[0001] The invention relates to a chair for training back and pelvic musculature. More particularly,
the invention relates to a chair which is rounded in its contact portion against the
supporting surface. The user of the chair must continuously activate the musculature
of the body to maintain a sitting position on the chair.
[0002] It is known within the specialist environment of physiotherapists and ergonomists
that the proportion of the population afflicted with back complaints is increasing.
It is also known that the proportion of children afflicted with back complaints is
Increasing. This may be owing to both children and adults sitting more than before
and being less active in physical play and physical work.
[0003] It is known that sitting on relatively large balls filled with air may have a preventative
effect on back complaints. When the user is sitting on a ball, the user must continuously
activate the musculature of the body to maintain the sitting position on the ball.
Even though it is known that to sit on a ball is beneficial, there are some disadvantages
to it. In its contact portion against the supporting surface, a ball filled with air
will be somewhat compressed. This dampens and retards the rolling movement of the
ball. This has the drawback of reducing the training effect somewhat. Another drawback
is that the substantially spherical shape of the ball gives a restricted possibility
for leg positioning, for example for placing the leg and foot to one side of and under
the seat portion. This reduces the sitting comfort over time. The spherical shape
also gives an impractically wide chair so that it bumps against table legs when the
user is working at a table. It is also impractical for two persons to sit next to
each other on separate balls at a table because of the space that the balls take up.
This makes it Impractical to sit on a ball for a longer time when the user Is working
at a table.
[0004] Further, there is a need for a chair which is suitable for use in a classroom, for
example, so that children can strengthen their back musculature when they are at school.
A spherically shaped chair may be rolled around and this may create unnecessary disturbance
of the teaching. A classroom may also be cramped, and there is a need for room for
keeping bags or rucksacks and also shoes. With known chairs, bags, rucksacks and shoes
can be placed on the floor under the chair between the legs of the chair.
[0005] The patent document
US 2007/0138850 discloses a chair provided with a base formed with a spherical contact surface against
the supporting surface. The seat of the chair is connected to the base via a centred,
elongated, straight connecting element. The weight of the base may be greater than
the overall weight of the seat and the connecting element. The chair is therefore
self-righting when not in use. The connecting element may be provided with means for
adjusting the height of the seat. The base is not arranged for storing objects as
these would fall off the base as the chair is tilted. The patent document
EP 0761136 discloses a similar chair with a centred, elongated, straight connecting element.
This one is not arranged for storing objects on the base, either, as they would fall
off the base as the chair is tilted.
[0006] The patent document
GB 22823331 discloses a child seat with a lower part provided with a spherically shaped contact
surface against the supporting surface. From the lower part of the child seat, along
the outer edge thereof, three straight and relatively narrow supports project upwards,
holding a ring. The seat proper is attached to the ring, and the child's legs will
be positioned over the lower part and within the outer edge of the lower part. The
child seat will function in the same way as a rocking chair when the child bends its
upper body alternately forwards and backwards or to the sides. This gives little or
no training effect for the back musculature. The child seat is not fit for storing
objects within the chair as they will get in the way for the child's legs.
[0007] The patent document
US 2,049,539 discloses a combined stool and basket particularly suited for gardening. The base
of the stool includes a flat middle portion and a convex side portion so that the
base of the stool forms a shallow tray or basket. The base further includes a downward
outer edge to prevent the chair from being slanted or tilted too much to one side.
The seat is attached to the side portion of the base with elongated, straight and
relatively narrow connecting elements. The stool is suitable for smaller objects to
be placed flat on the concave upper side of the base. Such objects may be smaller
garden implements, flowers and weeds, for example. The stool is not arranged for allowing
larger objects, such as a bag, to be stored.
DE202011101503 U1 also shows a chair of this kind with a rounded lower portion.
[0008] The invention has for its object to remedy or reduce at least one of the drawbacks
of the prior art, or at least provide a useful alternative to the prior art.
[0009] The object is achieved through features which are specified in the description below
and In the claims that follow.
[0010] According to the invention it is provided a chair as claimed in claim 1. It includes
a rounded lower portion, the convex side of the rounded lower portion being arranged
to rest on a supporting surface, and a seat portion; the chair is provided with a
rigid supporting element between the rounded lower portion and the seat portion; and
- the supporting element is made up of at least two outward-curving arms between the
peripheral portion of the rounded lower portion and the seat portion; and
- the outward-curving arms and the rounded lower portion form a curved joint. The rounded
lower portion is a spherical lower portion.
[0011] The width of the chair in the position of application is smaller than the height
of the chair and the depth of the chair. In a middle portion, the width of the supporting
elements is smaller than the width of the seat portion.
[0012] The seat portion may include a rounded portion, the convex side of the rounded portion
facing upwards. The seat portion may include a spherical portion.
[0013] The chair may be provided with an internal space defined by the internal surface
of the outward-curving arms and the concave upper side of the rounded lower portion.
The internal surface of the outward-curving arms may have a concave shape.
[0014] Each of the outward-curving arms may be split into an upper supporting arm and a
lower supporting arm, so that the chair includes a lower part and an upper part. The
chair may further be provided with at least two extension pieces for insertion between
the upper supporting arms and the lower supporting arms, so that the height of the
chair can be changed.
[0015] The chair may further be provided with an elastic band around the circumference of
the chair, the band being arranged to hold the upper part and the lower part of the
chair together. The band may be arranged to give the convex bottom side of the rounded
lower portion a sound-deadening surface against the supporting surface.
[0016] The rounded lower portion of the chair may be provided with a weighting means to
increase the stability of the chair. The weighting means of the chair may consist
of a material thickening in the wall of the rounded lower portion. The weighting means
of the chair may consist of a weight. The width of the seat portion may be smaller
than the width of the rounded lower portion.
[0017] In what follows, examples of preferred embodiments are shown, which have been visualized
in the accompanying drawings, in which:
- Figure 1
- shows a chair in accordance with the invention in perspective from three different
angles;
- Figure 2
- shows, on a smaller scale, a chair in an alternative embodiment in which the chair
is composed of an upper part and a lower part;
- Figures 3A-B
- show the chair in a further alternative embodiment;
- Figure 4
- show the chair in a further alternative embodiment;
- Figure 5
- shows the chair in a further alternative embodiment;
- Figure 6
- shows indications of the height, width and depth of the chair;
- Figures 7A-C
- show the chair in a further alternative embodiment; A the chair shown in section;
B the chair shown in an exploded view; C a portion of the chair shown in perspective
from below.
[0018] Positional indications such as "lower" and "upwards" refer to the position shown
in the figures, and the words are used in accordance with their normal meaning.
[0019] In the drawings, the reference numeral 1 indicates a chair in accordance with the
invention. As the chair is without a back, it may also be termed a stool. In what
follows, the invention will be termed a chair 1. The chair 1 is provided with a rounded
lower portion 2 and an upper seat portion 3. Two outward-curving supporting elements
4 extend between the rounded lower portion 2 and the upper seat portion 3. Each outward-curving
supporting element 4 is formed of at least one curved arm 42, 44. The convex bottom
side 2' of the rounded lower portion 2 rests on a supporting surface 9. The outward-curving
arms 42, 44 are fixed to the peripheral portion 20 of the rounded lower portion 2.
In one embodiment, the convex bottom side 2' of the rounded lower portion has a spherical
shape.
[0020] In the figures, the seat portion 3 of the chair 1 is shown as a portion formed in
a rounded shape with the convex side facing upwards. In one embodiment, the seat portion
3 of the chair 1 may be of a spherical shape. In an alternative embodiment, the seat
portion 3 may be flat (not shown). In a further alternative embodiment, the seat portion
3 may be saddle-shaped (not shown).
[0021] The outward-curving supporting elements 4 of the chair 1 are fixed to the peripheral
portion 20 of the rounded lower portion 2 in a curved joint 49 without discrete edges,
that is to say the joint 49 is rounded. It is thereby achieved that the user (not
shown) of the chair 1 experiences a continuous, rolling movement when the chair 1
is moved forwards or backwards. By large deflections of the chair 1 in a forward movement
or a backward movement, a lower portion of the supporting element 4 will be in contact
with the supporting surface 9. The outward-curving arms 42, 44 distribute a user's
weight to the lower portion in a different manner from that of a centred connecting
element. A centred connecting element would be an extension of the user's spine.
[0022] The chair 1 is shown as formed with a through hole 5. In the position of application,
the hole 5 has an axis 50 which is substantially horizontal, see figure 2. Viewed
along the axis 50, the chair 1 Is substantially ball-shaped, see for example the left-hand
chair 1 in figure 1, as the supporting arms 4 are curved outwards. In the position
of application, the width W of the chair 1 is smaller than the height H of the chair
1 as shown in figure 6. The depth D of the chair may be equal to or smaller than the
height H of the chair 1. When the depth D is equal to the height H, the chair 1 will
be approximately ball-shaped along a continuous outer jacket surface. This is shown
the most clearly in the chair to the left in figure 1. For a user, the height H of
the chair is the sitting height, whereas the width W of the chair 1 will be the extent
of the chair 1 in the user's hip width, that is to say in the extent of the user's
coronal plane. The depth D of the chair 1 will be the extent of the chair 1 in front
of and behind the user, that is to say the extent in the user's sagittal plane or
median plane. The supporting element 4 tapers towards a middle portion so that the
width W"' of the middle portion is smaller than the width W. This has the effect of
enabling the user to sit comfortably on the chair 1 with his thighs approximately
straight forwards and downwards with a medial rotation, whereas the knee may be bent
so that the leg is moved backwards and lower than the user's seat portion / hip portion
and somewhat to the side of this in a lateral direction, that is to say the leg is
abducted.
[0023] In one embodiment, the chair 1 may be split into an upper part 10 and a lower part
12. In this embodiment, the arm 42, 44 is split into an upper supporting arm 41, 43
and a lower supporting arm 45, 57. The lower supporting arm 45, 47 is fixed to the
peripheral portion 20 of the rounded lower portion 2 in a curved joint 49 without
discrete edges. By large deflections of the chair 1 in a forward movement or a backward
movement, a lower portion of the lower supporting arm 45, 47 will be in contact with
the supporting surface 9.
[0024] In one embodiment, in which the chair 1 is split, the upper part 10 and the lower
part 12 of the chair 1 may be held together by an elastic band 6 surrounding the chair
1 along the continuous outer jacket surface of the chair 1. The elastic band 6 also
has the advantage of deadening noise when the chair 1 is used on a supporting surface
9 having a hard surface. In figure 3A, the chair 1 is shown assembled and surrounded
by the band 6. In figure 3B, the chair 1 is shown with its main components.
[0025] In one embodiment shown in figure 4, the chair 1 may be split into an upper part
10 and a lower part 12, and an extension piece 7 has been inserted between the upper
supporting arm 41, 43 and the lower supporting arm 45, 57. A possibility of adjusting
the chair 1 to a user's sitting height is thereby achieved. In this exemplary embodiment,
the height H of the chair 1 is larger than the depth D. The extension piece 7 is positioned
in the middle portion of the supporting element 4 and has a width W"'.
[0026] In one embodiment shown in figure 5, the supporting arms 41, 43, 45, 47 may be divided
into two parts, the supporting arms 41, 41', 43, 43' 45, 45', 47, 47' respectively.
[0027] In its seat portion 3, the chair 1 may be provided with a pad 31 as shown in figures
4 and 5.
[0028] The weight of the rounded lower portion 2 of the chair 1 can be increased by increasing
the material thickness in the portion facing the supporting surface 9. In another
embodiment, the rounded lower portion 2 may be provided with a weighting means 29
such as a weight, for example, see figures 7B-C. This has the advantage of the chair
1 returning to an upright position and remaining in an upright position when the chair
1 is not in use. The weighting means 29 may be permanently or releasably fixed. In
a further alternative embodiment, the width W' of the seat portion 3 may be smaller
than the width W" of the rounded lower portion 2, see figure 6. The width W" will
also be the width W of the chair 1. In this embodiment as well, the centre of gravity
of the chair 1 is closer to the rounded lower portion 2 and the chair 1 will remain
in its upright position when the chair 1 is not in use. It may be advantageous for
the training effect when the chair 1 is being used that the rounded lower portion
2 does not have too large a mass relative to the seat portion 3 because the chair
1 will be slower in moving when the centre of gravity of the chair 1 is low.
[0029] The chair 1 is provided with an internal space 8. The space 8 is defined by the concave
upper side 2" of the rounded lower portion 2 and the internal surfaces 42", 44" of
the outward-curving arms 42, 44. The internal surfaces 42", 44" may have a concave
shape. In embodiments in which the chair 1 is provided with bipartite supporting arms
41, 43, 45, 47, the space 8 is defined by the Internal surfaces 45", 47" of the lower
supporting arms 45, 47. The internal surfaces 45", 47" may have a concave shape. Objects,
such as a bag, sack or shoes (not shown), will be held in place within the space 8
even if the chair 1 is subjected to large deflections forwards, backwards or to the
side, because the internal surfaces 2"; 42", 44'; 45", 47" provide sufficient support
and contact surface for the object to rest against them.
[0030] The chair 1 is shown in an alternative embodiment in figures 7A-C. The parts of the
chair 1 are formed of a polymer material. The upper part 10 and the lower part 12
of the chair 1 are held together by a locking piece 14 as shown in figure 7A. The
locking piece 14 is provided with locking dogs 16. The locking piece 14 is positioned
in a pocket 17 in the supporting arms 41, 43, 45, 47. One wall 18 of the pocket 17
is provided with a cut-out 19. The cut-out 19 may extend through the wall 18. The
locking piece 14 may be moved into a pocket 17 in the supporting arm 45, 47 until
the locking dog 16 engages the cut-out 19. At its opposite end portion, the locking
piece 14 projects above the pocket 17. Then the upper part 10 is positioned in such
a way that the pocket 17 in the supporting arm 41, 43 can be moved over the opposite
end portion of the locking piece 14 until the locking dog 16 engages the cut-out 19
of the upper part 10.
[0031] In this embodiment, the pad 31 of the chair 1 Is arranged to be attached in a recess
32 in the upper part 10. In its rounded lower portion 2, on its convex bottom side
2', the chair 1 is provided with a silencer 61 or a friction coating 61. The silencer
61 or the friction coating 61 is attached in a recess 63. The recess 63 may also include
a recess 63' arranged to accommodate the weight element 29.
[0032] The chair 1 may consist of a polymer material. The chair 1 may be rotation-moulded
or injection-moulded. The chair 1 may also consist of wood, such as press-shaped veneer,
or metal, such as aluminium.
1. A chair (1) which includes a rounded lower portion (2), the convex side (2') of the
rounded lower portion (2) being arranged to rest on a supporting surface (9), and
a seat portion (3); the chair (1) is provided with a rigid supporting element (4)
between the rounded lower portion (2) and the seat portion (3), wherein:
- the supporting element (4) of the chair (1) is formed of at least two outward-curving
arms (42, 44) between the peripheral portion (20) of the rounded lower portion (2)
and the seat portion (3);
- the outward-curving arms (42, 44) and the rounded lower portion (2) form a curved
joint (49); characterized in that:
- the rounded lower portion (2) is a spherical lower portion; and in that
- the supporting element (4) tapers towards a middle portion of the chair (1) so that
the width (W''') of the supporting element in the middle portion is smaller than a
width (W) of the seat portion (3).
2. The chair (1) in accordance with claim 1, wherein, in the position of application,
a width (W) of the chair (1) is smaller than a height (H) of the chair (1) and a depth
(D) of the chair (1).
3. The chair (1) in accordance with claim 1, wherein the seat portion (3) includes a
rounded portion, the convex side of the rounded portion facing upwards.
4. The chair (1) in accordance with claim 1, wherein the chair (1) is provided with an
internal space (8) defined by internal surfaces (42", 44", 47", 49") of the outward-curving
arms (42, 44; 47, 49) and the concave upper side (2") of the rounded lower portion
(2).
5. The chair (1) in accordance with claim 1, wherein each of the outward-curving arms
(42, 44) are split into an upper supporting arm (41, 43) and a lower supporting arm
(45, 57) so that the chair (1) comprises a lower part (12) and an upper part (10).
6. The chair (1) in accordance with claim 1, wherein the chair (1) is further provided
with at least two extension pieces (7) for insertion between the upper supporting
arms (41, 43) and the lower supporting arms (45, 57) so that the height (H) of the
chair (1) may be changed.
7. The chair (1) in accordance with claim 6, wherein the chair (1) is further provided
with an elastic band (6) around the circumference of the chair (1), and wherein the
band (6) is arranged to hold the upper part (10) and the lower part (12) of the chair
(1) together.
8. The chair (1) in accordance with claim 1, wherein the chair (1) is further provided
with an elastic band (6) around the circumference of the chair (1), the band (6) being
arranged to give the convex bottom side (2') of the rounded lower portion (2) a sound-deadening
surface against the supporting surface (9).
9. The chair (1) in accordance with claim 1, wherein the rounded lower portion (2) of
the chair (1) is provided with a weighting means to increase the stability of the
chair (1).
10. The chair (1) in accordance with claim 9, wherein the weighting means of the chair
(1) consists of a material thickening in the wall of the rounded lower portion (2).
11. The chair (1) in accordance with claim 9, wherein the weighting means of the chair
(1) consists of a weight.
12. The chair (1) in accordance with claim 2, wherein the width (W') of the seat portion
(3) is smaller than the width (W") of the rounded lower portion (2).
1. Stuhl (1), aufweisend einen abgerundeten unteren Abschnitt (2), wobei die konvexe
Seite (2') des abgerundeten unteren Abschnittes (2) angeordnet ist, um an einer Stützfläche
(9) aufzuliegen, und einen Sitzabschnitt (3); wobei der Stuhl (1) zwischen dem abgerundeten
unteren Bereich (2) und dem Sitzabschnitt (3) ein starres Stützelement (4) aufweist,
wobei:
- das Stützelement (4) des Stuhls (1) aus mindestens zwei nach aussen gebogenen Armen
(42, 44) zwischen dem Umfangsabschnitt (20) des abgerundeten unteren Abschnittes (2)
und dem Sitzabschnitt (3) gebildet ist;
- die auswärts gebogenen Arme (42, 44) und der abgerundete untere Abschnitt (2) ein
Kurvengelenk (49) bilden;
dadurch gekennzeichnet, dass
- der abgerundete untere Abschnitt (2) ein kugelförmiger unterer Abschnitt ist; und
dass
- das Stützelement (4) sich zu einem mittleren Abschnitt des Stuhls (1) hin verjüngt,
sodass die Breite (W") des Stützelements im mittleren Abschnitt kleiner ist als eine
Breite (W) des Sitzabschnittes (3).
2. Stuhl (1) gemäss Anspruch 1, wobei, in der Nutzungsstellung, eine Breite (W) des Stuhls
(1) kleiner ist als eine Höhe (H) des Stuhls (1) und eine Tiefe (D) des Stuhls (1).
3. Stuhl (1) gemäss Anspruch 1, wobei der Sitzabschnitt (3) einen abgerundeten Abschnitt
aufweist, wobei die konvexe Seite des abgerundeten Abschnittes nach oben hin gerichtet
ist.
4. Stuhl (1) gemäss Anspruch 1, wobei der Stuhl (1) einen inneren Raum (8) aufweist,
welcher durch innere Flächen (42", 44", 47", 49") der nach aussen gebogenen Arme (42,
44; 47; 49) und die konkave obere Seite (2") des abgerundeten unteren Abschnitts (2)
definiert ist.
5. Stuhl (1) gemäss Anspruch 1, wobei jeder der nach aussen gebogenen Arme (42, 44) in
einen oberen Stützarm (41, 43) und einen unteren Stützarm (45, 57) aufgeteilt sind,
sodass der Stuhl (1) einen unteren Teil (12) und einen oberen Teil (10) aufweist.
6. Stuhl (1) gemäss Anspruch 1, wobei der Stuhl (1) des Weiteren mindestens zwei Verlängerungsstücke
(7) aufweist, zum Einführen zwischen den oberen Stützarmen (41, 43) und den unteren
Stützarmen (45, 57), sodass die Höhe (H) des Stuhls (1) geändert werden kann.
7. Stuhl (1) gemäss Anspruch 6, wobei der Stuhl (1) des Weiteren ein elastisches Band
(6) um den Umfang des Stuhls (1) herum aufweist, und wobei das Band (6) angeordnet
ist, um den oberen Teil (10) und den unteren Teil (12) des Stuhls (1) zusammenzuhalten.
8. Stuhl (1) gemäss Anspruch 1, wobei der Stuhl (1) des Weiteren en elastisches Band
(6) um den Umfang des Stuhls (1) herum aufweist, wobei das Band (6) angeordnet ist,
um der konvexen unteren Seite (2') des abgerundeten unteren Abschnittes (2) eine schalldämpfende
Fläche gegen die Stützfläche (9) zur Verfügung zu stellen.
9. Stuhl (1) gemäss Anspruch 1, wobei der abgerundete untere Abschnitt (2) des Stuhls
(1) ein Beschwerungsmittel zur Erhöhung der Stabilität des Stuhls (1) aufweist.
10. Stuhl (1) gemäss Anspruch 9, wobei das Beschwerungsmittel des Stuhls (1) aus einer
Materialverdickung in der Wand des abgerundeten unteren Abschnittes (2) besteht.
11. Stuhl (1) gemäss Anspruch 9, wobei das Beschwerungsmittel des Stuhls aus einem Gewicht
besteht.
12. Stuhl (1) gemäss Anspruch 2, wobei die Breite (W) des Sitzabschnittes (3) kleiner
ist als die Breite (W") des abgerundeten unteren Abschnittes (2).
1. Une chaise (1) qui comporte une partie inférieure arrondie (2), le côté convexe (2')
de la partie inférieure arrondie (2) étant conçu pour reposer sur une surface d'appui
(9), et une partie de siège (3); la chaise (1) est pourvue d'un élément de support
(4) rigide entre la partie inférieure arrondie (2) et la partie de siège (3), dans
laquelle:
- l'élément de support (4) de la chaise (1) est formé d'au moins deux bras s'incurvant
vers l'extérieur (42, 44) entre la partie périphérique (20) de la partie inférieure
arrondie (2) et la partie de siège (3);
- les bras s'incurvant vers l'extérieur (42, 44) et la partie inférieure arrondie
(2) forment une jonction arrondie (49); caractérisée en ce que:
- la partie inférieure arrondie (2) est une partie inférieure sphérique; et en ce que
- l'élément de support (4) rétrécit vers la partie du milieu de la chaise (1) de sorte
que la largeur (W") de l'élément de support dans la partie de milieu est inférieure
à la largeur (W) de la partie de siège (3).
2. La chaise (1) selon la revendication 1, dans laquelle, dans la position d'application,
une largeur (W) de la chaise (1) est inférieure à une hauteur (H) de la chaise (1)
et à une profondeur (D) de la chaise.
3. La chaise (1) selon la revendication 1, dans laquelle la partie de siège (3) comprend
une partie arrondie, le côté convexe de la partie arrondie étant tourné vers le haut.
4. La chaise (1) selon la revendication 1, dans laquelle la chaise (1) est pourvue d'un
espace interne (8) défini par des surfaces internes (42", 44", 47", 49") des bras
s'incurvant vers l'extérieur (42, 44; 47, 49) et le côté supérieur concave (2") de
la partie inférieure arrondie (2).
5. La chaise (1) selon la revendication 1, dans laquelle chacun des bras s'incurvant
vers l'extérieur (42, 44) est divisé en un bras de support supérieur (41, 43) et un
bras de support inférieur (45, 57) de sorte que la chaise (1) comprend une partie
inférieure (12) et une partie supérieure (10).
6. La chaise (1) selon la revendication 1, dans laquelle la chaise (1) est en outre pourvue
d'au moins deux pièces d'extension (7) à insérer entre les bras de support supérieurs
(41, 43) et les bras de support inférieurs (45, 57) de sorte que la hauteur (H) de
la chaise (1) puisse être modifiée.
7. La chaise (1) selon la revendication 6, dans laquelle la chaise (1) est en outre pourvue
d'une bande élastique (6) autour de la circonférence de la chaise (1), et dans laquelle
la bande (6) est agencée pour maintenir la partie supérieure (10) et la partie inférieure
(12) de la chaise (1) ensemble.
8. La chaise (1) selon la revendication 1, dans laquelle la chaise (1) est en outre pourvue
d'une bande élastique (6) autour de la circonférence de la chaise (1), la bande (6)
étant agencée pour donner au côté inférieur convexe (2') de la partie inférieure arrondie
(2) une surface insonorisante contre la surface d'appui (9).
9. La chaise (1) selon la revendication 1, dans laquelle la partie inférieure arrondie
(2) de la chaise (1) est pourvue d'un moyen de lestage pour augmenter la stabilité
de la chaise (1).
10. La chaise (1) selon la revendication 9, dans laquelle le moyen de lestage de la chaise
(1) consiste en un matériau épaississant dans la paroi de la partie inférieure arrondie
(2).
11. La chaise (1) selon la revendication 9, dans laquelle le moyen de lestage de la chaise
(1) consiste en un poids.
12. La chaise (1) selon la revendication 2, dans laquelle la largeur (W) de la partie
de siège (3) est inférieure à la largeur (W') de la partie inférieure arrondie (2).