WO1993019644A1

WO1993019644A1 - Chair

Info

Publication number: WO1993019644A1
Application number: PCT/EP1993/000638
Authority: WO
Inventors: Michael Lammel
Original assignee: Martin Stoll Gmbh
Priority date: 1992-03-28
Filing date: 1993-03-18
Publication date: 1993-10-14
Also published as: JP2783913B2; EP0632701A1; EP0634901A1; JPH07505545A; WO1993019649A1; DE4210283C1; DE4210282C1; JPH07505546A

Abstract

A chair has a seat support (1), a seating plate (9) held so as to swivel thereon, a spring (4) secured to the seat support which resiliently positions a back (18) substantially in a perpendicular direction to the seating plate (9) and upon which the seating plate (9) is supported by its free end. In order to achieve a simplified design on the one hand and to increase the individual adaptability of the leaning forces, the spring (4) is a flat spring made of a fiber-reinforced composite material and extends from its fixing point (3) on the seat support below the seating plate (9) essentially in the horizontal direction and at the rear end of the seating plate substantially vertically upwards, and the stiffness of the spring (4) differs from section to section along its length.

Description

S U H

The invention relates to a chair with a seat support, a seat plate held pivotably thereon, a spring fixed to the seat support, which resiliently positions a seat back essentially perpendicular to the seat plate and on which the seat plate is supported with its free end.

Chairs of this type enable a user to experience support in the upright position by means of a seat plate which is pivoted upwards and a backrest which is pivoted forward, while when leaning back, he can support himself against the resilient seat plate and the resilient backrest, which are theirs Change the incline when leaning back.

Usually springs are used to support seat plates and backrests, which do not allow a fine adjustment of the forces required for the backrest inclination and for the seat plate inclination, either because gas pressure springs are used which only allow a linear increase in the spring force and at a certain point of the Attack mechanics, or because metallic belt springs are used, the spring characteristics of which are the same over the entire length. If different spring characteristics are desired when the chair is tilted, complicated mechanisms, for example toggle levers, must be used.

It is an object of the invention to improve a generic chair in such a way that on the one hand it enables an individually coordinated spring behavior and on the other hand that it is as simple as possible in its construction.

This object is achieved according to the invention in a chair of the type described in the introduction in that the spring is designed as a band spring made of a fiber-reinforced composite material, which extends from its clamping point on the seat support below the seat plate essentially horizontally and at the rear end of the seat plate essentially vertically upwards leading extends, and that the stiffness of the spring varies in regions over its length.

The use of a fiber-reinforced composite spring has the advantage that it is a simple and very light component that can exert very large holding forces in a small volume. In particular, it is advantageous that the rigidity of the spring, and thus the flexural rigidity, can be set differently in some areas, so that, for example, other forces in the support area of the seat plate lead to the same deformation as in the area of the seat back . This enables the required spring forces for the individual parts of the chair to be individually matched when only a single spring is used. In a preferred embodiment it can be provided that the spring is of different widths over its length and thus has areas of different stiffness, since wider areas have a greater stiffness.

In another embodiment, the spring can have a different thickness over its length and thus have regions of different rigidity.

It is also possible to create areas of different stiffness in that the springs have a different fiber content over their length or that fibers of different orientations are embedded in the spring over their length.

The measures mentioned to achieve a stiffness that varies over the length in some areas can be used individually, but also in any combination with one another.

It is particularly advantageous if the spring has a multi-layer design, on the one hand this allows different stiffnesses to be achieved in different layers, on the other hand it prevents the spring from giving in suddenly in the event of an overload, which could lead to breakage.

In the preferred embodiment, it is provided that the spring runs essentially rectilinearly at the clamping point, then essentially in one arcuate part that extends over more than 90 ", and that this is followed by a slightly counter-curved area, which in turn merges into a straight area, on which the seat back is held. It has been shown that such a shape The spring on the one hand has only a small space requirement, but on the other hand shows the desired deformation and movement characteristics, so that both the seat plate movement and the backrest movement can be coordinated in the desired manner.

It can be provided that the strength values of the spring are selected so that the direction of the free end in the unloaded and in the maximum loaded state differs by approximately 15 to 19 ", preferably by 18 °.

It is particularly advantageous if the spring consists of glass fiber reinforced plastic, but in principle it would also be possible, for example, to use a multi-layer wooden spring, the layers of which at least in regions consist of different types of wood.

It is particularly favorable if the seat plate is divided into two and the front part is pivotally articulated on the seat support, if both seat plate parts are pivotably connected to one another and if the front and rear seat plate parts are each supported by a support on the spring, preferably the support of the front seat panel part is arranged on the rear edge. On the one hand, this results in an inevitable change in the inclination of the front seat part when the user leans back and at the same time there is a greater inclination of the rear seat part which forms a support wedge as long as the user leans forward and which is pivoted into the plane of the front seat part when the user leans back.

In another embodiment it is provided that the seat plate is divided into two and the front part is rigidly connected to the seat support, that the rear seat plate part is pivotally connected to the front seat plate part and is supported on the spring via a support. In such an embodiment, only the rear seat plate part is pivotably arranged and is moved by the spring, while the front seat plate part remains unchanged. This is a simplified design with less design effort.

In a further embodiment it can be provided that the seat plate is formed in one piece and is supported on the spring via a support. In this case, the entire seat plate is pivotable and tilts in accordance with the leaning back of the user.

It is favorable if the spring rests in its uppermost position on an abutment surface of the seat carrier. This makes it possible to install the spring under an upward bias so that the user already works against a certain restoring force at the beginning of the leaning back, which ensures that he feels adequately supported.

The following description of preferred embodiments of the invention serves in conjunction with the drawing for a more detailed explanation. It shows: Fig. 1 is a longitudinal sectional view of the constructive

Parts of a chair according to a first preferred embodiment in an inclined position;

Figure 2 is a view of the chair of Figure 1 in the reclined position;

3 shows a schematic side view of the chair of FIG. 1 with different spring positions and with representations of the cross section of the spring at different positions in the spring length;

4 shows a view similar to FIG. 1 in a further preferred exemplary embodiment of a chair with a front, non-pivotable seat plate part and a rear, pivotable seat plate part and

Fig. 5 is a view similar to Fig. 1 in a further preferred embodiment with a one-piece seat plate.

The chair shown in the drawing has a seat support 1 which is rotatably held on a foot (not shown) and which ends at its upper end in an arm 2 which runs essentially horizontally. On the front part of the arm 2, one end of a band spring 4 is rigidly clamped in a horizontal holder 3 and is held immovably in the holder 3 relative to the seat support 1 over a certain length.

The band spring 4 extends in the area of the seat support 1 parallel to its upper side and, in the undeformed state, rests against an upper, horizontal stop surface 5 at the rear end of the seat support 1.

After leaving the seat support 1, the band spring 4 is bent upward in a substantially circular arc, the bending angle slightly exceeding 90 °, for example by 10 °. This circular arc region 6 is adjoined by a region 7 which extends essentially vertically upward and is slightly curved in the opposite direction, on which a backrest 18 which is only shown in dash-dotted lines in FIG. 3 is held.

The band spring 4 consists of a fiber composite material, for example of glass fiber reinforced plastic or of wood. The ribbon spring is preferably constructed in several layers, the different layers in particular having different fiber contents. When wood is used as a building material, the band spring can be a laminate of thin layers of different types of wood, the wood types of the individual layers also being able to change over the length of the band spring. The stiffness of the band spring is designed differently in the longitudinal direction. For this purpose, the width of the band spring can be different, as is clear from the illustration in FIG. 3, at the same time or alternatively the thickness of the band spring can be selected differently (FIG. 3). In both cases, this results in a different cross section of the band spring in different areas along the band spring.

As an alternative or in addition, the fiber content in the longitudinal direction can be different, and different fiber orientations can also be used. Both effects also lead to different stiffnesses along the band spring.

In the embodiment of FIGS. 1 and 2, the front part 8 of a two-part seat plate 9 is pivotally mounted on the seat support 1 in the area of the holder 3, which is supported on the band spring 4 by a support 10 on its rear edge. For this purpose, the support 10 projects through a recess 11 in the stop surface 5.

At the rear edge of the front part 8 of the seat plate 9, the rear part 12 of the seat plate 9 is pivotally articulated, which is also supported on the band spring 4 via a further support 13.

The dimensions are chosen so that when the chair is not under load, the front part 8 of the seat plate 9 is pivoted a little upwards relative to the upper edge of the seat support 1, while the rear part 12 with the front part 8 makes an angle of the order of between 12 and 16 ° occupies, for example 14 °. When the band spring is completely bent backwards, on the one hand the rear part 12 is pivoted relative to the front part 8 such that both parts 8 and 12 lie in one plane, while also the rear edge of the front part 8 and thus the front edge of the rear part 12 can be reduced slightly (FIG. 2). Overall, you get a quasi one-piece, flat seat plate, the inclination of which is slightly stronger than the inclination of the front part 8 in the unloaded chair.

At the same time, when the band spring is deformed, the backrest 18 is inclined from an upright position (FIG. 3) into a position pivoted to the rear, which position is not shown in the drawing.

As can be seen from the comparison of FIGS. 1 and 2, it can be seen that the band spring 4 deforms differently in different areas of its length.

Between the bracket 3 and the circular arc region 6, the band spring 4 receives a curvature opposite to the circular arc region 6, so that the lowering of the supports 10 and 13 is very different; the front support 10 is lowered much less than the rear support 13. The strength of the deformation of the band spring in the different areas along the band spring can be adjusted by a suitable choice of materials in the manner indicated, so that chairs with different deformation characteristics can be easily produced, which differ only in the choice of the band spring. It is also easily possible to replace this band spring if a different chair characteristic is required becomes. For example, in chairs for typists, it may be desirable that the recline can only be done against a relatively large resistance, while in the case of conference chairs, etc., recline is possible even with relatively low forces. Nevertheless, the inclination characteristic of the seat plate can be chosen to be the same, for example, if the stiffness properties in the front area of the band spring are the same.

In the embodiment of FIG. 4, in which the same parts have the same reference numerals, the front part 8 of the seat plate 9 is rigidly connected to the seat support 1, and the front support 10 is also missing. In this way, only the rear part 12 of the seat plate is 9 designed pivotable, but the rest of the chair is constructed the same.

In the embodiment of FIG. 5, in which the same parts are again denoted by the same reference numerals, the seat plate 9 is formed in one piece, this one-piece seat plate 9 is supported only on the band spring 4 via a support 10, one is therefore missing second support 13. In this chair, the entire seat plate is pivoted with the deformation of the band spring, there is no different pivoting in the front and in the rear part of the seat plate. Otherwise, the chair is constructed in the same way as in the embodiment of FIGS. 1 and 2.

Claims

P A T E N T A N S P R Ü C H E

Chair with a seat support, a seat plate held pivotably thereon, a spring fixed to the seat support, which resiliently positions a seat back substantially perpendicular to the seat plate and on which the seat plate is supported with its free end, characterized in that the spring (4) is made as a band spring a fiber-reinforced composite material is formed which extends from its clamping point (holder 3) on the seat support (1) below the seat plate (9) essentially horizontally and at the rear end of the seat plate (9) essentially vertically upwards, and that the stiffness of the spring (4) varies in some areas over its length.

2. Chair according to claim 1, characterized in that the spring (4) is of different widths over its length and thereby has areas of different stiffness.

3. Chair according to claim 1 or 2, characterized in that the spring (4) is of different thickness over its length and thereby has areas of different stiffness.

Chair according to one of the preceding claims, characterized in that the spring (4) has a different fiber content over its length and thus has areas of different stiffness.

5. Chair according to one of the preceding claims, characterized in that the spring (4) has fibers of different orientation over its length and thereby has areas of different stiffness.

6. Chair according to one of the preceding claims, characterized in that the spring (4) is formed multilayer aus¬.

7. Chair according to one of the preceding claims, characterized in that the spring (4) subsequent to the clamping point (3) is substantially rectilinear, then in a substantially circular part (6) merges, which extends over more than 90 °, and that this is followed by a slightly oppositely curved region (7) on which the seat back (18) is held.

8. Chair according to one of the preceding claims, characterized in that the strength values of the spring (4) are chosen so that the direction of the free end in the unloaded and in the maximum loaded state differs by about 15 to 19 °.

Chair according to one of the preceding claims, characterized in that the spring (4) consists of glass fiber reinforced plastic.

10. Chair according to one of the preceding claims, characterized in that the seat plate (9) is divided into two and the front part (8) on the seat support (1) is pivotally articulated, that both seat plate parts (8, 12) are pivotally connected to each other and that the front and rear seat plate parts (8 or 12) are each supported by a support (10, 13) on the spring (4).

11. Chair according to claim 10, characterized in that the support (10) of the front seat plate part (8) is arranged on des¬ sen rear edge.

12. Chair according to one of claims 1 to 9, characterized gekenn¬ characterized in that the seat plate (9) is divided into two and the front part (8) is rigidly connected to the seat support (1) that the rear seat plate part (12 ) is pivotally connected to the front seat plate part (8) and is supported on the spring (4) via a support (13).

13. Chair according to one of claims 1 to 9, characterized gekenn¬ characterized in that the seat plate (9) is integrally formed and is supported by a support (13) on the spring (4).

14. Chair according to one of the preceding claims, characterized in that the spring (4) abuts in its uppermost position on a stop surface (5) of the seat support (1).