WO1992007490A1

WO1992007490A1 - Chair

Info

Publication number: WO1992007490A1
Application number: PCT/EP1991/001601
Authority: WO
Inventors: Martin Stoll
Original assignee: Martin Stoll Gmbh
Priority date: 1990-10-25
Filing date: 1991-08-23
Publication date: 1992-05-14
Also published as: EP0554260A1; JPH06501399A; DE4033907C1

Abstract

The invention concerns a chair with a rigid seat carrier (2), and with a back (6) mounted so that it can pivot on a substantially horizontal support arm (5) fitted underneath the seat on a bearing about which it can rotate. A spring (13) is fitted which acts to keep the chair back in the upright position, the return force exerted by the spring increasing progressively as the seat back moves further out of position. The invention achieves this by virtue of the fact that an articulated lever (8) with one arm (10) attached to the chair seat and the other (9) attached to the chair-back support arm is mounted, to be able to rotate, at a point remote from the point of bearing of the chair-back support arm onto the chair seat. The spring acts on the articulated lever at a point remote from the points of articulation of the articulated-lever arms to the chair seat and seat-back support arm and in a direction which counters the extension of the articulated lever.

Description

DESCRIPTION

CHAIR

The invention relates to a chair with a rigid seat support, a seat back arranged thereon via a support arm arranged below the seat support, rotatably mounted thereon and essentially horizontally extending support arm, and having a seat back which moves the seat back into the upright position Feather.

Such a chair construction is known for example from the Swiss patent 524 982.

With such a structure, the back of a chair is cushioned and is resiliently pushed backwards by the user when leaning back. The user's center of gravity moves to the rear so that the backrest is subjected to a higher pressing force. In conventional chairs, this is not taken into account sufficiently, so that the backrest seems to be easier to swivel back the further the user leans back. It is an object of the invention to design a chair of the generic type in such a way that this easier pivoting of the backrest is counteracted as the pivoting back increases.

This object is achieved according to the invention in a chair of the type described at the outset in that a toggle lever with one arm on the seat support and the other arm on the support arm is rotatably articulated at a distance from the bearing point of the support arm on the seat support and in that on the toggle lever in Distance to the articulation points on the seat support and on the support arm, the spring engages in a direction that counteracts the extension of the toggle lever.

In this construction, when the backrest is raised, the support arm is very close to the seat support, so the toggle lever arranged between the two is folded up. When the seat back is pivoted backwards, the support arm is pivoted downward relative to the seat support, that is to say it moves away from it, the toggle lever being moved into the extended position. Due to the fact that a spring engages the toggle lever, which tries to move it into the folded position, the seat back is moved into the upright position. The restoring force increases with the inclination of the seat back, since the force of the spring on the toggle lever counteracts the stretching of the toggle lever, which increases with increasing extension of the toggle lever. The spring acts essentially transversely to the longitudinal direction of the extended toggle lever, it is particularly advantageous if the spring engages the joint of the toggle lever. In a preferred embodiment, the spring can be fixed with its other end to the bearing point of the seat support.

In a modified embodiment, it is also possible that the spring is rotatably mounted with its other end on the support arm. This bearing point can be arranged both in front of and behind the articulation point of the toggle lever, it is only essential that the spring acts essentially transversely to the longitudinal direction of the extended toggle lever and applies a force counteracting the extension of the toggle lever.

In a preferred embodiment, the spring is a gas pressure spring.

The following description of a preferred embodiment of the invention serves in connection with the

Drawing of the detailed explanation. Show it:

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Figure 1: a chair with the seat back in the erected position;

Figure 2: the chair of Figure 1 with the seat back in the pivoted back position;

Figure 3: a view similar to Figure 1 with a

Articulation of the compression spring at the rear end of the backrest support arm.

The chair shown in the drawing comprises a column 1 leading to a foot (not shown), which at its upper end has a horizontal column rigidly connected to the column 1. bound seat support 2 carries. In the illustrated embodiment, the seat support 2 is designed as a seat plate on which a seat cushion 3 is placed, but the seat support could also be designed as a separate part in the form of an arm or the like, which carries a seat plate which is movably mounted on it. In the exemplary embodiment, the simplest design is chosen, since the design of the seat surface is not important for the present invention.

The support arm 5 of a backrest 6 is mounted below the seat support 2 in the area of the column 1 on a bearing block 4 projecting downward from the seat support 2. This backrest 6 has at its lower end the support arm 5 which is initially bent approximately at right angles and which extends essentially parallel to the seat support, that is to say essentially horizontally, below the seat support 2 and finally with one upward at right angles protruding end piece 7 is rotatably mounted on the bearing block 4.

On the horizontally extending part of the support arm 5, a two-armed toggle lever 8 rotatably engages, which is rotatably mounted on the support arm 5 with its lower arm 9. The upper arm 10 is also rotatably mounted on the seat support 2, which carries a special bearing 11 for this purpose. When the backrest is raised, the support arm 5 runs parallel to the seat support 2, the toggle lever 8 is then folded (FIG. 1 ). If the backrest is pivoted backwards, the support arm 5 tilts downward, the toggle lever 8 is thereby stretched (FIG. 2).

At the articulation point 12 of the toggle lever 8 one end of a gas pressure spring 13 engages, the other end of which is articulated on the bearing block 4, in the present embodiment play concentrically with the articulation point of the support arm 5. The gas pressure spring can be pushed together by applying a substantially constant force, without external force being applied, the two parts of the gas pressure spring shift into an extended position.

The articulation point of the support arm 5 and the gas pressure spring 13 on the bearing block 4 is arranged approximately at the same height as the articulation point 12 when the backrest is upright (FIG. 1), the articulation points of the toggle lever 8 on the seat support 2 and on the support arm 5 lie one above the other, but not unrelated things exactly vertically one above the other, they can also be slightly offset to one side. As a result, the gas pressure spring 13 essentially extends horizontally, while the toggle lever 8 extends essentially vertically, ie the line of action of the gas pressure spring extends approximately perpendicular to the direction of extension of the toggle lever.

Without load, the gas pressure spring 13 moves the articulation point 12 to the rear, that is to say away from the bearing block 4, so that the toggle lever 8 thus comes into the folded position in which the support arm 5 is raised, the backrest is thus erected (FIG 1).

When the backrest is loaded, the support arm 5 is pivoted downward, the toggle lever 8 being stretched. This extension leads to the gas pressure spring 13 being pushed together, that is to say this extension of the toggle lever is counteracted by a restoring force by the gas pressure spring. This restoring force is greater the more the knee lever is stretched, ie the restoring force increases with the pivoting angle of the backrest. For the user, this means that the backrest does not "sag" in an uncontrolled manner with a greater inclination, that the leaning movement of the user is always opposed by a force which is perceived as being approximately constant.

In the embodiment shown in FIG. 3, which is constructed very similarly to that of FIGS. 1 and 2 and in which corresponding parts therefore have the same reference symbols, in contrast to the embodiment of FIGS. 1 and 2, the gas pressure spring 13 is not attached to the supported by the bearing block 4, but supported on its own bearing block 14, which is located in the vicinity of the vertical bend of the support arm 5. In this case, the toggle lever is pivoted forward in the pivoted-in state, but in the same way as in the embodiment of FIG. 1, the gas pressure spring 13 counteracts the extension of the toggle lever 8.

Claims

P A T E N T A N S P R Ü C H E

Chair with a rigid seat support, thereon a support which is pivotally mounted on a support arm arranged below the seat support, rotatably mounted on the support arm and running essentially horizontally, and with a spring which moves the seat back into the upright position, characterized in that rotate a toggle lever (8) with one arm (10) on the seat support (2) and with the other arm (9) on the support arm (5) at a distance from the bearing point (4) of the support arm (5) on the seat support (2) ¬ is articulated bar and that on the knee lever (8) at a distance from the articulation points on the seat support (2) and on the support arm (5) the spring (13) engages in a direction which counteracts the extension of the knee lever (8) ¬ counteracted.

Chair according to claim 1, characterized in that the spring (13) engages the joint (12) of the toggle lever (8). Chair according to claim 1 or 2, characterized gekennzeich¬ net that the spring (13) is fixed at its other end to a bearing block (14) on the support arm (5).

4. Chair according to claim 1 or 2, characterized gekennzeich¬ net that the spring (13) with its other end at the bearing point (4) of the support arm (5) is fixed.

Chair according to one of the preceding claims, characterized in that the spring (13) is a gas pressure spring.