EP1489945B1 - Ergonomic seating module and seat fitted with said module - Google Patents

Abstract

The seat module, e.g. for an office chair, consists of a support (10) with a pommel (20), and a frame (12) that is located above the base and equipped with a cantle (26). The support and frame are connected by an articulated joint (14) that allows the frame to tilt relative to the support about an axis perpendicular to its plane of symmetry. The frame is joined to the pommel by an elastic membrane that can be covered by a cushion with a lengthwise groove to accommodate the seated person's coccyx.

Description

The present invention relates to seats, both those intended to be static, such as chairs, chairs or stools, ..... those to equip vehicles. It relates, more particularly, both an ergonomic seat module and a seat equipped with this module.

It is understood that, for purposes of simplification, the expression "seat module" will sometimes be replaced in this document by the word "saddle", designating the part of the seat which forms a seat and on which the buttocks come. to ask.

In the static seats, the saddle is generally formed of a rigid material plate, which is optionally covered with a cushion. This saddle can be completed by a backrest and armrests. Certain seats, more particularly intended for persons working at an office, for example, by means of a computer, comprise articulations and elastic members making it possible to incline more or less the saddle and the backrest. The document GB-A-2176396 shows for example such a seat. Despite all the improvements made, health problems, especially those relating to the spine, continue to exist, causing serious harm to those who suffer from it and causing significant absenteeism, which is harmful to businesses.

The saddles of bicycles or motor-cycles, for example, generally comprise a rigid frame, comprising a pommel and a cantle, and a piece, generally triangular in shape connecting the pommel to the cantle and forming the support surface. This piece has a certain flexibility allowing adaptation to the position of the user, defined by the adjustment of the different parts of the vehicle. Saddles of this type have been arranged on fixed supports, in order to make static seats. If, in general, the comfort of a bicycle seat is not disputed, the application of the same principle to a fixed seat is unconvincing. it probably comes from the fact that, in a static situation, the user's organs, in contact with the saddle, remain fixed, while on a bicycle, they are in quasi-permanent movement.

To understand the issue of seats, it is good to remember the use that is made of them. Today, the sitting position has become one of the most representative positions of professional activity. In this context, two kinds of very distinct attitudes generally arise, depending on whether the occupation is "active" or "passive". The term "active" means an occupation in which the hands are heavily solicited, for example, for typing on a keyboard, drawing, all manual work sitting (watchmaking, electronics, laboratory, clothing, ...) or the driving a vehicle. The body must thus be placed in such a way that the hands can perform their function. It is thus generally with a trunk oriented substantially vertically. On the contrary, in "passive" occupations, such as discussions, moments of reflection or relaxation, the hands are much less stressed and the body can be placed so that the back is in support against a backrest, the inclined trunk rearward.

The designers of seats intended for seated work build them in such a way as to avoid any stress on the musculature. If this approach is right during the "passive" occupation phases, which allows the body to rest, it is detrimental to the body in "active" occupation phases. It appears, in fact, that what, initially, is perceived as additional comfort, leads to a weakening of the muscles of levitation, which can cause many inconveniences, lumbago is the most common.

Experience suggests that the health problems encountered by people working while sitting may be due to a weakening of the levitation muscles. This musculature does not participate directly in the mobility of the person, but allows him to ensure a position of balance, both when the person is standing, stopping or moving, as when sitting or squatting. It can not develop or maintain itself harmoniously only to the extent that it is solicited in a regular way, while avoiding a tension of one or the other muscle.

The object of the present invention is to provide a seat with an ergonomic saddle that practically forces the user to take a posture in which his levitation muscles are naturally and automatically solicited, thus avoiding health problems.

• un bâti muni d'un pommeau,
• un cadre muni d'un troussequin, ledit bâti et ledit cadre présentant une symétrie planaire,
• des moyens de liaison du cadre au bâti, comprenant une articulation qui permet au cadre de basculer, par rapport au bâti, autour d'un axe perpendiculaire au plan de symétrie, et
• une assise reliant le cadre au pommeau et constituée d'une membrane élastique ayant pour fonction de définir une position de repos du cadre par rapport au bâti et de tendre à le ramener dans cette position lorsqu'un utilisateur l'a fait basculer dans un sens ou dans l'autre.

More specifically, the invention relates to a seating module which comprises:

• a frame with a pommel,
• a frame provided with a cantle, said frame and said frame having a planar symmetry,
• means for connecting the frame to the frame, comprising a hinge that allows the frame to tilt, relative to the frame, about an axis perpendicular to the plane of symmetry, and
• a seat connecting the frame to the pommel and consisting of an elastic membrane whose function is to define a rest position of the frame relative to the frame and tend to bring it back to that position when a user has tilted in one direction or in the other.

• en position de repos, le cadre est incliné vers l'avant d'un angle d'environ 10° par rapport au sol;
• le bâti a, en plan, la forme d'un T, dont la jambe, disposée dans le plan de symétrie, s'étend vers l'avant et est recourbée vers le haut pour se terminer par le pommeau;
• les bras du T ont leurs extrémités relevées pour former l'articulation avec le bâti;
• le cadre est une fourche qui a, en plan, la forme d'un U d'axe disposé dans le plan de symétrie, dont la traverse, relevée, constitue le troussequin et dont les deux dents s'étendent vers l'avant, sensiblement jusqu'au pommeau, en dessous de lui;
• la membrane forme une surface d'appui convexe selon une ligne perpendiculaire au plan de symétrie et concave selon une ligne inscrite dans ce plan;
• la membrane est fixée entre le pommeau et le troussequin, entre les deux dents de la fourche, et entre les extrémités des dents et le pommeau;
• la membrane est recouverte d'une galette formant coussin et comporte une rainure longitudinale destinée à former un espace pour recevoir le coccyx de l'utilisateur.

The seat module according to the invention also comprises the following main features:

• in the rest position, the frame is inclined forwards at an angle of about 10 ° to the ground;
• the frame has, in plan, the shape of a T, whose leg, arranged in the plane of symmetry, extends forward and is curved upwards to end with the pommel;
• the arms of the T have their ends raised to form the articulation with the frame;
• the frame is a fork which has, in plan, the shape of a U axis arranged in the plane of symmetry, whose cross, raised, constitutes the cantle and whose two teeth extend forward, substantially to the pommel, below him;
• the membrane forms a convex bearing surface along a line perpendicular to the plane of symmetry and concave along a line inscribed in this plane;
• the membrane is fixed between the pommel and the cantle, between the two teeth of the fork, and between the ends of the teeth and the pommel;
• the membrane is covered with a cushion pad and has a longitudinal groove for forming a space for receiving the coccyx of the user.

The present invention also relates to a seat provided with a support in contact with the ground and a seat module as defined above, characterized in that the support comprises an arm extending towards the front and towards the top and carrying a crossbar forming a support to the knees of the user and padded to form a cushion.

• les figures 1 et 2 représentent le bâti et la fourche d'un module d'assise selon l'invention, respectivement vus de dessus et en coupe selon la ligne II-II de la figure 1;
• la figure 3 montre principalement la fourche, vue de dessus, dotée de sa membrane élastique;
• la figure 4 est une vue en coupe du module d'assise, toujours selon 11-11; et
• la figure 5 montre un siège selon l'invention.

Other features of the invention will emerge from the description which follows, given with reference to the appended drawing, in which:

• Figures 1 and 2 show the frame and the fork of a seat module according to the invention, respectively seen from above and in section along the line II-II of Figure 1;
• Figure 3 shows mainly the fork, seen from above, with its elastic membrane;
• Figure 4 is a sectional view of the seat module, still 11-11; and
• Figure 5 shows a seat according to the invention.

The seat module - or saddle - according to the invention essentially comprises a frame 10, a fork-shaped frame 12, a hinge 14 connecting, in an articulated manner, the frame 10 and the fork 12, and an elastic membrane 16, visible only in Figures 3 and 4. The seat has a symmetrical structure with reference to a vertical plane passing through the lines II-II of Figures 1 and 3.

More specifically, the frame 10 has, in plan, the shape of a T, whose leg 18, placed in the axis 11-11, extends forward and is curved upwards to end by a knob 20. The arms 22 of the T, perpendicular to the axis, have their ends 22a raised and pierced with a hole not visible in the drawing. The frame 10 has a central portion 24 provided with holes 24a for fixing the saddle on a support, as will be explained later.

The fork 12 has, in plan, the shape of a U axis II-II. Its crossbar 26, slightly raised and curved, acts as a cantle and its two teeth 28 extend forward substantially to the knob 20, below him, a few centimeters.

Note that, in the rest position of the saddle, shown in the drawing, the tip of the cantle 26 is substantially at the same height as the knob 20, and that the fork 12 is inclined forwardly of an angle d about 10 ° to the ground.

The teeth 28 of the fork are provided, substantially in their middle, a lug 30 extending downward, each adjacent to one end 22a of the frame and provided with a coaxial hole. Bearings engaged in these holes and rods, engaged in the bearings, form the hinge 14 which thus allows the fork 12 to pivot relative to the frame 10 about an axis A-A.

Advantageously, the frame 10 and the fork 12 are made respectively of aluminum and steel.

• premièrement, entre le pommeau 20 et le troussequin 26,
• deuxièmement, entre les deux dents 28 de la fourche 12, et
• troisièmement, entre les extrémités des dents 28 et le pommeau 20.

FIG. 3 shows that the elastic membrane 16 is fixed:

• first, between the knob 20 and the cantle 26,
• secondly, between the two teeth 28 of the fork 12, and
• thirdly, between the ends of the teeth 28 and the knob 20.

The membrane 16 may be made of any elastic material, for example PVC, in the form of fabric, as shown in FIGS. 3 and 4, or of film, of a piece or in strips. In the latter case, a first set of strips 16a connects the knob 20 to the cantle 26, a second assembly 16b interconnects the two teeth 28, this second set covering the first, and a third assembly 16c connects the ends of the teeth 28 to the pommel 20.

• de définir la position de repos de la fourche 12 par rapport au bâti 10, position prise lorsque personne n'est assis sur la selle, et
• de ramener la fourche 12 dans cette position de repos au moment où la selle est quittée par une personne qui l'a fait basculer vers l'avant ou vers l'arrière.

Due to the shape of the fork 12 and the position of the pommel 20, the membrane 16 has a horse saddle shape, with a concavity between the cantle 26 and the pommel 20 and a convexity between the two teeth 28. these characteristics, the membrane 16 has the function:

• to define the rest position of the fork 12 relative to the frame 10, position taken when no one is sitting on the saddle, and
• to return the fork 12 in this rest position at the moment when the saddle is left by a person who tipped it forwards or backwards.

As can be seen in FIG. 4, the saddle according to the invention may advantageously be completed by a pancake 32, forming a cushion, completely covering the membrane 16 and fixed thereto permanently or removably. This slab may consist of a fabric envelope containing an elastic padding or formed of a gel. Advantageously, it is provided with a longitudinal groove 34 extending over the entire length of the cushion. In this way, the coccyx of the occupant of the saddle is not compressed, which improves its comfort and avoids certain damage, especially in the spine.

FIG. 5 shows that the previously described seat module makes it possible to equip a seat formed with a support 36 which comprises, in known manner, a telescopic central column 38 and radially arranged feet 40, each provided with a wheel 42 The column 38 carries, at its upper end, a seat module 44 according to the invention, which is fixed by its frame 10.

Such a seat, thus forming a stool, can advantageously be used by people working essentially in the "active" position, for example a dentist or a watchmaker. It can be completed, as shown on this figure, by a backrest 46 fixed to the trousseau 26 and allowing to take a position "passive".

When the user frequently works in the "active" position, it is advantageous to provide the seat with a transverse support bar 48 for the knees, preferably padded and covered with a fabric or leather, so that the contact is pleasant . This bar is fixed to the support 36, permanently or removably, by means of an arm 50. The latter has a wheel 42 and is advantageously pivotally or slidingly connected to the support 36, so that it can be retracted. when the user must often leave his seat.

It will be noted that the pressure of the knees against the bar 48 is low. It therefore participates little in the seating of the user. It avoids, on the other hand, to cross the legs, and thus, some inconvenience associated with this habit.

As can be seen in Figure 5, the arm 50 is fixed to the support 36 in the vicinity of the feet 40, very close to the ground. In this way, it does not interfere with the movement when the user sits in or leaves the seat.

Finally, very advantageously, the seat module 44 can be hingedly mounted on the column 38 by means of a conventional mechanism 52 of adjustable seat rocker which benefits an armrest 54.

With the construction described, when the user sits to put himself in the "active" position, he finds the saddle 44 automatically placed in the rest position corresponding to the maximum comfort, that is to say with the femoral joint vertically to the articulation 14.

If the user leans forward, the fork 12 will accompany his movement, allowing him to adjust his posture in a process of self-levitation that helps strengthen the muscles of lift and tends to reduce the risk of health problems, as mentioned above.

When, to think or call, the user is placed "passive" position against the backrest 46, the fork 12 tilts backwards, so that it is in a posture for which all his musculature is at rest. This automatic adjustment provides optimal comfort due to the fact that the weight of the user is distributed very evenly over the buttocks and the back of the thighs.

In other words, the seat according to the invention allows, in the "active" position, adjustments of the posture favoring the work of the muscles of auto-levitation, while in "passive" position, these muscles can relax .

Both the seat module and the seat described above can be the subject of many variants. It is, for example, possible to provide adjusting members and, more particularly, stops (not shown) limiting, on both sides, the tilting movement of the fork 12 on the frame 10. The knob 20 can also be provided with means for modifying its position with reference to the frame 10. It is also possible to envisage an asymmetric structure, intended for a disabled user, either at the level of the wafer 32 or in the shape of the trumpet 26.

The articulated connection, by the hinge 14, between the frame 10 and the fork 12, can be provided by means of a ball joint. In this case, the self-levitation mechanism will be carried out from front to back as well as from side.

The position of the hinge 14 can also advantageously be adjustable in the front-rear directions, so that it is perfectly aligned with the ischions when the user is seated.

Other adjustment means are possible to vary the distance between the knob 20 and the cantle 26, in order to adjust the tension of the elastic membrane 16.

The saddle 44 is advantageously fixed to the support 36 by its frame 10. It is also conceivable to secure the fixation by the cantle 26 itself.

The spring function provided by the elastic membrane 16 may also be reinforced by springs arranged specifically for this purpose, for example torsion, traction or compression.

It will be noted, finally, that it may be advantageous to provide the backrest 46 with an independent lumbar support zone with permanent disengageable contact.

Claims (10)

1. Seating module for a chair, characterized in that it includes:

   - a structural framework (10) provided with a pommel element (20),

   - a frame (12) arranged above the structural framework and provided with a cantle element (26), said structural framework and said frame having planar symmetry,

   - means for connecting the frame to the structural framework, including a joint (14) which allows the frame (12) to tilt, in relation to the structural framework (10), about an axis perpendicular to the plane of symmetry, and

   - a seat connecting the frame (12) to the pommel element (20) and formed of an elastic membrane (16) whose function is to define a rest position of the frame (12) in relation to the structural framework (10) and to return it to this position when a user tilts it in one direction or another.
2. Seating module according to claim 1, characterized in that in the rest position, the frame (12) is inclined forwards by an angle of approximately 10° in relation to the ground.
3. Seating module according to claim 1, characterized in that, in plane, the structural framework (10) has a T-shape, the vertical bar (18) of which, arranged in the plane of symmetry, extends forwards and is bent upwards to end in said pommel element (20).
4. Seating module according to claim 3, characterized in that the ends (22a) of the horizontal bars (22) of the T are raised to form the joint with the structural framework (10).
5. Seating module according to claim 1, characterized in that the frame (12) is a fork, which has, in plane, the shape of a U with an axis disposed in the plane of symmetry, the raised cross bar (26) of which forms said cantle element and the two teeth (28) of which extend forwards, substantially as far as the pommel element (20), underneath it.
6. Seating module according to claim 5, characterized in that said membrane (16) forms a support surface that is convex along a line perpendicular to the plane of symmetry and concave along a line inscribed in said plane.
7. Seating module according to claim 6, characterized in that said membrane (16) is fixed:

   - between the pommel element (20) and the cantle element (26),

   - between the two teeth (28) of the fork (12), and

   - between the ends of the teeth (28) and the pommel element (20).
8. Seating module according to any of claims 1 to 7, characterized in that said membrane (16) is covered with a padding member (32) forming a cushion.
9. Seating module according to claim 8, characterized in that said padding member (32) includes a longitudinal groove (34) for forming a space to receive the user's coccyx.
10. Chair fitted with a support (36) in contact with the ground and a seating module (44) according to any of claims 1 to 9 and fixed to said support, characterized in that said support includes an arm (50) extending forwards and upwards and carrying a transverse bar (48) forming a support for the user's knees.

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