EP3576573B1 - Chair - Google Patents

Description

The invention relates to a chair, in particular an office chair, with a backrest that can be pivoted sideways.

DE 10 2011 104 972 A1 describes a piece of seating furniture, in particular an office chair, with a seat support for a seat surface and with a backrest support for a backrest, which is held laterally tiltable on the seat support, the backrest support having two laterally flexible and / or articulated support arms spaced apart from one another.

DE 10 2011 001 811 A1 describes a chair with a seat and a seat mechanism, the seat being coupled to the seat mechanism in such a way that the seat is mounted in a front end area so as to be pivotable about a first axis of rotation which is oriented parallel to the knee axis of a user. Furthermore, in its front end region, the seat is also mounted on the seat mechanism so as to be rotatable about a second axis of rotation oriented perpendicular to the first axis of rotation.

DE 10 2012 107 778 A1 describes a chair, in particular an office chair, with a seat plate that is arranged on an underframe, and a backrest, which allows a synchronous movement of the seat plate and backrest in the manner of a so-called synchronous mechanism, the seat plate being tilted laterally and the backrest comprising two backrest supports , the lower ends of which are pivotably mounted independently of one another on the underframe and on the seat plate are coupled in movement in such a way that one side of the seat plate is depressed by pivoting the support backwards on the same side and the opposite side is raised.

U.S. 5,022,709 A describes a spring and clasping element for a seat and / or a backrest comprising a pair of support means and a flexible sheet attached to the support means; wherein the flexible sheet comprises a central portion which is convex to the load-bearing direction of the element, and the two side walls extend outwardly from the central portion and are inclined to this direction; wherein the side walls are attached in the middle to the support means by connecting means which at least approximately form a hinge.

An office chair as exemplified in the Fig. 1 and 8th is shown is a rotatable chair with a seat 7 and a backrest 6, which can also have armrests 5. The office chair is mounted on rollers 2, which are attached to a so-called base 1, which has five arms in the example shown. In the middle of the base 1 there is a gas pressure spring 3 with which the seat height of the office chair can be adjusted. A chair mechanism 4, to which the backrest 6, the seat 7, and armrests 5 are attached, is mounted on the upper end of the gas pressure spring 3.

For ergonomic reasons, efforts have been made for many years to make the components of an office chair as mobile as possible absolutely and relative to one another, in order to allow the user to sit as dynamically as possible enable so that a maximum of physical movement can also take place while sitting. This promotes blood circulation and prevents poor posture.

The chair mechanism 4 can be designed, for example, as a so-called synchronous mechanism that couples the backrest 6 to the seat surface 7, an inclination of the backrest 6 typically causing the seat surface 7 to incline somewhat less.

Office chairs are also known in which the backrest 6 can not only be swiveled back and forth when a user leans against it, but which can also be swiveled sideways, for example about a horizontal axis of rotation, which can be realized by a joint arranged behind the seat surface 7 can. Typically, the backrest 6 is held in the upright position by a restoring element such as a spring or the like or moved back into the upright position when the backrest 6 has been deflected from the upright position. As a result, both the return element and the backrest 6 are free of force in the upright position.

• die Rückenlehne 6 an zwei Gelenken 8 befestigt ist, die zueinander parallele Drehachsen 10 aufweisen,
• die Drehachsen 10 einseitig an einer gemeinsamen Grundplatte 9 angebracht sind und mit einer Horizontalebene einen spitzen Winkel α einschließen,
• die Grundplatte 9 am hinteren Ende einer die Rückenlehne 6 mit der Sitzfläche 7 koppelnden Stuhlmechanik 4 lösbar angebracht ist,
• die Gelenke 8 mit je einem als Drehfeder ausgeführten Rückstellelement 12 wirkverbunden sind, die in entgegengesetzter Richtung wirken,
• auf jeder Drehachse 10 um selbige drehbar ein Befestigungsblock 11 sitzt, und
• die Befestigungsblöcke 11 an ihrer Unterseite jeweils eine Aussparung aufweisen, in der jeweils eine Drehfeder 12 angeordnet ist, die sich jeweils mit einem ersten Schenkel an ihrem Befestigungsblock 11 abstützt.

A chair, in particular an office chair, is proposed with a seat 7 and a backrest 6 that can be swiveled sideways, with

• the backrest 6 is attached to two joints 8 which have axes of rotation 10 parallel to one another,
• the axes of rotation 10 are attached on one side to a common base plate 9 and enclose an acute angle α with a horizontal plane,
• the base plate 9 is detachably attached to the rear end of a chair mechanism 4 coupling the backrest 6 to the seat surface 7,
• the joints 8 are each operatively connected to a return element 12 designed as a torsion spring, which act in the opposite direction,
• a mounting block 11 is seated on each axis of rotation 10 so that it can rotate about the same, and
• the fastening blocks 11 each have a recess on their underside, in each of which a torsion spring 12 is arranged, each of which is supported with a first leg on its fastening block 11.

To further improve known office chairs, it is proposed to fasten the backrest 6 to two joints 8 which have axes of rotation 10 parallel to one another. In other words, the backrest 6 should be pivotably mounted on two axes of rotation 10 parallel to one another. This results in a different course of movement of the backrest 6 compared to known chairs with a sideways pivoting backrest 6. In addition, the backrest 6 can be deformed by the selected type of mounting during the pivoting movement, whereby a three-dimensional movement of the backrest 6 and the generation of a restoring force can be achieved .

The axes of rotation 10 are attached to a common base plate 9 and the base plate 9 is detachably attached to a chair mechanism 4 coupling the backrest 6 to the seat surface 7. This makes it possible to use commercially available To use chair mechanisms 4, in which the attachment of the backrest 6 to two joints is not actually provided.

The axes of rotation 10 form an acute angle α with a horizontal plane. As a result, a lateral deflection to the left or right always causes a slight deflection of the backrest 6 forwards or backwards, which would not be the case, for example, with horizontally aligned axes of rotation 10, i.e. with a = 0.

The joints 8 are each operatively connected to a restoring element 12. Although the elastic deformation of the backrest 6, as explained above, already generates a restoring force which counteracts a lateral deflection of the backrest 6, it can be advantageous to support or strengthen this restoring force by the use of additional restoring elements 12 proposed here. It is further provided that the restoring elements 12 act in the opposite direction, i.e. one restoring element 12 counteracts a deflection to the left and the other restoring element counteracts a deflection to the right.

It can further be provided that the restoring elements 12 are pretensioned when the backrest 6 is in an upright position. It is thereby achieved that the restoring force, which counteracts a lateral deflection of the backrest 6, is increased.

According to a further embodiment it is provided that the seat back 6 has a frame which has an interruption in the area between the joints 8. This The interruption has the result that the backrest 6 can more easily deform elastically in the event of a lateral deflection, and such deformation creates an additional massage effect on the user's back. Such massage effects are very desirable because they counteract user fatigue and the development of back pain.

It can further be provided that at least one elastic element 14 is arranged in the interruption. Although this elastic element allows elastic deformation as described above within certain limits, it also increases the restoring force counteracting a lateral deflection. In addition, the elastic element can serve, on the one hand, to create the visual impression of an uninterrupted frame and, on the other hand, to assist in the fastening of a cover material for the backrest 6, for example. Such an elastic element can be, for example, a two-component component made of different elastic, ie differently difficult to deform plastics. Two material strips of a first plastic, which is comparatively hard and therefore difficult to deform, can enclose between them a material strip of a second, comparatively soft and therefore easily deformable plastic. The two harder strips of material can be used to fasten the elastic element 14 to the left and right of the interruption in the frame of the backrest 6 on this frame, for example to screw it on. The softer strip of material located in between then serves to allow a deformation of the backrest 6, but this deformation does Counteract restoring force.

• Fig. 1 bis 7 verschiedene Ansichten und Schnittdarstellungen von Details eines ersten Ausführungsbeispiels und
• Fig. 8 bis 15 verschiedene Ansichten und Schnittdarstellungen von Details einer beispielhaften Stuhlmechanik nicht Teil der Erfindung.

The invention is explained in more detail below with reference to two exemplary embodiments and associated drawings. Show it

• Figures 1 to 7 various views and sectional views of details of a first embodiment and
• Figures 8-15 Various views and sectional views of details of an exemplary chair mechanism are not part of the invention.

As from the representations of the Fig. 1 and 2 As can be seen, in the exemplary embodiment shown, the seat back has a frame which has an interruption in the area between the joints. At least one elastic element 14 can be arranged in this interruption. In the example shown, the interruption is filled by the elastic element 14. It can be, for example, a silicone rubber, polyurethane (PU) or similar rubber-elastic materials. Alternatively, a plurality of elastic elements 14 can also be arranged in the interruption which connect the two opposite edges of the interruption to one another. In this way, on the one hand, interesting aesthetic effects can be achieved, on the other hand, a fine coordination of the force effect of the elastic elements 14 on the two opposite edges of the interruption can be achieved.

Fig. 3 shows a chair mechanism 4, at the rear end of which the joints 8 are arranged. The Figures 4 and 5 show the Joint arrangement isolated and from two different perspectives.

According to the invention, a base plate 9 is attached to the rear end of the chair mechanism 4, to which two axes of rotation 10 are attached on one side. A fastening block 11 is seated on each axis of rotation 10 and is thus rotatable about the axis of rotation 10. The two fastening blocks 11 each have a recess on their underside, in each of which a reset element 12 is arranged. The restoring elements 12 are designed as leg springs, each of which is supported by a first leg on its fastening block 11. Leg springs, also known as torsion springs, are mechanical energy storage devices that absorb a torque when the legs are angularly / rotationally moved, which they release again when they are released.

In the embodiment shown here, a stop element 13 is arranged between the two axes of rotation 10, on which the two restoring elements 12 are each supported with a second leg. A rotation of a fastening block 11 on the associated axis of rotation 10 thus leads to the associated restoring element 12 building up a restoring force which is opposite to the rotation of the fastening block 11. It can also be seen from the illustration that, in the example shown, the restoring elements 12 act in the opposite direction. As a result, the backrest 6 is always held in the upright position in the unloaded state. The resetting elements 12 can be pretensioned when the backrest is in an upright position. The preload can also be adjustable.

It goes without saying that the joints 8 can also be designed differently than in the exemplary embodiment shown here.

Fig. 6 shows a three-dimensional representation of the chair mechanism 4 with the joints 8 arranged thereon. As can be seen particularly from the side view shown below, the axes of rotation 10 of the joints 8 enclose an acute angle α with a horizontal plane. This results in a three-dimensional form of movement of the backrest 6 with respect to the seat surface 7, which is shown in FIG Fig. 7 is shown schematically in a view from behind and a view from above.

That in the Figures 8 to 15 The example shown does not form part of the invention and has many similarities and some differences compared to the first exemplary embodiment.

In this case, the base plate 9 is a bent sheet metal part, the upper edge of which is designed so that the base plate 9 can be hooked into the chair mechanism 4 on its rear side. This connection between the base plate 9 and the chair mechanism 4 is secured by a locking screw (not shown) which is inserted into a threaded hole 15 provided on the underside of the base plate 9 for this purpose.

In this example, the joints 8 do not have any separate fastening blocks which can be rotated about the axes of rotation 10. Instead, the axes of rotation 10 are directly connected to the two lower extensions of the backrest 6. For this purpose, the lower extensions of the backrest 6 have bores into which the axes of rotation 10 are inserted. In order to axially secure the backrest 6 on the axes of rotation 10, locking pins 17 are arranged in aligned bores 16 of the backrest 6 and the axes of rotation 10.

In order to fix the restoring elements 12 in the axial direction of the axes of rotation 10, two spring locking clips 18 are arranged on the axes of rotation 10.

For aesthetic reasons, the adapter formed by the base plate 9, the axes of rotation 10 and the stop element 13 for attaching the backrest 6 to the chair mechanism 4 is covered by the adapter cover 19 and thus not visible from the outside.

List of reference symbols

1

Base

2

role

3

Gas spring

4th

Chair mechanics

5

armrest

6th

backrest

7th

Seat

8th

joint

9

Base plate

10

Axis of rotation

11

Mounting block

12th

Reset element

13th

Stop element

14th

elastic element

15th

Threaded hole

16

drilling

17th

Locking pin

18th

Spring locking clip

19th

Adapter cover

α

angle

Claims (5)

1. Chair, in particular office chair, having a seat surface (7) and a backrest (6) which can be pivoted sideways, wherein

   • the backrest (6) is fastened at two joints (8), which have rotary spindles (10) which are parallel to one another,

   • the rotary spindles (10) are fitted at one end on a common base plate (9) and enclose an acute angle (a) with a horizontal plane,

   • the base plate (9) is fitted in a releasable manner at the rear end of a chair mechanism (4), which couples the backrest (6) to the seat surface (7),

   • the joints (8) are operatively connected to a respective restoring element (12), the restoring elements being designed in the form of torsion springs and acting in opposite directions,

   • a fastening block (11) is seated on each rotary spindle (10) such that it can be rotated about the same, and

   • on their underside, the fastening blocks (11) each have an aperture in which is arranged a respective torsion spring (12), which is supported on its fastening block (11) in each case by way of a first limb.
2. Chair according to Claim 1, in the case of which the restoring elements (12) are in a prestressed state in the upright position of the backrest (6).
3. Chair according to Claim 1 or 2, in the case of which the seatback (6) has a frame with a gap in the region between the joints (8).
4. Chair according to Claim 3, in the case of which at least one elastic element (14) is arranged in the gap.
5. Chair according to Claim 4, in the case of which the elastic element (14) is a two-part component made of plastic materials which are elastic to different degrees.

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