WO2002067726A1

WO2002067726A1 - Chair, especially an office chair

Info

Publication number: WO2002067726A1
Application number: PCT/EP2002/002047
Authority: WO
Inventors: Andreas Struppler; Alexander Klingholz
Original assignee: Interstuhl Büromöbel GmbH & Co. KG
Priority date: 2001-02-28
Filing date: 2002-02-26
Publication date: 2002-09-06
Also published as: DE10109624C1; WO2002067726A8; CN1457240A; US20030075961A1; JP2004518507A

Abstract

The invention relates to a chair (1), especially an office chair, comprising a sitting part (15) and a downwards-inclined guiding track (9) for providing the sitting part (15) with a combined downwards and backwards movement or a combined upwards and forwards movement. Said sitting part thus slides along a pre-determined guiding track (9) which is spring-suspended backwards and downwards in many cases. In order to improve the ergonomy of one such chair, a pivoting device having at least one horizontal pivoting axis (13) is provided in order to arrange the sitting part (15) in a pivoting manner. The pivoting device is arranged between the sitting part (15) and the guiding track (9), and is arranged in a moveable manner together with the sitting part (15) along the guiding track (9). A combined movement of the sitting part (15) is thus created, said movement being composed of the co-operation of the pre-determined guiding track (9) and the pivoting movement about the pivoting axis (13) of the pivoting device.

Description

Chair, especially office chair

The present invention relates to a chair, in particular an office chair, with a seat part and a downwardly inclined guideway for providing a combined downward and backward movement or a combined upward and forward movement for the seat part.

Such a chair is e.g. known from DE 199 00 454 A1. There, the seat element, which is designed as a rigid seat shell, is arranged at its front end of the seat surface on a seat support which is guided in a guide element at the upper end region of the foot part. The seat carrier accordingly moves along a guide path in the guide element. Starting from a chair user, the rigid seat shell is moved in a combined movement both downwards and backwards when sitting on the chair. This movement takes place against the spring action of a specially designed spring device. In this publication, a spring device is described, the increase in spring force of which decreases from a certain deflection. The guide element is arranged inclined downwards and is designed to be convexly curved in the direction of the seat surface. The shift is therefore essentially along a circular path. This not only moves the seat down and back, but also the backrest follows this sequence of movements. By using an elastic seat shell, an additional inclination of the backrest can be brought about due to the greater leverage acting there.

Another generic chair is also known from DE 4331987 A1. Its seat element can be pivoted in a circular arc back and down about a pivot axis lying approximately in the ankle of a person sitting on it. For this purpose, an arcuate guide element is used, which is attached to a base. The seat support is slidably guided therein so that it can dip into the guide element in accordance with the pivoting movement of the seat element against the force of a compression spring. However, chair designs are also known in the prior art in which, in addition to a pivoting or tilting movement of the seat surface, there is also a force-coupled, translated tilting movement of the backrest. From EP 0645976 B1, for example, a four-bar linkage gearbox for generating such a movement is known. However, this chair design does not use a downward sloping guideway, which provides better options for a stable design.

A disadvantage of the generic chairs is that e.g. builds the guide system of DE 4331987 A1 relatively high and a relatively large downward movement takes place with small backward movements. A flatter design variant is already known from DE 199 00 454 A1. However, there is a need to improve the ergonomics of the chair.

It is therefore the object of the present invention to provide a chair of the type mentioned at the outset, which allows an ergonomic and structurally simple design.

This object is achieved according to the invention in that a swivel device with at least a horizontal swivel axis is provided for pivotably arranging the seat part and the swivel device is arranged movably together with the seat part along the guideway. In addition to moving along the guideway, it is therefore additionally possible for the seat part to be pivoted about the pivot axis of the pivoting device. As a result, an additional movement component can be provided. One example is that the seat part can tilt down much faster than the shape of the guideway alone allows. However, this configuration also opens up other movement sequences. Accordingly, the movement of the seat part is not solely dependent on the inclined guideway, but there is also the possibility of pivoting about the pivot axis of the pivoting Facility. For this purpose, the swivel device establishes the connection between the guideway and the seat part.

Moving or moving the swivel device along the guideway is a main movement that the seat part executes and not a compensating movement to avoid stresses and the like. Therefore, the maximum displacement path of the swivel device along the guideway is preferably greater than 30 mm, preferably 60 mm. In a special embodiment, it is between 120 and 130 mm. The combined downward and backward movement should therefore lead to a noticeable movement of the seat part.

Furthermore, it can be provided that the maximum swivel angle about the swivel axis of the swivel device is greater than 5 °, preferably 10 °. In a special embodiment, it is between 12 ° and 15 °. This is also intended to make it clear that the movements of the chair are noticeable to the chair user. In particular in combination with the travel path marked above, this enables an optimized, combinatorial movement of the seat part.

For reasons of wear, the guideway can be designed as a slideway or taxiway, so that even heavily used office chairs can have corresponding lifetimes. The seat part can then be moved along this slide or taxiway.

In one embodiment, a coupling gear can be provided that forcibly couples the displacement movement along the guideway and the pivoting movement about the pivot axis of the pivoting device. Accordingly, both movements are directly dependent on one another and cannot be carried out individually. Specified movement paths along the guideway thus lead to precisely defined swivel angles around the swivel axis. These movement parameters can be adapted to one another for optimal ergonomic configurations. LAD Pel gears per se are well known in the prior art, so that it is left to a person skilled in the art to bring about the desired movement sequences by selecting the suitable parameters.

The coupling gear mechanism can preferably be designed such that when the seat part moves downward and backward, a pivoting movement about the pivot axis of the pivoting device takes place to support a downward movement of a rear seat part area. The seat part tilts backwards faster than the direction of movement of the guideway, which is why flat guideways in combination with the swivel device lead to ergonomically favorable movements.

According to one variant, this effect can be enhanced in particular in that the pivot axis of the pivot device is arranged on a front part of the seat. As a result of this measure, the pivoting movement of the seat part about the pivot axis is particularly pronounced.

The coupling gear can comprise a coupling element which is arranged on the one hand to be pivotable about a basic pivoting point with a horizontal pivoting axis at a distance from the pivoting axis of the pivoting device and on the other hand is also arranged at a distance from the pivoting axis of the pivoting device with the seat part at a distance from the pivoting axis of the pivoting device. The distance of the base pivot point to the pivot axis of the pivot device and the distance of the base pivot point to the articulation and the distance of the articulation to the pivot axis of the pivot device can be adjusted according to the desired circumstances. Ergonomically favorable movement sequences are preferably predetermined by the coupling element. The term coupling element is to be understood to mean all individual elements and assemblies which support such a movement in accordance with a coupling gear. Split, symmetrical arrangements (on the left and right side of the chair) can be provided, which are to be understood as a coupling element in the sense of claim 8.

The guideway and the base pivot point for the coupling element can advantageously be arranged in a stationary manner relative to one another. These can then preferably absorb the entire support forces at fixedly defined locations, while the swivel device and the articulation point move on predetermined tracks.

An embodiment in which the coupling element is designed as part of a backrest is particularly favorable. As a result, the backrest is included in the entire motion sequence. It can therefore also be realized translation ratios between the inclination of the seat part and the backrest.

A variant provides that the coupling gear is designed such that a support surface of the backrest and a seat surface of the seat part are at an approximate angle ratio of 1.5: 1 to 2.5: 1, preferably approximately 2: 1 to the rear about the pivot axis the base pivot point or downward forcibly coupled about the pivot axis of the pivoting device displaced along the guideway. A gear ratio of approximately 2: 1 is considered to be ergonomically particularly favorable. In particular, in an embodiment in which the pivoting angle of the seat surface is greater than 5, preferably greater than 10 °, the pivoting angle of the backrest is accordingly at least 10 °, preferably 20 °. In a favorable embodiment, it is between 24 ° and 30 °.

A form that is very easy to implement in terms of construction provides, for example, that the pivoting device has a guide rail that is guided so as to be displaceable along the fixed guideway. This should be understood to mean, as far as possible, all telescopic or relatively movable components. Such constructions are very stable executable, which makes them very suitable even for heavy people.

In order to achieve the greatest possible stability, the pivoting device can preferably be supported on the guideway essentially in the middle of a standing area. Stand area is to be understood here as the plane spanned by the points of contact of the chair with the ground. If the swivel device e.g. be arranged in a front area of the seat part, suitable devices, e.g. mentioned guide rails can be provided, which are then supported in the central area to the footprint. This leads to an optimized introduction of force and lower loads on the guideway.

Furthermore, a spring device can be provided, against the spring action of which there is at least the downward and backward movement of the seat part. As a result, the seat part and, depending on the embodiment, also the backrest are automatically returned to the starting position after relieving the load on the chair. The spring mechanism can be used to influence seating comfort in innumerable ways. Spring devices are to be understood to mean all constructions which can be displaced against a restoring force. As a spring device e.g. a tension or compression spring, torsion spring, elastomer spring etc. can be used.

The spring device is well integrated into the overall structure if, according to one variant, the spring device has an effective direction which essentially runs along the guideway. The spring device therefore acts precisely in the direction of travel, so that its entire spring action is used, and not just components or parts thereof. If, according to one embodiment, the guideway is curved, the greatest possible approximation (tangent, chord, etc.) can take place, provided the spring action is not also curved, but rather straight. The spring device can preferably comprise an adjusting unit for adjusting the spring action. As a result, the chair can be adjusted to all weight classes as far as possible and achieve optimal spring deflection. As a rule, the setting unit will be designed to be adjustable manually using a suitable handle.

But there is also the possibility of providing a damping device which dampens the pivoting movement about the pivot axis of the pivoting device. This brings very good results in particular if the swivel device is attached to a front end region of the seat part.

Furthermore, the damping device can have an effective direction that acts essentially perpendicular to a swivel radius around the swivel axis of the swivel device. This measure results in an optimized introduction of force into the damping device. Since the direction of the radius to be considered changes constantly when swiveled, the damping device can be adapted to this swivel path with its direction of action or the greatest possible approximation can be achieved with a straight line of action (tangent, chord etc.). In particular, in interaction with a spring device that has an effective direction along the guideway, this results in effective directions that run transversely to one another and support one another in the case of a desired positive coupling.

In order to produce a kind of rocking chair effect, the damping device can be provided with a progressively increasing damping effect. This means that the larger the swivel path, the stronger the damping effect, so that an ever greater resistance is built up. In combination with a spring device in particular, this can produce a variety of desired spring damping effects. The damping device can be designed relatively inexpensively by means of an elastomer buffer. An initially low damping effect can easily be increased with this. With regard to elastomer buffers, there is sufficient excitation in the prior art for suitable configurations to achieve a specific damping effect.

In general, according to one embodiment, it is particularly good if a spring / damping device acts on the coupling gear which provides a progressively rising spring / damping device at least during the downward and backward movement of the seat part. The entire coupling gear is therefore involved in this spring / damping process of the associated device.

For the required movement sequences, it is a further advantage if, according to one variant, the guideway is convexly curved toward the seat part. In particular, circular-arc-shaped, parabolic-load-shaped, etc. configurations are possible here.

The averaged, theoretical center of curvature of the guideway can advantageously be located below a chair footprint. This leads to an extremely flat guiding device, since the curve allows relatively flat curves to be selected. In combination with the swivel device, an ergonomically favorable inclination course of the seat part can nevertheless be achieved.

Advantageously, a column base frame can be provided, on the upper end region of which the guideway is arranged. Here, e.g. common in office chairs, five-armed pedestals with a central support column and a roller are used at each end portion of a bracket.

The column base can preferably also be provided with the base pivot point at the upper end region. Supporting the basic swivel then takes place directly on the pedestal. The same applies to the embodiment with a guideway arranged thereon.

The column base frame can advantageously be designed to be adjustable in height. Such mechanisms are well known from office chairs and improve the overall adjustability of the chair.

The chair can preferably have a headrest. This is particularly advantageous if the seat part and any backrest are moved very far back or swiveled downwards. In addition, a backrest that may be provided need not be designed to be excessively high in order to fulfill a similar purpose.

The headrest can preferably be connected to the seat part. This gives a very special advantage. This is because the headrest executes the movement or swiveling movement of the seat part because it is connected to the swiveling device which can be moved along the guideway. If the back of the chair is positively coupled to the seat part, e.g. covers a larger swivel path than the seat part, the headrest comes towards the head of the user of the chair and supports this more with a backward swiveling movement of a backrest. The user is therefore given the feeling that the further he swings back, the better, especially in the head area, is supported. This gives an extremely comfortable feeling, especially when swiveling.

This idea is also reflected in claim 29, which relates to a chair, in particular according to one of the preceding claims. This comprises a pivotably arranged seat part, a pivotably arranged backrest and a forced coupling for forcibly coupled, translated pivoting of the seat part and backrest. Furthermore, a headrest is provided, which is connected to the seat part (directly or without translation). So far it has always been in the state of the art common to connect a headrest to a back of a chair. Arranging this now on a movable seat part gives the user of the chair a secure feeling of support, in particular when the seat part is pivoted far down and back. The term "motion-related" should be understood in the sense of a direct untranslated ("direct") connection to the seat part (for example pivoting angle and linear travel paths are the same size). The seat part and headrest thus carry out a common movement, while the backrest executes a movement which is translated for this purpose.

Exemplary embodiments of the invention are explained in more detail below with reference to drawings. Show it:

1 is a schematic side view of a first embodiment of an office chair in an upright zero position,

FIG. 2 shows a schematic side view of the office chair from FIG. 1 in a position tilted backwards, FIG.

3 shows a schematic side view of the office chair from FIG. 1 in a forward inclined position,

4 shows a schematic representation of the office chair from FIG. 1, in which both the zero position from FIG. 1 and the backward-inclined position from FIG. 2 are shown,

5 shows a schematic side view of a second exemplary embodiment of an office chair in an upright zero position,

6 shows a schematic side view of the office chair from FIG. 5 in a position inclined to the rear,

7 shows a schematic rear view of the office chair from FIG. 5, 8 shows a schematic exploded illustration of a third exemplary embodiment of an office chair, a seat surface and the backrest covering being omitted,

9 is a full section through the guideway of the office chair with the seat shown, the chair being in an upright zero position with the greatest weight setting,

10 is a view similar to FIG. 9, wherein the office chair is in a position inclined backwards,

11 shows a full section through the office chair according to FIG. 8 with the seat shown, the office chair being in an upright zero position with the lowest weight setting and

Fig. 12 is a view similar to Fig. 11, wherein the office chair is in a backward inclined position.

The office chair 1 shown in FIG. 1 essentially comprises a base area 2 and a seating area 3 arranged above it.

The base region 2 comprises a foot part 4 with five support arms 5 extending radially from a center, to the free end regions of which a downwardly projecting, pivotably arranged running roller 6 is fastened. In the center of the base area 2, a support column 7 rises upwards. The rollers 6 define with their lower contact points a chair footprint, which coincides with the surface when the rollers 6 are placed on a surface. At the upper end of the height-adjustable support column there is a base block 8, which ensures the coupling of the seating area 3 to the base area 2. The base block 8 on the one hand provides a guideway 9 which points obliquely upwards and is convexly curved. Furthermore, the base block 8 has a base pivot point 10 provided that has a horizontal pivot axis. The base block 8 is attached to the upper end of the support column 7 so as to be rotatable about a vertical axis. The guideway 9 is only shown schematically. The schematic guideway 9 is intended to be understood as representative of all guideway constructions along a sliding or rolling surface which permit a supported displacement movement.

A guide rail 11, also shown schematically, is displaceably guided on this guide track 9. The curvature of the guide rail 11 is adapted to the shape of the curvature of the guideway 9 and can slide along it in a defined manner. The center of curvature of the guide rail 11 or the guide track 9 is located below the theoretical chair footprint. As a result, the guide rail 11 builds relatively flat and occupies only a very small overall height for its complete movement. Of course, devices can be provided with which either the guide rail 11 engages behind the guideway 9 or vice versa, in order to achieve tilt-proof guidance.

A spring device can be provided within the system of guideway 9 and guideway 11. This can be of a similar construction to that of DE 4331987 A1 or DE 19900454 A1. However, there is also the possibility of dispensing with a degressive increase in spring force according to DE 19900454 A1. For example, could have a simple tension spring suspended on the base block 8, the other end of which on the guide rail

1 1 is suspended, a desired spring action can be achieved. The reference number 12 denotes an adjusting handle for adjusting the spring action of the spring device. By means of this spring device, the seat area 3 is always moved back into the position shown in FIG. 1. The adjustment handle is usually formed by a rotary knob, which can adjust a fastening base of the spring device via a thread mechanism or gear mechanism and the like. At the front end of the guide rail 11, which is part of a swivel device, there is a swivel axis 13 with a horizontal orientation. The front end region 14 of a seat part 15 is arranged pivotably on this pivot axis 13. The seat part 15 provided with a cushion pad 16 can accordingly be moved backwards as well as downwards in a combined manner by means of the guide rail 11 along the guide path 9, wherein additionally a pivoting movement about the pivot axis 13 is possible. In order for this movement to be forcibly coupled, a curved coupling element 17 is provided, which is pivotably attached to the base pivot point 10 on the base block 8 and merges into a backrest 18 of the seat region 3 in its upper region. At the rear end region, the seat part 15 is provided with a strut 19 which runs vertically in the zero position, the upper end of which is articulated on the coupling element 17 via a hinge point 20 with a horizontal hinge axis. The coupling gear produced in this way now ensures forcibly pivoting the seat surface 21 of the seat part 15 and the support surface 22 of the backrest 18.

It goes without saying that the tubular construction shown schematically in FIG. 1 can be constructed symmetrically on the other side of the chair, so that some of the components described above are also symmetrical on the other side and the gaps are provided by the cushion cover 16 and any kind of filling for the backrest 18 are filled.

Between the upper side 23 of the guide rail 11 and the lower side 24 of the seat part 15 or the cushion pad 16 there is a damping element in the form of an elastomer buffer 25, which ensures a progressive damping effect when the seat part 15 is pivoted about the pivot axis 13. The elastomer buffer 25 can for the desired damping effect in a variety of ways due to its material composition or be designed differently due to its shape. However, other damping devices can also be used to achieve the same or a similar effect.

The distance between the pivot axis 13 and the base pivot point 10 as well as the distance between the pivot axis 13 and the pivot point 20 and the distance of the pivot point 20 to the base pivot point 10 and their spatial grouping with respect to one another, under the influence of the shape of the guide track 9 and the guide rail 11, ensure the desired positively coupled movement, so that the seat part 15 moves both downwards and backwards when deflected and at the same time tilts backwards. Here, the inclination is not only about the pivot axis 13, but also about the average center of curvature, which is predetermined by the guideway 9. At the same time, however, the support surface 22 of the backrest 18 also tilts downwards and backwards. A translation between the seat surface 21 and the support surface 22 is generated by the forced coupling. In the present embodiment, the angular ratio between the support surface 22 of the backrest 18 and the seat surface 21 of the seat part 15 is 2: 1.

2, the reclining of the seating area 3 of the office chair 1 is now shown in more detail. In particular, it can be seen that the guide rail 11 has been moved backwards and downwards along the guide path 9. This reduces the distance between the pivot axis 13 and the base pivot point 10. The fact that the distance between the pivot axis 13 and the pivot point 20 and the distance between the base pivot point 10 and the pivot point 20 remain the same, leads to the above-mentioned translation , so that the support surface 22 is tilted back more than is the case with the seat surface 21. During this process, the spring device (not shown in detail) springs in and out of the spring track 9 and guide rail 11 system (depending on whether compression springs or tension springs are used). There is also a compression of the elastomer buffer 25 between the Top 23 of the guide rail 11 and the bottom 24 of the seat part 15 instead. This elastomeric buffer 25 ensures that the resistance increases with increasing movement backwards and forwards and that the chair user is given a safe sitting feeling.

It can also be seen from FIG. 3 that in addition to the zero position shown in FIG. 1, in which the seat surface 21 is arranged essentially horizontally, there is also the possibility of tilting it slightly forward. Here, e.g. by adjusting a stop of the guide rail 11, which is not described in more detail, the possibility is given to slide even further forward and upward along the guide track 9. In FIG. 3 it can be seen very clearly that the adjustment handle 12 is arranged much closer to the base block 8 than in FIG. 1. A seat surface 21 which is inclined slightly forwards is often very desirable for many seating situations, in particular at the workplace. Correspondingly, the support surface 22 of the backrest 18 also inclines forward due to the positive coupling of the coupling gear. By defining certain stops, it is also possible that this forward-inclined position 3 acts as a new zero position, at least for the spring device (not shown), so that the office chair 1 is always pushed back into this position when the load is released.

4, the effect of the entire construction can now be seen very clearly on the basis of a comparison of the positions from FIGS. 1 and 2. While the seat surface 21 is inclined by an angular amount α, this takes place in the support surface 22 of the backrest 18 by the angular amount β. In the present case, the angular amount β is twice as large as the angular amount α. As already described above, this is effected by the coupling gear, in particular the coupling element 17. It can also be seen very well in FIG. 4 that the pivot axis 13 moves very little downwards or downwards, so that the front end region 14 also lowers only very slightly, whereas the rear area of the seat surface 21 is nevertheless considerably lowered. At this point it should be noted that the angular amount α has a vertex displaced from the pivot axis 13. This is done by the combination movement along the guideway 9.

The construction according to the invention can be used, inter alia, Realize an office chair 1 which, from an ergonomic point of view, provides an optimized swiveling or tilting behavior with a construction that is as stable as possible. The translation between the seat surface 21 and the support surface 22 of the backrests 18, which is desired from an ergonomic point of view, does not lead to an excessive lowering of the seat surface 21. Rather, a pleasant rocking effect is achieved with a progressively increasing spring force, so that an unpleasant feeling of tipping backwards is avoided.

In addition, a headrest, armrests, backrest height adjustment, lumbar support and seat depth adjustment can be provided on the chair. Other setting options, such as those available in the office chair area, are also possible. Locks can also be present, which allow the seat part or the backrest to be fixed in any position or in preselected positions.

A second exemplary embodiment of an office chair 1 according to the invention is explained in more detail below with reference to FIGS. 5 to 7. Only the essential differences from the previous exemplary embodiment are dealt with, which is why reference is made to the preceding description with regard to elements of identical construction or effect. For this reason, the same reference numerals are used for components that are identical or have the same effect.

In addition to the somewhat different arrangement of the support arms 5 of the foot part 4 and a thicker support column 7, in which a spring damping device customary for office chairs is already arranged, the office chair 1 shown differs, inter alia, by its straight-line guide track 9. tion rail 11 is guided in a guideway 9, which is designed as an upside-down C-profile 27. As a result, a spring damping mechanism is completely covered upward by the closed crosspiece 26 of the C-profile 27 (see in particular FIG. 7). The elastomer buffer is therefore also arranged within the area enclosed by the C-profile 27. The handle 12 for adjusting the zero position is attached in the front area near the pivot axis 13. The handle 12 acts on a spindle 28 which effects the desired adjustment between the guide rail 11 and the C-profile 27.

Another significant difference from the previous exemplary embodiment is the configuration of the strut 19 of the seating area 3, which is now guided to the joint 20 via an intermediate piece 29. In the basic position shown in FIG. 5, the strut 19 runs parallel to an area of the coupling element 17 which merges into the backrest 18, while the intermediate piece 29 extends perpendicularly away from the strut 19 to the articulation point 20. This shape of the strut 19 creates a side boundary of the seating area 3, the strut 19 merging into an armrest 30 at its upper end. The armrest runs essentially parallel to the seat surface 21.

The exemplary embodiment shown in FIGS. 5 to 7 has a padded headrest 31 which is positioned above the upper end of the backrest 18. The headrest 31 is arranged on a swivel mount 32, but the swiveling can only take place against a resistance, for example in the form of a multiple detent fastening. The swivel mount 32 is followed by a push-on holder which is attached to the upper end of a support strut construction 34. The support strut construction 34 can be two struts or a single strut made by bending. Starting from the push-on bracket 33 in the basic position of the chair, the strut construction runs essentially parallel to the backrest 18. The free strut ends 35 are then guided outwards and to the articulation points 20. The free Strut ends 35 are connected in the area of the articulation point 20 to the intermediate piece 29 and thereby to the seating area 3. Accordingly, the headrest 31 together with the seat 21 performs the same swiveling and backward movement. This means that the pivoting angle of the seat surface 21, which results from a comparison of FIGS. 5 and 6, is the same as the pivoting angle of the headrest 31. In contrast, the backrest 18 pivots in the usual way at the gear ratio selected here by the coupling gear by twice the angular amount. It can be clearly seen in FIG. 6 that this causes the headrest 31 to protrude further from the upper end of the backrest 18 than is the case in FIG. 5. Accordingly, the headrest 31 comes towards the head of the chair user in comparison with the backrest 18 when the seat part 15 and the backrest 18 are pivoted backwards. Accordingly, the chair user is given the feeling that a stronger head support occurs when swiveling back, which gives a secure sitting feeling when swiveling back.

In principle, the headrest 31 can also be provided with a height adjustment, e.g. is executable in the upper plug-in area via the plug-on holder 33 and a corresponding shape of the holding strut construction 34. The support strut construction 34 is preferably a bent metal rod, which results in a relatively stable support.

A third exemplary embodiment of an office chair 1 according to the invention is explained in more detail below with reference to FIGS. 8 to 12. Only the essential differences from the previous exemplary embodiment are dealt with, which is why reference is made to the previous description with regard to identical construction or elements having the same effect. For this reason, the same reference numerals are used for components that are identical or have the same effect. In the present case, the base block 8 consists of a bent sheet metal part 36 and two box guides 37 arranged parallel to one another. The box guides 37 have a U-shape in cross section, so that a respective tension spring 38 arranged underneath is accommodated therein. The front end of the box guides 37 is closed with a holding plate 39. On the inside of the holding plate 39, one end of the respective associated tension spring 38 is attached. A receptacle 40 for a fastening pin 41 is provided in the center of the bent sheet metal part 36. The rotation relative to the foot part 4 usually takes place within the support column 7. Suitable systems for designing such support columns 7 are well known and are widely used.

The guide rail 11 is formed by a pair of side rails 42 which are connected to one another at their rear end via a reinforcing frame 43. Furthermore, the guide rail 11 comprises a rail cover 44, which is designed as a plastic part. The side rails 42 and the reinforcement frame 43 are arranged inside the rail cover 44. The side rails 42 lie on projections 46 at a parallel distance from the side walls 45 of the rail cover 44. The underside of the rail cover 44 therefore slides along the top of the box guides 37, while the side rails 42 are guided laterally along the box guides 37 open from the rear. The box guides 37 are fastened to the bent sheet metal part 36 via the centrally arranged mounting receptacle 40. The frame 43 is designed such that it can come into contact with the rear end face of the box guides 37 and thus serves as an end stop for the zero position of the office chair (will be in Described in detail below).

In the front area of the rail cover 44 there is a damper block receptacle 47 in which the elastomer buffer 25 is arranged. Below this receptacle 47 there is a threaded bore 48 which runs parallel to the direction of movement of the guideway 9. The spindle 28 is accommodated in and screwed out of this threaded bore 48. The head of the Spindle 28 is rotatably supported on a cross rail 49 which is connected to the front ends of the side rails 42. An adjusting handle 12 and a movement mechanism (not shown in more detail), for example in the form of a worm wheel engaging in the spindle 28 for moving the spindle 28, are arranged on this cross rail 49. By turning the adjusting handle 12, the spindle 28 rotates about its axis, so that the rail cover 47 moves along the spindle 28. The webs 50 running parallel along the side rails 42, in conjunction with the pins 51 arranged on the side of the box guides 37, ensure that the guideway 9 is secured against being lifted off.

The second end of the tension spring 38 is attached to a rear, closed end of the rail cover 44. Furthermore, a cover 52 is placed over this structure of the rail cover 44 for optical reasons.

A print rail 53 is attached to the frame of the seat part 15 in the front area and can be brought into contact with the elastomer buffer 25.

The elastomer buffer 25 protrudes beyond the top of the rail cover 44 and the cover 52 and can be compressed by the press-on rail 53.

Although the third embodiment is shown without armrests and headrest, it can of course also be equipped with these components according to the previous description with regard to the second embodiment.

The sequence of movements along the guideway 9 of the third exemplary embodiment is explained in more detail below with reference to FIGS. 9 to 12. 9 shows an upright zero position. The rail cover 44 has been moved completely backwards and downwards via the adjustment handle 12, so that the tension springs 38 are maximally prestressed in the zero position. In the zero position, the reinforcement frame 43 comes into contact with the rear of the box guides 37 and the fastening receptacle 40. The elastomer buffer 25 is completely relaxed, but is almost almost in contact with the underside of the push-on rail 53. Starting from this zero position, the chair is now loaded and transferred to a position inclined to the rear according to FIG. 10. It can be clearly seen that the tension springs 38 are tensioned even further. The path of travel of the rail cover 44 relative to the box guides 37 can be estimated on the basis of the distance of the reinforcement frame 43 from the rear of the box guides 37 and the fastening receptacle 40. The box guides 37 therefore protrude relatively far from the rail cover 44. By striking the receptacle 47 on the fastening receptacle 40, a precisely defined end position for pivoting back or shifting backward along the guideway 9 is also provided.

The elastomer buffer 25 is now considerably compressed by the push-on rail 53. In interaction with the tension springs 38, this results in a progressive spring / damping effect, as a result of which the chair user is given a secure feeling when swiveling backwards. By pressing the push-on rail 53 onto the front area of the elastomeric buffer 25, this unfolds its complete damping effect.

FIG. 11 differs from FIG. 9 only in that the rail cover 44 has been moved into its foremost position via the adjusting handle 12. As a result, the press-on rail 53 is already in contact with the central region of the elastomer buffer 25 in the zero position shown in FIG. 11. When swiveling backwards and sliding downwards along the guideway 9 into the position shown in FIG. 12, the push-on rail 53 only comes into operative relationship with a part of the elastomer buffer 25, which is why the damping behavior which is pronounced. The tension springs 38 in the zero position shown in FIG. 11 are also no longer preloaded as much as in FIG. 9. This setting is particularly suitable for light-weight people, whereas the setting from FIG. 9 is suitable for heavy-weight people. Also in the setting according to FIGS. 11 and 12, suitable stop means ensure a stop in the position shown in FIG. 12.

In addition, it should also be mentioned that due to the shape of the elastomer buffer 25 and the push-on rail 53, a variety of damping behaviors can be generated. The material properties of the elastomer buffer 25, as well as its construction or structure, permit a change in the damping behavior. Depending on the selected zero position (setting via the adjustment handle 12), the push-on rail 53 can be pressed onto differently designed elastomer buffers 25 (both material and shape or structure of the elastomer material) in order to obtain a predetermined damping curve via the course of the pivoting of the seat surface 21 , The elastomer buffer 25 can also be made of different types of material as a composition material.

Claims

claims

1. Chair, in particular office chair, with a seat part (15) and a downwardly inclined guide track (9) for providing a combined downward and backward movement or a combined upward and forward movement for the seat part (15), characterized in that a pivoting device With at least a horizontal pivot axis (13) is provided for pivotably arranging the seat part (15) and the pivot device is arranged to be movable together with the seat part (15) along the guideway (9).

2. Chair according to claim 1, characterized in that the guide track (9) is designed as a slide or taxiway.

3. Chair according to claim 1 or 2, characterized in that the maximum displacement path of the swivel device along the guide track (9) is greater than 30 mm, preferably 60 mm.

4. Chair according to one of claims 1 to 3, characterized in that the maximum pivoting angle about the pivot axis (13) of the pivoting device is greater than 5 °, preferably 10 °.

5. Chair according to one of claims 1 to 4, characterized in that a coupling gear is provided which forcibly couples the displacement movement along the guide track (9) and the pivoting movement about the pivot axis (13) of the pivoting device.

6. Chair according to claim 5, characterized in that the coupling gear is designed such that during a downward and backward movement of the seat part (15) there is a pivoting movement about the pivot axis (13) of the pivoting device to support a downward movement of a rear seat part region.

7. Chair according to one of claims 1 to 6, characterized in that the pivot axis (13) of the pivoting device is arranged on a front seat portion (14).

8. Chair according to one of the preceding claims, characterized in that the coupling gear comprises a coupling element (17) which is arranged on the one hand about a basic pivot point (10) with a horizontal pivot axis at a distance from the pivot axis (13) of the pivoting device and on the other hand at a distance from Basic pivot point (10) via a hinge connection (20) with a horizontal pivot axis with the seat part (15) is also arranged at a distance from the pivot axis (13) of the pivoting device.

9. Chair according to claim 8, characterized in that the guide track (9) and the base pivot point (10) for the coupling element (17) are arranged fixed to one another.

10. Chair according to claim 8 or 9, characterized in that the coupling element (17) is designed as part of a backrest (18).

11. Chair according to claim 10, characterized in that the coupling gear is designed such that a support surface (22) of the backrest (18) and a seat surface (21) of the seat part (15) in an angular ratio of 1.5: 1 to 2, 5: 1, preferably 2: 1, incline to the rear about the pivot axis of the base pivot point (10) or downward around the pivot axis (13) of the pivoting device displaced along the guideway (9).

12. Chair according to one of claims 1 to 11, characterized in that the pivoting device has a guide rail (11) which is guided displaceably along the fixed guideway (9).

13. Chair according to one of claims 1 to 12, characterized in that the pivoting device is supported on the guide track (9) essentially in the center of a standing area.

14. Chair according to one of claims 1 to 12, characterized in that a spring device is provided, against the spring action of which there is at least the downward and backward movement of the seat part (15).

15. Chair according to claim 14, characterized in that the spring device has an effective direction which extends essentially along the guide track (9).

16. Chair according to claim 14 or 15, characterized in that the spring device comprises an adjusting unit (12) for adjusting the spring action.

17. Chair according to one of claims 1 to 16, characterized in that a damping device (25) is provided which dampens the pivoting movement of the pivoting device.

18. Chair according to claim 17, characterized in that the damping device (25) has an effective direction which acts substantially perpendicular to a swivel radius around the swivel axis (13) of the swivel device.

19. Chair according to claim 17 or 18, characterized in that the damping device (25) is provided with a progressively increasing damping effect.

20. Chair according to claim 19, characterized in that the damping device (25) is designed as an elastomer buffer.

21. Chair according to one of claims 5 to 20, characterized in that a spring / damping device acts on the coupling gear, which provides a progressively increasing spring / damping force at least during the downward and backward movement of the seat part (15).

22. Chair according to one of claims 1 to 21, characterized in that the guide track (9) towards the seat part (15) is convexly curved.

23. Chair according to claim 22, characterized in that the averaged, theoretical center of curvature of the guideway (9) is below a chair footprint.

24. Chair according to one of claims 1 to 23, characterized in that a column base frame is provided, at the upper end region of which the guide track (9) is arranged.

25. Chair according to one of claims 1 to 24, characterized in that a column base frame is provided, at the upper end region of which the base pivot point (10) is arranged.

26. Chair according to claim 24 or 25, characterized in that the column base frame is designed to be adjustable in height.

27. Chair according to one of claims 1 to 26, characterized in that a headrest (31) is provided.

28. Chair according to claim 27, characterized in that the headrest (31) is connected to the seat part (15).

29. Chair, in particular according to one of the preceding claims, with a pivotably arranged seat part (15), a pivotably arranged backrest (18) and a forced coupling for the positively coupled, translated pivoting of the seat part (15) and backrest (18), characterized in that a headrest (31) is provided which is motionally connected to the seat part.