U.S. patent application number 11/750610 was filed with the patent office on 2007-11-29 for chair.
Invention is credited to Carsten Gehner.
Application Number | 20070273190 11/750610 |
Document ID | / |
Family ID | 38650225 |
Filed Date | 2007-11-29 |
United States Patent
Application |
20070273190 |
Kind Code |
A1 |
Gehner; Carsten |
November 29, 2007 |
CHAIR
Abstract
The invention relates to a chair with a seat, a base support and
a backrest, wherein the seat is pivotably mounted on the base
support and the backrest is pivotably mounted on the seat, and a
first spring system is provided between the base support and the
seat and a second spring system is provided between the seat and
the backrest. Furthermore, means are provided for adjusting the
spring behaviour of the two spring systems so that the pivotability
of the seat in relation to the base support and the pivotability of
the backrest in relation to the seat can be adapted to different
requirements, especially to users of different weights.
Inventors: |
Gehner; Carsten; (Hannover,
DE) |
Correspondence
Address: |
STITES & HARBISON PLLC
1199 NORTH FAIRFAX STREET, SUITE 900
ALEXANDRIA
VA
22314
US
|
Family ID: |
38650225 |
Appl. No.: |
11/750610 |
Filed: |
May 18, 2007 |
Current U.S.
Class: |
297/300.2 ;
297/302.1 |
Current CPC
Class: |
A47C 1/03255 20130101;
A47C 1/03288 20130101; A47C 1/023 20130101; A47C 31/126 20130101;
A47C 1/03294 20130101 |
Class at
Publication: |
297/300.2 ;
297/302.1 |
International
Class: |
A47C 1/024 20060101
A47C001/024 |
Foreign Application Data
Date |
Code |
Application Number |
May 22, 2006 |
DE |
10 2006 023 982.2 |
Claims
1. A chair with a seat, a base support and a backrest, wherein the
seat is pivotably mounted on the base support and the backrest is
pivotably mounted on the seat, and a first spring system is
provided between the base support and the seat and a second spring
system is provided between the seat and the backrest, wherein the
pivoting movement of the backrest in relation to the seat is not
mechanically coupled to the pivoting movement of the seat in
relation to the base support and wherein means are provided for
adjusting the spring behaviour of the two spring systems so that
the pivotability of the seat in relation to the base support and
the pivotability of the backrest in relation to the seat can be
adapted to different requirements, especially to users of different
weights.
2. A chair according to claim 1, characterized in that the first
spring system has at least one first spring member and the second
spring system has at least one second spring member.
3. A chair according to claim 1, characterized in that the first
spring system has at least one first spring member and a first
spring mechanism co-operating with the first spring member, and the
second spring system has at least one second spring member and a
second spring mechanism co-operating with the second spring
member.
4. A chair according to claim 2, characterized in that the means
for adjusting the spring behaviour of the two spring systems are
formed by means for adjusting the spring properties of the first
and/or second spring member and/or by means for adjusting the first
and/or second spring mechanism.
5. A chair according to claim 3, characterized in that the means
for adjusting the spring behaviour of the two spring systems are
formed by means for adjusting the spring rate and/or the prestress
of the first and/or second spring system, wherein the spring member
and/or the spring mechanism of the respective spring system are
optionally adjustable.
6. A chair according to claim 1, characterized in that the means
for adjusting the spring behaviour of the first spring system and
the means for adjusting the spring behaviour of the second spring
system are coupled together in such a way that the adjustment of
the spring behaviour of the one spring system automatically effects
adjustment of the spring behaviour of the other spring system.
7. A chair according to claim 1, characterized in that the two
spring systems and the means for adjusting the spring behaviour of
the two spring systems are adapted to one another so that, even for
users of different weights, substantially the same synchronous
relationship between the inclination of the seat and the
inclination of the backrest is rendered possible.
8. A chair according to claim 1, characterized in that the seat is
pivotable about a first articulation axis in the region of the
front end of the seat and the backrest is pivotable about a second
articulation axis in the region of the rear end of the seat.
9. A chair according to claim 1, characterized in that means are
provided for blocking the first and/or second spring system.
10. A chair according to claim 1, characterized in that the first
spring system has a first spring member and a first spring
mechanism co-operating with the spring member, and furthermore the
means for adjusting the spring behaviour of the spring system are
formed by means for adjusting different spring characteristics of
the spring system, wherein the spring system is formed so that the
spring member is unloaded in the normal position of the chair, also
for users of different weights, and in this unloaded starting
position of the spring member all the adjustable spring
characteristics of the spring system have a common origin.
11. A chair according to claim 1, in that, in the normal position
of the chair, the direction in which the spring mechanism is loaded
by the user lies at right angles to the direction in which the
spring mechanism acts on the spring member.
12. A chair according to claim 1, characterized in that the seat is
pivotable about a first articulation axis and the backrest is
pivotable about a second articulation axis, wherein the two
articulation axes are arranged so as to be displaceable relative to
one another.
Description
[0001] The invention relates to a chair with a seat, a base support
and a backrest.
[0002] Many different chair designs are known in practice. In the
so-called three-point mechanism, the seat, the base support and the
backrest are coupled together via three articulation points in such
a way that a predetermined synchronous relationship is established
between the inclination of the seat and the inclination of the
backrest. With respect to the location of the pivot point,
three-point mechanisms of this type represent a compromise between
different ergonomic requirements, which cannot be satisfied
independently of one another.
[0003] DE-B-103 18 759 describes a two-point mechanism in which the
seat is pivotably mounted on the base support with the
interposition of a spring system. Furthermore, means are provided
for adapting the spring behaviour of this spring member to
different requirements. The backrest is connected to the seat via
an articulation axis, wherein synchronisation between the
inclination of the seat and the inclination of the backrest is
rendered possible by means of a cable construction provided between
the base support, the seat and the backrest.
[0004] A chair which has a two-point mechanism is known from
DE-A-43 31 987, wherein the seat is pivotably mounted on the base
support and the backrest is pivotably mounted on the seat, and a
first spring system is provided between the base support and the
seat and a second spring system is provided between the seat and
the backrest. The special feature of this chair consists in that
the pivoting axis of the seat is provided in the region of the
user's ankles, and the pivoting axis of the backrest extends at
least approximately through his hip joints. In this arrangement,
the pivoting movement of the backrest in relation to the seat is
not mechanically coupled to the pivoting movement of the seat in
relation to the base support.
[0005] The object of the invention is to develop the chair further
so that it can be adapted in a simple manner to different
requirements, especially to users of different weights.
[0006] According to the invention, this object is achieved by the
features of claim 1.
[0007] The chair according to the invention substantially has a
seat, a base support and a backrest, wherein the seat is pivotably
mounted on the base support and the backrest is pivotably mounted
on the seat, and a first spring system is provided between the base
support and the seat and a second spring system is provided between
the seat and the backrest, wherein the pivoting movement of the
backrest in relation to the seat is not mechanically coupled to the
pivoting movement of the seat in relation to the base support.
[0008] Furthermore, means are provided for adjusting the spring
behaviour of the two spring systems so that the pivotability of the
seat in relation to the base support and the pivotability of the
backrest in relation to the seat can be adapted to different
requirements, especially to users of different weights.
[0009] Further developments of the invention form the
subject-matter of the sub-claims.
[0010] As the pivoting movement of the backrest in relation to the
seat is not mechanically coupled to the pivoting movement of the
seat in relation to the base support, the two pivoting regions of
the chair can be individually adapted to greatly differing
requirements. Owing to the elimination of the mechanical coupling
between the two articulations, less installation space is required
for the chair mechanism and new chair design possibilities are
opened up.
[0011] According to a preferred embodiment, the first spring system
has at least one first spring member and the second spring system
has at least one second spring member. Furthermore, the first
spring member can co-operate with a first spring mechanism and the
second spring member can co-operate with a second spring
mechanism.
[0012] The means for adjusting the spring behaviour of the two
spring systems can be formed by means for adjusting the spring
properties of the first and/or second spring member and/or by means
for adjusting the first and/or second spring mechanism.
[0013] According to an especially advantageous development, the
means for adjusting the spring behaviour of the first spring system
and the means for adjusting the spring behaviour of the second
spring system are coupled together in such a way that the
adjustment of the spring behaviour of the one spring system
automatically effects adjustment of the spring behaviour of the
other spring system. In this case, the two spring systems and the
means for adjusting the spring behaviour of the two spring systems
can be adapted to one another so that, even for users of different
weights, substantially the same synchronous relationship between
the inclination of the seat and the inclination of the backrest is
rendered possible.
[0014] The means for adjusting the spring behaviour of the two
spring systems can be formed e.g. by means for adjusting the spring
rate and/or the prestress of the first and/or second spring system,
wherein the spring member and/or the spring mechanism of the
respective spring system are optionally adjustable.
[0015] In a further development of the invention, the first spring
system has a first spring member and a first spring mechanism
co-operating with the spring member, and the means for adjusting
the spring behaviour of the spring system are formed by means for
adjusting different spring characteristics of the spring system,
wherein the spring system is formed so that the spring member is
unloaded in the normal position of the chair, also for users of
different weights, and in this unloaded starting position of the
spring member all the adjustable spring characteristics of the
spring system have a common origin.
[0016] In a further development of the invention, the seat is
pivotable about a first articulation axis and the backrest is
pivotable about a second articulation axis, wherein the two
articulation axes are arranged so as to be displaceable relative to
one another. In this way, the depth of the seat can be adjusted,
whereby the seat depth can, in particular, be adapted to the
distance between the knee joint and the hip joint in users of
different heights.
[0017] Further developments and advantages of the invention will be
further explained hereinbelow with the aid of the description and
the drawings, wherein:
[0018] FIG. 1 shows a schematic side view of a chair in an upright
normal position;
[0019] FIG. 2 shows a side view of the chair in a tilted-back
position;
[0020] FIG. 3 shows a schematic representation of the two spring
systems according to a first embodiment;
[0021] FIG. 4a shows a schematic representation of an alternative
spring system in the normal position;
[0022] FIG. 4b shows a schematic representation of the alternative
spring system according to FIG. 4a in the tilted position;
[0023] FIG. 5a shows a schematic representation of the two spring
systems according to a second embodiment (in the upright normal
position);
[0024] FIG. 5b shows a schematic representation of the two spring
systems according to FIG. 4 in the tilted-back position;
[0025] FIG. 6 shows a representation of the spring characteristic
of the first spring system according to a first variant;
[0026] FIG. 7 shows a representation of the spring characteristic
of the first and/or second spring system according to a second
variant;
[0027] FIG. 8 shows a side view of a chair with seat-depth
adjustment in a first position;
[0028] FIG. 9 shows a side view of the chair with seat-depth
adjustment in a second position.
[0029] The chair shown in FIGS. 1 and 2 substantially comprises a
seat 1, a base support 2 and a backrest 3, wherein the seat is
pivotably mounted on the base support and the backrest is pivotably
mounted on the seat. A first spring system 4 is provided between
the base support 2 and the seat 1 and a second spring system 5 is
provided between the seat 1 and the backrest 3.
[0030] The base support 2 is conventionally mounted on a foot or
swivel frame 6. The seat and the backrest can in particular also
comprise a seat support and a backrest support respectively.
[0031] In order to permit the pivoting movement of the seat or
backrest, a first articulation axis 7 is provided between the base
support and the seat and a second articulation axis 8 is provided
between the seat and the backrest. In this arrangement, the
pivoting movement of the backrest 3 in relation to the seat 1 is
not mechanically coupled to the pivoting movement of the seat 1 in
relation to the base support 2. Therefore, this is a two-point
mechanism.
[0032] As can be seen from FIG. 3 in particular, the first spring
system 4 comprises a first spring member 4a and a first spring
mechanism 4b co-operating with the spring member.
[0033] In the embodiment shown, the spring member 4a is formed by a
suitable foamed material wedge, for example made of Celasto, while
the first spring mechanism 4b co-operating with the first spring
member is formed by a counter or thrust bearing which is pivotable
about the first articulation axis 7. Furthermore, first means 9 are
provided for adjusting the spring behaviour of the first spring
system 4 and are represented purely schematically by a double
arrow. The first spring mechanism 4b (counter or thrust bearing) is
rotatable about the first articulation axis 7 by these first means
9 for adjusting the spring behaviour and thereby prestresses the
first spring member 4a to a greater or lesser extent.
[0034] The second spring system 5 in the region of the second
articulation axis 8 comprises a second spring member 5a and a
second spring mechanism 5b co-operating therewith. In this case
too, the second spring member 5a is formed by a foamed material
wedge, for example made of Celasto. The second spring mechanism 5b
is formed here by a compression body 50 which is adjustable by
means 10 for adjusting the spring behaviour of the second spring
system 5. For their part, the means 10 are represented purely
schematically by a double arrow.
[0035] While the adjustment of the spring behaviour of the first
spring system, especially during compression of the first spring
member 4a, requires some expenditure of force, the compression body
forming the second spring mechanism can be displaced in a
substantially force-free manner in the unloaded, upright normal
position of the backrest.
[0036] It goes without saying that the same or also different
spring systems, for example compression springs, can be used for
the two articulations within the scope of the invention. An
alternative spring system will be described hereinbelow with
reference to FIGS. 4a and 4b, which spring system could also be
applied to other chair mechanisms, especially a three-point
mechanism. The chair shown in FIGS. 4a and 4b has at least two
parts which are movable relative to one another, especially a seat
1 and a base support 2 which are movable relative to one another
between a normal position (FIG. 4a) and a tilted position (4b),
wherein a spring system 4 is provided between the two parts and has
a spring member 4a and a spring mechanism 4b co-operating with the
spring member, and furthermore wherein means are provided for
adjusting different spring characteristics of the spring system so
that the movability of the two parts can be adapted to different
requirements, especially to users of different weights. The spring
member is formed e.g. by a suitable foamed material wedge, for
example made of Celasto, while the spring mechanism can have a
pendulum rod 40, one end of which is mounted on the base support 2
about an articulation axis 41 and the other end of which is in
contact with the seat 1 via a rolling body 42. In this embodiment,
the means for adjusting different spring characteristics of the
spring system are formed by a compression body 43 which is
adjustable in the direction of the double arrow 9.
[0037] The spring system 4 is formed so that the spring member 4a
is unloaded in the normal position of the chair, also for users of
different weights, and in this unloaded starting position of the
spring member all the adjustable spring characteristics of the
spring system have a common origin. By displacement of the
compression body 43, in particular the spring characteristics a, b
and c shown in FIG. 7 can be adjusted in this way.
[0038] According to a preferred development of the chair, in the
normal position thereof, the direction (arrow 12) in which the
spring mechanism is loaded by the user lies at right angles to the
direction (arrow 13) in which the spring mechanism acts on the
spring member. In this normal position, displacement of the
compression body 43 is possible without great expenditure of force,
although the seat can be loaded by a user.
[0039] When the user leans back, the pendulum rod is deflected
about the articulation point 41 as the rolling body 42 moves along
the underside of the seat 1 in the direction of the first
articulation axis 7, whereby the spring member 4a is compressed in
accordance with the load (see FIG. 4b).
[0040] In FIGS. 5a and 5b, a further embodiment is shown in the
upright normal position (FIG. 5a) and the tilted-back position
(FIG. 5b). In this case, the first spring system 4 is formed in
accordance with the spring system shown in FIGS. 4a and 4b, while
the second spring system 5 corresponds to the second spring system
in FIG. 3.
[0041] For its part, the first spring system 4 has a first spring
member 4a which co-operates with a first spring mechanism 4b having
a pendulum rod 40, one end of which is mounted on the base support
2 about an articulation axis 41 and the other end of which is in
contact with the seat 1 via a rolling body 42. In the upright
normal position of the chair as shown in FIG. 4, the pendulum rod
40 is disposed almost perpendicularly to the seat 1. When the user
leans back, the pendulum rod is deflected about the articulation
point 41 as the rolling body 42 moves along the underside of the
seat 1 in the direction of the first articulation axis 7, whereby
the first spring member 4a is compressed in accordance with the
load. In order to change the spring behaviour of the first spring
system, the first spring mechanism 4b is also provided with a
compression body 43, which is adjustable by schematically shown
means 9.
[0042] Furthermore, additional coupling means 11 can be provided
which couple together the means 9 for adjusting the spring
behaviour of the first spring system 4 and the means 10 for
adjusting the spring behaviour of the second spring system 5 in
such a way that the adjustment of the spring behaviour of the one
spring system automatically effects adjustment of the spring
behaviour of the other spring system. These coupling means can be
formed e.g. by a Bowden cable and effect simultaneous displacement
of the compression bodies 43 and 50.
[0043] By suitable co-ordination of the two spring systems 4, 5,
the spring behaviour of the two spring systems can be adapted to
the desired requirement in a single operation. In this way, it is
ensured in particular that, even for users of different weights,
substantially the same synchronous relationship between the
inclination of the seat and the inclination of the backrest is
rendered possible.
[0044] In FIG. 3, the angle at which the seat is inclined relative
to the base support is designated by .alpha. and the angle at which
the backrest 3 is inclined relative to the starting position is
designated by .beta.. In this case, a suitable synchronous
relationship of .alpha./.beta. in the range from 1:1.5 to 1:3.5 is
produced.
[0045] FIG. 6 shows the spring characteristic of a progressive
spring member such as could be used e.g. for the first spring
system. Different spring rates should advantageously be provided
for the adjustment angle .alpha. for users of different weights.
The spring member is formed e.g. by the foamed material wedge shown
in FIG. 3, which can be prestressed from 0 to 30.degree. by the
spring mechanism 4b.
[0046] The spring characteristic shown in FIG. 6 can be divided
e.g. into three portions of equal size in which an approximately
linear spring characteristic is established, namely portion I for
light persons, portion II for persons of average weight and portion
III for heavy persons. Owing to the progressive spring
characteristic, variously high average spring rates are produced in
the individual portions. In order to pass from one portion to the
next and thereby change the average spring rate of the spring
member, the foamed material wedge is further prestressed by
15.degree. each time. It goes without saying that any intermediate
positions can also be set.
[0047] However, depending upon the spring system, some prestress
may already have to be exerted on the spring member for the
lightest setting. It would therefore be desirable if adjustment of
the spring rate is rendered possible without the need for special
expenditure of force by prestressing the spring member. This is
made possible by the particular configuration of the two spring
systems 4 and 5 according to FIGS. 4a, 4b, 5a and 5b. By
displacement of the compression body 43 or 50, the spring rate of
the spring member 4a or 5a can be adjusted in a manner relatively
free of force in that only the frictional force has to be overcome
for displacement of the compression body. According to the position
of the compression body in conjunction with the particular spring
mechanism, the spring characteristics shown in FIG. 7 can be set,
wherein characteristic a is intended for a heavy user,
characteristic b for a user of average weight and characteristic c
for a light user. In this case, the angle of inclination .alpha. of
the seat is plotted towards the right and the torque is plotted
upwards.
[0048] The independence of the pivoting movements of the seat and
the backrest provides the possibility of arranging the two
articulation axes 7, 8 so as to be displaceable relative to one
another in order to permit adjustment of the seat depth, which will
be further described with reference to FIGS. 8 and 9.
[0049] The seat 1 comprises a first seat supporting part 1a, a
second seat supporting part 1b and a seat cushion 1c. The two seat
supporting parts 1a and 1b are arranged so as to be displaceable
relative to one another by a suitable mechanism, wherein the first
seat supporting part 1a is connected to the base support 2 via the
first articulation axis 7 and the second seat supporting part 1b is
connected to the backrest 3 via the second articulation axis 8.
[0050] In this way, the seat depth can be specifically adapted to
the respective user by displacing the two seat supporting parts
relative to one another. As the distance between hip and knee joint
can vary in length in different persons according to their build,
optimum adjustment of the chair is permitted in this manner.
Although it can be possible to fix the seat-depth setting, it is
provided in a particular development of the invention that the seat
depth is set automatically when the user sits down. In this case,
it is possible for a spring member to be provided between the two
seat supporting parts so that the seat adopts a contracted position
in the unloaded state.
[0051] The adjustability of the two spring systems permits optimum
adaptation of the chair to the respective requirements. In
addition, the independence of the two articulations gives rise to
new design possibilities because an additional connecting mechanism
is not required. Furthermore, the two independent articulation
points permit adjustment of the seat depth without having to forego
the ergonomically favourable adjustment of the seat and backrest in
a particular synchronous relationship.
[0052] In a further development (not shown in further detail) of
the invention, means for blocking the first and/or second spring
system can be provided in the above described chairs. There is then
the possibility of fixing the rear or front articulation in order
to obtain a simple rocker mechanism. In this case, the angle
between the backrest and the seat or between the seat and the base
support would remain constant when the user leans back. One would
then have the possibility of switching between a simple rocker
mechanism and synchronous tilting of the seat and backrest.
[0053] The above described embodiments each have a first and a
second spring system. It is naturally also possible to include
further joints of the body (ankle joint, neck vertebrae, etc.) by
means of additional spring systems in accordance with the present
principle.
* * * * *