FR2810931A1 - Self adjusting headrest for motor vehicle has light source fixed to vehicle interior and actuating motor for headrest adjustment, via sensor - Google Patents

Abstract

The self adjusting headrest for a motor vehicle seat (1) has a light source (13) fixed to the vehicle interior (12) opposite the seat to emit a light beam against the front face of the headrest (6). A sensor (10) for the light beam is fixed to the front face of the rest to control an adjusting motor which varies the position of the rest.

Description

The invention relates to a headrest of a seat arranged in a clothing

  motor vehicle tackle comprising an automatic adjustment device

only in height.

  Modern motor vehicle seats, whether the driver's seat or the passenger seats, include

  numerous means of adjustment to ensure comfort and safety

rity of the seat occupant.

  In particular, motor vehicle seats most of the time have a headrest mounted on the upper part of the seat back and

  extending the backrest to the height of the head of the seat occupant.

  In particular, the headrest improves safety conditions

  rity while the motor vehicle is in motion, for the occupant of the seat. In the event of a shock, the head of the seat occupant is restrained so as to avoid bending and injury to the occupant's neck and spine.

seat.

  However, for the safety of the passenger to be satisfactorily ensured, it is essential that the headrest is correctly placed, that is to say that its front support part is located at the height of the head of the passenger. In order to be able to adapt the seat to the morphology of

  different passengers successively taking their places in the seat, the

  Motor vehicle drivers produce adjustable head restraints which can be, in particular, adjusted in height with respect to the seat back.

  In practice, few users think of adapting the position of the device.

  then head to their morphology, when they take their place in the seat of the motor vehicle. As a result, the security of these users is not optimal.

  In addition, the head restraints of the rear passengers of the motor vehicle

  bile may interfere with the driver, for example when maneuvering or changing lanes, since they are likely to reduce the visibility of

  the environment offered to the driver of the motor vehicle through

diary of the rear-view mirror (s).

  Motor vehicle seats are known comprising many

  many adjustment means, some of which can allow automatic adjustment

  matique of the seat to the morphology of the passenger. However, we do not know

  does not know hitherto of a device making it possible to adjust automatically and under entirely satisfactory conditions, the position of the headrest of a seat of a motor vehicle, at the time of the installation of an occupant

on the vehicle seat.

  The object of the invention is therefore to provide a headrest for a seat arranged in a passenger compartment of a motor vehicle comprising an automatic height adjustment device which makes it possible to adapt the headrest of

  simple and effective way to the morphology of a seat occupant and as-

  provide good visibility to the driver of the motor vehicle, when the

  seat is a rear seat of the motor vehicle and is not occupied.

  For this purpose, the automatic height adjustment device according to the invention comprises:

  - a light source fixed in a part of the passenger compartment, facing

  screw of the seat, so as to emit a light beam towards a

  anterior face of the headrest intended to provide support for the head of an oc-

seat cup,

  - a light beam detector fixed on a part of the an-

  front of the headrest and directed forward, and - a motor means for moving the headrest relative to the seat, in the vertical direction up and down comprising a

  actuation control means connected to the light beam detector

nous.

  In order to clearly understand the invention, we will describe by way of example

  ple with reference to the attached figures, a headrest according to the

  vention comprising an automatic adjustment device and its operation-

  ment in several cases of use of the seat of the motor vehicle.

  Figure 1 is a side elevational view of the upper part of the

  seat of the motor vehicle and the headrest and its restraint

  automatic gliding to ensure the comfort and safety of a passenger.

  FIG. 2 is a partial view in elevation and in section similar to

  the view of FIG. 1 showing the use of the automatic adjustment device

  than the headrest in an initial installation phase of the occupant.

  Figures 3, 4 and 5 are side elevational views in partial section of the passenger compartment of a motor vehicle showing a motor vehicle seat equipped with a headrest according to the invention, in different

  use of the seat by an occupant.

  In Figure 1, we see the upper part of the backrest 2 of a seat

  motor vehicle generally designated by the reference 1.

  The seat 1 of the vehicle is equipped with a headrest 3 according to the invention.

  The headrest 3 which is mounted on the upper part of the backrest 2 comprises

  a frame 4 made of a rigid material such as a metal or a plastic material

  and a padding 5 covering the frame 4. The padding 5 comprises

  carries an anterior surface 5a intended to ensure the support of the head 6a of a

  occupying 6 of the vehicle seat 1, for example in the case of an acceleration

  tion or shock exerting a force directed backwards on the head 6a of

occupant 6.

  The frame 4 of the headrest 3 includes a support part 4a

  secured in a corresponding guide part of the upper part

  seat 2, so that the headrest 3 can be moved in the direction

  tion vertically with respect to the backrest 2 of the seat 1. In the upper part of the seat is fixed an electric motor or geared motor 7 comprising for example an output pinion 7a meshing with part of the support 4a of

  the headrest 5 constituted by a rack.

  One can of course imagine other means of movement in the vertical direction of the headrest 3 relative to the seat back 2

1, by motor means.

  The motor 7 is connected to a control box 8 ensuring its supply

  mentation, for example in electric current, to ensure displacements

desired headrest 3.

  Inside the padding 5 of the headrest 3 is disposed, inside

  laughing of a cavity 9, a light detector such as a photoelectric cell

  which is connected, by at least one electrical conductor 11 passing through the interior

  of the support 4a of the headrest, to the control box 8 of the motor 7

movement of the headrest.

  Inside the passenger compartment 12 of the motor vehicle in which is

  disposed the seat 1 is placed a light source 13 which can be constituted

  killed for example by an easily identifiable light source, for example an infrared source with coding. These light sources are used for example for locking and unlocking the doors of a motor vehicle from outside the vehicle. The light source 13 will generally be placed at a level higher than the upper level of the

seat back 2 1.

  Preferably, the light source 13 is fixed on an upper part.

  of the windshield 14 of the motor vehicle and for example on the rear view mirror

  sor 15, in the case where the vehicle seat 1 is a front seat and in particular

driver's seat.

  FIG. 1 shows the zone 16 for capturing light by

  the photoelectric cell 10 disposed inside the cavity 9 of the mat-

  lassure 5 of the headrest 3. The shape and dimension of the capture zone 16 depend on the dimension and the arrangement inside the cavity 9

of the photocell 10.

  In particular, the arrangement of the photoelectric cell 10 inside

  laughter of the cavity 9 with a small aperture makes it possible to prevent lights from entering

  do not disturb the automatic adjustment device of the support

head 3.

  In addition, the use of coded infrared light in combination with an appropriate photoelectric cell makes it possible to greatly limit or practically eliminate the risks of disturbances of the device by a

stray light.

  In Figure 2, there is shown the headrest 3 of the seat 1, at the time

  o a passenger 6 has just taken place in the seat 1 of the motor vehicle

  bile inside the passenger compartment 12, so that the head 6a of the passenger 7 partially obscures the capture zone 16 of the photocell and

  the residual capture zone no longer contains the light source 13.

  In this case, the photoelectric cell 10 emits a signal which is received by the control unit 8 of the headrest 3 which corresponds to an absence of

  reception of light from the source 13.

  The automatic headrest adjustment device 3 is put into operation.

  operation either manually by the user 6, when he takes place on the seat of the motor vehicle, or, preferably, automatically, by an activation means constituted for example by a sensor for detecting closing the door of the motor vehicle that was used by occupant 6 of seat 1 or by an occupancy detector

  of the seat 1 constituted for example by a pressure sensor.

  In all cases, an activation signal 8 ′ is transmitted to the control unit 8 of the adjustment device, so as to transmit to the motor 7

  a movement command corresponding to the signal received from

  photoelectric cell 10.

  For example, in the case represented in FIG. 2, the signal received by the control unit 8 drives a power supply to the motor 7 ensuring the movement of the headrest 3 in the vertical direction and upwards,

  as shown by arrow 17.

  The movement in the vertical direction and upwards of the mobile part of the headrest 3 stops, either when the cell 10 receives a light signal of predetermined intensity from the source 13, or when the part of

  support 4a of the headrest 3 comes into contact with a high stop.

  In all cases, the bearing surface 5a of the padding 5 of the device

  pui-tête 3 arrives in a position facing the head 6a of the step-

  sager 6 to ensure comfort and safety.

  Several actuation logics can be used to com-

  request the movements of the headrest.

  First of all, we can plan a systematic start of the support-

  head from a maximum low position, which allows in particular, in the case of rear seats of the motor vehicle, to place the head restraints in the low position, when the seats are not in use. So we release

  rear space to improve visibility for the vehicle driver

  automobile vehicle, in the case of maneuver.

  It is also possible to provide for an automatic lowering of the headrest of the motor vehicle seat, after

  use of the seat by an occupant, only a stop of the headrest in the po-

  adjustment position that was obtained when using the seat.

  In the second case, the automatic adjustment of the headrest includes

  a first step of lowering the headrest, to its maximum position

male bass.

  In the case of a seat user of sufficient size, the harness

  the light source 13 is obscured by the passenger's head, as shown

  Figure 2 and the automatic adjustment is carried out by the

  vertical and upwards at low speed of the headrest, until detection

  tion of the light from the light source 13 by the photocell 10

  or up to the upper stop, as explained above.

  In the case of the use of the seat by a small passenger whose head does not obscure the beam of the light source 13, the appuitete

  stays in its maximum low position.

  You can also use control logic with start-

rage in the high position.

  In this case, the automatic adjustment includes a first step of

  rise of the headrest to its maximum high position then a des-

  cente of the slow speed headrest produced by the motor 7 controlled by the control unit 8, until the head 6a of the passenger 6

  begins to obscure the beam of the light source 13. Stopping the mo-

  tor 7 is then controlled by a variation of the signal supplied by the photoelectric cell 10. The limit of the shadow area produced by the head of the passenger 6a is thus detected, which makes it possible to stop the headrest 3 in a

  ideal position in which the bearing surface 5a is perfectly facing

  screw of head 6a of occupant 6 of seat 1.

  Finally, it is also possible to carry out a threshold search to place the headrest 3 in an ideal position. In this case, the control unit 8 detects a predetermined change of state of the cell 10 or a signal

limit switch.

  In all cases, in order to avoid permanent displacement of the device

  positive, actuation of the adjustment system is ensured by triggering

  manual or by automatic detection of seat occupancy or closing

  of a vehicle door.

  In Figure 3, there is shown the vehicle seat 1 inside the passenger compartment 12 of the motor vehicle in the case where the seat 1 is occupied

  by a small passenger 6. In this case, the mobile part of the support-

  head 3 is placed at the end of adjustment in its maximum low position which,

  vant the cases, can be obtained without displacement, if the movable part of

  The headrest is in the low position at the initial instant and that the head 6a of the occu-

  pant 6 does not obscure the beam from the source 13 or by moving downwards the movable part of the headrest 3, in the case where the movable part of the headrest 3 has been stopped previously either by high stop position either in a previous adjustment position, when occupying the seat

  by an occupant of a larger size.

  In Figure 4, there is shown the seat 1, when the seat is used by an occupant 6 of medium size taking place after the use of the seat by a large passenger or when the headrest is brought back in high position after using the seat. In this case, the automatic adjustment of the movable part of the headrest 3 is carried out by displacement downwards, as represented by the arrow 18, until the moment when the head 6a of the passenger 6 begins to obscure the beam of the source. light 13. In Figure 5, there is shown the seat 1 of the motor vehicle

  The interior of the passenger compartment 12, in the case of the use of the seat by an occu-

  large pant 6 succeeding a small or large passenger

  medium, in the case where the movable part of the headrest 3 has remained in

  sition after the departure of the previous occupant. In this case, the head 6a of the large passenger 6 obscures the beam of the light source 13, which controls the movement in the vertical direction and upwards,

  as represented by arrow 19, of the movable part of the headrest 3, up to

  when cell 10 detects the light emitted by the light source

  neuse 13 or up to a high stop stop of the mobile part of the support

head 3.

  In all cases, an effective automatic adjustment of the headrest 3 of the motor vehicle is obtained, so that the safety and comfort of a seat occupant are satisfactorily ensured. The invention is not strictly limited to the embodiment which has

been described.

  This is how we can use any type of motor means.

  to move the moving part of the headrest and let the light sensor

  The light source may be of any type.

  The light source can be placed inside the passenger compartment 12 in a different arrangement from that which has been described and associated with a

  interior element different from a rear view mirror.

  The device may include both a low stop and a high stop or at least one of a high stop and a low stop. The initial position of the headrest, before adjustment, can be a maximum position

  low, a maximum high position or an intermediate position.

  The invention applies to all types of motor vehicles and in particular

  particular to motor vehicles which are used successively by a

  driver or passengers of different sizes.

Claims (10)

  1.- Headrest of a seat (1) arranged in a passenger compartment (12) of vehicle   motor vehicle, comprising an automatic height adjustment device   tor, characterized in that the automatic height adjustment device   tor comprises: - a light source (13) fixed in a part of the passenger compartment (12) of the motor vehicle, facing the seat (1), so as to emit a light beam towards a face front (5a) of the headrest (3) intended to support the head (6a) of an occupant (6) of the seat (1), - a light beam detector (10) fixed on a part of the front face (5a) of the headrest (3) and directed towards the front, and   - a motor means (7) for moving a mobile part of the support -   head (3) relative to the seat (1), in the vertical direction, up and down, comprising an actuation control means (8) connected   to the light beam detector (13).   2.- headrest according to claim 1, characterized in that the light source is an easily identifiable light source which can be distinguished from stray light, for example a lamp emitting a infrared light with coding.   3.- headrest according to any one of claims 1 and 2, ca-   characterized by the fact that the light beam detector is fixed in the   bottom of a cavity (9) formed in a part (5) of padding of the device   pui-tête (3), set back towards the inside of the padding (5) of the headrest (3),   relative to the anterior face (5a) of the headrest (3).   4.- headrest according to any one of claims 1 to 3, ca-   characterized by the fact that the light beam detector is a photoelectric cell.   5.- headrest according to any one of claims 1 to 4, ca-   characterized by the fact that the actuation control means (8) of the motor means (7) is an electrical control unit connected by at least   an electrical conductor (11) to the light beam detector (10).   6.- Headrest according to any one of claims 1 to 5, ca-   characterized by the fact that the actuation control means (8) is connected to an activation means constituted by one of the following means: manual control, closing sensor of a door of the motor vehicle,   seat occupancy sensor (1) of the vehicle, such as a pressure sensor if we.   7.- headrest according to any one of claims 1 to 6, ca-   characterized by the fact that it comprises at least one of a low stop and a high stop for stopping the movable part of the headrest (3) in position   maximum low or maximum high position, respectively.   8.- Headrest according to any one of claims 1 to 7, ca-   characterized by the fact that the actuation control means (8) is reali-   dried so as to ensure the starting of the motor means (7) for movement   of the movable part of the headrest (3), for the movement of the mo-   bile of the headrest (3) downwards, when the light beam detector (10) detects a light signal coming from the source (13) and a stop of the displacement motor means, when the light beam detector ( 10) no longer detects a light signal from the light source (13) or when the moving part of the headrest (3) has reached a   maximum low position and to ensure the upward movement of the   moving part of the headrest (3), when the light beam detector (10) does not detect a light signal coming from the light source (13) and the movement of the moving part of the headrest stops (3), when the light beam detector (10) detects a light signal from the light source (13) or when the movable part of the headrest (3) is   reached a maximum high position.   9.- Headrest according to any one of claims 1 to 8, ca-   characterized by the fact that the actuation control means (8) of the motor means (7) is produced so as to place, in one of an initial phase or a final phase of the adjustment, the movable part of headrest (3)   in one of a maximum low position and a maximum high position.   10.- Headrest according to any one of claims 1 to 9, ca-   characterized by the fact that the light source (13) is arranged in the home   key (12) of the motor vehicle in a location located on a higher level   laughing at the upper level of the backrest (2) of the seat of the motor vehicle (1).