12), • a second right-angle gear wheel (17) mounted in the geared motor (4a, 4b) so as to be able to rotate along a third axis (18) perpendicular to said second axis.

4. Headrest (1) according to any one of the preceding claims, characterized in that the worm screw (9) is mounted on the motor (5) so as to be able to rotate along the first axis (6).

5. Headrest (1) according to any one of the preceding claims, characterized in that the shaft (11) is axially hollowed out so as to define a conduit of non-circular section, a rod (19) of complementary section being fitted into said conduit, said rod projecting laterally on either side of said shaft and being provided at each of its ends with a pinion (13) cooperating with a respective rack (14a, 14b).

6. Headrest (1) according to any one of claims 1 to 5, characterized in that: • the first element (2a) is in the form of a frame (20) intended to be mounted on a back of the seat, said frame comprising two parallel metal rods (21) extending vertically, two primary racks (14a) extending respectively along each of said rods, • the second element (3a) is in the form of a main block (22) mounted to slide vertically on said frame, the cushion being supported by said block, a primary geared motor (4a) being fixed to said second element.

7. Headrest (1) according to any one of claims 1 to 5, characterized in that: • a first element (2a) is in the form of a frame (20) intended to be mounted on a back of the seat, said frame comprising two parallel metal rods (21) extending vertically, two primary racks (14a) extending respectively along each of said rods, • a second element (3a) is in the form of a main block (22) mounted in vertical sliding on said frame, a primary geared motor (4a) being fixed to said second element,

8.

9. • an intermediate block (23) is mounted in longitudinal sliding on said main block, the cushion being integral with said intermediate block. Headrest (1) according to any one of claims 1 to 5, said headrest comprising a frame (20) intended to be mounted to a back of the seat, said headrest being characterized in that: • a first element (2b) is formed by a main block (22) mounted in vertical sliding on said frame, secondary enamel racks (14b) being integral with said first element, • a second element (3b) is formed by an intermediate block (23) mounted in longitudinal sliding on said main block, the cushion being integral with said intermediate block, a secondary geared motor (4b) being fixed to said intermediate block. Headrest (1) according to any one of claims 1 to 5, said headrest comprising a frame (20) intended to be mounted on a back of the seat, said frame comprising two parallel metal rods (21) extending vertically, said headrest further comprising a main block (22) mounted to slide vertically on said frame and an intermediate block (23) 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, a primary geared motor (4a) being fixed to said second element, two primary racks (14a) extending respectively along each of said rods, • 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, a secondary geared motor (4b) being fixed to said intermediate block and secondary racks (14b) being integral with said main block and extending longitudinally.

10. Headrest (1) according to any one of claims 1 to 5, characterized in that the first element (2b) is in the form of a frame (20) intended to be fixed to a back of the seat, the second element (3b) being in the form of an intermediate block (23) mounted to slide longitudinally relative to said frame, the cushion being integral with said block, a secondary geared motor (4b) being fixed to said block and secondary racks (14b) being integral with said frame.

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