EP0300957B1 - Office chair - Google Patents

Abstract

The chair has a seat (11) with a cover (47) and cushion (49) which also extend to the reverse side of the backrest (13). The reverse side of the backrest (13) is provided with a covering (51) which has a round shell (54) with an extension towards the bottom and only partially covers the backrest (13) such that the cover (47) can also be seen at the back of the backrest. The backrest (13) can have any desired shape. Thus the designer has virtually unlimited possibilities. It is also not significant whether or not an adjustment mechanism (15) is used. If an adjustment mechanism (15) is used it can be of the same design for all chairs. <IMAGE>

Description

The present invention relates to a chair, in particular an office or work chair, with a seat and a backrest provided with a cover made of textile, leather or the like.

In recent years, fashion currents have covered more and more areas that were previously practically free of such currents. Furthermore, these currents are changing more frequently and more rapidly. The area of chairs has also not been spared and is posing considerable problems for chair manufacturers. On the one hand, the chair manufacturers are forced to adapt to fashion trends and manufacture products that are required by the market, but on the other hand they also have to try to keep the manufacturing costs under control in order not to be forced out of the market. These requirements contradict each other. In order to keep the manufacturing costs as low as possible, large series are required which enable the use of injection molds. Injection molds are very expensive. If a chair model goes out of style faster than expected, the high investments in the manufacture of injection molds will prove to be bad investments. In order to avoid the risk of such bad investments, deep drawing tools are now used instead of injection molds in the manufacture of chairs. Thermoformed tools are cheaper than injection molds, but the parts made with them are much more expensive than parts that are injection molded in large quantities.

Another problem with which chair manufacturers are confronted is the different types of chairs. Today there are chairs with very different levels of comfort. For example, there are chairs in which the seat and backrest are firmly arranged to one another. Then you will find chairs with an adjustable backrest. There are various adjustment mechanisms for this. In the so-called synchronous chairs, an adjustment mechanism is provided which, when the inclination of the backrest changes, also causes a change in the inclination of the seat and the distance of the seat from the backrest. A work chair of this type is described for example in CH-PS 524982. In this work chair, the backrest support extends upwards in the form of a rod and is bent there by 90 ° in order to support the backrest by means of a flange.

A somewhat more modern version of a work chair is shown in CH-PS 659179. There the backrest support consists of an approximately L-shaped bent plastic shell. In the lower part of the plastic shell, the side walls are bent upwards and encompass the rear part of the seat. The upper part of the plastic shell also has curved side walls. These side walls laterally enclose the backrest cushion arranged in the upper part of the plastic shell. The backrest cushion is therefore not visible from behind. The disadvantage here is that a new plastic shell is necessary each time the chair shape is changed. Another disadvantage is that the chair gives a somewhat cold impression due to the large plastic surface on the back. So the chair is neither easy to change nor adaptable.

Another problem of chair manufacturers must be pointed out. Because of the large number of chair models required by fashion and comfort requirements and often only short-lived, there are considerable storage and spare parts problems. It is expected that the chair manufacturer will keep spare parts for repairs in stock for chairs that are no longer manufactured. The camps are therefore increasing rapidly. Now, however, large warehouses with many sub-positions make rational warehouse management difficult and also block a lot of space and capital that could be used for other purposes.

As previously described with reference to CH-PS 659179, it has become common, particularly in the so-called synchronous chairs, that the back of the backrest is formed by a plastic shell. This gives the chair the "plastic look". In order to avoid this, some chair manufacturers have started to cover the plastic shell of the backrest with textiles. However, this is very expensive and also has the disadvantage that the backrest continues to feel hard.

US-A-4643480 shows a car seat whose backrest has a steel frame. The shape of this steel frame gives the backrest the outer contour. Inside the steel frame, two wires each run at a constant distance from the steel tube over long distances, so that a slot is created between them. The cover pulled around the edge of the backrest is inserted into this slot and fastened inside the steel frame. Furthermore, the slot also serves to hang in a cover made of synthetic leather or textile, which necessarily has a shape that corresponds to the course of the slot.

US-A-4390210 describes a chair according to the preamble of claim 1 with a backrest having a cover in the form of a shell. This outer shell is expressly said to extend over the back of the backrest. It is further noted that the edges of the outer shell and the inner shell are located close to each other, with the drawn portion of the padding and seat cover being sandwiched between edge portions of the two shells. The fasteners The shell is served by a connector located away from the edge of the shell.

It is an object of the present invention to at least partially avoid the disadvantages mentioned above. A chair construction should be found that is much more change-friendly than previous chair designs. The chair designer should not be limited in his freedom as before by manufacturing constraints. Furthermore, the new chair design should make it possible to largely use the same parts for different chair types and chair families, so that these parts can be efficiently manufactured in large quantities and storage with little space and capital is possible.

This is achieved according to the invention by the features of patent claim 1.

Thanks to the shape of the cover, a variety of backrest shapes are possible without having to change the cover. The different backrest shapes can be quickly combined with a variety of different chair frames and different seat shapes according to the fashion trends and / or the comfort and other needs. A synchronous adjustment mechanism can also be used if this is desired. The new chair construction therefore has a high degree of flexibility to adapt to the changing needs of the market. The designer has great freedom in the design of the backrest and in combination with different chair frames. Since the backrest support can remain the same for all synchronous chairs, the same synchronous adjustment mechanism can always be used. The great freedom of the designer has the advantage that even design requests from different customers can be taken into account to a certain extent "à la carte". This is also the case if only small series are ordered. Later deliveries can also be made in small series, if necessary. It is therefore no longer necessary for the economically thinking buyer to buy off-the-shelf chairs. Rather, the customer has it in his hand to procure chairs that carry his individual signature, so to speak, and reflect the image of the company in which they are used.

Despite the large possible variety of shapes, many identical parts can be used in all chairs, which enables rational and cheap production and storage.

The cover can advantageously have a round, oval or polygonal shell. This enables the cover to be used with a variety of backrest shapes. Purpose, moderately, an extension extends downward from the shell. This extension can partially surround the backrest support so that it is shielded from view. Its appearance is therefore irrelevant, which allows particularly cheap production. The chrome plating and polishing that are customary in known backrest supports can therefore be dispensed with.

The invention also relates to a building system for the manufacture of chairs, which is characterized by a large number of different chair frames and seats with different shapes and colors and backrests with different shapes and colors and a cover of basically uniform shape but different possible colors.

This construction system enables a large number of chairs to be assembled quickly by combining the various components.

• Fig. 1 einen Schnitt durch einen Arbeitsstuhl gemäss einem Ausführungsbeispiel der Erfindung,
• Fig. 2 eine Vorderansicht eines Arbeitsstuhls gemäss einem Ausführungsbeispiel der Erfindung,
• Fig. 3 eine Ansicht von hinten eines Arbeitsstuhls gemäss Figur 2,
• Figuren 4 und 5 einen Arbeitsstuhl wie in Figuren 2 und 3, jedoch mit anderen Sitz- und Rückenlehnenformen,
• Fig. 6 ein Ausführungsbeispiel eines Arbeitsstuhls mit einem anderen Sitzgestell und einer weiteren Ausgestaltung der Sitz- und Rückenlehnenform.

Embodiments of the invention will now be described with reference to the drawing. It shows :

• 1 shows a section through a work chair according to an embodiment of the invention,
• 2 is a front view of a work chair according to an embodiment of the invention,
• 3 is a rear view of a work chair according to FIG. 2,
• FIGS. 4 and 5 a work chair as in FIGS. 2 and 3, but with different seat and backrest shapes,
• Fig. 6 shows an embodiment of a work chair with a different seat frame and a further embodiment of the seat and backrest shape.

Figures 1 to 3 show a work chair with seat 11, backrest 13 and adjustment mechanism 15. In this chair, the support 17 is usually carried by a base 19 with stand tube 21 and height lift 23 (Figures 2 and 3). As FIG. 1 shows, the seat 11 is pivotally mounted about an axis 25 in the region of the front end. The backrest support 27 is L-shaped and is connected in an articulated manner to the part 29, which projects under the seat 11, with an axis 31 with the seat support 33 and with an axis 35 with a lever 37. The lever 37 is in turn articulated with the axis 39 on the support 17. A lockable spring assembly 41, for example a gas spring, is connected at one end to the front end of the support 17 via a joint 43 connected. At its other end, the spring assembly 41 is articulated to the axle 35.

. The adjustment mechanism 15 functions in such a way that when the user of the chair causes the backrest 13 to move backwards from the position shown, a corresponding movement of the seat 11 takes place. The change in the angle of inclination of the seat 11 taking place is approximately half the size of that of the backrest 13.

It is now important to note that the upright part 30 of the L-shaped backrest support 27 does not have the shape of a shell, such as in CH-PS 659179, but is approximately rod-shaped, as is known for example from CH-PS 524982. On the part 30 of the backrest support 27, the backrest 13 is fastened, for example, with screws 44. The backrest 13 consists, for example, of a core 45 made of plywood with a covering 47 made of textile material, leather or the like. Under the cover 47 there is advantageously an upholstery 49. The cover 47 and advantageously also the upholstery 49, which expediently consists of foam plastic, also extend to the back of the backrest 13, from above and from the side to near the upright part 30 of the backrest support 27.

The cover 51, which e.g. is releasably attached to the backrest support 27 with a plug connection 53. The cover 51 is advantageously made of plastic. As FIG. 3 shows, the cover 51 does not completely cover the backrest 13, but only partially, so that the cover 47 of the backrest 13 is also visible and tangible at the rear. The chair therefore also has a pleasant, warm appearance from behind and also feels correspondingly pleasant when it is grasped at the backrest 13. As FIGS. 3 to 6 show, the cover 51 has a round shell 54 with an extension 55 which extends downwards and which partially surrounds the backrest support 27. This is therefore not visible in Figures 2 to 6. The chairs according to these figures can have an adjustment mechanism 15, but need not. The cover 51 can therefore also be used in chairs without an adjustment mechanism 15.

The shape of the shell 54 can also be oval or polygonal instead of round. It is particularly advantageous that the same cover 51 can be used for a wide variety of chair types and chair shapes. For example, FIG. 3 shows the use of the cover with a round backrest 13, FIG. 4 with a square backrest 13, FIG. 5 with a backrest 13 having a headrest 17 and FIG. 6 with a backrest 13 having ears 16.

It follows from the preceding examples according to FIGS. 2 to 6 that the shape of the backrest 13 can be easily adapted to the prevailing fashion trends. It is also possible to take customer requests into account and to rationally manufacture chairs with a special backrest shape, even in small quantities. It is also possible to retrofit a chair with another backrest with little effort. It is not necessary for a synchronous chair to also change the backrest support 27 (FIG. 2). As an example, it can be mentioned that the backrest of the chair of FIG. 3 could easily be interchanged with that of the chair of FIG.

In summary, it can be said that it is possible to assemble different shapes and colors of chairs of different types with a simple kit of elements. With synchronous chairs, it is important that the backrest support 27 and thus also the adjustment mechanism 15, of which the backrest support 27 is a part, can always be the same. In principle, a uniform cover 51 can also be used for all chairs. However, if a different color is desired for the cover 51, such covers 51 can be produced with the same shape. This allows large quantities, which in turn has the advantage that the investments are worthwhile for an injection mold that allows rational production at a low unit price. The chair design described allows a quick adjustment to fashion trends and customer requirements with minimal effort. Storage is also considerably simplified. The chairs create a homely atmosphere because the colors of the textile or leather upholstery cover also come into play on the back of the backrest and the chairs feel warm and comfortable even when you touch the backrest.

Claims (7)

1. Chair, in particular office or work chair, comprising a seat (11) and a back rest (13, which is provided with a cover (47) of textile material, leather or the like extending around the edge of the back rest (13) to cover it, and a cover element (51) located at the back of the back rest and having a shell (54) and at least one plug connector (53) for securing the shell, characterised in that the cover (47) extends from the edge further over the back of the back rest (13) and in that the shell only partly covers the back rest so that the same shell can be used for different back rest forms.

2. Chair according to claim 1, characterised in that the cover (47) extends on the back of the seat back (13) from the top and from the sides near to the seat back support (27).

3. Chair according to claim 1 or 2, characterised in that the back of the seat back (13) is also upholstered.

4. Chair according to claim 2 or 3, characterised in that the seat back support (27) is part of an adjusting mechanism (15).

5. Chair according to claims 1 to 4, characterised in that an extension (55) extends downward from the shell (54).

6. Modular system for manufacturing chairs according to one of the claims 1 to 5, characterised by a plurality of different chair frames and seats (11) with different shapes and colours, seat backs (13) with different shapes and colours, and a cover (54) of uniform shape but different possible colours.

7. Modular system for manufacturing function chairs, in particular synchronous chairs, characterised in that an uniform adjusting mechanism is provided for all chairs.

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