Chair

Abstract

A chair includes a seat surface and a laterally pivotable backrest. The backrest is secured to two joints, which have mutually parallel axes of rotation.

Claims

1. A chair comprising a seat surface and a laterally pivotable backrest, wherein: the backrest is secured to two joints, which have mutually parallel axes of rotation, the axes of rotation are attached on one side to a common base plate, extend backwards from the base plate at an acute angle (a) with a horizontal plane, the base plate is detachably attached to the rear end of a chair mechanism which couples the backrest to the seat surface, the joints are each operatively connected to restoring elements which are torsion springs which act in opposite directions, and wherein the seat backrest has a frame having a gap in an area between the joints.

2. The chair according to claim 1, wherein the restoring elements are preloaded with the backrest in an upright position.

3. The chair according to claim 2, wherein at least one elastic element is positioned in the gap.

4. The chair according to claim 3, wherein the elastic element is a two-component element made from different elastic plastics.

5. The chair according to claim 1, wherein at least one elastic element is positioned in the gap.

6. The chair according to claim 5, wherein the elastic element is a two-component element made from different elastic plastics.

7. The chair according to claim 1, wherein the torsion springs comprise: a first torsion spring disposed over one of the mutually parallel axes of rotation, and a second torsion spring disposed over another of the mutually parallel axes of rotation.

8. The chair according to claim 7, comprising: a stop element positioned between the mutually parallel axes of rotation, wherein a limb of each of the first and second torsion springs are braced against the stop element.

9. A chair comprising a seat surface and a laterally pivotable backrest, wherein: the backrest is secured to two joints, which have mutually parallel axes of rotation, the axes of rotation are attached on one side to a common base plate, extend backwards from the base plate at an acute angle (a) with a horizontal plane, the base plate is detachably attached to the rear end of a chair mechanism which couples the backrest to the seat surface, the joints are each operatively connected to restoring elements which are torsion springs which act in opposite directions, wherein the seat backrest has a frame having a gap in an area between the joints, and wherein at least one elastic element is positioned in the gap.

10. The chair according to claim 9, wherein the at least one elastic element is a two-component element made from different elastic plastics.

11. The chair according to claim 9, wherein the restoring elements are preloaded with the backrest in an upright position.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

(1) In the following, the invention is illustrated in more detail by way of two exemplary embodiments and associated drawings in which:

(2) FIGS. 1 to 7 show various views and sectional views of the details of a first exemplary embodiment, and

(3) FIGS. 8 to 15 show various views and sectional views of the details of a second exemplary embodiment.

DETAILED DESCRIPTION

(4) As can be seen from the representations in FIGS. 1 and 2, in the exemplary embodiment shown the seat backrest has a frame which has a gap in the area between the joints. At least one elastic element 14 may be positioned in this gap. In the example shown, the gap is filled by the elastic element 14. This may be a silicone rubber, polyurethane (PU) or similar rubber elastic material, for example. Alternatively, multiple elastic elements 14 which connect the opposite edges of the gap with one another may also be positioned in the gap. Through this, an interesting aesthetic effect can be achieved on the one hand, and on the other hand fine adjustment of the force effect of the elastic elements 14 on the two opposite edges of the gap can be achieved.

(5) FIG. 3 shows a chair mechanism 4, on the rear end of which the joints 8 are positioned. FIGS. 4 and 5 show the joint arrangement released and from two different perspectives.

(6) In this concrete exemplary embodiment, a base plate 9 to which the two axes of rotation 10 are secured on one side is attached to the rear end of the chair mechanism 4. A securing block 11 which is thus rotatable about the axis of rotation 10 sits on each axis of rotation 10. The two securing blocks 11 each have a recess on their underside, in each of which a restoring element 12 is positioned. The restoring elements 12 are realized as torsion springs which are each braced with a first limb on their securing block 11. Torsion springs, also known as rotational springs, are mechanical energy stores which absorb torque during an angular/rotational movement on the limb, which they release again when relaxed.

(7) In the exemplary embodiment shown here, a stop element 13 on which the two restoring elements 12 are each braced with a second limb is positioned between the two axes of rotation 10. A rotation of a securing block 11 on the associated axis of rotation 10 then results in the associated restoring element 12 building a restoring force which is opposed to the rotation of the securing block 11. It can be seen from the representation that, in the example shown, the restoring elements 12 act in opposite directions. As a result, the backrest 6 is always held in an upright position in its unloaded state. The restoring elements 12 may be preloaded with the backrest in the upright position. The preloading may furthermore be adjustable.

(8) It is to be understood that the joints 8 may also have a different design to that shown here in the exemplary embodiment. In particular, the concrete assembly of base plate 9, axes of rotation 10, securing blocks 11 and restoring elements 12 is by no means mandatory. For example, the moving part of a joint 8 may also be part of the backrest 6.

(9) FIG. 6 shows a three-dimensional representation of the chair mechanism 4 with the joints 8 positioned thereon. As can be seen in particular from the side view presented below, the axes of rotation 10 of the joints 8 with a horizontal plane involve an acute angle .

(10) This results in a three-dimensional movement pattern of the backrest 6 vis--vis the seat surface 7, which is schematically shown in FIG. 7 in a rear view and in a top view.

(11) The second exemplary embodiment presented in FIGS. 8 to 15 has many similarities and a few differences in comparison with the first exemplary embodiment.

(12) In this case, the base plate 9 is a bent metal component, the upper edge of which is designed such that the base plate 9 can be suspended on the rear side of the chair mechanism 4. The connection between the base plate 9 and the chair mechanism 4 is secured by a retaining screw (not shown) which is attached to a threaded hole 15 which is provided on the underside of the base plate 9 for this purpose.

(13) In this exemplary embodiment, the joints 8 do not have separate securing blocks which are rotatable around the axes of rotation 10. Instead, the axes of rotation 10 are directly connected to the bottom two spurs of the backrest 6. The bottom spurs of the backrest 6 have holes to this end into which the axes of rotation 10 are inserted. In order to secure the backrest 6 axially on the axes of rotation 10, securing pins 17 are positioned in holes 16 in the backrest 6 and the axes of rotation 10 which are aligned with one another.

(14) In order to hold the restoring elements 12 in place in an axial direction of the axes of rotation 10, two spring securing clips 18 are positioned on the axes of rotation 10.

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

Chair

LIST OF REFERENCE NUMERALS

(16) 1 Star base 2 Caster 3 Gas pressure spring 4 Chair mechanism 5 Armrest 6 Backrest 7 Seat surface 8 Joint 9 Base plate 10 Axis of rotation 11 Securing block 12 Restoring element 13 Stop element 14 Elastic element 15 Threaded hole 16 Hole 17 Securing pin 18 Spring securing clip 19 Adapter clip Angle