EP3102069A1

EP3102069A1 - Chair

Info

Publication number: EP3102069A1
Application number: EP15797103.7A
Authority: EP
Inventors: Simon Desanta
Original assignee: Desanta Simon
Current assignee: Desanta Simon
Priority date: 2015-02-19
Filing date: 2015-11-19
Publication date: 2016-12-14
Anticipated expiration: 2035-11-19
Also published as: EP3102069B1; US20190159596A1; WO2016131504A1; US11071387B2; PL3102069T3; WO2016131485A1

Abstract

Disclosed is a chair (10, 100) comprising a seat plate (14, 104), an underframe (12, 102) which supports the seat plate (14), and comprising a seat back (16, 106), said chair characterised in that the seat back (16, 106) is pivotally mounted on the underframe (12, 102) about a rear transverse axis (26, 120) that runs transversely to the chair (10, 100), and in that the seat plate (14, 104) is at least partially deformable and, by means of at least one rigid support piece (28, 122) that extends out from the lower end of the seat back (16, 106) in the direction of the seat plate (14, 104) and that is rigidly connected to the seat back (16, 106), the seat plate is supported or reinforced in such a way that during a pivoting movement of the seat back (16, 106), a region of the seat plate (14, 104) that is located in front of the end of the support piece (28, 122) is lifted or lowered depending on the pivoting direction.

Description

CHAIR

The present invention relates to a chair having a seat panel, a base frame supporting the seat panel, and a seat back.

Chairs are known to exist in extremely diverse embodiments. In its simplest embodiment, the backrest is rigidly attached to the seat plate, which in turn is supported by a base with four legs. Chairs used for seating halls and function rooms often have side panels that can be laterally connected to a neighboring chair. In addition, such row chairs are conveniently stackable, so that they can be stored to save space. Such a row chair is known for example from WO 2008/064886.

To improve seating comfort and ergonomics, it is desirable for the chair to be able to accommodate, to some extent, the load of the person sitting thereon. So the backrest should give way under load, but at the same time provide sufficient support for the occupant. Also, the seat plate can be designed resilient and coupled to the backrest so that adjusts a balance of power, which changes dynamically when changing the body position.

Such chairs usually have a comparatively simple spring technology, in which the spring pressure is designed for comparatively heavy or tall people. Lighter persons can therefore hardly use the movement mechanism of the chair and the associated comfort. In addition, the known stackable row chairs from the unloaded position, which corresponds to the stacking position, while bringing into a relaxation position in which the backrest is tilted slightly backwards. However, you can not bring in a supported front seating position in which the backrest is pivoted forward from the unloaded position and the person sitting on the chair also supported in a forward pushed seating position. For long periods of sitting, however, such mobility is advantageous and increased the ergonomics. Corresponding solutions, however, are mechanically too expensive and costly for row chairs and are therefore previously used only in office chairs or work chairs. The constructions used in this case, however, are relatively complex and expensive and therefore can not be easily transferred to row chairs.

It is therefore an object of the present invention to develop a chair which despite a comparatively simple and inexpensive design offers a high degree of ergonomics and comfort and is particularly suitable as a row chair or for comparable purposes. In particular, this chair should be equally comfortable and comfortable for people of different body weight and also provide a supported front seating position of the type described above.

This object is achieved by a chair with the features of claim 1.

In the chair according to the invention, the backrest is pivotally mounted on the base frame, so that it can yield under load from the back of the person sitting. From the lower end of the backrest, a support part extends in the direction of the seat plate, which is formed at least partially deformable. For example, the seat plate may be elastically deformable as a whole, or it may have various portions which are connected, for example, by a kind of hinge, so that a pivoting mechanism is formed between mutually deformable parts. By contrast, the support part is rigidly and rigidly connected to the backrest so that it can follow its pivotal movement about the transverse axis mounted on the rear of the undercarriage. If the backrest is thus pivoted backwards, the support part follows this pivoting movement upwards or correspondingly downwards, when the backrest is pushed forward. The supporting part supports or reinforces the seat plate in such a way that, as described above, a region of the seat plate located in front of the end of the support part is raised or lowered during pivoting movement of the backrest, depending on the pivoting direction. That is, the backrest is coupled via the support member so with the seat plate that the loaded by a person sitting thereon part of the seat plate can be raised or lowered.

Leaning the seated person back, presses the support member together with the rear of the backrest, the loaded area of the seat plate upwards. If the person leans forward, there is a slightly forward seating position with the backrest pushed forwards. It is thus automatically achieved a certain suspension effect. Overall, a dynamic equilibrium sets in depending on the load.

The mechanism according to the invention offers the user a relaxed reclined position, but also an advanced seating position with the backrest pushed forward. The ergonomic advantages of this chair are essentially independent of the weight of the user usable. The mechanism of the chair according to the invention is relatively simple and can therefore be installed inexpensively in chairs that are used in large numbers, especially in row chairs for hall seating. Another advantage is that the construction according to the invention can be installed in substructures due to their simplicity, which are preferably suitable for row chairs, so are laterally connected to adjacent chairs and stackable.

According to a preferred embodiment of the present invention, the support member reinforces or is integrally formed with a rear portion of the seat panel. This means that the support part cuts the rear area of the seat plate in sections. stiffens, so that it is no longer flexible, but can follow the pivotal movement of the backrest.

Further preferably, the support member reinforces each one of the two rear Eckberei- surface of the seat plate, and a lying between these corner region central rear portion of the seat plate is separated from the corner areas by slots extending from the backrest into the seat plate inside. In this case, therefore, only the corner regions are stiffened, while the region lying in between can have a certain mobility and flexibility due to its flexibility.

According to a further preferred embodiment, the front end of the seat plate is firmly connected to the base frame.

In an alternative embodiment, the front end of the seat plate rests freely on the front end of the underframe.

Preferably, the seat plate is elastically deformable. It thus tends to return to its original shape when a force acting on it, ie by a weight load or a force acting on the seat plate via the support member, subsides. The elasticity thus acts as a restoring moment.

Further preferably, the support member is formed as a lever which extends from behind under the seat plate and is connected via a hinge whose hinge axis is parallel to the rear transverse axis of the backrest, with the seat plate.

Further preferably, a front part of the seat plate, which extends forwardly from the hinge, is connected to the underframe by a pivot bearing disposed in front of the hinge, by which the front part of the seat plate is pivotally supported on the underframe in the up and down direction. Further preferably, the chair comprises a return member for returning the lever and the seat plate from a deflected position to a rest position. This may be, for example, a suitable spring mechanism that holds the chair in the unloaded state in the rest position.

According to a further preferred embodiment, the pivot bearing comprises a fixedly arranged on the base pivot axis, which rests with play in a bearing sleeve which is fixedly mounted on the underside of the front end of the front part of the seat plate or formed therewith, so that the bearing sleeve forward and backward is displaceable on the pivot axis. This means that the front part of the seat plate rests with a certain play in the pivot bearing. This clearance may be required to allow the up and down pivotal motion described above.

According to a further embodiment, the return member comprises springs which lie in the bearing sleeve between the sleeve wall and the pivot axis opposite and hold them in the unloaded state in a rest position, which represents an intermediate position between a maximum feed position and a maximum retreat position within the bearing sleeve. The springs thus press the pivot axis back into a rest position, which can represent a middle position within the bearing sleeve.

Preferably, a rear part of the seat plate is hinged to a front part thereof by a film hinge. This allows the front and the rear part of the seat plate to perform a certain pivotal movement against each other.

Further preferably, the chair according to the invention is stackable on an identical chair. Other features and advantages of the present invention will be apparent from the following description of a preferred embodiment with reference to the following accompanying drawings.

Fig. 1 is a schematic representation of a chair according to a

Embodiment of the present invention in a side view, in which the chair assumes a rest position;

Figs. 2 and 3 are illustrations of the chair of Fig. 1 in different

Deflection positions of the backrest and the seat plate;

Figs. 4 to 6 are side views of a second embodiment of the chair according to the invention in three different positions of the backrest and the seat plate;

Figures 7 to 9 are detail views of the chair of Figures 4 to 6, also in different positions;

Fig. 10 is a schematic detail view of the return member of the second embodiment of the chair according to the invention;

11 and 12 are perspective views of the second embodiment of the chair according to the invention in different positions;

Fig. 13 shows three identical copies of the second embodiment of the chair according to the invention in stacked state;

Fig. 14 is a perspective view of the second embodiment of the chair according to the invention obliquely from below; and Fig. 15 is a view of the second embodiment of the chair according to the invention vertically from below.

The chair 100 shown in Fig. 1 comprises a base 102, a seat panel 104 and a backrest 106. In a conventional manner, the seat panel 104 is oriented substantially horizontally while the backrest 106 is inclined slightly rearwardly. It is noted that the terms "front", "rear", "side", etc. refer to the perspective of a person sitting on the chair 100. That is, the backrest 106 is located at the rear of the back of the chair 100, and all other positions and spatial directions refer to it.

The backrest 106 is slightly inclined backwards relative to the vertical position and encloses an angle of a little more than 90 degrees with the seat plate 104. The position shown in Fig. 1 represents a rest position of the chair 100 in the unloaded state, from which various parts of the chair 100 in the positions in Figs. 2 and 3 are movable, as will be clarified in more detail below.

The undercarriage 102 conventionally comprises four chair legs, of which only the right rear chair leg 108 and the right front chair leg 110 can be seen in FIG. 1. The chair legs 108, 110 are each connected on one side of the chair 100, ie on its right and left sides by a substantially horizontal strut 112. In the present embodiment, the strut 112 has a slight bend, so that it comprises a rear part 114 which is slightly inclined upwards towards the backrest 106, and a front part 116, which is inclined slightly upwards to the front end of the chair 100. Overall, the chair legs 108, 110, together with the substantially horizontal strut 112, form an assembly that is substantially in the shape of an inverted letter "U". In the upper rear corner of this arrangement, in which the upper end of the right rear chair leg 108 coincides with the rear end of the strut 112, a bearing 118 for a horizontal transverse axis 120 is disposed. This transverse axis 120 is directed transversely to the chair 100 and held on the not visible in Fig. 1 left chair side in a comparable camp. Around this transverse axis 120, the backrest 106 is pivotable, so that its inclination is variable.

From the lower end of the backrest 106 is a pair of support members 122 extending in the direction of the seat plate 104. Specifically, from each rear corner of the chair 100, a support member 122 extends forward and reinforces the respective rear corner portion of the seat panel and stiffen it. For example, the support member 122 may rest against the seat surface 104 over its entire length from below and be secured thereto. However, it is also conceivable that the support member 122 is formed or formed integrally with the seat plate 104 in this corner region.

While the seat panel 104 may be made of an elastically deformable material, the respective support members 122 are rigid. In the reinforced or supported rear corner regions, the seat plate 104 is thus no longer elastic. On the other hand, a middle region of the seat plate 104 lying between the corner regions may have a certain elasticity and for this purpose be separated from the reinforced and stiffened corner regions, for instance through slots extending into the seat plate 104 from the backrest 106.

The support member 122 is rigidly coupled to the seatback 106 and follows its pivotal movement about the transverse axis 120, as shown below. As a result, an area of the seat plate 104 located in front of the front end of the support part 122 is raised or lowered, depending on the pivoting direction of the backrest 106. , C) _

2 shows, for example, how the backrest 106 is pivoted to the rear. This situation may occur, for example, when a person sitting on the chair 100 leans back and thus a pressure force is exerted backwards on the backrest 106. The following this pivotal movement (counterclockwise in Fig. 2) support member 122 exerts from below a pressure against the seat plate 104, which causes an approximately central portion of the seat plate 104, which is located at a distance from the backrest 106, slightly is raised. Since the front end of the seat plate 104 in the present embodiment is fixedly connected to the base 102, the flexible seat plate 104 is deformed in itself, i. H. arched upwards, against the weight of sitting on the chair 100 user. By this weight load, the seat plate 104 seeks back to its original shape in Fig. 1 (ie, down) back, and due to the rigid coupling between the support member 122 and the backrest 106, the backrest 106 is pressed forward against the back of the user.

Thus, depending on the weight of the user and his body position, which can cause a shift in weight, a new equilibrium position of backrest 106 and seat plate 104 is established. It is noted that unlike the embodiment shown here, the front end of the seat plate 104 does not necessarily have to be firmly fixed to the base 102. Rather, the front end of the seat plate 104 can also rest freely on the base frame 102 and be held on the front upper edge of the base frame 102 solely by the weight of the user, who is exercised in particular by his resting on the front end of the seat plate 104 thigh.

If, from the position in FIG. 2, the backrest 106 is pivoted in the opposite direction (that is, in a clockwise direction) beyond the rest position shown in FIG. 1, the position shown in FIG. 3 is reached, in which the seat plate 104 is moved out of its position - the rest position is slightly curved downwards, ie in the opposite direction. This position can be achieved when the user of the chair 100 leans forward slightly. In this case, the seat plate 104 yields slightly downward due to its elasticity. The seat plate 104 may be secured to the base 102 such that during this movement to the position in Fig. 3, a stop is achieved in which the left and right side edges of the seat plate 104 rest on the horizontal strut 112 of the base 102, so that a further deflection in the downward direction is no longer possible.

From the position in Fig. 3, the seat plate 104 and backrest 106 can move back to the position in Fig. 1, for example, when the user stands up and thus relieves the weight on the seat plate 104. Then, due to its elasticity, the seat plate 104 strives to return to the horizontal position, and the restoring force acting in this case is transmitted via the support part 122 to the backrest 106 rigidly coupled thereto.

The effect according to the invention of creating a dynamic equilibrium position of the seated person is essentially achieved by the support plate 122, which is firmly coupled to the backrest 106, pushing the seat plate 104 upward or downward during a pivoting movement of the backrest 106 allows and thus this area or a front of the end of the support member 122 located portion of the seat plate 104 is raised or lowered. For this purpose, the seat plate 104 may be elastically deformable in itself, for example by selecting a suitable flexurally elastic material, or may be divided by a hinge, such as a film hinge in a front and a rear portion which are slightly pivoted against each other. There are thus various embodiments conceivable to ensure the deformability of the seat plate 104. It is also conceivable that the support member 122 is formed by a rear reinforced portion of the seat plate 104, that is, it is not a separate part, but the seat plate 104 itself is rigid at a rear, the backrest 106 facing portion and bie - a formed portion 104 is elastic or separated from this rear rigid portion by a living hinge or the like.

The chair 100 according to the first embodiment may be formed as a stackable chair or further developed to such. In this regard, details in Figures 1 to 3, insofar as they oppose such stackability, are not to be taken as limiting the present invention. However, the mechanism according to the invention is not exclusively tied to stackable chairs, but can also be applied to other frame Unterkostruktionen, for example, on office chairs with a turnstile frame.

FIGS. 4 to 15 show a second embodiment of the chair 10 according to the invention. Like the chair 100 shown in FIGS. 1 to 3, the chair 10 according to the second embodiment comprises a base frame 12, a seat panel 14 and a backrest 16. In the usual way, the seat panel 14 is substantially horizontal and only slightly rearward , d. H. sloping down to the backrest 16 on the base 12 is arranged.

The backrest 16 is inclined slightly backwards relative to the vertical position and encloses an angle of a little more than 90 degrees with the seat plate 14. The position shown in Fig. 4 represents a rest position of the chair 10 in the unloaded state, from which various parts of the chair 10 are movable to other positions, as will be clarified in more detail below. The base 12 includes in a conventional manner four chair legs, of which in Fig. 4, only the right rear chair leg 18 and the right front chair leg 20 can be seen. The chair legs 18, 20 are each connected on one side of the chair 10, ie, on its right and left sides by a substantially horizontal and forward slightly sloping strut 22. The right chair legs 18,20 form together with the right strut 22 thus an arrangement which has substantially the shape of an inverted letter "U".

At the upper rear corner of this arrangement, at which the upper end of the right rear chair leg 18 coincides with the rear end of the right strut 22, a bearing 24 for a horizontal transverse axis 26 is arranged. This transverse axis 26 is directed transversely to the chair 10 and held on the not visible in Fig. 4 left side of the chair in a comparable camp. Around this transverse axis 26, the backrest 16 is pivotable so that its inclination is variable.

From the lower end of the backrest 16, a pair of levers extend, which extend from under the seat plate 14 from behind. These levers form in the present second embodiment of the chair 10, the support member for supporting the seat plate 14. In the side views of Figures 4 to 6, only one lever 28 can be seen, to which reference should be made in the following description. The lever 28 (as well as its counterpart on the opposite side of the chair 10) may for example be fixedly attached to the transverse axis 26, which rotates together with the backrest 16 within the bearings 24. The lever 28 thus follows the pivoting movement of the backrest 16. When the backrest 16 is tilted backwards, the front end of the lever 28 rises and exerts a pressure against the seat plate 14 from below.

The seat plate 14 is divided transversely into substantially two parts, namely a longer front part 30 and a shorter rear part 32. The front part 30 is connected to the rear part 32 by a living hinge 34, whose hinge axis approximately in the Top, that is in the actual seat of the seat plate 14. The two parts 30, 32 of the seat plate 14 are thus flexibly connected to each other, so that the rear part 32 can exert a slight pivoting movement relative to the front part 30. The seat plate 14 is thus deformable in itself. The rear end 36 of the front part 30 of the seat plate 14 is connected at the bottom of the seat plate 14 via a hinge 38 with the end of the lever 28. The hinge axis of this hinge 38 is horizontal and parallel to the rear transverse axis 26. The front end 40 of the front part 30 of the seat plate 14 is connected to the base 12 by a pivot bearing 42, which allows the front part 30 of the seat plate 14 in Up and down direction relative to the base frame 12 is pivotable, so that the rear end of this front part 30 can raise or lower. Specifically, this pivot bearing 42 includes a pivot axis 44 which rests with play in the forward and backward direction in a bearing sleeve 46 which is formed integrally on the underside of the front end 40 of the front part 30 of the seat plate 14. This game allows in addition to the pivotability of the front part 30 of the seat plate 14 in the upward and downward direction so a slight displacement of the front part 30 in the forward and backward direction.

The pivot axis 44 is horizontal in the transverse direction of the chair, so parallel to the rear transverse axis 26, and is held by a pair of center struts 48, which are an integral part of the base 12 and run centrally below the seat plate 14, starting from the rear transverse axis 26 forward. They are located on a not visible in Fig. 4 front cross member 60 (see FIG. 14) of the undercarriage 12, which see between the upper ends of the front chair legs 20, and have in the region of the joint 38 a slight kink, from which, starting from the longer front ends of the center struts 48 and the shorter rear ends are inclined upwards. At their rear ends, the center struts 48 are pivotally connected to the rear transverse axis 26.

The rear part 32 of the seat plate 14 rests with its rear end 50 on the rear transverse axis 26 and is thus supported by this. Overall, the seat plate 14 is thus essentially divided into two parts, namely in the front part 30 and the rear part 32, which are flexibly connected by the film hinge 34 so that they are mutually movable. This inwardly movable seat plate 14 is supported from its underside by the lever 28 which extends solidly from the backrest 16, so that a movement of the backrest 16 on the rear transverse axis 26, the lever 28 and the hinge 38 transmitted to the seat plate 14 becomes. This mechanism will be explained in more detail below.

If the seat plate 14 of the chair 10 is loaded from the unloaded position in FIG. 4 from above, for example by the weight of a person sitting on the chair 10, the seat surface 14 initially yields downward, as shown in FIG. 2 , Here, the rear end 36 of the front part 30 of the seat plate 14 is pivoted about the pivot axis 44 of the pivot bearing 42 down, so that the rear end 36 is lowered and exerts a pressure from above on the end of the lever 28. This is also pressed down. Due to the rigid coupling between the lever 28 and backrest 16, the backrest 16 is pressed forward against the back of the user. Since this applies a back pressure on the backrest 16 when leaning back, depending on the weight of the user and his body position, which can cause a weight shift, a new equilibrium position of the backrest 16 and seat plate 14 a. If the user moves the weight backwards, he presses the backrest 16 backwards, so that the lever 28 exerts a pressure from below against the seat plate 14. As a result, the rear end 36 of the rear part 30 of the seat plate 14 is raised again. Such a raised position beyond the rest position of Fig. 4 addition is shown in Fig. 6. Here, the position of the front portion 30 of the seat panel 14 is further approximated to the horizontal position, while the rear portion 32 of the seat panel 14 drops further downwardly and rearwardly from the axis of the film hinge 34. While the front part 30 and the rear part 32 of the seat plate 14 in the rest position in Fig. 4 are nearly aligned with each other, ie approximately in one plane, the two parts are 30,32 in the extreme positions in Figs. 5 and 6 in different directions against each other kinked. The rear end 50 of the rear part 32 is always in the different positions on the rear transverse axis 26 and is supported by this. Since the rear transverse axis 26 and the front pivot axis 44 of the pivot bearing 42 with respect to the base 12 are stationary and have a fixed distance from each other, the front part 30 of the seat plate 14 with a certain play in the forward and backward direction on the base 12 must be stored to to be able to compensate for the changing distance between the hinge 38 and the pivot axis 44 during the pivoting movement. This clearance is made possible by the fact that the bearing sleeve 46 in the forward and backward direction has a greater width than the diameter of the pivot axis 44, so that the bearing sleeve 46 on the pivot axis 44 is displaceable back and forth. This becomes clear in FIGS. 5 and 6. In Fig. 5, in which the rear end 36 of the front part 30 of the seat plate 14 is lowered, this front part 30 is pulled slightly backwards, so that the pivot axis 44 abuts against a front wall of the bearing sleeve 46. The reverse case occurs in Fig. 6, in which the front part 30 of the seat plate 14 during the upward movement of its rear end 36 is pushed slightly forward, so that the pivot axis 44 approaches a rear wall of the bearing sleeve 46.

The coupling of the movement of the individual parts together again becomes particularly clear in the detail views in FIGS. 7, 8 and 9, in which FIG. 7 again represents the rest position of the chair 10 according to FIG. 4, while FIGS Positions from Figs. 5 and 6 correspond.

To return the lever 28 and the seat plate 14 from a deflected position, as shown in Figs. 5 and 6, in the rest position of Fig. 4, the chair 10 includes a return member 52 within the pivot bearing 42 with two springs 54,56, the in the bearing sleeve 46 between the sleeve wall 58 and the pivot axis 44 hedge lying opposite, as shown schematically in Fig. 10. Through the two springs 54,56, which are arranged opposite to the pivot axis 44, the pivot axis 44 is pressed into the rest position shown in Fig. 10. While the front part 30 of the seat plate 14 performs the pivotal movement shown in Figs. 4 to 6 and 7 to 9, this part 30 is simultaneously displaced back and forth with respect to the pivot axis 44. For example, the pivot axis 44 is displaced in the loaded position of the chair 10 in Fig. 5 forward within the pivot bearing 42, or the bearing sleeve 46 is shifted relative to the fixedly positioned pivot axis 44 to the rear, so that the spring 56 in Fig. 10 compressed becomes. If the chair 10 is relieved from the position in Fig. 5, the spring 56 pushes the front side of the sleeve wall 58 of the bearing sleeve 46 forward, so that the pivot axis 44 in this respect is moved backwards and again the rest position shown in FIG 4 or Fig. 7 is taken.

Conversely, in the position shown in FIG. 9 or FIG. 12, the bearing sleeve 46 is displaced forward with respect to the pivot axis 44 so that the opposing spring 54 is compressed and upon release, presses the bearing sleeve 56 back into the rest position with respect to the pivot axis 44.

The positions from FIGS. 5 and 6 or 8 and 9 thus represent maximum feed positions and retraction positions of the pivot axis 44 with respect to the bearing sleeve 46, between which the position according to FIGS. 4, 7 and 10 represents an intermediate position.

The present embodiment of the chair 10 allows stacking of a plurality of identical chairs 10 on each other, as shown in Fig. 13. This is possible due to the very simple mechanism of the chair 10, by which the base 12 can be easily constructed. It is also possible to provide on the horizontal lateral struts 22 connecting means for the respective connection of a chair 10 with a left or right adjacent chair 10. Such stacking is also possible with the chair 100 of the first embodiment. 14 and 15 it can be seen how the pair of center struts 48 extending between the rear transverse axis 26 and the front pivot axis 44 extends between the levers 28 on the left and right sides of the chair 10. Each of the two levers 28 is assigned a joint 38 for connection to the front part 30 of the seat plate 14.

The mechanism described above with the inventive features of the seat plate 14 and the backrest 16 and their coupling means can be made relatively inexpensive and thus suitable for use in chairs that are commonly used in large quantities, for example, for seating event space.

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Claims

A chair (10, 100) comprising a seat panel (14, 104), a base (12, 102) supporting the seat panel (14), and a seat back (16, 106), characterized in that - the backrest (14) 16, 106) about a transverse to the chair (10, 100) directed rear transverse axis (26, 120) pivotally mounted on the base frame (12, 102), and that the seat plate (14, 104) is at least partially deformable and by at least one rigid support member (28, 122) extending from the lower end of the backrest (16, 106) towards the seat panel (14, 104) and being rigidly connected, so supported or reinforced with the backrest (16, 106), in that, in the case of a pivoting movement of the backrest (16, 106), a region of the seat plate (14, 104) located in front of the end of the support part (28, 122) is raised or lowered depending on the pivoting direction.

2. Chair according to claim 1, characterized in that the support part (122) a rear portion of the seat plate (104) is reinforced or integrally formed therewith.

3. Chair according to claim 1 or 2, characterized in that in each case a support member (122) reinforces one of the two rear corner regions of the seat plate (104), and that a lying between these two corner regions central rear region of the seat plate (104) of the corner regions is separated by slots extending in the seat back (106) into the seat panel (104).

4. Chair according to one of the claims 1 to 3, characterized in that the front end of the seat plate (104) is firmly connected to the underframe (102).

5. Chair according to one of the claims 1 to 3, characterized in that the front end of the seat plate (104) rests freely on the front end of the underframe (102).

6. Chair according to one of the preceding claims, characterized in that the seat plate (104) is elastically deformable.

7. Chair according to claim 1, characterized in that the supporting part is designed as a lever (28) which extends from behind under the seat plate (14) and via a joint (38) whose axis of articulation parallel to the rear transverse axis of the backrest (28). 16) is connected to the seat plate (14).

8. Chair according to claim 7, characterized in that a front part (30) of the seat plate (14) extending from the joint (38) to the front, with the base (12) by a front of the joint (38) arranged Swivel bearing (42) is connected, by which the front part (30) of the seat plate (14) is pivotally mounted on the underframe in the upward and downward direction.

9. Chair according to claim 7 or 8, characterized by a rear part member (52) for returning the lever (28) and the seat plate (14) from a deflected position hung in a rest position.

10. Chair according to one of claims 8 or 9, characterized in that the pivot bearing (42) comprises a fixed to the base frame (12) arranged pivot axis (44), which rests with play in a bearing sleeve (46), the firm the bottom of the front end of the front part (30) of the seat plate (14) is mounted or formed with this, so that the bearing sleeve (46) on the pivot axis (44) is displaceable forward and backward.

11. Chair according to claim 10, characterized in that the rear part member (52) comprises springs (54,56), in the bearing sleeve (46) between the sleeve wall and the pivot axis (44) opposite hedge and these in the unloaded state in a rest position hold, which represents an intermediate position between in a maximum feed position and a maximum retreat position within the bearing sleeve (46).

12. Chair according to one of the preceding claims, characterized in that a rear part (32) of the seat plate (14) is hinged to a front part (30) thereof by a film hinge (34).

13. Chair according to one of the preceding claims, characterized in that the chair (10, 100) on an identical chair (10, 100) is stackable.