U.S. patent application number 10/488358 was filed with the patent office on 2005-03-24 for method for moving a headrest in the event of a rear-end collision and arrangement of a headrest on a vehicle seat.
Invention is credited to Eberle, Walter, Itinger, Albert.
Application Number | 20050062330 10/488358 |
Document ID | / |
Family ID | 7697412 |
Filed Date | 2005-03-24 |
United States Patent
Application |
20050062330 |
Kind Code |
A1 |
Eberle, Walter ; et
al. |
March 24, 2005 |
Method for moving a headrest in the event of a rear-end collision
and arrangement of a headrest on a vehicle seat
Abstract
A method for moving a head restraint of a vehicle seat in the
event of a rear-end collision and an arrangement of a head
restraint on a vehicle seat are provided. In the event of a
rear-end collision, the head restraint can be moved in the forward
direction of travel by a drive device, and an impact device absorbs
a rearward movement of an upper body of an occupant located on the
vehicle seat.
Inventors: |
Eberle, Walter; (Hochdorf,
DE) ; Itinger, Albert; (Berglen, DE) |
Correspondence
Address: |
CROWELL & MORING LLP
INTELLECTUAL PROPERTY GROUP
P.O. BOX 14300
WASHINGTON
DC
20044-4300
US
|
Family ID: |
7697412 |
Appl. No.: |
10/488358 |
Filed: |
October 18, 2004 |
PCT Filed: |
August 8, 2002 |
PCT NO: |
PCT/EP02/08863 |
Current U.S.
Class: |
297/408 |
Current CPC
Class: |
B60N 2/4228 20130101;
B60N 2/888 20180201; B60N 2/806 20180201 |
Class at
Publication: |
297/408 |
International
Class: |
A47C 001/10 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 1, 2001 |
DE |
101 42 926.6 |
Claims
1. A method for moving a head restraint of a vehicle seat in the
event of a rear-end collision, the head restraint being moved in
the forward direction of travel, characterized in that the movement
of the head restraint (3) in the forward direction of travel (Y)
takes place, firstly, by means of at least one driving device (4,
4') and, secondly, is assisted by a movement of an upper body of an
occupant located on the vehicle seat (1).
2. The method as claimed in claim 1, characterized in that the
movement of the head restraint (3) in the forward direction of
travel by means of the drive device (4, 4') takes place in terms of
time before the displacement is assisted as a consequence of a
rearward movement of the upper body of the vehicle occupant.
3. An arrangement of a head restraint on a vehicle seat of a motor
vehicle, in particular for carrying out a method as claimed in
claim 1 or 2, characterized in that, in the event of a rear-end
collision, the head restraint (3) can be moved in the forward
direction of travel (Y) by means of a drive device (4, 4') and an
impact device (5) which absorbs a rearward movement of an upper
body of an occupant located on the vehicle seat (1).
4. The arrangement of a head restraint on a vehicle seat as claimed
in claim 3, characterized in that the drive device (4, 4') and the
impact device (5) are arranged with respect to each other in such a
manner that the impact device (5) assists a preceding movement of
the head restraint (3) via the drive device (4) in the forward
direction of travel.
5. The arrangement of a head restraint on a vehicle seat as claimed
in claim 3 or 4, characterized in that a frame (6) for holding the
head restraint (3) can be pivoted by the drive device (4, 4') in
the forward direction of travel about an axis of rotation (15)
fixed on the seat back.
6. The arrangement of a head restraint on a vehicle seat as claimed
in claim 5, characterized in that the frame (6) is guided in a
guide (24) fixed on the seat back.
7. The arrangement of a head restraint on a vehicle seat as claimed
in one of claims 3 to 6, characterized in that the impact device
(5) is connected to the drive device (4, 4').
8. The arrangement of a head restraint on a vehicle seat as claimed
in one of claims 5 to 7, characterized in that an application of
force to the impact device (5) causes the frame (6) for holding the
head restraint (3) and the drive device (4, 4') to additionally be
pivoted through a further angle of rotation about the axis of
rotation (15) fixed on the seat back.
9. The arrangement of a head restraint on a vehicle seat as claimed
in one of claims 3 to 8, characterized in that the impact device
(5) has an impact plate (20) or an impact strap provided to absorb
a movement of the upper body of an occupant.
10. The arrangement of a head restraint on a vehicle seat as
claimed in one of claims 5 to 9, characterized in that the impact
device (5) is guided on a guide (24) fixed on the seat back, the
frame (6) for holding the head restraint (3) and the impact device
(5) preferably being guided on a common guide (24) fixed on the
seat back.
11. The arrangement of a head restraint on a vehicle seat as
claimed in one of claims 3 to 10, characterized in that the drive
device (4) has at least one spindle drive (9).
12. The arrangement of a head restraint on a vehicle seat as
claimed in claim 11, characterized in that the spindle drive (9)
has a spindle (10) which can be driven by a motor (11) in such a
manner that a rotatable holder (12) which is connected to the frame
(6) for holding the head restraint (3) and is intended for the
spindle (10) is moved axially on the latter.
13. The arrangement of a head restraint on a vehicle seat as
claimed in claim 12, characterized in that the spindle (10) has a
self-locking device.
14. The arrangement of a head restraint on a vehicle seat as
claimed in one of claims 5 to 13, characterized in that the axis of
rotation (15) runs through two pivots (16, 17) which are arranged
symmetrically to each other, are fixed on the seat back and about
which a respective spindle drive (9) can be pivoted.
15. The arrangement of a head restraint on a vehicle seat as
claimed in one of claims 3 to 14, characterized in that the drive
device (4) has at least one electric motor (11) and/or a pneumatic
drive and/or a hydraulic drive.
16. The arrangement as claimed in one of claims 1 to 10,
characterized in that the drive device is designed as a pneumatic
drive (4').
17. The arrangement as claimed in claim 16, characterized in that
the pneumatic drive (4') has an airbag (32) which can be deployed
and which is connected to the frame (6) for holding the head
restraint (3) via a first securing device (29, 30) and to the
impact device (5) with a second securing device (31).
18. The arrangement as claimed in claim 16 or 17, characterized in
that the pneumatic drive (4') is supplied with air via an air
supply of the vehicle.
19. The arrangement as claimed in claim 16 or 17, characterized in
that the pneumatic drive (4') can be driven via a pressure
accumulator with an igniter.
20. The arrangement of a head restraint on a vehicle seat as
claimed in one of claims 3 to 19, characterized in that the
arrangement is of reversible design.
Description
BACKGROUND OF THE INVENTION
[0001] This application claims the priority of 101 42 926.6, filed
Sep. 1, 2001, the disclosure of which is expressly incorporated by
reference herein.
[0002] The present invention relates to a method for moving a head
restraint of a vehicle seat in the event of a rear-end collision,
and to an arrangement of a head restraint on a vehicle seat, which
arrangement is provided in particular for carrying out this
method.
[0003] Investigations have revealed that, in particular in the
event of rear-end collisions, serious injuries to the cervical
spine occur in large numbers. Such injuries to the cervical spine
have proven problematic, in particular because the healing process
is often very drawn out and is associated with high healing costs
and corresponding demands made of insurance companies.
[0004] It is, therefore, a great matter of concern for the vehicle
industry to provide devices for protecting occupants in vehicles,
in which the devices reduce or even prevent injuries to the
cervical spine, particularly in the event of rear impact
collisions, in which whiplash trauma occurs even at low impact
speeds of between approximately 10 km/h and 40 km/h.
[0005] In the opinion of medical experts, injuries to the cervical
spine and the known whiplash trauma due to a movement of the head
relative to the upper body occur if the head is moved relative to
the upper body in the rearward direction of travel. In addition,
injuries to the cervical spine are also incurred due to the neck
muscles being over-rotated after what may be referred to as a
"rebound".
[0006] On account of these findings, devices for reducing or
avoiding injuries to the cervical spine in a "rear-end crash" aim
to support the head and the back of a vehicle occupant in such a
manner that, in the event of a crash, there is no relative movement
of the head toward the upper body and a movement of the upper body
in the forward direction of travel is suppressed as far as
possible.
[0007] To date, the prior art has disclosed a number of different
systems in order to reduce or even avoid injuries to the cervical
spine. Thus, for example, DE 197 43 339 A1 discloses a seat and
head restraint arrangement having a seat backrest frame with an
upper and a lower part. The upper part of the seat backrest frame
has a transverse frame element and the lower part has at least one
lower section comprising a pair of spaced apart side elements.
Furthermore, this arrangement has a head restraint which is fitted
to the transverse frame element, an impact mechanism which is
positioned between the side elements of the lower part and is
fastened to the upper part, and a rotary joint which connects the
upper and the lower part and defines an axis of rotation. The upper
part and the head restraint can be pivoted about this axis of
rotation forward from a normal position and can thereby pivot the
impact mechanism to the rear from a normal position. Furthermore, a
spring pretensions the upper part, the head restraint and the
impact mechanism into their normal position.
[0008] If, in the case of an arrangement of this known type, the
rear of the vehicle is exposed to an impact, most of the upper body
of the occupant has a tendency to move in a relative manner to the
rear while the shoulders and the head have a tendency to move in
the forward direction of travel. In this known arrangement, the
body acts on an impact plate which pivots out to the rear. This
pivoting movement has the effect of moving the upper part of the
seat backrest frame and the head restraint forward about the axis
of rotation toward the occupant's shoulders and head. Therefore,
when the occupant moves rearward, the upper part of the seat
backrest frame and the head restraint are moved forward thereby
counteracting injuries to the cervical spine in the event of a
rear-end crash.
[0009] In the case of this system which is activated by the
relative rearward movement of the occupant, it has proven
disadvantageous that the triggering of the system is dependent
solely on the weight and the position of the occupant. For this
reason, it is always necessary in such a system for it to be
matched to the particular occupant. A further disadvantage of this
solution is that the movement of the occupant cannot be
sufficiently counteracted in the case of a minor rear-end
crash.
[0010] In addition, the prior art also discloses what are referred
to as active systems, in which an active head restraint can be
designed such that an airbag is contained in the head restraint.
Depending on the outlay on sensors, the activation of a system
having an airbag can take place taking account of the weight and
the position of the vehicle occupant or irrespective thereof.
However, in order to ensure that the airbag is triggered even in
relatively minor accidents, low triggering thresholds are
frequently set, so that the airbag is always completely deployed
even in minor rear-end collisions.
[0011] This means that the occupant's forward movement, which is
actively triggered by the airbag, is always of the same magnitude
no matter how severe the rear-end collision actually is. There is
thus no differentiation between relatively minor and more severe
accidents, so that, under some circumstances, the active system
always causes a sharp forward movement of the head region of the
vehicle seat which may result in the occupant being injured in the
event of only a minor rear-end collision.
SUMMARY OF THE INVENTION
[0012] Starting from this prior art, the invention is based on the
An object of the present invention is to provide a method for
moving a head restraint in the event of a rear-end collision and an
arrangement of a head restraint on a vehicle seat, with which the
injuries in the region of the cervical spine in the event of a
rear-end crash can be reduced even further without unnecessarily
harming the occupant.
[0013] This object is achieved by a method first using at least one
driving device to effect the movement and assisting the movement by
vehicle occupant's upper body located on the vehicle seat and by an
arrangement of a head restraint in a rear-end collision, the head
restraint is movable in the forward direction of travel by the at
least one drive device and an impact device which absorbs a
rearward movement of the vehicle occupant's upper body located on
the vehicle seat.
[0014] In the case of the method and the arrangement of a head
restraint on a vehicle seat according to the invention, the
combination of the movement of the head restraint in the event of a
rear-end collision in the forward direction of travel by way of a
drive device and this movement being assisted by a movement of an
upper body of an occupant located on the vehicle seat being
transmitted has proven very advantageous. A system operating in
such a manner, in which preferably first of all the activation by
way of the drive device takes place followed by the assistance by
the occupant, ensures that the head restraint is displaced in good
time and to a sufficient extent in the forward direction of travel
both in minor and also in severe rear-end collisions. This provides
a system which counteracts injuries to the cervical spine and which
can be activated irrespective of the vehicle occupant's weight and
position.
[0015] The method and the arrangement according to the invention
provide the further advantage that, in the event of a rear-end
crash, the movement of the head restraint in the forward direction
of travel does not take place over a predetermined, maximum path of
displacement, but rather is assisted by the relative movement of
the upper body of the occupant and therefore takes place in a
proportioned manner. Thereby, the movement of the occupant is
correspondingly smaller in the event of an only minor rear-end
impact and the path of displacement of the head restraint is
correspondingly shorter than in the case of a more severe rear-end
impact.
[0016] Furthermore, the method and arrangement according to the
invention are distinguished by the fact that a complex adaptation
to a backrest and cushion structure and also stiffness of the
vehicle seat is rendered superfluous, and a conflict between
designing the vehicle seat and the head restraint in terms of
comfort and safety is avoided.
[0017] Other objects, advantages and novel features of the present
invention will become apparent from the following detailed
description of the invention when considered in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a simplified front view of an arrangement
according to the present invention of a head restraint on a vehicle
seat in the normal position;
[0019] FIG. 2 is a side view of the arrangement of a head restraint
on a vehicle seat according to FIG. 1 but without the cushion
elements;
[0020] FIG. 3 is a front view of the arrangement of a head
restraint on a vehicle seat according to FIGS. 1 and 2 during a
movement of the head restraint in the forward direction of travel
as a consequence of a rear-end collision;
[0021] FIG. 4 is a side view of the arrangement according to FIG. 3
without the cushion elements;
[0022] FIG. 5 is a perspective front view of an arrangement of a
head restraint on a vehicle seat with an alternative drive device
to the variant according to FIGS. 1 to 4; and
[0023] FIG. 6 is a perspective rear view of the arrangement
according to FIG. 5.
DETAILED DESCRIPTION OF THE DRAWINGS
[0024] With reference now to the drawing figures, an upper region
of a vehicle seat 1 of a motor vehicle is illustrated in part and
in simplified form, with a backrest 2 (shown schematically) being
connected to a head restraint 3.
[0025] The arrangement of the head restraint 3 on the vehicle seat
1 is provided such that, in the event of a rear-end collision, the
head restraint 3 is moved in the forward direction of travel by way
of a drive device 4 and an impact device 5 which absorbs the
movement of an upper body of an occupant located on the vehicle
seat 1.
[0026] A frame 6 which protrudes with two column-like tubes 7, 8
into the upholstery of the head restraint 3 is provided for holding
the head restraint 3. The columns 7, 8 can be vertically adjustable
in a conventional manner, thus enabling the height of the head
restraint 3 to be matched to the height of the vehicle occupant's
head.
[0027] In its region facing the backrest 2, the frame 6 forms an
approximately U-shaped profile with two limbs, each of which is
connected to a spindle drive 9. Each spindle drive 9 has a spindle
10 which can be driven by a motor 11 which is configured here as an
electric motor, and by a step-down gear 19.
[0028] Alternatively, a drive may also be provided by just one
motor which acts on a spindle drive and, via a connecting shaft,
also on the second spindle drive. In such a variant, in which just
one motor, which can be driven electrically, pneumatically or
hydraulically, is required, a greater tolerance in respect of the
exact synchronism of the drives of the spindle drives is
permissible.
[0029] When the spindle drive 9 is actuated, a holder or spindle
nut 12 which can be rotated on the spindle 10 and is connected to
the frame 6 via two spindle-nut holders 13 is moved axially on the
spindle 10. Thus, in the event of a rear-end collision, the spindle
10 is driven by the electric motor 11 so that the spindle nut 12 is
moved away from the electric motor 11 in a direction of movement
designated by an arrow X in FIG. 4. In this case, the spindle 10
advantageously has a self-locking device.
[0030] The frame 6 can be pivoted via an oscillating link 14 about
an axis of rotation 15 fixed on the seat back. The pivot axis 15 in
the illustrated embodiment runs through two pivots 16, 17 which are
arranged symmetrically to each other and in the present case are
formed in turn by a screw fastening to a seat back structure (not
illustrated in detail). Furthermore, the impact device 5 is
connected pivotably via a further oscillating link 18 to the seat
back structure by the screw fastenings 16, 17.
[0031] The impact device 5 has an impact plate 20 which extends
between the U-limbs of the frame 6, in a plane running essentially
parallel to the backrest 2, level with the upper body of a vehicle
occupant. In the illustrated embodiment, the impact plate 20 is
fastened on a frame 21 which has a similar geometry to the frame 6
for holding the head restraint 3. The frame 21 forms an
approximately U-shaped profile within the U-profile of the frame 6
and, toward the head restraint 3, has two guide rods 22, 23 which
are guided in a guide 24 fixed on the seat back.
[0032] The guide 24 which is fixed on the seat back at the same
time constitutes a guide sleeve for the columns 7, 8 of the frame
6. The respective passage 25 of the column 7 or 8 through the guide
sleeve 24 is designed with a kinematic pivoting point 26 which
permits the frame 6 to pivot about the axis of rotation 15.
[0033] A strut-like holder 27 is fastened in each case to the
U-limbs of the frame 21 of the impact device 5, as an extension of
those limbs. The holder 22 is connected fixedly in turn to a
securing device 28 for the electric motor 11 of the drive device to
create a fixed connection between the impact device 5 and the drive
device 4.
[0034] In operation of the present arrangement, the head restraint
3 is actuated, in the event of a rear-end collision, from the
normal position, which is shown in FIG. 1 and FIG. 2, in such
manner that it moves in the forward direction of travel Y, as
illustrated in FIG. 3 and FIG. 4.
[0035] In the event of a rear-end collision which can be detected
by a known sensor mechanism, a suitable controller which may, for
example, be already present in the vehicle, is used to activate the
drive device 4 by the electric motor 11 thereof driving the spindle
drive 9 to move the spindle nut 12 axially to the rear on the
spindle drive in the installed position. The frame 6 for holding
the head restraint 3 is thereby pivoted by the oscillating link 14
about the axis of rotation 15 and the kinematic pivoting point 26
in the guide sleeve 24, so that the head restraint 3 is displaced
in the forward direction of travel Y as seen in FIG. 4. In this
case, the displacement of the head restraint 3 takes place
irrespective of the weight of the occupant who is to be protected
and whose head is moved in a relative manner to the rear in the
event of a rear-end collision.
[0036] Depending on the path of adjustment on the spindle 10 and
the pivoting angle about the axis of rotation 15, provision may be
made for the displacement of the head restraint 3 by the drive
device 4 to take place irrespective of the severity of the accident
so that, even in the event of a very minor accident, a required
deflection of the head restraint 3 is always ensured. However, the
activation of the drive device 4 may also take place as a function
of certain parameters, such as, for example, an occupant's position
or a deceleration of the vehicle or further parameters defining the
severity of the accident, with the result that the displacement of
the head restraint 3 takes place in a proportioned manner.
[0037] In the event of a rear-end collision, the upper body of a
vehicle occupant is always moved to the rear too, this movement
taking place, however, relative to the movement of the head. In the
present arrangement, the rearward movement of the upper body is
used to assist the forward movement of the head restraint 3.
[0038] If, in the event of a rear-end collision, the occupant is
pushed with his upper body to the rear into the vehicle seat 1, the
occupant presses the impact plate 20 of the impact device 5. The
plate 20 is arranged in the seat backrest 2, away to the rear, in
which case the impact plate 20 and the frame 21 are likewise
pivoted about the axis of rotation 15. Since the drive device 4
which is connected to the frame 6 for holding the head restraint 3
is connected to the impact device 5 via the motor-securing device
27, the drive device 4 is pivoted together with the impact device 5
through a further angle of rotation about the axis of rotation 15
fixed on the seat back. Consequently the head restraint 3 being
further displaced in the forward direction of travel Y.
[0039] The beginning of the movement of the impact device 5 is
illustrated in FIG. 3 and FIG. 4. With this combined system, in
which first of all the head-restraint forward movement is activated
by the drive device 4, the movement then being assisted by the
impact device 5 on account of the movement of the occupant, the
activation of the head restraint 3 can be set so that, even with
lightweight people and relatively minor rear-end collisions, for
example at a differential speed of up to 10 km/h, the drive device
4 causes the head restraint 3 to be deflected in good time and
sufficiently for the head of the occupant located on the vehicle
seat 1 to come into contact with it while, however, even in the
case of a very severe rear-end crash, the head restraint 3 can be
sufficiently displaced under assistance by the impact device 5.
[0040] The actuation of the drive device 4, which preferably takes
place before the actuation of the impact device 5, should take
place at such an early point that the problem, as known in the case
of airbags, of the head restraint "shooting at" and causing a loud
noise in the ear is avoided by an appropriately slower movement of
the head restraint 3.
[0041] FIG. 5 and FIG. 6 show an arrangement of a head restraint on
a vehicle seat corresponding essentially to the arrangement
according to FIGS. 1 to 4, and so the same reference numbers are
used here for functionally identical structural elements.
[0042] In contrast with the variant according to FIGS. 1 to 4, the
drive device used in FIGS. 5 and 6 is a pneumatic drive 4' which
has a deployable airbag 32. The airbag 32 is connected to the frame
6 for holding the head restraint via a first securing device,
comprising a fastening plate 29 on the frame 6 and a holder 30
which bears directly against the airbag 32 and is connected fixedly
to the plate 29. At the other end the airbag 32 is connected to the
impact plate 20 of the impact device 5 with a second securing
device which essentially comprises a U-shaped holder 31.
[0043] In order to activate the pneumatic drive 4', the airbag 32
is filled with air. It is contemplated for the airbag to be
connected for this purpose to a general, already existing air
supply in the vehicle. In order to make an even more rapid opening
of the airbag 32 possible, it can also be driven in the manner
known for airbags, via a pressure accumulator with an igniter.
[0044] With regard to its manner of operation, the pneumatic drive
4' operates in the manner of the previously described drive device
4 with the spindle drive 9, with the embodiment according to FIGS.
5 and 6 being distinguished by a compact manner of construction and
a simple design.
[0045] In all of the currently contemplated embodiments, it is
particularly advantageous that they are reversible and can
therefore be reused after being activated. With a reversible design
of this type, the stipulations placed on the triggering reliability
of the control electronics can be kept correspondingly less
demanding because a possible erroneous triggering does not require
the system to be completely replaced.
[0046] Of course, the arrangement according to the invention is not
restricted to the structural embodiments shown here, because these
can have numerous design variants. Thus, for example, instead of
the described impact plate, the impact device may have an impact
strap which is integrated with a correspondingly adapted securing
device into the arrangement according to the invention.
[0047] In further contemplated embodiments, instead of the spindle
drive and the pneumatic drive with an airbag, the drive device may
also have other inflatable cushion elements or self-locking
pneumatics with a cylinder or a hydraulic cylinder, as are well
known in the prior art.
* * * * *