Abstract: The invention relates to an item of seating furniture (2), in particular an office chair, with a substantially curved supporting shell (14) which has two raised, curved, flexible curved arms (24) and a rigid central piece (16) arranged between said curved arms. Furthermore, the item of seating furniture (2) comprises a covering (30) which is clamped in the manner of a secant between the curved arms (24) of the supporting shell (14), wherein, when the covering (30) is loaded, at least one curved arm (24) is at least partially increasingly raised and/or is at least partially curved in the direction of the central piece (16).

Abstract: The invention relates to a seat (1), in particular an office chair, comprising a seat support (3) for a seating surface (6) and comprising a backrest support (4) of a backrest (5), which is held on the seat support (3) so as to be able to move in a tillable manner to the side, wherein the backrest support (4) comprises two support arms (4a, 4b) which are configured to be flexible and/or articulated laterally and spaced apart from one another. Preferably, the seating surface (6) and/or the backrest (5) comprises a curved seat shell and/or backrest shell (6a, 5a) provided with a cover (6b, 5b) with a number of flexible curved ribs (15, 16) on the edge of the shell, wherein the cover is stretched by the seat shell and/or backrest shell (6a, 5a) such that when the cover (6b, 5b) is loaded, the bending of the curved ribs (15, 16) is altered.

Abstract: An adjusting mechanism is used to adjust a restoring force that acts on a backrest of a chair. The adjusting mechanism has a spring element for creating the restoring force, a support, and a backrest support that is pivotably mounted about a support axis on the support. An adjusting element configured as a pair of scissors containing a first scissor arm and a second scissor arm is provided, and the scissor arms are rotatably connected to each other about a scissor axis. The first scissor arm is pivotably mounted on the backrest support about an adjusting axis. A spring force produced by the spring element acts on the second scissor arm. A first actuating lever length is defined between the support axis and the scissor axis. The lever length is changeable using an adjusting element for adjusting the restoring force by pivoting the adjusting element about the adjusting axis.

Abstract: A seat, in particular an office chair, has a synchronous mechanism with a weight-adapting mechanism. An automatic adaptation of a spring force acting on the synchronous mechanism depends on the weight momentarily exerted on the seat. Therefore, the spring force is transmitted to the synchronous mechanism via a lever whereof the active arm length of the lever can be modified to adjust the spring force. The weight-adapting mechanism is configured such that the active arm length is automatically adapted to the weight momentarily exerted on the seat.

Abstract: A seat, in particular an office chair, has a synchronous mechanism with a weight-adapting mechanism. An automatic adaptation of a spring force acting on the synchronous mechanism depends on the weight momentarily exerted on the seat. Therefore, the spring force is transmitted to the synchronous mechanism via a lever whereof the active arm length of the lever can be modified to adjust the spring force. The weight-adapting mechanism is configured such that the active arm length is automatically adapted to the weight momentarily exerted on the seat.

Abstract: In the case of a backrest (1), in particular for an office chair, having a lordosis support (3) comprising supporting ribs (2) arranged in a manner such that they run parallel to one another, said supporting ribs are precurved in a flexurally elastic manner in their starting position. An adjusting element (9), which can be actuated via an adjusting member (6) and is intended for setting the lordosis curvature (18), is guided on the curvature side (12) of the lordosis support (3) in such a manner that the lordosis curvature (18) decreases during a tensile loading of the adjusting element (9).

Abstract: In the case of a backrest (1), in particular for an office chair, having a lordosis support (3) comprising supporting ribs (2) arranged in a manner such that they run parallel to one another, said supporting ribs are precurved in a flexurally elastic manner in their starting position. An adjusting element (9), which can be actuated via an adjusting member (6) and is intended for setting the lordosis curvature (18), is guided on the curvature side (12) of the lordosis support (3) in such a manner that the lordosis curvature (18) decreases during a tensile loading of the adjusting element (9).

Abstract: The chair, particularly an office chair, has a backrest articulated to a seat support by way of a rest support. A seat surface is movable synchronously with the backrest. A front region of the seat surface is connected to the seat support via a sliding guide and a rear region is connected to the seat support via a seat link. A distance from an upper pivot point, which connects the seat link to the seat surface, to the backrest is shorter than the distance from a lower pivot point, which connects the seat link to the seat support, to the backrest. The movements of the backrest and of the seat surface are synchronized by a sliding guide provided between the seat link and the rest support.

Abstract: A chair, in particular an office chair, is described. The chair has a backrest that is inclinable with regards to a seat carrier via a backrest carrier. The chair has a seat surface that can be moved synchronously with the backrest and is supported on the seat carrier via at least one seat link. A coupling link is provided for synchronization between the movement of the backrest and the movement of the seat surface. The coupling link is connected rotatably, on one side to the seat surface and, on another side, to the backrest link.

Abstract: A chair, in particular an office chair, has a backrest that is articulated on a seat carrier via a backrest carrier, and has a seat surface that can be moved synchronously with the backrest. The front region of the seat surface is connected to the seat carrier via a sliding guide. The rear region of the seat surface is connected to the seat carrier via a seat link. A top point of rotation connects the seat link to the seat surface. A bottom point of rotation connects the seat link to the seat carrier. The distance between the top point of rotation and the backrest is smaller than the distance between the bottom point of rotation and the backrest. A sliding guide for the seat surface is provided in the backrest carrier for synchronizing the movement of the backrest and the movement of the seat surface.

Abstract: A chair, in particular an office chair, is described. The chair has a backrest that is inclinable with regards to a seat carrier via a backrest carrier. The chair has a seat surface that can be moved synchronously with the backrest and is supported on the seat carrier via at least one seat link. A coupling link is provided for synchronization between the movement of the backrest and the movement of the seat surface. The coupling link is connected rotatably, on one side to the seat surface and, on another side, to the backrest link.

Abstract: A spring unit (11) for the weight setting of a chair (1), in particular an office chair, having a gas spring (12) and having a number of further spring elements (17, 18, 19; 27, 28) which can be connected up to the gas spring (12) individually or in combination. The spring unit (11) is expediently arranged between a seat carrier (7) connected to a rotary column (8) of the chair (1), and the seat (3), or a backrest link (4) which extends at least approximately parallel to said seat (3) and belongs to a backrest (2).

Abstract: A footrest is fastened via a telescopically extendable connecting element to an office chair, in particular to an office chair having a backrest that can be tilted into a rest position. This results in an especially comfortable and ergonomic seating position, and in particular a situation in which the office chair is pushed away from the footrest when the footrest is not needed.

Abstract: A chair (1, 1′), in particular an office chair, having a backrest (6) which is arranged such that it can be rotated about a first point of rotation (8) in relation to a seat carrier (2) and which can be inclined from a rest position, and having a seat surface (10) which is connected to the backrest (6) such that it can be rotated about a second point of rotation (12) and which can be inclined synchronously with the backrest, is intended, in particular in terms of its tendency to tilt, also to be suitable for a particularly pronounced inclination movement of the backrest (6) with an inclination of, for example, up to 40° in relation to the starting position of the same. For this purpose, according to the invention, in the rest position, the first point of rotation (8) is positioned at approximately the same height as, or higher than, the second point of rotation (12).