U.S. patent application number 10/488365 was filed with the patent office on 2005-02-10 for backrest.
Invention is credited to Forkel, Michael.
Application Number | 20050029847 10/488365 |
Document ID | / |
Family ID | 7698943 |
Filed Date | 2005-02-10 |
United States Patent
Application |
20050029847 |
Kind Code |
A1 |
Forkel, Michael |
February 10, 2005 |
Backrest
Abstract
A backrest for a vehicle seat with a backrest frame including an
arching element, running in a planar manner on the backrest frame
with the upper and lower end sections thereof, in the backrest
longitudinal direction, each fixed to the backrest, or to a
component arranged on the backrest and an adjuster device with
which the arching of the arching element may be adjusted in a
middle region between the both end sections thereof. At least one
limiting element is provided on the backrest frame with one end
connected to the middle region of the arching element in order to
limit the extent of the arching of the arching element.
Inventors: |
Forkel, Michael; (Coburg,
DE) |
Correspondence
Address: |
CHRISTIE, PARKER & HALE, LLP
PO BOX 7068
PASADENA
CA
91109-7068
US
|
Family ID: |
7698943 |
Appl. No.: |
10/488365 |
Filed: |
March 2, 2004 |
PCT Filed: |
September 4, 2002 |
PCT NO: |
PCT/DE02/03328 |
Current U.S.
Class: |
297/284.4 |
Current CPC
Class: |
B60N 2/66 20130101; B60N
2/6671 20150401; B60N 2/6673 20150401; B60N 2/667 20150401 |
Class at
Publication: |
297/284.4 |
International
Class: |
A47C 007/46 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 7, 2001 |
DE |
101 45 207.1 |
Claims
1. A backrest for a vehicle seat comprising: a backrest frame; a
curvature forming element which extends with a flat area adjacent
the backrest frame and which is fixed on the backrest frame or on a
structural element mounted on the backrest frame by at least one of
an upper end section and a lower end section in the longitudinal
direction of the backrest; and an adjusting device with which a
bowing of the curvature forming element is adjusted in a middle
region between the upper and lower end sections; wherein on the
backrest frame or on a structural element mounted on the backrest
frame there is at least one limiting element which is connected by
one end to the middle region of the curvature forming element in
order to limit the extent of curvature of the curvature forming
element.
2. The backrest according to claim 1, wherein the limiting element
is elongated.
3. The backrest according to claim 1 or 2, wherein the limiting
element is tautened as the bowing of the middle region
increases.
4. The backrest according to claim 1, wherein the limiting element
is elastically deformable.
5. The backrest according to claim 1, wherein the limiting element
is formed by traction means which as the bowing of the curvature
forming element increases exerts a tensile force on its middle
region.
6. The backrest according to claim 1, wherein the limiting element
is formed by one of an elastically deformable plastic element,
cable, belt and wire.
7. The backrest according to claim 1, wherein the limiting element
is fixed with the other end on the backrest frame or on a
structural element mounted on the backrest frame.
8. The backrest according to claim 1, wherein several limiting
elements are provided.
9. The backrest according to claim 8 wherein the limiting elements
are mounted one behind the other in the longitudinal direction of
the backrest.
10. The backrest according to claim 1 wherein the adjusting device
has as an adjusting element which acts on the curvature forming
element (1) one of a tensioning element and a curved body.
11. The backrest according to claim 1 wherein the limiting element
is fixed with its other end on an adjusting element of the
adjusting device which acts on the curvature forming element.
12. The backrest according to claim 1 wherein between the curvature
forming element and a backrest cushion mounted in front of the
curvature forming element there is a support element which extends
over a large surface area.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a National Phase Patent Application of
International Application Number PCT/DE02/03328, filed on Sep. 4,
2002, which claims priority of German Patent Application Number 101
45 207.1, filed on Sep. 7, 2001.
FIELD OF THE INVENTION
[0002] The invention relates to a backrest for a motor vehicle
seat.
BACKGROUND
[0003] A backrest comprises a backrest frame; a curvature forming
element which extends flat against the backrest frame and which is
fixed by its upper and lower end sections (seen in the longitudinal
direction of the backrest, i.e. in the extending direction of the
spinal column of a person seated on the seat) on the backrest frame
or on a structural element mounted on the backrest frame; as well
as an adjusting device with which the curvature of the curvature
forming element can be adjusted in a region between the two said
end sections (hereinafter called the middle region).
[0004] With a vehicle seat of this kind there is the problem that
as the bowing of the curvature forming element increases, its
curvature becomes very marked in the middle region, which goes
against the desired large surface area contact of the curvature
forming element against the seat cushion and the large surface area
support of the back of a vehicle occupant associated therewith.
SUMMARY
[0005] The object of the invention is to provide a backrest which
is characterised by a large adjusting region of the curvature
forming element through a large surface area support of the back of
the person seated on the seat.
[0006] According to this at least one limiting element is provided
on the backrest frame and is connected by one end to the middle
region of the curvature forming element in order to limit the
degree of bowing of the curvature forming element.
[0007] The degree of bowing which is thereby to be permitted in
each individual case (i.e. with a specific backrest) is fixed
through the choice of an appropriate limiting element.
[0008] In that the (preferably elongated) limiting element is fixed
by one end on the seat frame or a structural assembly mounted
thereon and by the other end on the middle region of the curvature
forming element, the maximum extension of the limiting element
across the extension plane of the backrest frame limits the maximum
bowing or curvature of the curvature forming element. An increase
in the curvature is equal to an increasing distance of individual
points of the curvature forming element from the backrest frame. By
limiting the maximum possible distance of the middle region of the
curvature forming element from the backrest frame through a
limiting element to a maximum value it is also possible to fix at
the same time the maximum possible curvature.
[0009] By the middle region of the curvature forming element is
thereby meant the entire region which extends between the upper and
lower end sections of the curvature forming element (viewed in the
longitudinal direction of the backrest). The middle region
comprises therefore expressly not only a region surrounding the
centre point of the curvature forming element, but rather any
region which extends between the upper and lower end section of the
curvature forming element and thus between the upper and lower
fixing points of the curvature forming element and is spaced
therefrom. It is however advantageous throughout if the middle
region extends around the centre point of the curvature forming
element.
[0010] The limiting element is preferably formed by a tightening
element, e.g. in the form of a cable, belt or wire which becomes
taut as the curvature of the middle region of the curvature forming
element increases and which ultimately permits no additional
curvature once the tension is sufficiently taut.
[0011] Furthermore the limiting element can also be formed by an
elastically deformable traction means, e.g. in the form of an
elastically deformable plastic rod.
[0012] Depending on which curvature is desired with a specific type
of backrest it is also possible to provide several limiting
elements of the said kind which can be arranged side by side both
in the longitudinal direction of the backrest and across the
longitudinal direction.
[0013] The solution according to the invention can be used
independently of the type of adjusting device used for adjusting
the curvature of the curvature forming element. For example an
adjusting device can be used here where a tensioning element acts
on the curvature forming element or where a curved body such as
e.g. in the form of an eccentric disc serves as the adjusting
element.
[0014] If a tensioning element such as a cable or wire is used as
the adjusting element then the limiting element can be fixed by its
end remote from the curvature forming element on the adjusting
element. In this case the adjusting element for adjusting the
curvature as well as the limiting element for restricting the
curvature of the curvature forming element form one structural
assembly which can be supplied fully pre-assembled where
applicable.
[0015] The solution according to the invention is furthermore
independent of whether between the backrest frame and the backrest
cushion of a vehicle seat there is only one single curvature
forming element on which on one side an adjusting device acts for
adjusting the curvature and which on the other side bears against
the backrest cushion, or whether between the backrest frame and the
backrest cushion there are two or more large area elements which
interact to adjust the curvature of the backrest. The limiting
element provided according to the invention can be used with any
type of curvature forming element which serves to fix the curvature
of the backrest of a vehicle seat.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Further features and advantages of the invention will now be
explained in detail with reference to the following description of
an embodiment illustrated in the drawings.
[0017] They show:
[0018] FIG. 1a a plan view of an curvature forming element for the
backrest of a motor vehicle seat;
[0019] FIG. 1b a section through the curvature forming element
according to FIG. 1a in a non-curved state;
[0020] FIG. 2 a section through the curvature forming element
according to FIG. 1a in a markedly curved state;
DETAILED DESCRIPTION
[0021] FIGS. 1a and 1b show a large surface curvature forming
element 1 which is mounted against a backrest frame 6 of a vehicle
seat serving as the lordosis support for a vehicle occupant and
shown only diagrammatically in FIG. 1a.
[0022] The base body of the curvature forming element 1 is
substantially H-shaped and has two side sections 11, 12 which
extend in the longitudinal direction L of the backrest and are
connected together by a cross bar 13. The side sections 11, 12 of
the curvature forming element 1 each have bent over side ends 11a,
12a and a reinforcement rib 14 and are hereby formed stiffer than
the lighter bowing cross bar 13. The side sections 11, 12 of the
curvature forming element 1 are thereby each partially uncoupled
from the cross bar 13 through a slot 15 extending in the
longitudinal direction L of the backrest.
[0023] The backrest longitudinal direction corresponds when the
backrest is upright (according to the illustration in FIG. 1b) to
the vertical axis of the vehicle (z-axis) which extends from the
vehicle floor to the vehicle roof.
[0024] In order to adjust the bowing of the curvature forming
element 1 and thus a backrest cushion P mounted in front of the
curvature forming element 1, shown diagrammatically in FIG. 1b, a
tensioning element 2 is provided in the form of a traction member
of wire which is mounted on the backrest, more particularly on the
backrest frame. The tensioning element 2 is fixed in the region of
its lower end 22 through a transverse connecting element 25 and
fixing elements 27 connected thereto to corresponding fixing points
17a on the lower end section 17 of the curvature forming element 1.
(The fixing of the tensioning element 2 in the region of its lower
end 22 to the transverse connecting element 25 is shown
diagrammatically in FIGS. 1a and 2 by a black fixing spot).
[0025] The curvature forming element 1 is on the other hand fixed
in the region of its upper end section 16 in the region of upper
fixing points 16a to the backrest frame (not shown in the figures)
of the vehicle seat by suitable fixing elements 26 which are
connected together through a transverse connecting element 25'. As
opposed to the lower transverse connecting element 25 however the
upper transverse connecting element is not connected to the
tensioning element 2.
[0026] In short the upper end section 16 of the curvature forming
element 1 is fixed directly on the backrest frame through fixing
points 16a and through fixing elements 26 (connected together by
means of the upper transverse connecting element 25') whilst the
lower end section 17 of the curvature forming element 1 is fixed on
the tensioning element 22 through fixing points 17a, fixing
elements 27 and a lower transverse connecting element 25.
[0027] In order to adjust the bowing of the curvature forming
element 1 a force is exerted on the tensioning element 2 by means
of a manual or electric drive unit so that the lower end 22 is
moved upwards along the vertical vehicle axis (z-axis) in the
longitudinal direction L of the backrest. At the same time the
lower end section 17 of the curvature forming element 1 is hereby
raised since this is fixed on the lower end 22 of the tensioning
element 2 through fixing elements 27 and the transverse connecting
element 25.
[0028] The upper end section 16 of the curvature forming element 1
remains however spatially unchanged since it is fixed directly on
the backrest frame through the associated connecting elements
26.
[0029] As a result by exerting a force on the tensioning element 2
upwards in the direction of the vertical vehicle axis z the lower
end section 17 of the curvature forming element 1 is moved up
towards its upper end section 16. The two end sections 16, 17
hereby move closer together and the curvature forming element 1 is
curved or bowed to an increasing amount, see the change in the
curvature forming element 1 from the non-curved state (FIG. 1b)
into the curved state (FIG. 2).
[0030] Basically the increase in the bowing also leads to an
increase in the curvature of the curvature forming element 1 which
with a very marked curvature goes against the desired largest
possible surface support of the back of a vehicle occupant over the
curvature forming element.
[0031] Here however the bowing and thus in particular the curvature
of the curvature forming element 1 in its middle region between the
two end sections 16, 17 is restricted by two limiting elements 3, 4
(hold-down plates) which are each fixed by one end 31, 41 on the
tensioning element 2 and by the other end 32, 42 on the cross bar
13 of the curvature forming element 1. The two longitudinally
extended limiting elements 3, 4 are thereby mounted on the upper
and lower ends of the cross bar 13 spaced from each other in the
longitudinal direction L of the backrest.
[0032] In the non-curved state of the curvature forming element 1
illustrated in FIG. 1b the limiting elements 3, 4 which are made of
plastic are each deformed so that despite their elongated design
they are located between the tensioning element 2 and the cross bar
13.
[0033] As the bowing of the curvature forming element 1 increases,
so the limiting elements 3, 4 become aligned in a straight line,
see FIG. 2. The length of the limiting elements 3, 4 with a
rectilinear alignment defines the maximum distance from the
tensioning element 2 (and thus the backrest frame overall) which
the cross bar 13 can occupy across the longitudinal direction L of
the backrest. The bowing of the curvature forming element 1 is
hereby restricted which increases with increasing distance of the
middle region of the curvature forming element 1 from the
tensioning element 2. It can clearly be seen that the curvature
forming element 1 bears with a large surface area against the
backrest cushion P even in the state of maximum curvature
illustrated in FIG. 2, and thus enables the back of the occupant to
be supported with the large surface area.
[0034] The curvature forming element 1 need therefore not adjoin
the backrest cushion P directly. It is possible throughout to
provide an additional backrest shell between the curvature forming
element 1 and the backrest cushion P.
[0035] Furthermore the invention can be designed with any type of
means for adjusting the curvature of the curvature forming element
1. The use of tensioning means 2 described here for adjusting the
curvature of the curvature forming element 1 is therefore only
given by way of example. When using other means for adjusting the
curvature of the curvature forming element 1 the ends 31, 41 of the
elongated limiting elements 3, 4 remote from the curvature forming
element 1 are advantageously attached to the seat frame (backrest
frame).
* * * * *