EP2769642A1 - Synchronisation mechanism for office chairs with autoadaptive reset force coupled to the user's centre of gravity - Google Patents

Abstract

The mechanism has a seat support plate (5), which is elastically resilient, bendable and is raised according to pivoting movement of a backrest support (6) when a weight support is lifted by a user. The seat support plate is deformed upward against gravitational force of the user by application of an elastic restoring force. First and second steering wheels (3, 16) include longitudinal axes, which are aligned in a forward direction. A longitudinal axis of a third steering wheel (4) is positioned opposite to longitudinal axes of other wheels.

Description

The invention relates to a synchronous mechanism for office chairs coupled to the user center of gravity auto-adaptive restoring force according to the preamble of claim 1.

A synchronous mechanism for office chairs is with the subject of DE 20 2007 001 395 U1 known. In the local office chair, a backrest (backrest support) is connected via a swivel mechanism consisting of two handlebars with a seat support plate which can be raised and lowered.

The seat support plate is connected in a first, forward pivot point via a front link pivotally connected to a fixed seat support. Further, the seat support plate is pivotally connected to the seat support via a second link arranged spaced from the first link. On the pivotable part of the backrest carrier attacks one end of a drive belt, the other end engages the pivotable part of the second link. In order for a pivoting movement of the backrest support drives the predominantly directed in the vertical direction pivotal movement of the seat support on the consisting of two links pivoting mechanism. A rearward tilting movement of the user on the backrest support is thus translated into an upward pivotal movement of the seat. Accordingly, the user weight on the seat support plate also increases the restoring force on the back support in the direction of an upright position.

In this office chair only an increase in the seat is effected with backrest pivoting backrest. For this purpose, the document shows two - with respect to the longitudinal axis of the seat support - spaced apart, each obliquely forwardly directed arm, which are arranged substantially parallel to each other.

Disadvantage of the known office chair is therefore that the seat itself does not perform pivotal movement, but shifts substantially parallel and vertically upwards against the user weight. In the realization of ergonomic synchronous mechanisms, however, it is required that a certain seat back opening angle is achieved.

This means that when swinging back the backrest support a larger pivot angle with respect to the backrest than the seat should be achieved. However, this is not achieved in the aforementioned synchronizing mechanism, because the seat essentially lifts only vertically, but does not assume an angular position.

This results in an uncomfortable seat feeling and the user weight acts in the known synchronous mechanism only a total of two-dimensionally on the vertically movable seat support plate. However, there is the disadvantage that the user weight itself is applied only flat on the seat and can not be used for increasing the restoring force of the backrest support of the body of the user.

The invention is therefore based on the object, an office chair with synchronous mechanism according to the preamble of claim 1 so that an increase in the restoring force of the backrest support is achieved depending on the user weight, with a retention of the ergonomically required synchronous ratio with respect to the seat back opening angle is to be obtained ,

To solve the problem, the invention is characterized by the technical teaching of claim 1.

An essential feature of the invention is that the seat support plate in its front region with a first, obliquely forward link is supported relative to the seat support, that it is pivotally connected in its central region via a second, obliquely forwardly directed arm with the seat support, that the seat support plate with a third, obliquely rearwardly directed arm is pivotally supported relative to the seat support plate, and that the Seat support plate at least in the region of the second link - preferably in the middle region - is designed elastically resilient and when Nachhintenschwenken from the backrest support the weight bearing force of the user deformed the seat support plate by applying an elastic restoring force.

In the given teaching, the advantage is achieved that the back-pivoting backrest support pivots the seat support directed upward and - preferably in the form of a convex bending curve - elastically deformed resiliently. This is done against the approximately on the center of the seat support stored user weight, which has its focus there.

It is therefore essential that the chair is raised not only at the front, but also in the middle, a little less than the front. Thus, in addition to the upward movement, there is additionally a downward pivoting movement of the seat support plate in the rear region.
By detecting the user's weight predominantly in the front area and in the middle area of the deflectable seat carrier, there is the advantage that the degree of elevation of the seat carrier in the front area is reduced in comparison with the degree of elevation of the seat carrier in the central area. In the rear area, however, the seat support is not raised.

This has the advantage that when leaning back the pressure on the underside of the thighs of a person sitting on it becomes smaller.

Preferably, the degree of increase at the seat leading edge is now only 20 mm, while in known office chairs, such as after

Subject of the DE 20 2007 001 395 U1 , the degree of elevation exceeds 20 mm and therefore an unpleasant pressure on the underside of the thighs is present.

It is important that the deflection of the seat support generates a restoring force on the backrest support.

In the rest position, when the user sits on the seat without a backrest that is tilted backwards, the backrest support is held in an upright position via the front first link. As soon as the user leans against the backrest support with his upper body, the seat support according to the invention now convexly curves upwards approximately in the middle of the seat support via the second link there and generates a resilient restoring force on the backrest mechanism.

The farther the user leans backward, the farther his center of gravity is displaced rearwardly toward the backrest support, so that the body weight force in the center of gravity of the body is also moved to the center of the seat support and thus generates an increased restoring force via the second, central link the backrest.

Consequently, the seat support is used as an additional force element or energy storage. The seat support acts as a convex upward curved (flat) leaf spring, which is pressed down from the body center of gravity of the seated person in the middle area - against their spring force. The seat support plate wants to straighten itself due to their elastic restoring force, and thus the restoring force of the elastically deformable seat support plate is introduced in addition to the user's weight on the second, middle arm on the backrest, thereby achieving a much higher restoring force.

Essentially, the seat support plate is an elastically deformable flexure plate, and this flexure plate (seat support plate) is raised in the pivot joint of the center link while applying an elastic restoring force, with the two ends of the elastically deformable seat post plate directed in the longitudinal direction of the seat substantially no deflection.

So there is a convex deflection of the seat support plate with generation of a resilient restoring force, which causes an additional against the back of the user directed Lehnenverstellkraft on the backrest support.

In a first embodiment of the invention it is provided that the middle link is coupled directly to the deflectable seat support plate. In this area, a pivot point is arranged. It is therefore a direct coupling.

In a second embodiment of the invention, an indirect coupling is provided in which the middle link has in its upper pivotable part a roller which rolls with its outer periphery on a slide on the underside of the seat support plate. This has the advantage that the restoring force on the degree of deflection of the seat support plate can be adjusted on the backrest support by the slope of the slide on the underside of the seat support plate.

As a third embodiment of the invention, it is provided that an indirect coupling is created by the second, middle link being coupled to the underside of the seat support plate via a further link connected therebetween.

Advantage of this measure is that compared to a possibly wear-prone sliding surface now a solid coupling exists, but which acts indirectly. About the position of this other link can a Weight regulation or a fine adjustment of the restoring force depending on the user's weight. As indicated above, the weight setting may be changed to the restoring force of the back support by the position of the second, smaller arm, which is coupled to the larger, second link, on the degree of deflection of the seat support plate.

Instead, in a fourth embodiment, the link (coupler link) may be coupled firmly, and instead, the force accumulator, which is preferably designed as a compression spring, changed in position.

For all variants applies that the pressure force of the force accumulator, which is preferably designed as a helical compression spring, can also be designed adjustable.

The term "auto-adaptive restoring force" means that when the user leans back, his upper-body force FGR, which he initiates on the backrest support, is converted into a counterforce FR, which acts on the backrest support in the direction of an upright position. This is automatically controlled by the weight forces FGV and FGM depending on the user weight at two (or more) points.

The fact that the seat support plate raises due to the user weight in the central region, the user will additionally and depending on his own body weight apply a restoring force on the backrest. A light person will apply less force and thus less restoring force on the backrest than comparatively a heavy person applying more restoring force to the backrest. This control of the restoring force of the backrest is placed under the name "auto-adaptive restoring force" in the center of the invention.

Although the degree of deflection of the seat support plate is essentially always the same, because the degree of deflection of the geometry and the mechanical structure of the seat support plate dependent. However, different is the weight exerted by the body weight of the person sitting on this seat support plate. Accordingly, the restoring force on the backrest support is also changed automatically.

The restoring force with respect to the deflection of the seat support plate is essentially independent of the user. It is only dependent on the geometry of the handlebar and the mechanical structure of the seat support plate itself, that is, on their deflection capacity, their thickness and other mechanical Materialbeschaffenheiten. The deflectable seat support plate can be a steel spring or a plastic spring or a multiple slotted plate or similar bending elements or combinations of such elements.

The advantage is that with the seat support plate another power storage is formed, which claims no installation space, which is small and compactly installed and which is inexpensive and yet exerts a high restoring force due to its geometry and the weight of the user on the backrest support.

This achieves improved properties of a synchronous mechanism with auto-adaptive restoring force with fewer parts.

In a preferred embodiment of the invention, it is stated that with a Lehnenschwenkwinkelgrad of, for example, 26 degrees to the rear, a seat tilt to the rear by about 7 degrees is achieved. This is a significant advantage of the synchronous mechanism according to the invention in comparison to conventional synchronous mechanisms with automatic weight detection, because such a seat tilt to the rear by an angle of about 7 degrees in the subject of DE 20 2007 001 395 U1 is not achieved.

In a preferred embodiment of the invention, the seat support is moved to the rear by a distance of about 40 mm. Such Embodiment will be in the later drawings using the FIG. 4 ff described. This has the advantage that no noticeable loss of pelvic contact on the backrest support is to be feared, because the pelvis always remains in contact with the back-pivoting backrest support.

Another advantage of the invention is that there is no noticeable vertical displacement of a shirt of a user or a blouse of a user when pivoting back the backrest support in comparison to the also backwards pivoting backrest support.

Another advantage of the invention is that there is a slight lifting of the seat support in the front region by about 15 mm when pivoting back of the backrest support. This leaves you well below the maximum conducive value of 20 mm, which is therefore indicated in order to avoid an unduly high pressure on the thigh muscles. Because of this low Anhebeweges of, for example, only 15 mm, no noticeable pressure on the thigh muscles when pivoting back of the backrest support is generated.

The seat plate is arched in a preferred embodiment in the central region about 7 mm in relation to a horizontal reference plane still above. All of the abovementioned numerical values are merely exemplary values which in no way are intended to limit the invention. It is essential that the body weight of the user is used for the restoring force of the backrest carrier.

Due to the geometry of the front, first link, which is arranged between the front end of the seat support plate and the seat support, this link causes a limitation of the lifting of the seat support to the front. However, the user is slightly raised, and the energy accumulator generated thereby is used for the return of the backrest support.

With the pivoting movement to the rear, the seat is pulled backwards and downwards in the rear area. This achieves the tilted backward pivoting of the seat support by about 7 degrees. This also achieves a synchronous ratio to the rear of approximately 1: 3 to 1: 4 between seat support and backrest support.

In a particular embodiment of the invention, a fine adjustment to the user's weight can take place in that the coupling of the middle link to the middle pivot point on the seat support plate is adjustable. In such a fine adjustment, the restoring force can be adjusted to the user, for example, in two, three or more stages, from neutral to weaker or stronger.

In a preferred embodiment of the invention, moreover, the further advantage that in the forward synchronized movement (that is, when pivoting back of the backrest support in its rest position) a synchronous movement over the zero-degree position of the seat and back forward in the ratio of about 1: 1 to 1: 2 is reached. Normally the seat support plate is horizontal for a relaxed posture. Depending on the working posture of the user is ergonomically required that the seat support plate lowers slightly forward. This happens especially in a forward working posture, when the thigh muscles press on the front edge of the seat support plate. In this position, therefore, the seat support plate should be slightly inclined forward and takes in the ratio of about 1: 1 to 1: 2 with the backrest support. In a preferred embodiment, the backrest support then goes forward by about 5 degrees, and the seat support plate descends approximately 4 degrees forward from the bottom.

In general, therefore, a lowering of the seat leading edge is achieved in a relaxed, forward working posture, and the position of the back to the backrest support remains unchanged. Therefore, there is the advantage that even in prevented working posture of the back of the User is retained to the back. This avoids a round back, which could otherwise result in a Sitzvorneigung.

When Nachvornebeugen the user's body then follows the backrest support the back of the user and remains in contact with the back. Thus, the said round back is avoided at Sitzvorneigung.

The subject of the present invention results not only from the subject matter of the individual claims, but also from the combination of the individual claims with each other.

All information and features disclosed in the documents, including the abstract, in particular the spatial design shown in the drawings, are claimed to be essential to the invention insofar as they are novel individually or in combination with respect to the prior art.

In the following the invention will be explained in more detail with reference to drawings showing only one embodiment. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

• Figur 1: Aufbau der Mechanik in aufrechter Position des Benutzers
• Figur 2: Aufbau und Wirkweise der Mechanik in zurückgelehnter Position des Benutzers
• Figur 3: Bewegungsablauf von aufrechter zur zurückgelehnter Position
• Figur 4: Aufbau der Mechanik mit zusätzlicher Steuerlasche für die Steuerung der Sitztragplatte in der Bewegung nach hinten und Steuerung der Durchbiegung über "Schiefe Ebene" oder Kurvenbahn
• Figur 5: Aufbau der Mechanik mit zusätzlicher Steuerlasche in zurückgelehnter Position
• Figur 6: Bewegungsablauf der Mechanik mit zusätzlicher Steuerlasche von aufrechter zur zurück gelehnter Position
• Figur 7: Aufbau der Mechanik mit Feinjustiermöglichkeit der Rückstellkraft über verstellbare "Schiefe Ebene" oder Kurvenbahn
• Figur 8: Aufbau der Mechanik mit zusätzlicher Steuerlasche für die Steuerung der Sitztragplatte in der Bewegung nach hinten und Steuerung der Durchbiegung über Lenker (Variante von Figur 4)
• Figur 9: Aufbau der Mechanik mit zusätzlicher Steuerlasche und Lenker in zurückgelehnter Position
• Figur 10: Bewegungsablauf der Mechanik mit zusätzlicher Steuerlasche und Lenker von aufrechter zur zurückgelehnter Position
• Figur 11: Aufbau der Mechanik mit Feinjustiermöglichkeit der Rückstellkraft über Verstellung der Lenker (Variante von Figur 7)
• Figur 12: Unteransicht von Figur 1 (Sitzträger für Ansicht offen)
• Figur 13: Wie Figur 8, jedoch mit Verstellung des Kraftspeichers als Feinjustierung der Rückstellkraft
• Figur 14: Aufbau der Mechanik mit geändertem Drehpunkt des Lehnenträgers zur besseren Nutzung des Kraftspeichers 15
• Figur 15: Aufbau und Wirkweise der Mechanik nach Figur 14 in zurückgelehnter Position
• Figur 16: Aufbau und Wirkweise der Mechanik nach Figur 14 und 15 in zurückgelehnter Position mit stärkerer Erfassung des Benutzergewichts und Verstellmöglichkeit der Lehnenrückstellkraft
• Figur 17: Aufbau der Mechanik mit Waage zur Kraftübertragung des Benutzergewichts
• Figur 18: Aufbau der Mechanik nach Figur 17 in zurückgelehnter Position
• Figur 19: Aufbau der Mechanik nach Figur 17 mit virtueller Achse für eine Drehbewegung des Sitzes um die Längsachse

Show it:

• FIG. 1 : Structure of the mechanics in upright position of the user
• FIG. 2 : Structure and mode of action of the mechanism in the user's reclined position
• FIG. 3 : Movement from upright to reclined position
• FIG. 4 : Mechanism with additional control lug for the control of the seat base in the backward movement and control of the deflection over "inclined plane" or curved path
• FIG. 5 : Structure of the mechanism with additional control tab in a reclined position
• FIG. 6 : Movement of the mechanism with additional control tab from upright to leaned back position
• FIG. 7 : Structure of the mechanism with fine adjustment possibility of the restoring force via adjustable "inclined plane" or curved path
• FIG. 8 Design of the mechanism with additional control tab for the control of the seat support plate in the movement to the rear and control of the deflection over handlebar (variant of FIG. 4 )
• FIG. 9 : Structure of the mechanism with additional control tab and handlebar in reclined position
• FIG. 10 : Movement of the mechanism with additional control tab and handlebar from upright to reclined position
• FIG. 11 : Structure of the mechanism with fine adjustment of the restoring force via adjustment of the handlebars (variant of FIG. 7 )
• FIG. 12 : Bottom view of FIG. 1 (Seat support open for view)
• FIG. 13 : As FIG. 8 , but with adjustment of the energy storage as fine adjustment of the restoring force
• FIG. 14 : Structure of the mechanism with a changed pivot point of the backrest support for better use of the energy accumulator 15
• FIG. 15 : Structure and mode of action of the mechanics after FIG. 14 in a reclined position
• FIG. 16 : Structure and mode of action of the mechanics after FIG. 14 and 15 in a reclined position with greater detection of the user weight and adjustment of the Lehnenrückstellkraft
• FIG. 17 : Structure of the mechanism with scale for power transmission of the user weight
• FIG. 18 : Structure of the mechanics after FIG. 17 in a reclined position
• FIG. 19 : Structure of the mechanics after FIG. 17 with virtual axis for a rotational movement of the seat about the longitudinal axis

In FIG. 1 the synchronous mechanism according to the invention is shown on a work chair. On a seat support 1, which is fixed in a conventional manner to a gas spring 2 for seat height adjustment, a first link 3 is arranged in the front region of the seat support 1, with the seat support 1, the lower pivot point 11 and with its other, opposite end upper pivot point 12 forms. It is therefore a simple coupling joint.

Instead of such a link 3, a sliding link can be used, in which the upper pivot bearing 12 is not fixed, but in the region of a slot is displaceable, which is arranged in the seat support 1.

In the middle region of the seat support 1, a further link 16 is arranged, which was referred to in the general description as "second link", and in turn with the seat support 1, a lower pivot point 9 with its free pivotable end an upper pivot point 10 with the seat support plate fifth formed.

It is also stated that the pivot point 12 of the first link 3 is also arranged on the seat support plate 5, namely at its front free end.

The pivoting path C describes the path that the pivot point 12 of the first link 3 executes when reclining a backrest support 6.

The second link 16 is connected as a material-integral or as a multi-piece part with the backrest support 6, which carries in a conventional manner a backrest pad 7, against which the user presses with his force of the back, the term FGR means that the user weight FG is exerted from the back (R) ago.

It is important that in the rear region of the seat support plate 5, a third link 4 is arranged, which forms an upper pivot point 14 with the seat support plate 5 and a lower pivot point 13 with the seat support 1. On the seat support plate 5 a seat cushion 8 is arranged in a known manner.

An energy accumulator 15, for example in the formation of a helical compression spring or as a gas spring, is supported with its front free end opposite the seat support plate 5 and with its rear free end on the seat support 1. By the force accumulator 15, a basic restoring force is generated on the backrest support 6 by the force accumulator 15, the seat support plate 5 always moves forward, that is contrary to the indicated arrow direction C.

When Nachhintenschwenken the backrest support 6, however, pivots the upper pivot point 12 on the handlebar 3 in the direction of arrow C backwards and the pivot point 10 on the second arm 16 in the direction of arrow B backwards and further on the third arm 4 of the pivot point 14 in the direction of arrow D backwards.

In this case, it is preferred if the longitudinal axis is rectified (but not necessarily parallel) by the front link 3 with the longitudinal axis through the middle link 16 and is formed opposite to the longitudinal axis directed by the rear link 4. This means that the front link 3 is approximately the same obliquely forward - but at a different angle - as the longitudinal axis is directed by the handlebar 16, while these two links 3 and 16 - oppositely directed to link 4 - the third link 4 to the rear is directed.

This achieves that when the reclining or swinging back of the backrest support the two front handlebars 3 and 16 lift while the seat support plate 5 is slightly raised, while the rear handlebar 4 lowers and pivoted the rear of the seat support plate 5 down.

The user weight force FG is introduced to the seat support plate 5 in the central region as the user weight force component FGM approximately at the center of the seat support plate 5 and approximately near the middle link 16.

A proportion of the user weight is transmitted via the thighs on the front part of the seat support plate 5 and is referred to there as the user weight component FGV.

According to FIG. 2 is the rearward pivoting of the backrest support 6 exerted a weight from the back of the user on the backrest support 6, but at the same time a counterforce FR arises. Importantly, the resetting weight force FR is dependent on the user's body weight on the seat support plate 5, as described below.

When Nachhintenschwenken the backrest support 6 of the backrest support, which is connected directly to the middle arm 16 acts in the direction of an upward pivoting movement in the direction of arrow 25 upwards on the underside of the seat support plate 5. But after the seat support plate 5 in the rear pivot point 14 and the front pivot point 12th is positively controlled and is held by the handlebars 3 and 4, there is a convex deflection of the entire seat support plate 5 in the central region, as it is based on FIG. 2 was shown. The force FS is created by the material restoring behavior of the rigid seat support plate 5.

In this deflection, a rightward torque M2 is generated about the pivot point 9 of the middle arm 16 in the direction of arrow 26. At the same time, a torque M1 directed to the right in the direction of arrow 27 is again generated around the lower pivot point 11 about the front link 3.

The two torques M1 and M2 are different. Because the middle handlebar 16 straightens, and first according to FIG. 1 has a flat pivot position and is then transferred to a vertical pivot position, the middle region of the seat support plate 5 is directed more, while this is not the case with the other arms 3 and 4, so that the seat support plate only about in the region of the middle arm 16 elastic is raised resiliently against a restoring force FS generated thereby.

The measure of the restoring torque M2 by the deflection of the seat support plate, which is bent convexly due to their now resulting curvature, is determined by the force FS and the user weight. A heavy user with a relatively high weight force FGM will generate an associated high restoring force on the seat support plate 5, and thus achieve a relatively high torque M2. A light weight FGM user generates less torque in Arrow direction 26. According to this weight force so that the restoring force FR is changed to the backrest support. The higher the weight force FGM trying to bring the seat supporting plate 5 to its unbent basic position, the higher the moment M2 and the higher the restoring force FR on the backrest support 6.

The same process is also carried out by the user weight FGV, which bears on the seat support plate 5 in the front region, which in turn generates a torque M1 acting in the direction of the arrow 27, in dependence on the force of the user at the point FGV.

Thus, the total user weight acts at two different locations on the seat support plate 5 and thus generates a restoring moment (M1 and M2) on the backrest carrier and thereby a large proportion of the force FR.

Because the center of gravity moves with the pivotal movement of the backrest support, the user weight force for the restoring force FR is preferably used at two different areas, namely at the areas FGM and FGV.

However, the invention is not limited thereto. In another embodiment, it may be provided that the front weight of the user FGV is not used to increase the restoring force FR on the backrest support 6. It then suffices to generate a return of the backrest support with the force FR only with the user force FGM acting on the seat support plate 5 in the middle region.

In FIG. 3 are the two pivoting movements after the FIGS. 1 and 2 the sake of clarity in a single figure, wherein the same parts are provided with the same reference numerals. The swung back position is indicated by the letters a characterized. Thus, the change in position of the individual parts can be compared.

The FIGS. 4 to 7 show the indirect coupling of the middle arm 16 to the seat support plate. 5

For this purpose, more parts compared to the execution FIGS. 1 to 3 present, namely a control tab 20 which is attached to the left end via a pivot point 18 below the pivot point 14 on the rear link 4 and thus controls the pivoting movement of the rear link 4 in response to the pivotal movement of the central link 16.

The other end of the control tab 20 is received in the axis 23 of the handlebar 16.

Instead of the connection of the control tab 20 directly in the axis 23 of the handlebar 16, a further pivot bearing 16 may be provided on the middle arm.

It is important that the middle arm 16 has at its upper, free and pivotable end an axis 23 with a roller 17 or a sliding member which with the outer periphery of an inclined slide 19 on the underside of the seat support plate 5 in the direction of arrow B and in the opposite direction is displaceable or unrollable.

The inclination of the slide 19 in comparison to the horizontal influences the degree of deflection of the seat support plate 5 in the central region. Since the seat support plate 5 further moves in the pivoting movement of the backrest support 6 to the rear than the roller 17, a rolling of the roller takes place on the seat support plate forward.

The stronger the inclination of the slide 19 in relation to the horizontal, the lower the deflection of the seat support plate 5 in the central region.

The slide 19 does not necessarily have to be designed as a flat slideway. It may also be curved in shape to influence and control a certain deflection of the seat support plate 5 over the entire pivoting range. It may also have steps or interruptions to provide certain and sensible detent or glide levels to the user.

By pivoting the middle arm 16 in the direction of arrow B thus this handlebar 16 is directed and pushes the middle part of the seat support plate 5 upwards. At the same time the rear link 4 is taken by the control tab 20 and pivoted backwards in the direction of arrow D.

The FIG. 5 shows in comparison to FIG. 4 Now, the roller or the sliding member 17 has a certain displacement along the slide 19 performed and due to the oblique inclination of the slide, the seat support plate 5 is convexly deformed in the central region upwards.

The FIG. 6 shows the intertwined FIGS. 4 and 5 where the changes in the different positions of the handlebars are recognizable. The pivoted position is indicated by the letter a.

In the FIG. 7 An adjustment of the slide 19 is described in detail. The flat slideway is designated 19b, which has an angle β to the horizontal, while the steeper slideway is provided with the reference numeral 19 and has a greater inclination α with respect to the horizontal.

The end positions of the pivoted slideways are in each case with the letters 19a (to the initial position 19) and 19c (to the initial position 19b) in FIG. 7 shown.

In this embodiment, it is shown how, depending on the setting of the angle of the slide a deflection of the seat support plate 5 can be adjusted. The deflection of the seat cushion 8 at an angle α is denoted by 8a, while the deflection at the angle β is denoted by the reference numeral 8c.

The adjustment of the slide 19 may be e.g. be adjusted by a slide button, by a rotary or by a wedge slide or the like, so that so the user himself can adjust the deflection of the seat support plate 5 and thus the restoring force FR.

The slideway is fixedly arranged on the underside of the seat support plate 5 or it is formed as a separate component. In the case of adjustment of this slide it is designed as a separate part and has approximately a minimum width of about 40 mm, but may also have approximately the entire width of the seat support plate 5, on which the roller or the sliding member 17 rolls.

The FIGS. 8 to 10 show another embodiment of the indirect coupling. There is no free displacement of a roller or sliding member 17 on a slide track 19. Instead, there is an indirect coupling via a further link 21, which serves the weight fine adjustment.

In this embodiment, at the upper part of the middle arm 16 a pivot point 24, in which the lower part of the arm 21 is received, which is received at its upper end in the upper pivot point 22 which is fixed in the center region of the seat support plate 5.

Accordingly, the middle link 16 is indirectly coupled via the interposed link 21 on the underside of the seat support plate 5.

The other parts are substantially the same as described above, and previously based on the FIG. 4 mentioned control tab 20 for controlling the pivoting movement of the rear link 4 is also present in this embodiment.

By the involvement of a fixed link 21, the same movement is achieved as in the roller 17, which is arranged freely displaceable on a slide 19 on the underside of the seat support plate 5. Any signs of wear that could be caused by a roller or a sliding member are avoided in this embodiment. Otherwise, the deflection of the seat support plate 5 is also changed according to the setting of the pivoting movement of the handlebar 21. The FIG. 9 shows the pivoted backwards position of the backrest support 6 and thereby caused rearward pivoting of the handlebar 21st

The FIG. 10 shows the intertwined FIGS. 8 and 9 to represent the changing handlebars and pivotal movements in a drawing. By the letter a in each case the pivoted-back position of the entire arrangement is marked.

The FIG. 11 shows the possibility of weight fine adjustment by the handlebar 21st

The steepness of the link 21 influences the deflection of the seat support plate 5. The steepness of the link 21 is thereby made adjustable by the pivot point 22 is designed to be displaceable. For this purpose, it is provided that the upper end of the arm 21 is not fixedly received on the underside of the seat support plate 5, but via an adjustable intermediate part, for example via a spindle adjustable in length or by an eccentric part, which is eccentrically adjustable and the Pivot 22 changeable designed.

According to the displacement of the pivot point 22 thus different initial positions of the arm 21 can be achieved, according to the drawing FIG. 11 are given with the angle data γ and δ.

When the pivoting angle γ is reached, the deflection of the seat cushion 8 is achieved in the position 8a, upon reaching the pivoting angle δ the greater deflection of the seat cushion is achieved in the position 8c.

If the initial position of the link 21 is shallower (γ), the reclined position pivoted backward (21c) is also steeper, and accordingly the deflection on the seat cushion 8 is also stronger.

The Figures 14 and 15 show an embodiment in which the pivot point 9 of the backrest support 6 and the middle arm 16 is displaced upwards and below the seat support plate 5, so that the free pivot point 28 of the central arm 16 is offset downwards, so that this additionally the recording of the energy storage 15 allows. Thus, the backrest support 6, the middle arm 16 and the pivot point 28, on which the force accumulator 15 can attack, about the pivot point 9 in the direction of E. This has the advantage that the force FK now at both ends for the restoring force on the backrest support can be used. The control of the rear link 4 and thus the movement of the seat support plate 5 to the rear is effected by the control tab 20, which is offset in this embodiment also down. The deflection of the seat support plate is effected in the same manner as in the other embodiments and has the same functions. Also, as described above, the degree of deflection of the seat plate 5 can be used for a fine-weight adjustment. The degree of deflection is set here as described above. FIG. 15 shows in comparison to FIG. 14 the backward pivoted position of the back support 6. The auto-adaptive restoring force is achieved in this embodiment in the same manner as in the other embodiments. The user is raised in the front area of the seat 8 and in the middle area against his weight (FGV and FGM). In the after

FIG. 14 and 15 As shown embodiment, the seat support plate 5 is bent convexly by the roller 17 in the central region. By the restoring force of the seat support plate and the user weight force FGM an upward force FS1 is achieved in the rear link 4, which causes a right-handed torque M3 on the rear link 4. Depending on the user weight and degree of deflection, this torque will be larger or smaller and thus automatically control the restoring force FR on the user back. In this case, the roller 17 acts as a fulcrum of a "rocker", so that a higher user weight force FGM (to the right of the roller 17) also causes a larger force FS1 (left of the roller 17).

FIG. 16 shows an embodiment analogous to Figures 14 and 15 in which it is provided, by the shape of the roller or by an intermediate part 29 which is coupled to the central link 16, to directly connect the deflection of the seat support plate and the elevation of the user with the backrest pivoting movement. Thus, the seat support plate is not just as in FIG. 14 and 15 Passively bent by lowering the seat support plate in the rear area and by resting on the roller up, but also actively by raising the intermediate part 29, which moves with the backrest support 6 in the pivoting movement to the rear about the pivot point 9 upwards. This results in the contact point 30 by the force FS2 also to the clockwise torque M3 additional right-handed torque M4. Due to this additional moment M4, the user weight force FGM is considered more auto-adaptive for the backrest restoring force FR.
In a further embodiment variant is provided, which can be moved by changing the distance f of the contact point 30. Thus, the effective lever travel of FS2 and thus also the right-handed moment M4 changes. Further, this also changes the degree of deflection of the seat support plate 5 and thus the size of the force FS2.

The FIG. 12 shows a bottom view of the entire synchronous mechanism, this bottom view applies essentially to all previously and subsequently illustrated embodiments.

In this embodiment, it can be seen that, for example, the rear link 4 is formed in two parts and consists of two spaced-apart link parts. However, the invention is not limited thereto. Instead of a bipartite each handlebar assembly, a continuous, one-piece handlebar can be provided. Only for Gewichtsersparnis-, assembly and cost reasons, the handlebars are usually formed in two parts. It is important that the links are spaced from each other to achieve a stable support at the respective articulation points on the underside of the seat support plate 5.

Of the FIG. 1 starting from the bottom view of FIG. 12 recognizable that the fulcrums 9 and 10 are formed as axes extending over a certain longitudinal extent through two spaced legs of a seat support 1 therethrough.

Of course, the seat support 1 may also be formed as a continuous plate. Only for weight saving reasons, the seat support 1 according to FIG. 12 in the central region, that is in the region of the gas spring 2, continuously formed as a plate and then extends with two legs in the region of the front link 3 inside. The seat support 1 may also be closed by a bottom below.

The invention is not limited to that the axes which form the pivot points 11 are interrupted. These axes can also be formed continuously.

In the FIG. 12 is not the aforementioned control tab 20 located, but which could also be present in this embodiment. The The omission is only for illustrative reasons. It has previously been stated that in some embodiments a control tab 20 is present and not in others.

In FIG. 13 is compared to another embodiment FIG. 11 shown that the weight fine adjustment does not have to be done on the displacement of the pivot point 22 on the handlebar 21. In contrast, in a different embodiment, the pivot point 22 remains fixed and instead the force accumulator 15 is changed.

Therefore, in the illustrated embodiment, the power storage 15 is shown in its lower position and in the other, raised position as a force storage 15 '. His point of attack on the seat support can thus be designed to be adjustable in the direction of arrows E up or down.

In the upward adjustment E, the pressing force and thus the restoring force on the backrest support 6 is greater, while in the direction of arrow E downward adjustment or pivoting of the lower point of the energy storage leads to a lower restoring force on the backrest support 6.

This embodiment also shows that, as an additional adjusting force for the return of the backrest support, the restoring force of the force accumulator can additionally be used. This embodiment can be combined with all the aforementioned embodiments. It therefore enjoys protection in isolation, but also protection in any combination with one or more of the aforementioned embodiments.

A further embodiment is disclosed in US 5,356,067 Figures 17 and 18 described. Here, the weight of the user is not transmitted directly to the middle handlebar. The weight is on the point 34 on a scale 33 transmitted, which in turn on the slide 19 transmits its force to the roller 17 and the middle arm 16. Thus, the full weight (FGH and FGM) can be transmitted to the central handlebar without loss relevant to the invention in the rear handlebar 4, a slot 31 is mounted. Through the slot 31, a power transmission is avoided on the rear handlebar, since the seat support plate 5 transmits the entire weight on point 34 to the balance 33 by their material and geometry-related stiffness. The slot length a determines the spring travel 32 of the seat support plate 5 by the weight of the user, since the seat support plate can not be absolutely rigid. Users with a large body weight will take up almost the entire travel, users with a low body weight correspondingly less travel. The length of a must ideally be chosen so that even heavy users do not fully reach the full length a, so that the full weight can be transferred to the scale.

According to the invention, a heavy weight is thus transmitted to the scale 33 and thus to the middle link in the case of heavy users, which effects a large restoring force on the backrest 6. For lighter users, a smaller restoring force is correspondingly effected. As a result, the user weight is used for the control of the restoring forces. This distinguishes an auto-adaptive chair mechanism.

The rear link 4 has in this embodiment, only the function of the movement control of the seat support plate to the rear via the control tab 20th

In a further embodiment, the power transmission point 34 can also be made displaceable in the direction E. By shifting in direction E, the path ratio b: c can be influenced. This makes the distribution of weight forces on the front and middle handlebars adjustable. This can be for a regulation of the restoring force on the user be used with a pivoting of the backrest in direction A as a fine adjustment.

In the FIG. 18 the mechanism is shown in a backward pivoted position. The power distributions are shown. By the weight forces FGV (weight force front), FGM (weight center) and FGH (weight rear) a force (FG) 37 dependent on the user weight is generated via the force transmission point 34 on the balance. This controls the moment (M2) 26 as a function of the user weight. By the force accumulator 15, a force (FK) 38 is generated, which causes the restoring moment (M1) 27. The restoring moment M1 is also influenced by the weight force FGV, which again depends on the user weight and on the ratio b: c (35:36). The sizes of M1 and M2 are thus dependent on the size of the weight of the user. The moments M1 and M2 are rectified and bring about the front link 3, the seat support plate 5 and the control tab 20 via the central link 16, the restoring force 39 (FR).
The bending of the seat support plate 5 described in the other embodiments as an additional energy storage can also be advantageous in this embodiment, but is not a prerequisite for the task of an auto-adaptive chair mechanism.

FIG. 19 shows another function of the embodiment as described above. Through the slot 31 in the rear handlebar 4, the seat support plate 5 and thus the seat 8 can perform a movement about a virtual longitudinal axis 40. The user's seat and thus the user's pelvis will move 40 in the direction 41 (F) up or down. The dimension a (32) of the slot determines the amount of movement of the pivoting of the seat about the virtual axis 40. Thus, the seat can pivot about 2 ° to 4 ° in the longitudinal direction. This movement promotes active and dynamic sitting and thus the movement of the user required by the ergonomists for the care of the Intervertebral discs with tissue fluid. An embodiment in which this movement is damped by, for example, elastic components is advantageous.

With all embodiments, a flat design with few components is achieved, with only a few pivotable parts are present, which are subject to undesirable wear. The further advantage of the invention is that the user weight on the seat support plate 5 at two different locations (namely, once approximately in the middle area and once in the front area) is detected and used for the return movement of the backrest support 6. This has the advantage that a corresponding restoring force is generated on the backrest support even in a prone work position of the user on the seat support plate, in which the body weight acts substantially on the front region of the seat support plate. Likewise, in the case of a backwards inclined working position of the user via the middle link, the correct restoring force is produced on the backrest carrier, although the front link is relieved of load.

In an alternative embodiment, it is provided that the seat support plate 5 is formed slippery and that only the middle, transversely spaced apart handlebars 16 press with an acted upon by the pivotal end of the arm 16 pressure plate against the underside of the seat support plate 5. The resilient restoring force is then generated by the nature and design of the links 16 and / or connected to these links 16 pressure plate which presses against the underside of the pliable seat support plate 5 when the backrest support 6 tilts to the rear. A pliable design of the seat support plate is achieved for example by a simple or multi-layered cloth body. The seat support plate 5 can therefore also be designed as a (slippery or only slightly elastic) cloth body. Based on this one possible design of the seat support plate, this can also be created from a little bendable plastic or metal plate or a plastic-metal composite. The elastic resilience is then not affected by the nature and material properties of the seat support plate formed, but by the pressing of the underside of the seat support plate against the seat support plate pressure pad.

drawing Legend

• 1 seat carrier
• 2 gas spring (seat height adjustment)
• 3 handlebars front (first)
• 4 rear handlebars (third)
• 5 seat support plate
• 6 back support
• 7 backrest cushions
• 8 seat cushions
• 9 Fulcrum Backrest support - seat support, center of rotation Handlebar center (one part with 6) - seat support
• 10 pivot middle handlebar - seat support plate
• 11 Pivot handlebar front - seat carrier
• 12 pivot handlebar front - seat support plate
• 13 Pivot handlebar rear - seat carrier
• 14 Fulcrum Handlebar rear - seat support plate
• 15 energy storage
• 16 middle handlebars (second)
• 17 roller or sliding part
• 18 pivoting handlebar rear - control tab
• 19 slideway (inclined plane, curve, ...)
• 20 control tab
• 21 handlebar weight fine adjustment
• 22 Pivot handlebar Weight fine adjustment - seat support plate
• 23 Axle handlebar middle - roller, sliding part
• 24 Pivot Handlebar Center - Handlebar Weight Fine Adjustment
• 25 Arrow direction Lifting seat support plate (5)
• 26 Arrow direction Movement Handlebar center (16) and M2
• 27 Arrow direction Movement Handlebar front (3) and M1
• 28 Freedom of rotation at the middle of the handlebar (16)
• 29 intermediate part
• 30 Attachment intermediate part - Slideway (19)
• 31 long hole handlebar rear 4
• 32 spring travel of the seat support plate. 5
• 33 Libra
• 34 Abstützpunkt seat support plate 5 on the scale 33rd
• 35 Distance pivot point Front handlebar Seat support plate to support point 34
• 36 Distance between the middle of the handlebar and the support point 34
• 37 restoring force FG
• 38 power FK
• 39 force FR
• 40 Virtual axis in the longitudinal direction
• 41 Movement direction F for movement Seat in longitudinal direction

Claims (14)

Synchronous mechanism for office chairs with the user center of gravity (FGM) coupled restoring force of the backrest support (6), wherein the backrest support (6) via a plurality of links (3, 4, 16) existing pivoting mechanism raising and lowering of a user of the weight (FG) loaded seat support plate (5) generated, characterized in that the seat support plate (5) is elastically resiliently bendable and when Nachhintenschwenken from the backrest support (6) the weight bearing force (FG) of the user is raised and the seat support plate (5) with application of an elastic restoring force ( FS) is deformed against the weight (FG) of the user directed upwards. Synchronous mechanism according to claim 1, characterized in that the seat support plate (5) in its front region with a first link (3) relative to the seat support (1) is supported, that in its central region via a second link (16) pivotally connected to the Seat support (1) is connected, and that the seat support plate (5) with a third link pivotally relative to the seat support plate (1) is supported, and that the seat support plate (5) at least in the region of the second link (16) - preferably approximately in the middle region - elastically resiliently bendable is formed. Synchronous mechanism according to claim 2, characterized in that the first and the second link (3, 16) are aligned with their longitudinal axes approximately in the same direction (forward), and that the longitudinal axis of the third link (4) is directed opposite. Synchronous mechanism according to one of claims 1 to 3, characterized in that the seat support plate (5) in the form of a convex bending curve against the downwardly directed weight force (FG) of the user is elastically deformable. Synchronous mechanism according to one of claims 1 to 4, characterized in that the seat support plate (5) in addition to the upward movement in the front and middle area additionally performs a rearwardly directed downward pivotal movement in the rear area. Synchronous mechanism according to one of claims 1 to 5, characterized in that the degree of increase of the seat support (5) in the front region in comparison to the degree of increase of the seat support in the central region is greater. Synchronous mechanism according to one of claims 1 to 6, characterized in that in a direct coupling of the pivoting mechanism to the seat support plate (5) of the central link (16) is coupled directly to the deflectable seat support plate (5). Synchronous mechanism according to one of claims 1 to 6, characterized in that in an indirect coupling of the pivoting mechanism to the seat support plate (5), the middle link (16) in its upper pivotable part has a roller or sliding member (17), which extends with its outer periphery on a slide track (19) on the underside of the seat support plate (5) rolls. Synchronous mechanism according to one of claims 1 to 8, characterized in that in an indirect coupling of the pivoting mechanism to the seat support plate (5) of the second, middle link (16) via another, interposed link (21) with the underside of the seat support plate (5 ) is coupled. Synchronous mechanism for office chairs with the user center of gravity (FGM) coupled restoring force of the backrest support (6), wherein the backrest support (6) via a plurality of links (3, 4, 16) existing pivoting mechanism raising and lowering of a user of the weight (FG) loaded seat support plate (5), characterized in that the seat support plate (5) is formed slippery and that middle, transversely spaced apart link (16) with a pivotable end of the handlebar (16) acted upon pressure plate against the underside of the seat support plate (5 ) and deform them against the user weight (FG) directed upward when the backrest support (6) tilts backwards. Synchronous mechanism according to one of claims 1 to 10, characterized in that the weight of the user via a point (34) on a balance (33) is transferable via a slide (19) its force on the roller or sliding member (17) and on transmits the middle handlebar (16). Synchronous mechanism according to claim 11, characterized in that in the rear link (4) a slot (31) is mounted, which avoids a power transmission to the rear handlebar, after the seat support plate (5) by their material and geometry-related stiffness the entire weight force on the Point (34) transfers to the scale (33). Synchronous mechanism according to claim 12, characterized in that the length a of the slot (31) determines the spring travel (32) of the seat support plate (5) by the weight of the user. Synchronous mechanism according to one of claims 12 or 13, characterized in that through the slot (31) in the rear arm (4), the seat support plate (5) and thus the seat (8) perform a movement about a virtual longitudinal axis 40.

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