EP3741258A1 - Chair with seat tilt mechanism - Google Patents

Abstract

The invention relates to a chair, in particular an office chair, and a seat tilt mechanism for a chair. The invention proposes that a cross strut of a seat tilt mechanism forms a spring device, this spring device having at least one torsion element.

Description

The invention relates to a chair, in particular an office chair, with the features of the preamble of claim 1 and a seat tilt mechanism with the features of the preamble of claim 10.

Such a chair is well known and is regularly used as an office chair which can be adjusted to a user in terms of seat height and tilt behavior. The known chair comprises a base with a roll cross and a foot column on which a base support with a seat element and a seat back is mounted. The height of the foot column is adjustable so that the height of the seat unit can be adjusted. The seat tilt mechanism is designed so that the seat back can be tilted or inclined in the vertical direction. The seat tilt mechanism comprises a spring which biases the seat back in such a way that it is positioned in a front end position. When the chair is used by a person, the seat back can be tilted against the spring force into a rear end position when the person is supported on the seat back. It is also known to move the seat element together with the seat back via the seat tilt mechanism. Depending on the design of the seat tilt mechanism, the seat element can be tilted together with the seat back or moved in the longitudinal direction of a seat surface. The seat tilt mechanism can be designed together with the spring in the manner of a lever mechanism. The seat element and also the seat back can be formed from a shell formed from metal or plastic or from a frame with upholstery and a cover or a covering made from a textile fabric.

The disadvantage of the known chairs with a seat tilt mechanism is that, due to the design of the seat tilt mechanism and its connection to the foot column, the seat element and the seat back, they are formed from many parts. In particular, the lever mechanism of the seat tilt mechanism often consists of a number of levers and springs which are made of metal due to the stability to be guaranteed. The manufacture of such a chair or a seat tilt mechanism therefore requires a large number of parts with a high outlay on assembly.

The invention is based on the object of creating a chair and a seat tilt mechanism of the type mentioned in the introduction, which are designed to be optimized with regard to the above-mentioned problems.

According to the invention, this object is achieved by the subjects of the independent claims. Advantageous embodiments of the invention are specified in the subclaims.

The invention proposes that a cross strut of a seat tilt mechanism of a chair, in particular an office chair, forms a spring device, this spring device having at least one torsion element. In particular, it is proposed that a cross strut be designed as an integral, deformable torsion element that is integrated in one part of a component of the chair. The torsion element not only enables deformability of the chair component, eg a base support, a seat support or a backrest support, this deformability advantageously resulting in a functionality of the chair component based solely on this deformability. As an energy store, the torsion element also provides a counterforce that is directed against a functional deformation, for example a deflection.

The invention proposes providing storage elements as integral, deformable components (torsion elements) of the chair mechanism (seat tilt mechanism). In other words, instead of spring elements to be produced separately and mounted in the mechanical assembly, at least one of the chair components that are already present to provide the functionality of the seat tilt mechanism, in particular base support, seat support and / or backrest support, should be used as a storage element. In addition, real pivot points, in particular those that were previously realized by swivel joints, can be replaced by virtual pivot points in this way. In this way, the number of components required for the seat tilt mechanism and thus the manufacturing and assembly costs for chair mechanisms can be reduced. By reducing the number of real pivot points, the stress on the material and wear and tear on axles guided in bearings, and thus the risk of failure, are minimized and the service life of the chair mechanics is increased. Further advantages result from new construction and design approaches that are made possible with the integrated construction. For example, seat tilt mechanisms that require significantly less installation space can be provided. In particular, mechanics with a significantly flatter structure can arise.

The torsion elements are preferably deformable due to an impact on the chair component aimed at achieving movement, in other words deform due to their integral design when the chair component is deliberately subjected to a force or a moment. The torsion element according to the invention is thus characterized in that its deformation on an intended and thus desired movement of the chair component in which it is integrated.

The torsion elements are preferably made of a plastic material. Since plastic materials have long been used in the manufacture of seating furniture components, in particular office chair components, suitable devices and systems for manufacturing and assembly are already available. There is therefore no need to make any changes in this regard. In addition to the use of plastic materials, other materials that allow an elastically deformable energy store to be provided, such as e.g. the use of wood materials.

In a particularly preferred embodiment of the invention, the torsion element according to the invention is used to enable a desired movement of a chair component in the first place. In other words, this movement of the chair component would not be possible at all without this element. A seat tilt mechanism according to the invention embodied in this sense comprises a number of interacting components, the interaction of which is used to execute a movement taking place in a certain manner, ie allow intended mobility and therefore functionality of the seat tilt mechanism, and is characterized in that at least one of these components is due to its execution with the torsion element according to the invention is at least partially elastically deformable under load, in particular under the action of a force or a moment, such that the intended mobility of the device is achieved. It is preferably only the deformability of this at least one torsion element that the intended mobility the mechanism or the chair. Unless otherwise stated, the term “deformable” is always used in the sense of “elastically deformable”. In other words, the deformation element changes its shape under the action of a force, and when the force acting on it ceases, it returns to its original shape.

Multi-articulated coupling gears, as they are known from the prior art, can be viewed as a kinematic chain. Because of the joints of such a coupling mechanism, these coupling mechanisms have degrees of freedom of movement. According to a preferred embodiment of the invention, a multi-articulated coupling mechanism for a seat tilt mechanism of a chair, in particular an office chair, can be provided which theoretically no longer has such a degree of freedom when using ideally rigid materials. According to the invention, a movement of the coupling mechanism is only made possible through the use of the torsion element, which when the invention is applied to a seat tilt mechanism is designed as an integral part of the coupling mechanism, in particular as one of the coupling mechanisms of the coupling mechanism or as part of one of the coupling mechanisms of the coupling mechanism. In addition to a number of real pivot points (ie one or more real pivot points), the kinematic chain thus formed comprises at least one virtual pivot point, but preferably several virtual pivot points. The torsion element can be designed in such a way that it consists of a series of virtual pivot points. In other words, it is proposed to replace pivot points and / or coupling elements, the latter completely or partially, by a number, ie one or more, component-integrated torsion elements.

With the help of the invention, parts, components and assemblies of seating furniture, in particular chairs, as well as seat tilt mechanisms of any type, can therefore be provided in a simple and inexpensive manner, which have a large number of precisely defined pivot points. The position of these pivot points can be stationary, that is, unchangeable, as well as changeable. In particular, the position of the pivot points can also change during the movement of the chair or the movement of a component, a component or an assembly of the chair. In this way, mechanical devices with highly complex movement characteristics can be manufactured with just a few components. Through a targeted design of the torsion element, the type of deformation of the element can be defined and used specifically to provide a desired movement of a loaded component, in particular a component of the seat tilt mechanism or the chair.

With the aid of the torsion element according to the invention, seat tilt mechanisms can be produced in a particularly simple manner with a small number of components. The term seat tilt mechanism used here also includes chair mechanisms that, in addition or as an alternative to a tilting movement in the longitudinal direction of the chair, i.e. backwards or forwards, also enable a lateral tilting movement of one or more chair components, i.e. a movement to the right or left.

According to the invention, the torsion element also serves as an energy storage element which is integrated in the mechanical component that provides the torsion element. The torsion element can thus not only have a restoring force for one Define pivoted mechanical components but also serves to define a pivot resistance of a mechanical component. The storage element experiences a reversible deformation under the influence of load. The elasticity of the storage element causes a restoring moment when it is acted upon, by means of which it automatically moves back into its non-deformed initial shape as soon as the forces or moments acting on it cease to exist.

In particularly preferred embodiments of the invention, the rigidity of the torsion element is dependent on the direction of action of the force acting on the torsion element. In other words, the deformation element is designed in such a way that it deforms differently depending on the effective direction of the force acting on it. This is preferably achieved through a suitable structural design of the torsion element.

By integrating the energy store according to the invention into an existing component of the seat tilt mechanism, the number of components (individual parts, assemblies) can be reduced compared to the seat tilt mechanisms known from the prior art. This reduces the effort involved in parts storage and assembly.

In the manufacture of that mechanical component that has the torsion element, either only a single plastic material is used during the injection molding process or two or more different plastics are used (multi-component injection molding). It is not necessary to change the material composition during injection molding if the desired deformation properties of the deformation element can only be achieved through a structural design.

The material suitable for producing the torsion element has, on the one hand, the necessary rigidity to ensure the required stability and strength of the component. On the other hand, the material is elastic enough to provide the desired deformability with the desired movement.

The deformation behavior of the torsion element can be changed in the installed state with the help of suitable adjustment mechanisms. This can be, for example, mechanically acting mechanisms which completely or partially restrict or block the deformability of a part of the torsion element or the deformability of the entire torsion element. To change the deformation behavior, however, the rigidity of the torsion element can, for example, also be changed in a targeted manner by temporarily changing a material property of the torsion element.

When using torsion elements made of plastic, as proposed by the invention, the counterforce to be overcome by the user of the chair during the movement of the seat tilt mechanism is generated by the plastic material.

Since component-integrated torsion elements made of plastic material are used instead of spring elements or energy stores made of steel, the weight of the seat tilt mechanism and thus the weight of the chair can be reduced compared to conventional designs. This is particularly advantageous in the case of chairs if they are intended for portable installation, as is the case with office chairs. At the same time, the recycling of such assemblies is simplified, since there is no need to separate materials.

The torsion element according to the invention can be used in a variety of ways. Although the principle on which the invention is based is explained below using the example of seat tilt mechanisms for office chairs, the invention is not limited to the fact that it is used in a seat tilt mechanism with the described movement characteristics, nor that the torsion element is part of a specific chair component , for example of the basic carrier acts. The idea of the invention can also be realized with the help of deformable parts of other construction elements or assemblies of chair mechanisms. In addition, the concept of the invention can be implemented with different types of chair mechanisms, in particular with synchronous mechanisms in which the backrest is pivoted with a certain relative movement of the seat and backrest to each other, and with rocker mechanisms in which the backrest is pivoted together with the seat as a movement unit . A seat tilt mechanism within the meaning of the invention is understood to mean any conceivable chair mechanism, including asynchronous mechanisms in which the backrest is pivoted independently of the seat or when the seat is immobile.

The torsion element according to the invention can in particular be used as part of a base support, as part of a seat support or as part of a backrest support. The torsion element can, however, also form the entire base support, seat support or backrest support. In these cases, a minimum number of rigid or essentially rigid areas are preferably provided on the torsion element, which form non-deformable connecting areas which are required for these assemblies to interact with other assemblies or components.

In particular, the torsion element according to the invention can form part of a one-piece base support-seat support combination, part of a one-piece base support-backrest support combination, part of a one-piece seat support-backrest support combination or part of a one-piece seat support-base support-backrest support combination.

The torsion element can, however, also form an entire one-piece base support-seat support combination, an entire one-piece base support-backrest support combination, an entire one-piece seat support-backrest support combination or an entire one-piece seat support-base support-backrest support combination. In these cases, a minimum number of rigid or essentially rigid areas are preferably provided on the torsion element, which form non-deformable connecting areas that are required for the interaction of the respective combination with other components or parts.

If the invention is applied to a chair mechanism, this mechanism does not necessarily have to be a mechanism in which the degree of freedom required for the execution of the movement is only provided with the use of the torsion element. The torsion element according to the invention can also be used in traditionally constructed chair mechanisms in which steel springs or other separate spring elements are used. In other words, it is possible to combine the use of a torsion element according to the invention with conventional spring arrangements. In hybrid mechanics of this type, the combination of separate and integrated energy stores results in a wide range of design options, which are ergonomically advantageous for both Movement sequences as well as for the realization of particularly small or flat chair mechanisms and for the creation of particularly elegant mechanisms can be used.

According to a first and second embodiment of the invention, a chair, in particular an office chair, is proposed which comprises a pedestal with a foot column on which a seat element and a seat back are mounted via a seat tilt mechanism, the seat tilt mechanism comprising a base support connected to the foot column to which a backrest support and a seat element support are articulated and the seat element and the seat back are connected to one another via an articulated connection of the seat tilt mechanism, a cross strut of the seat tilt mechanism forming a spring device, the cross strut extending in the transverse direction of the chair and the spring device having at least one torsion bar spring.

According to the first embodiment, the cross strut is connected to the base support, the backrest support, together with the base support and the torsion bar spring, being formed in one piece, in particular in one piece, from plastic. According to the second embodiment, the base support or the seat element support is formed in one piece, in particular in one piece, from plastic together with the torsion bar spring. According to a third embodiment of the invention, the torsion bar springs are formed in one piece, in particular in one piece, together with the base carrier and the seat element carrier and / or together with the backrest carrier.

Because the cross strut of the seat tilt mechanism forms a spring device, a structural component of the seat tilt mechanism can be used to generate a spring force for resetting the seat back. By on the base support and / or on the seat element support and / or on the Cross strut connected to the backrest carrier, which forms the spring device, makes it possible to significantly reduce the number of parts of the seat tilt mechanism. A chair with a common range of functions can thus be manufactured in a comparatively easier and more cost-effective manner.

The spring device has at least one torsion bar spring or is at least one torsion bar spring. The torsion bar spring can then be designed particularly simply as a bar-shaped spring or torsion bar. In particular, the cross strut itself can form the torsion bar spring. The one-piece, in particular one-piece design of the torsion bar spring with further chair components made of plastic can be carried out particularly cost-effectively in large numbers, for example by means of injection molding or compression molding. A special assembly of the base support or the seat element support with the torsion bar springs is then no longer necessary.

It can be provided that the spring device is designed with a bias. For example, the seat tilt mechanism can be mounted with the cross strut in such a way that the cross strut exerts a spring force on the seat back which always causes the seat back to be returned to a forward end position in the unloaded state.

Preferably, two torsion bar springs of the spring device can be integrally connected to the base support and, in relation to a vertical longitudinal center plane of the chair, can be connected to a lever of the seat tilt mechanism at their respective distal ends. The cross strut connected to the base support can then form two torsion bar springs which are each molded onto the base support. Respective proximal ends of the torsion bar springs can accordingly be molded onto the base support and one can be connected to the base support via a lever at each distal end of the torsion bar springs Torsion bar springs caused spring force are transmitted. The lever can extend essentially orthogonally relative to a longitudinal axis of the torsion bar spring or the cross strut.

According to the first embodiment, the backrest support, together with the base support and the torsion bar springs, can be formed in one piece, in particular in one piece, from plastic and can form the levers of the seat tilt mechanism. For example, the backrest support can be designed in the manner of a frame, at the lower end of which the base support for connection to the foot column is molded. The cross brace is then formed from a lower, vertical rod of the frame. The bars or legs of the frame that are connected to the cross brace and run parallel then each form the lever of the seat tilt mechanism. A further frame for receiving a backrest cushion or a covering can be arranged or integrated on the frame. An inclination of the frame as a result of the weight of a person then causes a torsion of the cross strut, since this is firmly connected to the base support on the foot column.

The seat element carrier can be formed from struts hinged to the base carrier and rear pivot joints which are arranged on the levers and which can hold the seat element. The struts can also be formed integrally with the base carrier made of plastic and extend in the direction of a front edge of the seat element. The seat element can easily be mounted on the front on the struts and on the rear on the rear swivel joints. The swivel joints can be formed, for example, by a recess in a frame of the backrest support, into which axes formed on the seat element are respectively inserted. Alternatively, the axes can be molded onto the frame and inserted into recesses in the seat element.

Furthermore, at least one front swivel joint that can be displaced in an elongated hole can be formed between the struts and the seat element, whereby a pivoting of the backrest support on the torsion springs can cause a displacement of the seat element in the longitudinal direction of the chair relative to the base support. The elongated hole or the front pivot joint can be formed at the distal ends of the struts, wherein a correspondingly formed pivot joint or an axis or an elongated hole can be formed on the seat element. The swivel joint or the axis can then be displaced and pivoted in the elongated hole, so that it is possible to move the seat element in the longitudinal direction of the chair with the seat back when the seat back is pivoted.

The spring device can have an adjusting device for adjusting a spring constant of the torsion bar springs, wherein the adjusting device can be formed from support elements displaceable in the longitudinal direction of the groove. The support elements can enlarge a profile cross-section of the respective torsion bar and thus a section modulus. For example, the support elements can be inserted into the groove and displaced along the groove so that when the support elements are displaced in the direction of the foot column, a comparatively lower spring stiffness is achieved and when the support elements are displaced towards a distal end of the torsion bar springs, a comparatively greater spring stiffness is achieved can.

The support elements can each be designed as a threaded pin with an inner profile, the opposing threads of which can engage in transverse grooves formed in the groove, the support elements being displaceable in the longitudinal direction of the groove by means of a rotation of an actuating shaft of the adjusting device inserted in the inner profile can be formed. The threaded pins can then be pushed onto the actuating shaft, with a rotation of the actuating shaft carried out for example by means of a hand-operated crank causing the threaded pins to move relative to or away from each other, depending on the direction of rotation, due to the opposing threads. The inner profile is preferably designed to match a cross section of the actuating shaft. The transverse grooves, which can run orthogonally to the groove, can be formed simply by machining or shaping. Moving the threaded pins by turning the actuating shaft also adjusts the spring constant.

According to the invention, according to the first embodiment, a seat tilt mechanism for a chair, in particular an office chair, is proposed which has a base support that can be connected to a foot column of the chair, two torsion bar springs of the seat tilt mechanism being integrally connected to the base support and, based on a vertical chair longitudinal center plane, to one at their respective distal ends Lever of the seat tilt mechanism are connected, whereby a backrest support of the chair together with the base support and the torsion bar springs is formed in one piece, in particular one piece, from plastic and forms the lever of the seat tilt mechanism, with a seat element support of the chair made up of struts hinged to the base support and rear levers arranged on the levers Rotary joints that hold the seat element are formed, with at least one front rotary joint being formed between the struts and the seat element, which can be displaced in an elongated hole, with the backrest support pivoting on the torsion bar springs causes a displacement of the seat element in the longitudinal direction of the chair relative to the base support.

In addition, an adjusting device for a chair, in particular an office chair, is proposed according to the invention, the adjusting device serving to adjust a spring constant of torsion bar springs of a seat tilt mechanism of the chair, the torsion bar springs being formed from a rod-shaped profile section with a groove running at least in sections in a longitudinal direction of the profile section , the adjustment device being made up of support elements that can be displaced in the longitudinal direction in the groove, the support elements each being designed as a threaded pin with an internal profile, the opposing threads of which engage in the groove formed transverse grooves, the support elements by means of a rotation of an actuating shaft inserted in the internal profile the adjusting device are displaceable in the longitudinal direction of the groove. Regarding the advantages of the adjustment device, reference is made to the description of the advantages of the chair according to the invention. Further advantageous embodiments of an adjusting device emerge from the description of features of claims 1 to 10.

According to the second advantageous embodiment, the base support, together with the torsion bar springs, can be formed in one piece, in particular in one piece, from plastic and can form the levers of the seat tilt mechanism. The base support can for example extend in the direction of a front edge of the seat element, wherein the torsion bar springs can be molded onto a front end of the base support. At the same time, the levers of the seat tilt mechanism can be formed on the cross strut or the torsion bar springs essentially orthogonally relative to a longitudinal axis of the latter. It is also possible to connect the levers directly to the seat element and to transmit a restoring force of the swivel joints to the movement of the seat back via the seat element.

The backrest support can be connected to the base support via a lower swivel joint. For example, the backrest support can be designed in the manner of a frame, which can be provided with a backrest cushion or a textile covering. The frame can be attached pivotably to the base support directly or via a connecting section which is integrally formed on the frame. This pivotable attachment can be designed simply via the lower swivel joint and thus enable pivoting of the backrest support or the seat back.

Furthermore, the seat element carrier can be formed from at least one strut articulated on the backrest carrier and the levers that hold the seat element. The strut can also be designed in one piece, in particular in one piece, with the backrest support and serve to connect to the seat element. The strut can be connected to the seat element in a rear region and support it. Optionally, several struts can also be molded onto the backrest support, which are then connected to the seat element. The levers can also be directly connected to the seat element, so that the seat element is supported directly on the levers in a front region of the seat element.

A rear swivel joint can be formed between the strut and the seat element, and the levers can each be connected to the seat element via a front swivel joint, whereby a pivoting of the backrest support at the lower swivel joint can cause a displacement of the seat element in the longitudinal direction of the chair relative to the base support. A pivoting of the backrest support on the lower swivel joint can accordingly cause the seat element to be displaced in the longitudinal direction of the chair by connecting the seat element to the rear swivel joint or the strut. The lever that connects to the seat element via the front swivel joint are connected, are then moved by the displacement of the seat element in the longitudinal direction of the chair, which causes a torsion of the torsion bar springs and thus the formation of a spring force or restoring force.

Two torsion bar springs of the spring device can be connected to the seat element at their respective distal ends in relation to a vertical longitudinal center plane of the chair and connected to a front swivel joint of the seat tilt mechanism on the base support via a lever formed integrally with the torsion bar springs.

The distal ends of the torsion bar springs can be screwed to the seat element or molded onto it.

A rear swivel joint can be formed between the seat element support and the seat element, and the lever can be connected to the base support via the front swivel joint, whereby a pivoting of the backrest support at the lower swivel joint can cause a displacement of the seat element in the longitudinal direction of the chair relative to the base support.

The seat element carrier can be formed from a frame that forms the cross strut, whereby two torsion bar springs of the spring device can be connected to the frame at their respective distal ends in relation to a vertical longitudinal center plane of the chair and to a front swivel joint of the seat tilt mechanism via a lever formed integrally with the torsion bar springs Basic support can be connected.

A rear swivel joint can be formed at a rear end of the frame, and the backrest support can be connected to the seat element support via the rear swivel joint, wherein pivoting the backrest support at the lower swivel joint can cause the seat element to be displaced in the longitudinal direction of the chair relative to the base support.

According to the invention, according to the second embodiment, a seat tilt mechanism for a chair, in particular an office chair, is proposed which comprises a base support that can be connected to a foot column of the chair, an extension of a backrest support of the chair that is hinged to the base support and a seat element support, with two torsion bar springs being integral with the base support or the Seat element carriers are connected and, based on a vertical longitudinal center plane of the chair, are connected at their respective distal ends to a lever of the seat tilt mechanism or to the seat element carrier, the extension being connected to the base carrier via a lower swivel joint, the seat element carrier consisting of at least the extension and the lever, which holds the seat element, is formed, wherein a rear swivel joint is formed between the extension and the seat element, and the lever is connected to the seat element or the seat element carrier via a respective front swivel joint, with pivoting of the backrest support with the extension on the lower swivel joint causes a displacement of the seat element in the longitudinal direction of the chair relative to the base support.

According to further embodiments of the invention, the torsion elements, in particular in the form of torsion bar springs, can be designed in one piece, in particular in one piece, together with the base support and the seat element support and / or together with the backrest support and the seat element support and / or together with the base support and the backrest support. In other words, the torsion elements are integrally connected to the base carrier and / or integrally to the seat element carrier and / or integrally to the backrest carrier.

Advantageously, the seat tilt mechanism has a plurality of one-piece, in particular one-piece, transverse struts so that the number of real swivel joints and required components can be further reduced.

According to the invention, the invention provides a seat tilt mechanism for a chair, in particular an office chair, which comprises a base support to which a backrest support and a seat element support are hinged, characterized in that a transverse strut of the seat tilt mechanism forms a spring device, the transverse strut extending in the transverse direction of the chair and wherein the spring device has at least one torsion element, in particular a torsion bar spring, and wherein the torsion element together with the base support or the backrest support or the seat element support is formed in one piece, in particular in one piece, from plastic. This does not exclude that the seat tilt mechanism comprises several cross struts with spring devices, the torsion elements of these spring devices, depending on the arrangement of the cross struts on different components of the chair mechanism, also integral with the base support and / or with the seat element support and / or with the backrest support, in particular in one piece, can be formed.

All embodiments have in common that the torsion bar spring or torsion bar springs can be formed from a rod-shaped profile section with a groove running at least in sections in a longitudinal direction of the profile section. In principle, the groove can also be designed in the manner of a continuous elongated hole on the cross strut. It is essential that a cross-section of the profile section is such that a moment of resistance suitable for developing a spring force is formed. The torsion bar spring can then, on the one hand, be easily elastically deformed and, on the other hand, can be manufactured inexpensively from plastic, for example. A desired The spring constant of the torsion bar spring can then be formed by a corresponding design of the groove.

The spring device can have a further torsion bar spring made of spring steel, the further torsion bar spring being inserted into the groove and fastened in a rotationally fixed manner at its proximal end to the base support or the seat element support or the backrest support and at the distal end to the lever of the seat tilt mechanism. With the further torsion bar spring made of spring steel, a spring constant of the torsion bar spring can be easily adapted. For example, it is then also possible to adapt a chair to different weight classes of users. The further torsion bar spring can be formed from the spring steel wire, wherein the proximal end and the distal end can be cranked. In the area of the groove, two bores for receiving the proximal or distal end can be formed. The further torsion bar spring can then be fixed simply by inserting it into the bores at the proximal end and the distal end. The further torsion bar spring can also be fixed to the bores with the proximal end and the distal end in such a way that the further torsion bar spring is pretensioned.

Regarding the advantages of the seat tilt mechanism according to the embodiments, reference is made to the description of the advantages of the chair according to the invention. Further advantageous embodiments of a seat tilt mechanism emerge from the feature descriptions of the claims.

Further advantages and advantageous embodiments of the objects according to the invention can be found in the description, the drawing and the claims.

Fig. 1

eine Sitzneigemechanik (Stand der Technik),

Fig. 2

eine Seitenansicht eines Stuhls nach der Erfindung (erste Ausführungsform),

Fig. 3

eine weitere Seitenansicht des Stuhls aus Fig. 2,

Fig. 4

eine perspektivische Explosionsdarstellung des Stuhls aus Fig. 2,

Fig. 5

eine Ausführungsform eines Grundträgers in einer perspektivischen Ansicht,

Fig. 6

eine weitere perspektivische Ansicht des Grundträgers aus Fig. 5,

Fig. 7

eine Fortbildung des Grundträgers aus Fig. 5 in einer perspektivischen Ansicht,

Fig. 8

eine weitere perspektivische Ansicht des Grundträgers aus Fig. 7,

Fig. 9

eine perspektivische Explosionsdarstellung des Grundträgers aus Fig. 7,

Fig. 10

eine weitere Fortbildung des Grundträgers aus Fig. 5 in einer perspektivischen Ansicht,

Fig. 11

eine Schnittdarstellung des Grundträgers aus Fig. 10,

Fig. 12

eine perspektivische Explosionsdarstellung einer weiteren Fortbildung des Grundträgers aus Fig. 7,

Fig. 13

eine Seitenansicht eines Stuhls nach der Erfindung (zweite Ausführungsform),

Fig. 14

eine weitere Seitenansicht des Stuhls aus Fig. 13,

Fig. 15

eine perspektivische Explosionsdarstellung des Stuhls aus Fig. 13,

Fig. 16

eine Teilschnittansicht des Stuhls aus Fig. 15,

Fig. 17

eine Seitenansicht eines weiteren Stuhls nach der Erfindung,

Fig. 18

eine weitere Seitenansicht des Stuhls aus Fig. 17,

Fig. 19

eine Unteransicht des Stuhls aus Fig. 17,

Fig.20

eine perspektivische Explosionsdarstellung des Stuhls aus Fig. 17,

Fig. 21

eine weitere perspektivische Ansicht des Querträgers aus Fig. 20,

Fig. 22

eine Seitenansicht eines weiteren Stuhls nach der Erfindung,

Fig. 23

eine weitere Seitenansicht des Stuhls aus Fig. 22,

Fig. 24

eine Unteransicht des Stuhls aus Fig. 22,

Fig. 25

eine perspektivische Explosionsdarstellung des Stuhls aus Fig. 22,

Fig. 26

eine Unteransicht eines Rahmens aus Fig. 25.

Exemplary embodiments of a chair according to the invention are shown schematically in simplified form in the drawing and are explained in more detail in the following description. It shows:

Fig. 1

a seat tilt mechanism (state of the art),

Fig. 2

a side view of a chair according to the invention (first embodiment),

Fig. 3

another side view of the chair Fig. 2 ,

Fig. 4

an exploded perspective view of the chair Fig. 2 ,

Fig. 5

an embodiment of a base support in a perspective view,

Fig. 6

another perspective view of the base support Fig. 5 ,

Fig. 7

a further training of the basic organization Fig. 5 in a perspective view,

Fig. 8

another perspective view of the base support Fig. 7 ,

Fig. 9

a perspective exploded view of the base support Fig. 7 ,

Fig. 10

a further training of the basic carrier Fig. 5 in a perspective view,

Fig. 11

a sectional view of the base support Fig. 10 ,

Fig. 12

a perspective exploded view of a further development of the base support Fig. 7 ,

Fig. 13

a side view of a chair according to the invention (second embodiment),

Fig. 14

another side view of the chair Fig. 13 ,

Fig. 15

an exploded perspective view of the chair Fig. 13 ,

Fig. 16

a partial sectional view of the chair Fig. 15 ,

Fig. 17

a side view of another chair according to the invention,

Fig. 18

another side view of the chair Fig. 17 ,

Fig. 19

a bottom view of the chair Fig. 17 ,

Fig. 20

an exploded perspective view of the chair Fig. 17 ,

Fig. 21

a further perspective view of the cross member Fig. 20 ,

Fig. 22

a side view of another chair according to the invention,

Fig. 23

another side view of the chair Fig. 22 ,

Fig. 24

a bottom view of the chair Fig. 22 ,

Fig. 25

an exploded perspective view of the chair Fig. 22 ,

Fig. 26

a bottom view of a frame Fig. 25 .

The Fig. 1 shows the state of the art. The Figures 2 to 12 show a first embodiment and its variants that Figures 13 to 26 show a second embodiment and its variants.

None of the figures show the invention to scale, but only schematically and only with its essential elements Components. The same reference symbols correspond to elements with the same or comparable function.

"Front" or "front" means that a component is arranged at the front in the longitudinal direction of the chair or refers to a component extending in the direction of the front seat edge or pointing in this direction, while "rear" or "rear" means that a component is arranged at the rear in the longitudinal direction of the chair or relates to a component that extends or points in the direction of the backrest or the backrest support or the rear seat edge. The information "above" or "upper" or "higher" and "below" or "lower" or "lower" refer to the intended use of the office chair or the office chair mechanics.

In Fig. 1 a seat tilt mechanism generally known from the prior art is shown in greatly simplified form to illustrate the pivoting principle. This is a synchronous mechanism 139 in which the three main components of the mechanism, namely base support 1, seat element support 3 and backrest support 4, are coupled to one another via swivel joints, so that a pivoting movement of the backrest support 4 in the pivoting direction 7, seen in the longitudinal direction 146 of the chair towards the rear a synchronous following movement of the seat element carrier 3 is induced, while the base carrier 1 remains stationary and immobile. The mechanism is mounted with its base support 1 on a foot column 2, which stands up with a cross chair on the floor. The backrest support 4 forms with its articulation to the base support 1 on the one hand and the rear area of the seat element support 3 or the seat shell or the seat frame on the other hand, a rear coupling element 140 integrated in the backrest support 4, while a separate front coupling element 141 connects the base support 1 with the connects the front area of the seat element carrier 3 or the seat shell or the seat frame. In this way, four pivot points are created, realized by four swivel joints, each swivel joint being assigned a transverse axis. These are the first swivel joint 142 for connecting the base support 1 to the rear coupling element 140, the second swivel joint 143 for connecting the rear coupling element 140 to the seat element support 3, the third swivel joint 144 for connecting the base support 1 to the front coupling element 141 and the fourth Rotary joint 145 for connecting the front coupling element 141 to the seat element carrier 3.

According to the invention, in principle, all of the real pivot points implemented by swivel joints 142, 143, 144, 145 can be replaced by virtual pivot points that are provided by one or more torsion elements according to the invention.

The transverse axis of the seat tilt mechanism according to the invention, which has the spring device, can serve to form any swivel joints of the seat tilt mechanism. For example, a front, upper transverse axis serving to form the swivel joint 145 can have the spring device according to the invention. Alternatively or additionally, a front, lower transverse axis serving to form the swivel joint 144 can have the spring device according to the invention. Alternatively or additionally, a rear, upper transverse axis serving to form the swivel joint 143 can have the spring device according to the invention. Alternatively or additionally, a rear, lower transverse axis serving to form the swivel joint 142 can have the spring device according to the invention.

The invention is not directed to the use of a single transverse axis according to the invention in a seat tilt mechanism limited. A seat tilt mechanism can have several such transverse axes with spring devices. For example, transverse axes according to the invention can form all front swivel joints of a seat tilt mechanism, seen in the longitudinal direction of the chair, and / or transverse axes according to the invention can all form rear swivel joints of a seat tilt mechanism, seen in the longitudinal direction of the chair. Likewise, transverse axes according to the invention can form all lower pivot joints assigned to the base support of a seat tilt mechanism and / or transverse axes according to the invention can form all upper pivot joints associated with the seat element carrier of a seat tilt mechanism. It is also possible to design the swivel joints through the transverse axes according to the invention "crosswise" (for example, design of the swivel joints at the front bottom and rear top). In principle, any arrangements of the transverse axes according to the invention are possible to form a single swivel joint, several selected swivel joints or all swivel joints of the seat tilt mechanism.

Each of the transverse axes according to the invention comprises a spring device with at least one torsion element, in particular a torsion bar spring. In this case, transverse axes can be provided which are essentially completely formed from a single torsion element. However, transverse axes can also be provided which have several torsion elements. These torsion elements can be arranged one behind the other along the longitudinal direction of the transverse axis. In this case, the torsion elements can also be spaced from one another. For example, the torsion elements of a transverse axis can be designed as axle sections which are connected to one another via axle sections with less twistability or via rigid axle sections. Designs are also conceivable in which the transverse axis has several in Has torsion elements arranged parallel to one another in the longitudinal direction of the axis.

The use of the transverse axes according to the invention is also not limited to seat tilt mechanisms with four-bar coupling. It can also be used in seat tilt mechanisms with a different coupling geometry. It is also possible to use one or more transverse axes according to the invention in seat tilt mechanisms in which deformation elements that also run in the longitudinal direction of the chair are used, which deform, in particular bend, due to a tensile or pressure load.

A first embodiment of the invention will now be described. The in Fig. 1 The rotary joint 142 shown is replaced by a virtual pivot point with the aid of a cross strut according to the invention.

In the Figs. 2 to 4 a chair 232 according to the invention is shown, which comprises a foot column 233 with a caster not shown, a seat tilt mechanism 234, a seat element 235, a seat back 236 and a base support 237 connected to the foot column 233. A cross strut 238 of the seat tilt mechanism 234 forms torsion bar springs 239. In particular, a substantially frame-shaped backrest support 240 of the seat back 236 together with the base support 237 and the torsion bar springs 239 is formed in one piece, in particular in one piece, from plastic. Parallel legs 241 of the backrest support 240 form levers 242 of the seat tilt mechanism 234 formed on the torsion bar springs 239. Struts 243, which hold the seat element 235, are also formed on the base support 237. In a seat shell 244 of the seat element 235, elongated holes 245 are formed, into each of which an axis 246 of the strut 243 is movably inserted. The slot 245 and the axis 246 form a front pivot 248. In addition, a rear swivel joint 247 is formed between each leg 241 or lever 242 and the seat shell 244. A rearward inclination of the seat back 236, as in FIG Fig. 7 shown, causes, in addition to tilting the seat back 236, a displacement of the seat element 235 to the rear, the axis 246 also being displaced in the elongated hole 245. The torsion bar springs 239 are each formed with a groove 249 running in the longitudinal direction of the torsion bar spring 239. Overall, the chair 232 is essentially formed from the backrest support 240, which is formed integrally with the base support 237 made of plastic, and the seat shell 244.

The Fig. 5 and 6 show a schematic representation of an embodiment of a base carrier 250 made of plastic, which has a spring device 251 with torsion bar springs 252. The torsion bar springs 253 are formed by a cross strut 253 with a continuous groove 254, a pivotable lever 256 being formed on each distal end 255 of the torsion bar springs 252. Furthermore, a flange 257 is formed in the base support 250 on the cross strut 253 for connection to a foot column of a chair, not shown here. As from the Fig. 6 As can be seen, the levers 226 can be inclined by an angle α, which causes the formation of a spring force and a deformation of the torsion bar springs 252.

The Figures 7 to 9 show a base support 258, which differs from the base support from Fig. 5 an adjusting device 259. The setting device 259 comprises threaded pins 260 which can be rotated with an actuating shaft 261 via a crank 262 and are displaceable on the actuating shaft 261 in a longitudinal direction. The threaded pins 260 engage in transverse grooves 263 which are formed in a groove 264 in torsion bar springs 265 of a transverse strut 266. Depending on the displacement of the threaded pins 260 For example, a moment of resistance of the torsion bar springs 265 can be changed so that a spring constant or the torsion bar springs 265 can be set to be harder or softer.

The Fig. 10 and 11 show a base support 267, which in contrast to the base support from Fig. 9 has further torsion bar springs 268 made of spring steel. The further torsion bar springs 268 are inserted into a groove 269 and attached to the base support 267 in a rotationally fixed manner. By arranging the further torsion bar springs 268 on the base support 267, a spring constant of the torsion bar springs 270 designed in this way can be significantly influenced.

The Fig. 12 shows a base support 271, which to the Figs. 7-10 described basic carrier combined.

In terms of related to the Figures 2 to 12 The first embodiment of the invention described is characterized in particular by the fact that it is a chair 232, in particular an office chair, which comprises a pedestal with a foot column 233 on which a seat element 235 and a seat back 236 are mounted via a seat tilt mechanism 234 The seat tilt mechanism comprises a base support 237, 250, 258, 267, 271 connected to the foot column, to which a backrest support 240 and a seat element support are articulated and the seat element and the seat back are connected to one another via an articulated connection 221 of the seat tilt mechanism, characterized that a cross strut 238, 253, 266 of the seat tilt mechanism forms a spring device 251, the cross strut extending in the transverse direction of the chair 100 and being connected to the base support, the spring device having at least one torsion bar spring 239, 252, 265, 270, the backrest support together with the Base support and the torsion bar once is formed, in particular in one piece, from plastic.

This chair is advantageously characterized in that the spring device 251 is designed with a bias.

This chair is advantageously characterized in that two torsion bar springs 239, 252, 265, 270 of the spring device 251 are integrally connected to the base support 237, 250, 258, 267, 271 and, in relation to a vertical chair longitudinal center plane, at their respective distal ends 255 to a lever 242 , 256 of the seat tilt mechanism 234 are connected.

This chair is advantageously characterized in that the backrest support 240 together with the base support 237, 250, 258, 267, 271 and the torsion bar springs 239, 252, 265, 270 are made in one piece, in particular one piece, from plastic and the levers 242, 256 of the Seat tilt mechanism 234 forms.

This chair is advantageously characterized in that the seat element carrier is formed from struts 243 hinged to the base carrier 237, 250, 258, 267, 271 and rear pivot joints 247 arranged on the levers 242, 256 which hold the seat element 235.

This chair is advantageously characterized in that between the struts 243 and the seat element 235 there is at least one front swivel joint 248 which can be displaced in an elongated hole 245, with a pivoting of the backrest support 240 on the torsion bar springs 239, 252, 265, 270 shifting the seat element 235 in the longitudinal direction of the chair relative to the base support 237, 250, 258, 267, 271.

This chair is advantageously characterized in that the torsion bar spring 239, 252, 265, 270 consists of a rod-shaped Profile section is formed with a groove 249, 254, 264, 269 running at least in sections in a longitudinal direction of the profile section.

Advantageously, this chair is characterized in that the spring device has an adjusting device 259 for adjusting a spring constant of the torsion bar springs 265, 270, the adjusting device being formed from support elements displaceable in the longitudinal direction in the groove 264, 269.

This chair is advantageously characterized in that the support elements are each designed as a threaded pin 260 with an inner profile, the opposing threads of which engage in the groove 264, 269 formed transverse grooves 263, the support elements by rotating an actuating shaft 261 of the setting device inserted in the inner profile 259 are displaceable in the longitudinal direction of the groove.

This chair is advantageously characterized in that the spring device has a further torsion bar spring 268 made of spring steel for each torsion bar spring 270, the further torsion bar spring being inserted into the groove 269 and at its proximal end on the base support 267, 271 and at its distal end on the lever the seat tilt mechanism is non-rotatably attached.

In terms of related to the Figures 2 to 12 The embodiment of the invention described is characterized in particular by the fact that it is a seat tilt mechanism 234 for a chair 232, in particular an office chair, which comprises a base support 237, 250, 258, 267, 271 that can be connected to a foot column 233 of the chair , characterized in that two torsion bar springs 239, 252, 265, 270 of the The seat tilt mechanism are integrally connected to the base support and, based on a vertical longitudinal center plane of the chair, are connected at their respective distal ends 255 to a lever 242, 256 of the seat tilt mechanism, a backrest support 240 of the chair, together with the base support and the torsion bar springs, being made in one piece, in particular made of plastic and forms the lever of the seat tilt mechanism, a seat element carrier of the chair being formed from struts 243 hinged to the base carrier and rear pivot joints 247 arranged on the levers, which hold the seat element 235, with at least one in an elongated hole 245 between the struts and the seat element displaceable front swivel joint 248 is formed, whereby a pivoting of the backrest support on the torsion bar springs 239, 252, 265, 270 causes a displacement of the seat element in the longitudinal direction of the chair relative to the base support 237, 250, 258, 267, 271.

In terms of related to the Figures 2 to 12 described embodiment of the invention, the solution according to the invention is characterized in particular by the fact that it is an adjusting device 259 for a chair 232, in particular an office chair, the adjusting device being used to set a spring constant of torsion bar springs 265, 270 of a seat tilt mechanism of the chair, the Torsion bar springs are formed from a rod-shaped profile section with a groove 264, 269 running at least in sections in a longitudinal direction of the profile section, the adjustment device being formed from support elements that can be displaced in the longitudinal direction in the groove, the support elements each being designed as a threaded pin 260 with an inner profile, whose oppositely arranged threads engage in transverse grooves 263 formed in the groove, the support elements by means of a rotation of an actuating shaft 261 inserted in the inner profile Adjusting device 259 are displaceable in the longitudinal direction of the groove.

A second embodiment of the invention will now be described. The in Fig. 1 The pivot joint 145 shown is replaced by a virtual pivot point with the aid of a cross strut according to the invention.

In the Figs. 13 to 16 a chair 10 according to the invention is shown schematically, which is designed as an office chair and which is therefore adjustable with regard to its seat height, its seat depth and its inclination behavior.

The chair 10 comprises a foot column, not shown in detail, which is designed to be telescopic and at the lower end of which a roller cross designed in the usual way is arranged.

A seat tilt mechanism 11, a seat element 12 and a seat back 13 of the chair 10 are arranged on the foot column. The seat tilt mechanism 11 comprises a base support 14 connected to the foot column, to which a backrest support 15 and a seat element support 16 are articulated. The seat element 12 is formed from a seat shell 17 with a seat cushion 18 and the seat back 13 from a backrest shell 19 with a backrest cushion 20.

The seat element 12 is connected to the seat back 13 via an articulated connection 21. The seat tilt mechanism 11 comprises two torsion bar springs 22 which are formed from a cross brace 23. The torsion bar springs 22 are molded onto the base support 14 and have levers 25 at outer, distal ends 24, which are connected to the seat shell 17 via a front swivel joint 26. Furthermore, a lower swivel joint 27 is formed on the base support 14, via which an extension 28 of the seat back 13 the Seat back, as in Fig. 14 shown, mounted pivotable to the rear.

Furthermore, a strut 29 is integrally formed on the seat back 13 or the extension 28 and is connected to the seat shell 17 via a rear swivel joint 30. How out Fig. 14 As can be seen, a rearwardly inclined seat back 13 on the lower swivel joint 27 leads to a displacement of the seat element 12, the torsion bar springs 22 being twisted. The transverse strut 23, which forms the torsion bar springs 22, is designed with a groove 31 running in the longitudinal direction of the transverse strut 23, which facilitate torsion of the transverse strut 23 or the torsion bar springs 22. The chair 10 is essentially formed from the one-piece, in particular one-piece, plastic base support 14, the backrest support 15 and the seat shell 17 or the seat element support 16.

In the Figs. 17 to 21 a chair 32 according to the invention is shown which comprises a foot pillar 33 with a roller cross (not shown in detail), a seat tilt mechanism 34, a seat element 35, a seat back 36 and a base support 37 connected to the foot pillar 33. Here, too, a cross strut 38 of the seat tilt mechanism 34 forms torsion bar springs 39.

Here, too, a cross strut 38 of the seat tilt mechanism 34 forms torsion springs 39. Distal ends 40 of the torsion bar spring 39 are each screwed to the seat element 35 with screws not shown here. A lever 41 is formed in one piece, in particular in one piece, in the center of the torsion bar springs 39 or the cross strut 38. The lever 41 is connected to the base support 37 via a front swivel joint 42. A lower swivel joint 43 together with an extension 44 of the seat back 36 is also formed on the base support 37. On the extension 44 is also a rear pivot joint 45 together with the Seat element 35 is formed. A backward inclination of the seat back 36 now causes, as in FIG Fig. 18 can be seen, a displacement of the seat element 35 in the longitudinal direction of the chair relative to the base support 37. In the embodiment of the chair 32 shown here, the extension of the seat back 36 is formed independently of a backrest support 46. A continuous groove is also formed in the cross strut 38.

The Figures 22 to 26 show a chair 48 in which, in contrast to the chair from Figs. 17 to 21 a seat element carrier 49 is formed from a frame 50. The frame 50 forms a cross strut 51 with the torsion bar springs 52. The frame 50 is formed in one piece, in particular in one piece, from plastic, in particular together with the torsion bar springs 52 and a lever 53 formed here on the torsion bar springs 52. A seat element 54 is placed on the frame 50 and fastened to it.

In terms of related to the Figures 13 to 26 described embodiment of the invention, the solution according to the invention is characterized in particular by the fact that it is a chair 10, 32, 48, in particular an office chair, which comprises a pedestal with a foot column 33 on which a seat element is attached via a seat tilt mechanism 11, 34 12, 35, 54 and a seat back 13, 36 are mounted, the seat tilt mechanism comprising a base support 14, 37 connected to the foot column, to which a backrest support 15, 46 and a seat element support 16, 49 are hinged and the seat element and the seat back over an articulated connection 21 of the seat tilt mechanism are connected to one another, characterized in that a cross strut 23, 38, 51 of the seat tilt mechanism forms a spring device, the cross strut extending in the transverse direction of the chair 100, the spring device having at least one torsion bar spring 22, 39, 52, the Basic support or the seat element support is formed in one piece, in particular in one piece, from plastic together with the torsion bar spring.

This chair is advantageously characterized in that the spring device is designed with a bias.

This chair is advantageously characterized in that two torsion bar springs 22 of the spring device are integrally connected to the base support 14 and are connected to a lever 25 of the seat tilt mechanism 11 at their respective distal ends 24 in relation to a vertical chair longitudinal center plane.

This chair is advantageously characterized in that the base support 14, together with the torsion bar springs 22, is made in one piece, in particular in one piece, from plastic and forms the lever 25 of the seat tilt mechanism 11.

This chair is advantageously characterized in that the backrest support 15 is connected to the base support 14 via a lower swivel joint 27.

This chair is advantageously characterized in that the seat element carrier 16 is formed from at least one strut 29 hinged to the backrest carrier 15 and the levers 25 which hold the seat element 12.

This chair is advantageously characterized in that a rear swivel joint 30 is formed between the strut 29 and the seat element 12, and the levers 25 are each connected to the seat element via a front swivel joint 26, with a pivoting of the backrest support 15 at the lower swivel joint 27 Displacement of the seat element in the longitudinal direction of the chair relative to the base support 14 causes.

In a further embodiment, the chair referred to above can advantageously be characterized in that two torsion bar springs 39 of the spring device are connected to the seat element 35 at their respective distal ends 40 in relation to a vertical longitudinal center plane of the chair and to a front rotary joint via a lever 41 formed integrally with the torsion bar springs 42 of the seat tilt mechanism are connected to the base support 37. In this case, this chair is advantageously also characterized in that the distal ends 40 of the torsion bar springs 39 are screwed or molded onto the seat element 35 and / or this chair is, characterized in that a rear swivel joint between the seat element support and the seat element 35 45 is formed, and the lever 41 is connected to the base support 37 via the front swivel joint 42, whereby a pivoting of the backrest support 46 on the lower swivel joint 43 causes a displacement of the seat element in the longitudinal direction of the chair relative to the base support.

In a further embodiment, the chair referred to above can advantageously be characterized in that the seat element carrier 49 is formed from a frame 50 which forms the cross strut 51, two torsion bar springs 52 of the spring device being connected to the frame at their respective distal ends in relation to a vertical center longitudinal plane of the chair and are connected to a front swivel joint 42 of the seat tilt mechanism on the base support 37 via a lever 53 formed integrally with the torsion bar springs. In this case, this chair is advantageously also characterized in that a rear swivel joint 45 is formed at a rear end of the frame 50, and the backrest support 46 is connected to the seat element carrier 49 via the rear swivel joint, the backrest support pivoting on the The lower swivel joint 43 causes the seat element 54 to be displaced in the longitudinal direction of the chair relative to the base support 37.

In a further embodiment, the chair referred to above can advantageously be characterized in that the torsion bar spring 22 is formed from a rod-shaped profile section with a groove 31 running at least in sections in a longitudinal direction of the profile section. In this case, this chair is advantageously also characterized in that the spring device has a further torsion bar made of spring steel for each torsion bar spring, the further torsion bar spring being inserted into the groove and at its proximal end on the base support or the seat element support and at its distal end on the Lever of the seat tilt mechanism is non-rotatably attached.

In terms of related to the Figures 13 to 26 described embodiment of the invention, the solution according to the invention is particularly characterized in that it is a seat tilt mechanism 11, 34 for a chair 10, 32, 48, in particular an office chair, which has a base support 14, 37, which can be connected to a foot column 33 of the chair. comprises an extension 28, 44 of a backrest support 15, 46 of the chair hinged to the base support and a seat element support 16, 49, characterized in that two torsion bar springs 22, 39, 52 are integrally connected to the base support or the seat element support and referred to a vertical longitudinal center plane of the chair their respective distal ends 24, 40 are connected to a lever 25 of the seat tilt mechanism or to the seat element carrier, the extension being connected to the base carrier via a lower swivel joint 27, 43, the seat element carrier consisting of at least the extension and the lever that holds the seat element holds, is formed, between the the extension and the Seat element a rear swivel joint 30, 45 is formed, and the lever is connected to the seat element or the seat element carrier via a respective front swivel joint 26, 42, whereby a pivoting of the backrest carrier with the extension on the lower hinge causes a displacement of the seat element in the longitudinal direction of the chair relative to the base carrier causes.

It applies to all embodiments that a seat element carrier is understood in the broader sense to mean a part that carries or holds the seat element. If the seat element consists on the one hand of a seat frame or a seat shell or the like and on the other hand of a cushion, a cover or the like, then in preferred embodiments a seat element carrier in the narrower sense also includes the seat frame or the seat shell, since these parts also have a carrying or holding function exercise for the actual seat. The seat element support is always hinged to the base support. According to the in Fig. 1 In the illustrated basic structure, the term seat element carrier can include, for example, the seat frame 3 and / or the front coupling element 141. With the chair 232, as in the Figs. 2 to 4 shown, for example, the seat shell 244 and / or the front swivel joint 248 serves as a seat element carrier. With the chairs 10, 32 according to Figures 13 to 26 For example, the seat element supports 16, 49 are provided. The seat shell 17 or the seat frame 50 can also serve there as seat element carriers.

The positions of the pivot points relative to one another and relative to other structural elements of the mechanism mentioned in connection with the exemplary embodiments of individual seat tilt mechanisms described above are only to be understood as examples of specific advantageous variants of the invention. The invention is also applicable to seat reclining mechanisms which have a different arrangement of the pivot points. All of the structural and functional features, properties and advantages in connection with spring devices having cross struts explained for an exemplary embodiment of the invention can also be transferred to the other exemplary embodiments.

All of the features shown in the description, the following claims and the drawing can be essential to the invention both individually and in any combination with one another.

List of reference symbols

1

Basic carrier

2

Foot pillar

3

Seat element carrier, seat frame

4th

Backrest

7th

Swivel direction

10

chair

11

Seat tilt mechanism

12

Seating element

13

Seat back

14th

Basic carrier

15th

Backrest

16

Seat element carrier

17th

Seat shell

18th

Seat pad

19th

Backrest shell

20th

Backrest upholstery

21st

Articulated connection

22nd

Torsion bar

23

Cross brace

24

distal end

25th

lever

26th

front swivel

27

rear pivot

28

Appendix

29

strut

30th

rear pivot

31

Groove

32

chair

33

Foot pillar

34

Seat tilt mechanism

35

Seating element

36

Seat back

37

Basic carrier

38

Cross brace

39

Torsion bar

40

distal end

41

lever

42

front swivel

43

lower swivel joint

44

Appendix

45

rear pivot

46

Backrest

47

Groove

48

chair

49

Seat element carrier

50

frame

51

Cross brace

52

Torsion bar

53

lever

54

Seating element

100

Cross direction of the chair

139

Synchronous mechanism

140

rear coupling element

141

Seat element carrier, front coupling element

142

first swivel joint

143

second swivel joint

144

third swivel joint

145

fourth swivel joint

146

Lengthways direction of the chair

232

chair

233

Foot pillar

234

Seat tilt mechanism

235

Seating element

236

Seat back

237

Basic carrier

238

Cross brace

239

Torsion bar

240

Backrest

241

leg

242

lever

243

strut

244

Seat shell

245

Long hole

246

axis

247

rear pivot

248

front swivel

249

Groove

250

Basic carrier

251

Spring device

252

Torsion bar

253

Cross brace

254

Groove

255

distal end

256

lever

257

flange

258

Basic carrier

259

Adjustment device

260

Grub screw

261

Operating shaft

262

crank

263

Transverse groove

264

Groove

265

Torsion bar

266

Cross brace

267

Basic carrier

268

another torsion bar

269

Groove

270

Torsion bar

271

Basic carrier

Claims (10)

A chair (10, 32, 232), in particular an office chair, comprising a base frame with a foot column (33, 233) on which a seat element (35, 235) and a seat back (36, 236) are mounted via a seat tilt mechanism (34, 234) The seat tilt mechanism comprises a base support (37, 237, 250, 258, 267, 271) connected to the foot column, to which a backrest support (15, 240) and a seat element support (16, 49) are articulated and the seat element (35 , 235) and the seat back (36, 236) are connected to one another via an articulated connection (21) of the seat tilt mechanism (34, 234), characterized in that a cross strut (38, 238, 253, 266) of the seat tilt mechanism (34, 234, 11) forms a spring device (251), the cross strut (38, 238, 253, 266) extending in the transverse direction of the chair (100) and wherein the spring device (251) has at least one torsion element, in particular a torsion bar spring (39, 239, 252, 265, 270, 22,), and wherein the torsion element together with the base support (37, 237, 250, 2 58, 267, 271) and / or the backrest support (15, 240) and / or the seat element support (16, 49) is formed in one piece, in particular in one piece, from plastic. Chair (10, 32, 232) according to Claim 1, characterized in that two torsion elements of the spring device (251), in particular torsion bar springs (39, 239, 252, 265, 270, 22), are integral to the base support (37, 237, 250, 258, 267, 271, 14) and are connected to a lever (242, 256, 25, 93, 85) of the seat tilt mechanism (34, 234) at their respective distal ends (255, 24) in relation to a vertical chair longitudinal center plane. Chair (232) according to claim 1 or 2, wherein the at least one torsion element is connected to the base support (237, 250, 258, 267, 271) and together with the backrest support (240) and the base support (237, 258, 267, 271) is formed in one piece, in particular in one piece. Chair (232) according to claim 3, characterized in that the backrest support (240) together with the base support (237, 250, 258, 267, 271) and the torsion bar springs (239, 252, 265, 270) are made in one piece, in particular in one piece Is made of plastic and forms the levers (242, 256) of the seat tilt mechanism (234), in particular in such a way that the seat element carrier consists of struts (243) hinged to the base carrier (237, 250, 258, 267, 271) and to the levers (242, 256) arranged rear swivel joints (247), which hold the seat element (235), is formed. Chair (10, 32) according to Claim 1 or 2, the at least one torsion element being formed in one piece, in particular in one piece, together with the base carrier (14, 37) or the seat element carrier (16). Chair (10, 32) according to claim 5, characterized in that the base support (14) together with the torsion bar springs (22) is formed in one piece, in particular one piece, from plastic and forms the lever (25) of the seat tilt mechanism (11) and that the Backrest support (15) is connected to the base support (14) via a lower swivel joint (27), in particular such that the seat element support (16) consists of at least one strut (29) hinged to the backrest support (15) and the levers (25), which hold the seat element (12) is formed. Chair (10, 32) according to Claim 5 or 6, characterized in that two torsion bar springs (39) of the spring device are attached to their respective vertical central longitudinal planes of the chair distal ends (40) are connected to the seat element (35) and are connected to a front swivel joint (42) of the seat tilt mechanism on the base support (37) via a lever (41) formed integrally with the torsion bar springs, in particular in such a way that the distal ends (40 ) the torsion bar springs (39) are screwed to the seat element (35) or molded onto it. Chair (10, 32) according to claim 5 or 6, characterized in that the seat element carrier (49) is formed from a frame (50) which forms the cross strut (51), two torsion bar springs (52) of the spring device in relation to a vertical one Chair longitudinal center plane are connected at their respective distal ends to the frame and are connected to a front swivel joint (42) of the seat tilt mechanism on the base support (37) via a lever (53) formed integrally with the torsion bar springs. Chair (10, 32) according to Claim 8, characterized in that a rear swivel joint (45) is formed at a rear end of the frame (50), and the backrest support (46) is connected to the seat element carrier (49) via the rear swivel joint , whereby a pivoting of the backrest support at the lower swivel joint (43) causes a displacement of the seat element (54) in the longitudinal direction of the chair relative to the base support (37). Seat tilt mechanism (34, 234) for a chair (10, 32, 232), in particular an office chair, comprising a base support (37, 237, 250, 258, 267, 271) on which a backrest support (15, 240, 72) and a Seat element supports (16, 49) are articulated, characterized in that a cross strut (38, 238, 253, 266) of the seat tilt mechanism (34, 234) forms a spring device (251), the cross strut (38, 238, 253, 266 ) extends in the transverse direction of the chair (100) and wherein the spring device (251) has at least one torsion element, in particular a torsion bar spring (39, 239, 252, 265, 270, 22), and wherein the torsion element together with the base support (37, 237, 250, 258, 267, 271) and / or the Backrest support (15, 240) and / or the seat element support (16, 49) is formed in one piece, in particular in one piece, from plastic.

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