U.S. patent application number 09/733892 was filed with the patent office on 2001-11-08 for chair structure.
Invention is credited to rn Eklind, Bj?ouml.
Application Number | 20010038233 09/733892 |
Document ID | / |
Family ID | 20411626 |
Filed Date | 2001-11-08 |
United States Patent
Application |
20010038233 |
Kind Code |
A1 |
Eklind, Bj?ouml;rn |
November 8, 2001 |
Chair structure
Abstract
Chair structure (1) for a vehicle comprises a backrest (2), a
seat (3) which has a front part (31) and a rear part (32), a
support (4) which carries the squab (3), and means (10) to fasten
the support to a vehicle floor. The chair structure (1) also
includes a means (6) that makes the backrest (2) tilt forwardly
relatively to the squab (3) in the event of an accident.
Inventors: |
Eklind, Bj?ouml;rn;
(Harestad, SE) |
Correspondence
Address: |
TRACY W. DRUCE, ESQ.
KILPATRICK STOCKTON LLP
11130 SUNRISE VALLEY DRIVE
SUITE 300
RESTON,
VA
20191-4329
US
|
Family ID: |
20411626 |
Appl. No.: |
09/733892 |
Filed: |
December 9, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09733892 |
Dec 9, 2000 |
|
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PCT/SE99/01026 |
Jun 9, 1999 |
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Current U.S.
Class: |
297/216.13 ;
297/216.14; 297/216.15 |
Current CPC
Class: |
B60N 2/42736 20130101;
B60N 2/42745 20130101; B60N 2/4221 20130101; B60N 2/888
20180201 |
Class at
Publication: |
297/216.13 ;
297/216.14; 297/216.15 |
International
Class: |
B60N 002/427 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 9, 1998 |
SE |
9802033-2 |
Claims
What is claimed and desired to be secured by Letters Patent is as
follows:
1. A seat structure configured to be mounted in a vehicle, said
seat structure comprising: a backrest; a seat having a front part
and a rear part; a stand arranged to support the seat in a vehicle;
means for securing the stand in a vehicle; and means for generating
a forward pivoting of the backrest relative to the seat when a
collision or the like occurs, said means for forwardly pivoting the
backrest configured to cooperate mechanically with the stand via a
connection means that comprises a wire connecting said stand to the
backrest.
2. The seat structure as recited in claim 1, wherein the means for
forwardly pivoting the backrest comprises a mounting plate on which
the wire is intended to be wound up when a collision occurs.
3. The seat structure as recited in claim 1, wherein said wire is
arranged to be rolled up on a mounting plate when the seat is
displaced forwards in the vehicle's direction from its first
initial position.
4. The seat structure as recited in claim 1, wherein said stand
further comprises a first member designed to allow the seat to be
displaced, in a trajectory relative to the means for securing the
stand, from a first initial position, which the seat has prior to a
collision, to a second position when the seat is subjected to the
force of fa collision.
5. The seat structure as recited in claim 4, wherein the first
member further comprises an articulated arm construction configured
so that when the seat is displaced forwards from its first initial
position, the front part of the seat moves upwards and the rear
part of the seat moves downwards.
6. The seat structure as recited in claim 5, wherein the
articulated arm construction further comprises a front articulated
arm mechanism and a rear articulated arm mechanism, the front
articulated arm mechanism, which is secured to the front part of
the seat, being longer than the rear articulated arm mechanism,
which is secured to the rear part of the seat.
7. The seat structure as recited in claim 6, wherein the rear
articulated arm mechanism is secured essentially at right angles to
a longitudinal axis of the vehicle and the front articulated arm
mechanism forms an angle with the longitudinal axis.
8. The seat structure as recited in claim 7, wherein the wire is
secured to the rear articulated arm mechanism.
9. The seat structure as recited in claim 4, wherein the front
articulated arm mechanism further comprises means for changing the
length of the articulated arm pair.
10. The seat structure as recited in claim 1, wherein the front
articulated arm mechanism is of telescopic design.
11. The seat structure as recited in claim 10, wherein the front
articulated arm mechanism and the rear articulated arm mechanism
each further comprise an articulated arm pair.
12. The seat structure as recited in claim 1, wherein the backrest
further comprises an upper frame part connected in an articulated
manner to a lower frame part, the wire is secured to the upper
frame part, the means for forward pivoting of the backrest relative
to the seat being arranged also to generate a forward pivoting of
the upper frame part relative to the lower frame part.
13. The seat structure as recited in claim 2, wherein the first
member further comprises an articulated arm construction configured
so that when the seat is displaced rearwards from the first initial
position, the front and rear parts of the seat move downwards.
14. A seat structure configured to be mounted in a vehicle, said
seat structure comprising: a backrest; a seat having a front part
and a rear part; a stand arranged to support the seat in a vehicle;
a securing mechanism adapted to secure the stand in a vehicle; and
a pivoting mechanism arranged to forwardly pivot the backrest
relative to the seat in a collision, the pivoting mechanism being
configured to cooperate mechanically with the stand via a
connection therebetween that comprises a wire connecting the stand
to the backrest.
15. The seat structure as recited in claim 14, wherein the pivoting
mechanism comprises a mounting plate upon which the wire is wound
when a collision occurs.
16. The seat structure as recited in claim 14, wherein said wire is
arranged to be rolled upon a mounting plate when the seat is
displaced forwards from an initial position.
17. The seat structure as recited in claim 14, wherein said stand
further comprises: a first member configured to allow the seat to
be displaced in a trajectory relative to the securing mechanism
from an initial position assumed by the seat prior to a collision
condition, to a second position assumed by the seat responsive to
forces applied thereupon in a collision condition.
18. The seat structure as recited in claim 17, wherein the first
member further comprises: an articulated arm configured so that
when the seat is displaced forwards from the initial position, the
front part of the seat is moved upwards and the rear part of the
seat is moved downwards.
19. The seat structure as recited in claim 18, wherein the
articulated arm further comprises: a front articulated arm
mechanism and a rear articulated arm mechanism, the front
articulated arm mechanism, which is secured to the front part of
the seat, being longer than the rear articulated arm mechanism
which is secured to the rear part of the seat.
20. The seat structure as recited in claim 19, wherein the rear
articulated arm mechanism is secured at substantially right angles
to a longitudinal axis of the vehicle and the front articulated arm
mechanism forms an angle with the longitudinal axis of the
vehicle.
21. The seat structure as recited in claim 20, wherein the wire is
secured to the rear articulated arm mechanism.
22. The seat structure as recited in claim 17, wherein the front
articulated arm mechanism further comprises: a pair of front
articulated arms; and an adjustment mechanism configured to change
a length of the pair of front articulated arms.
23. The seat structure as recited in claim 22, wherein the
adjustment mechanism is telescopically adapted for changing the
length of the pair of front articulated arms.
24. The seat structure as recited in claim 23, wherein the front
articulated arm mechanism and a rear articulated arm mechanism each
further comprise an articulated arm pair.
25. The seat structure as recited in claim 14, wherein the backrest
further comprises: an upper frame part connected in an articulated
manner to a lower frame part; the wire secured to the upper frame
part; and the pivoting mechanism configured to pivot the backrest
relative to the seat is arranged to generate a forward pivoting of
the upper frame part relative to the lower frame part.
26. The seat structure as recited in claim 15, wherein the first
member further comprises: an articulated arm configured, so that
when the seat is displaced rearwards from the first initial
position, the front and rear parts of the seat move downwards.
Description
RELATED PATENT APPLICATIONS
[0001] This is a continuation patent application of International
Application No. PCT/SE99/01026 filed Jun. 9, 1999 entitled CHAIR
STRUCTURE that designates the United States. The full disclosure of
said application, in its entirety, is hereby expressly incorporated
by reference into the present application.
TECHNICAL FIELD
[0002] The present invention relates to a seat structure intended
to improve the safety of a passenger in a vehicle. The invention
relates, in particular, to a seat structure that includes a means
for generating a forward pivoting of the backrest when a collision
or the like occurs, usually because the carrying vehicle has been
involved in a collision or similar circumstance.
BACKGROUND OF THE INVENTION:
[0003] Crash safety is an important and much discussed area in the
development of modern cars. Attempts at improving passenger safety
are being made in many different ways. Among these is the provision
of bar structures and bodyworks with crumple zones, active seat
belts and airbags. These structures have been designed to absorb
and spread, by means of controlled deformations, the energy impulse
which the vehicle, together with the driver and passengers, are
subjected to during a collision. A seat has traditionally been
mounted in the vehicle in a fixed manner and has not been designed
to absorb and spread the energy impulse or force in any defined
way. In order to further improve safety, constructions have
therefore recently been proposed in which energy absorbing elements
are added to the seat structures; these elements being configured
to absorb energy in a controlled manner when the seat is subjected
to an energy impulse in the event of a collision.
[0004] A serious problem in collisions is the risk of neck
injuries, also referred to as whiplash injuries to passengers of
the crashed vehicle. These injuries can also occur when collisions
take place at relatively low speeds and with relatively low energy.
The risk of injuries occurring increases when the passenger is not
sitting directly against the backrest and headrest. During the
course of a rear-end collision, the occupant is flung forwards even
if that occupant is wearing a seat belt. When the restrictive
limits of the seat belt are reached (the passenger presses against
the seat belt and the seat belt becomes taught), then the occupant,
in reaction to hitting the limiting seat belt, is flung backward
against the backrest and headrest. The risk of injures is increased
by the lack of ways to coordinate between these movements of the
occupant and the movement of the back rest and the headrest.
[0005] Another problem in collisions is the risk of the passenger
slipping forwards. This means that during a collision the passenger
tends to slip forwards on the seat, and the passenger's knees risk
hitting the front structure causing injury. A way of reducing the
risk of slipping forwards is described in International Patent
Application WO 93/01950 in which the seat structure allows the
seat-cushion to move along a controlled, predetermined trajectory
which is configured so that the front part of the seat moves
upwards and forwards in a front-end collision. This means that the
passenger, in order to slip forwards, has to do so along an upward
slope. As the passenger moves along the upward slope, the normal
force between the passenger's body and the seat is greater than it
is in the case where the upward slope is not present. This causes
the friction between traveler and the seat to be greater, and
therefore the force component in the direction of movement is less.
Both of these phenomena contribute to reducing the risk of the
passenger slipping forwards. In addition, energy-absorbing members
can be mounted on the seat structure and they contribute to the
absorption of energy when the seat is moving along the predefined
trajectory.
[0006] Seat structures like those described in WO 93/01950,
however, have the following problems: The seat structure is mounted
in a frame construction with milled-out tracks. This construction
causes the total weight of the seat structure to be relatively
high. Since great efforts are being made to reduce the weight of
vehicles in order to achieve better economic operation and reduce
impact on the environment, it is not acceptable for parts included
in the vehicle to be made heavier than is necessary. In addition,
seat structures according to WO 93/01950 have no movement
trajectory for cases where the collision occurs from behind in a
rear-end impact collision. This means that the risk of neck
injuries occurring in rear impact collisions is not benefitted by
this type of structure. Another disadvantage of seat structures
according to WO 93/01950 is that the backrest does not include any
function for increasing adaptability or coordination between the
passenger and the backrest in the event of a collision, which among
other things reduces the risk of whiplash injuries in a rear impact
collision.
[0007] In view of the above described deficiencies associated with
conventionally designed vehicular carried chair structures, the
present invention has been developed. These enhancements and
benefits are described in greater detail hereinbelow with respect
to several alternative embodiments of the present invention.
DISCLOSURE OF THE INVENTION
[0008] The present invention in its several disclosed embodiments
alleviates the drawbacks described above with respect to
conventionally designed chair structures for vehicles and
incorporates several additionally beneficial features.
[0009] In one aspect, the invention provides an improved seat
structure for a vehicle which reduces the above problems or
disadvantages of other seat designs. The seat structure is designed
to permit adaptability or compensation between the passenger's
movement and movement of the backrest and headrest of the seat
structure in the event of a collision or the like. In particular,
the seat structure includes means or mechanisms for generating a
forward pivoting of the backrest assembly when a collision occurs.
This reduces the risk of the passenger suffering neck injuries.
[0010] The invention contemplates a seat structure having a
backrest, a seat portion that includes a front part and a rear
part, a stand that supports the seat structure in the vehicle and
which includes a means or arrangement for securing the stand in a
vehicle. The invention is characterized by the included feature of
a means or mechanism for generating a forward pivoting of the
backrest when a collision or the like occurs.
[0011] In a preferred embodiment of the invention, the seat
structure includes an articulated arm construction designed so that
when the seat is displaced forwards relative to the vehicle and
from its initial position, the front part of the seat moves upwards
and the rear part of the seat moves downwards. Using this
articulated arm construction, instead of a construction comprising
a frame with milled-out tracks, the seating arrangement is made
considerably lighter, while also maintaining passenger safety. The
articulated arm construction also allows the movement of the
articulated arm to be transformed in a functional manner into
pivoting movement that pivots the backrest of the seat forwards in
order to improve adaptability (conformance) between the backrest
and the occupant; a functional feature that contributes to reducing
the risk of passenger neck injuries.
[0012] The beneficial effects described above apply generally to
the exemplary devices, mechanisms and methods disclosed herein for
vehicular chair structures. The specific structures through which
these benefits are delivered will be described in detail
hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS:
[0013] The invention will now be described in greater detail in the
following way, by example only, and with reference to the attached
drawings, in which:
[0014] FIG. 1 is a schematic representation of a seat structure in
a first position before a collision has occurred.
[0015] FIG. 2 is a schematic representation of the seat structure
in a second position which is assumed when the seat has been
displaced forwards in the vehicle after a collision has
occurred.
[0016] FIG. 3 is a schematic representation of a seat structure in
a second position which is assumed when the seat has been displaced
rearwards in the vehicle after a collision has occurred.
[0017] FIG. 4 is a schematic representation of a seat structure
that includes a member for setting and/or modifying the angle of
the backrest.
[0018] FIG. 5 shows a detail of the member for setting the angle of
the backrest.
[0019] FIG. 6 shows a member for adjusting the height of the rear
part of the seat.
MODE(S) FOR CARRYING OUT THE INVENTION:
[0020] As required, detailed embodiments of the present invention
are disclosed herein; however, it is to be understood that the
disclosed embodiments are merely exemplary of the invention that
may be embodied in various and alternative forms. The figures are
not necessarily to scale, some features may be exaggerated or
minimized to show details of particular components or processes.
Therefore, specific structural and functional details disclosed
herein are not to be interpreted as limiting, but merely as a basis
for the claims and as a representative basis for teaching one
skilled in the art to variously employ the present invention.
[0021] Referring to FIG. 1, a seat structure 1 is shown
diagrammatically/schematically, that includes a backrest 2, a seat
3 and a stand 4 which supports the seat 3 and the backrest 2. The
seat 3 and the backrest 2 are connected to each other so as to
pivot relative to one another via a hinge 26. The seat comprises a
front part 31 and a rear part 32. The stand includes a means or
mechanism 10 for affecting securement in a carrying vehicle. The
means/mechanism 10 for securing the stand 4 to the vehicle
preferably includes a pair of rails 11 that extend longitudinally
with respect to the vehicle and in a runner 12 is secured in each
and is configured to slide relative thereto. Arranged in a
conventional manner on each runner 12 and rail 11 are locking
members (not shown) for locking each respective runner 12 to its
respective rail 11.
[0022] The locking members may be of the type that includes
spring-tensioned or biased pins which are arranged to engage in
recesses to achieve locking. When the locking member(s) have been
brought into their open or unlocked positions, the stand 4 can
slide, and the position of the seat 3 can be adjusted by the
occupant to a desired position in the longitudinal direction
parallel to a longitudinal axis 103 of the vehicle thereby
obtaining the best possible comfort for that occupant. When the
locking means/mechanism 10 has been brought to its locked position,
the runner 12 is fixed to the rail 11 in such a secured manner that
even if the seat structure 1 is subjected to high stresses, such as
in the event of a collision, the locked connection will be
maintained.
[0023] The stand 4 further includes a first member 40,50 arranged
to allow the seat 3 to be displaced in a trajectory relative to the
mechanism 10 from a first initial position 100 assumed by the seat
3 prior to a collision or the like, and a second position 101 ,102
that the seat 3 assumes after having been subjected to the forces
of a collision or similar occurrence.
[0024] The first member 40,50 includes an articulated arm
construction arranged to allow the seat 3 to be displaced in a
predetermined trajectory when the seat 3 is subjected to great
force, such as in a collision. According to a first preferred
embodiment, and which is shown in FIG. 1, this first member 40,50
includes a front articulated arm mechanism 40 and a rear
articulated arm mechanism 50; front and rear being defined with
respect to the direction of the longitudinal axis 103 of the
vehicle. Both the front articulated arm mechanism 40 and the rear
articulated arm mechanism 50 are preferably designed with
articulated arm pairs 41,51 which have two parallel and essentially
straight rods that are joined to transverse rods to obtain good
stability of the articulated arm mechanisms 40,50. The front pair
of articulated arms 41 has an upper end 42 that is secured to that
part of the stand 4 supporting the seat 3, and a lower end 43 that
is secured to that part of the stand 4 which adjoins the
means/mechanism 10 for securing the assembly to the vehicle. The
rear pair of articulated arms 51 has in the same way an upper end
52 that is connected to that part of the stand 4 that supports the
seat 3, and a lower end 53 that is connected to that part of the
stand 4 which adjoins the means/mechanism 10 for securing the
assembly to the vehicle.
[0025] To obtain an advantageous form of the trajectory which the
seat 3 moves along during a collision, the front articulated arm
pair 41 and the rear articulated arm pair 51 are designed as
described hereinbelow. The front articulated arm pair 41 is longer
then the rear articulated arm pair 51. The front articulated arm
pair 41 is longer than the rear articulated arm pair 51 so that the
distance between the upper 44 and lower 45 pivot points or axes of
rotation of the front articulated arm pair is greater than the
distance between the upper 54 and lower 55 pivot points of the rear
articulated arm pair.
[0026] The front articulated arm pair 41 is secured in such a way
that when the seat 3 assumes an initial position 100, the front
articulated arm pair 41 extends along a main axis 46 which forms an
angle with a longitudinal axis 103 of the vehicle. This means that
the front articulated arm 41 slopes obliquely towards the rear when
the seat 3 is in the initial position 100 and in such a way that
the upper end 42 of the front articulated arm is placed behind the
lower end 43 of the front articulated arm.
[0027] The rear articulated arm pair 51 is secured in such a way
that when the seat assumes the initial position 100, the rear
articulated arm pair 51 extends along a main axis 56 which extends
essentially at right angles to the longitudinal axis 103 of the
vehicle.
[0028] Both the front and the rear articulated arm mechanisms 40,50
are secured pivotably in a conventional manner to the seat 3 on the
one hand, and on the other hand to the means/mechanism 10 for
securing the seat structure 1 to the floor of the vehicle. This
means that the articulated arm mechanisms 41,51, together with the
seat 3, can be moved reciprocatingly along a predetermined path
which is defined by the length of the articulated arms 41,51
included in the articulated arm mechanisms 40,50 and by their
mutual attachment to the seat 3. On the seat 3 or the articulated
arm mechanisms 40,50, there is a locking member (not shown) which
holds the seat and the articulated arms in a predefined position
referred herein to a first initial position 100 for so long as the
seat structure is not subjected to great forces in a collision or
the like.
[0029] When such a collision or the like occurs, the seat is
conveyed forwards or rearwards depending on the direction of the
force. This means that if the collision impact is from the front,
which is the case when a vehicle is rapidly braked in a collision
against an object or when an object collides with the front of the
vehicle, the seat, the backrest and the stand are subjected to
forces which convey these structures forwards in the vehicle.
Conversely, the seat, the backrest and the stand will be conveyed
rearwards in the vehicle if the vehicle is impacted from
behind.
[0030] The movement of the seat is defined, as mentioned above, by
the length of the articulated arms and by their mutual attachment
to the seat. The rear articulated arm mechanism 50 is, as has
already been mentioned, mounted essentially at right angles to the
longitudinal direction of the vehicle, i.e. the upper 54 and lower
55 pivot points of the rear articulated arm mechanism are located
essentially at the same length coordinates in the vehicle when the
seat 3 is placed in its initial position. This means that when the
seat is displaced from its first initial position 100, the distance
between the upper pivot points 54 of the rear articulated arm
mechanism and a plane which runs through the lower pivot points
45,55 of the front and rear articulated arm mechanisms will
decrease. This means that the rear part 32 of the seat 3 is
displaced in the direction towards the vehicle's floor structure
when the seat 3 is displaced from its initial position 100,
irrespective of whether the seat 3 is displaced forwards or
rearwards with respect to the vehicle. As has been mentioned above,
the front articulated arm mechanism 40 is secured in such a way
that when the seat 3 assumes an initial position 100, the front
articulated arm pair 41 extends along a main axis 46 which forms an
angle a with a longitudinal axis in the vehicle 103. According to
what has been described above, this angle is less than 90.degree.
when the seat is placed in its initial position 100. This means
that when the seat is moved forwards in the vehicle's direction
from its first initial position, the distance between the upper
pivot points 44 of the front articulated arm mechanism and a plane
which runs through the lower pivot points 45,55 of the front and
rear articulated arm mechanisms will increase. This in turn means
that the front part of the seat is displaced in the direction away
from the vehicle's floor structure. If the seat is moved rearwards,
however, the opposite takes place; this means that when the seat is
moved rearwards in the vehicle from its initial or first position,
the front part of the seat will be displaced in the direction
towards the vehicle's floor structure.
[0031] The above should be understood to mean that when the seat 3
is displaced forwards in the vehicle's direction, the angle b
between the horizontal plane 104 of the vehicle and a plane 105
running along the main extent of the seat 3 will increase. This
means that in a collision from the front, in order to slip
forwards, an occupant of the vehicle must do so along an upward
slope with a greater inclination than is the case when the seat is
in its initial position. This counteracts the tendency to
detrimentally slip forwards as has been discussed hereinabove.
[0032] When the seat 3 is displaced rearwards, the distance between
the upper pivot points of both the front and the rear articulated
arm mechanisms and the horizontal plane of the vehicle decreases.
Since on the one hand the front articulated arm mechanism 40 is
longer, and on the other hand the rear articulated arm mechanism 50
is mounted essentially at right angles to the horizontal plane of
the vehicle, the angle b between the plane 105 and the horizontal
plane 104 of the vehicle increases. In this case where the seat is
moved rearwards in the vehicle's direction, the increase in the
angle b is less than when the seat is moved forwards in the
vehicle's direction. Since the seat is displaced rearwards with
respect to the vehicle in those cases where the collision is from
the rear, he risk of slipping forwards does not arise. In this
case, the occupant is pressed rearwards against the seat structure,
which means that the slighter increase in inclination is also
advantageous.
[0033] In order to set the vertical position of the seat 3, both
the front and rear articulated arm pairs 41,51 may be equipped with
means/mechanism 47 for adjusting the length of both of the
articulated arm pairs. In a preferred embodiment, these
means/mechanisms for length adjustment include telescopically
arranged articulated arms. The front articulated arm is preferably
made telescopic, while the rear articulated arm is made rigid. This
achieves a good adjustability, while at the same time the effective
function of the system is ensured. In this case, the height of the
rear part of the seat is regulated by an expandable member 8, for
example a cushion, being mounted in the rear part of the seat as is
exemplarily shown in FIG. 6.
[0034] In the illustrated instance, the expandable member 8 is
mounted between a supporting frame 33 of the seat 3 and a
reinforcement 34, for example a support plate 34 to which the seat
padding 35 is secured. The supporting frame 33 forms a link part in
the link parallelogram formed by the front articulated arm
mechanism 40, rear articulated arm mechanism 50 and the supporting
frame 33.
[0035] First members 9 for setting the angle of the backrest 2 are
attached to the seat 3 or to the stand 4. These members are of a
convention type and are therefore not further described herein.
[0036] Referring again to the Figures, there is means/mechanism 6
provided for generating a forward pivoting of the backrest 2 when
the seat structure 3 is subjected to a collision or the like. The
function and construction of the means/mechanism 6 will be
described in greater detail in connection with the description of
FIGS. 4 and 5.
[0037] A third member 7 is arranged on the seat 3 or stand 4 for
absorbing energy when the seat 3 moves along its predetermined
trajectory in the event of a collision or the like. This
energy-absorbing third member 7 preferably has a gas damper which
absorbs energy as the damper is compressed and/or drawn out.
[0038] The backrest 2 can be equipped with members for: setting the
position of a headrest which forms part of the backrest, for
setting a lumbar support, for setting the hardness of the backrest,
or other conventional possibilities of setting comfort and safety
aspects and properties of the seat 3.
[0039] FIG. 2 shows the seat when it is displaced from its first
initial position 100 forwards to a second position 101. FIG. 3
shows the seat when it has been displaced from its first initial
position 100 rearwards to a second position 102.
[0040] FIG. 4 shows a seat structure essentially conforming to that
which has already been described with reference to FIG. 1. Only
those details which are of importance for the first member 9 for
setting the angle of the backrest 2, and the means/mechanism 6 for
generating a forward pivoting of the backrest 2 when the seat
structure 1 is subjected to a collision or the like will now be
described in detail. The means/mechanism 6 for forward pivoting of
the backrest 2 when a collision or the like occurs are arranged to
cooperate mechanically with the first members via a connection
61.
[0041] The connection 61 includes a wire 63 which is secured on the
one hand to the backrest 2 and on the other hand to a
means/mechanism 62 for straining the wire 63. In a preferred
embodiment, this means/mechanism 62 for straining the wire 63
includes members that are connected to the rear articulated arm
mechanism 50 and which cooperate with the articulated arm mechanism
50 in such a way that when a collision or the like occurs, the
movement of the articulated arm is converted to a straining of the
wire 63. The fact that it is a mechanical process which controls
the tightening of the wire 63 and thereby the forward pivoting of
the seat 3 is advantageous since the speed and magnitude of the
pivot movement can be controlled considerably more accurately than
if a pyrotechnic strain device were to be used. In a preferred
embodiment, a mounting plate 67 is used which can be given a
variable diameter if variation of the speed of the change of angle
of the backrest is desired as a function of the angle of the said
backrest.
[0042] A securing arrangement 66 for a wire 63 is arranged at the
upper pivot point 54 of the rear articulated arm mechanism 50. The
wire 63 has a first end 64 and a second end 65. The first end 64 is
secured in the securing arrangement 66. The backrest 2 is secured
to the supporting frame 33 of the seat via a hinge 26. The second
end 65 is secured to a point on the backrest 3 which is located
above the hinge 26. The hinge 26 is located on a first projection
36 which is situated on the supporting frame 33 of the seat and
which extends essentially upwards from the plane 105. A
corresponding second projection 24 is located on the frame
construction 20 of the backrest. This means that the pivot point
which is formed by the hinge 26 between the supporting frame 33 of
the seat and the frame construction 20 of the backrest is located
slightly in front of the outermost end 37 of the supporting frame
of the seat. Ideally, in order to obtain great adaptability between
the movement of the occupant and the backrest in the event of a
collision or the like, the pivot point 28 for the pivoting movement
of the backrest will be located at the same point as the axis of
rotation between the back and legs of the occupant, i.e.
essentially at the same point as the occupant's hip joints. In this
embodiment, this is achieved, in accordance with the above
description, by the positioning of the hinge 26.
[0043] Connected to the hinge 26 are means/mechanism 27 for fixing
the wire 63. In order to obtain a forward movement of the backrest
2 in the event of a collision or the like, it is necessary for the
wire 63 to be designed to run in front of, as viewed with respect
to the longitudinal axis of the vehicle, the axis of rotation 28
defined by the hinge 26. The wire preferably runs in a rack (not
shown) which fixes the wire in position. The wire 63 is thus
connected between the securing arrangement 66 and the backrest 2
via the fixing means/mechanism 27 connected to the hinge 26.
[0044] The securing arrangement 66 is constructed as shown in FIG.
5. A mounting plate 67 is connected to the upper part of the rear
articulated arm. The wire 63 is secured to this mounting plate 67
in suitable ways. When the rear articulated arm 51 is pivoted
either forwards or rearwards, the wire 63 will be wound up on the
periphery 68 of the mounting plate.
[0045] The winding can be achieved by ensuring that the rear
articulated arm is mounted essentially at right angles in relation
to the longitudinal direction of the vehicle. When the articulated,
arm is displaced from this position in a collision, the distance
between the point of attachment of the wire 63 on the mounting
plate 67 will be displaced in relation to the point of deflection
27 of the wire. Since the distance increases between the point of
deflection and the point of attachment on the mounting plate, the
wire will be wound up on the mounting plate whether the articulated
arm is pivoted forwards or rearwards.
[0046] In order to ensure that the wire 63 is wound up in the
correct way, tracks can be provided in the mounting plate 67. This
pivoting causes the wire 63 to be stretched, which means that the
second end 65 of the wire is moved downwards in the direction
towards the rear articulated arm mechanism 50, which in turn gives
rise to the backrest 2 being pivoted forwards. This results in a
greater adaptability between the occupant's body and the-backrest 2
in the event of a collision or the like, which means that the risk
of whiplash injuries in particular is reduced.
[0047] In order to obtain sufficient tightening of the wire 63 when
the rear articulated arm mechanism 50 is pivoted, the size of the
mounting plate 67 can be varied, or the pivot movement can be
changed by means of a gear member being inserted between mounting
plate 67 and the articulated arm mechanism 40, 50. In a preferred
embodiment, the frame construction of the backrest has a lower
frame pat 22 and an upper frame part 21 which are joined at a hinge
23. In this case, the second end 65 of the wire is connected to the
upper frame part 21. For a tensile force transmitted via the wire
63 to be able to give rise to a pivoting torque via the hinge 23,
the upper frame part 21 of the backrest is equipped with a
projection 25 to which the upper end 65 of the wire is secured.
Such a mounting gives rise to the upper part of the backrest being
pivoted forwards with a greater deflection than the lower part of
the backrest. This gives rise to a greater fit between the back and
neck and the backrest and headrest, respectively, in the event of a
collision or the like.
[0048] The pivoting of the seat in a collision or the like is
limited by deflection-limiting members connected preferably to the
hinge 26 or connected to the energy-absorbing member 7.
[0049] Arranged between the frame 33 of the seat and the frame
structure 20 of the backrest is a member 9 for setting the angle of
the backrest. This member 9 has means/mechanism for displacing and
fixing the angle of the seat within a small range in the absence of
a collision or the like. In the event of a collision or the like
occurring, the securement is released utilizing breakpins, tear
bands or some other member which yield in the event of a collision
or the like because of forces imposed thereupon. The member for
setting the angle of the backrest can be, for example, an eccentric
screw located between the frame structure of the backrest and the
frame of the seat. The frames can then be spring-loaded so as to be
pressed towards the eccentric screw. The spring element which
exerts the spring loading/biasing can be designed such that it
ruptures in the event of a collision or the like.
* * * * *