EP3989775B1 - Piece of furniture - Google Patents

Description

The invention relates to a piece of furniture with a joint arrangement according to claim 1.

Such joint arrangements are used, for example, to adjust the height of a piece of seating furniture or a table. The joint arrangement is preferably designed in such a way that two pairs of support legs can be pivoted between a basic or normal position, in which the support legs run approximately parallel to one another or are slightly U- or V-shaped relative to one another, into a scissor or cross-over position.

The design of a joint arrangement enabling such a pivoting is described, for example, in the publications US$2,932,344 and DE 1 292 344 A described. Accordingly, a piece of seating furniture is designed with four support legs that are pivotally connected to a seat body, for example a frame of a seat. Two support legs are joined together to form a pair of support legs, with both pairs of support legs being operatively connected by means of a joint arrangement such that the two pairs of seat legs can be pivoted synchronously between the normal position and the crossover/scissor position in the manner described above. In these two pivot positions, the pairs of seat legs each rest against stops. The joint arrangement has a coupling arm that is pivotally mounted on a base of the seating furniture, the end sections of which are each connected to a pivoting link, which in turn engages one of the support legs. The coupling arm and the two swivel links connected to its end sections synchronize the swivel movement of the two pairs of support legs and, in the normal position described, assume an approximately stretched position in which the links (coupling arm and connected swivel links) are slightly zigzagged relative to each other. When adjusted to the cross position, the angle of attack between the links is reduced, with the coupling arm being swiveled towards a vertical position (relative to the base of the furniture). The two pairs of support legs are each connected to each other via cross braces, so that only one coupling link arrangement is required to synchronize the swivel movement.

In these known solutions, a tension spring, which is attached to a frame or base of the piece of furniture, engages in the connection area of the coupling arm with one of the swivel links. This tension spring is positioned in such a way that the two pairs of support legs are held at the stops in the two positions (normal position, cross position) by a pre-tension of the tension spring and support the swivel movement towards the stop during swiveling in the end swivel range.

In the print DE 20 2013 100 020 U1 A similar joint arrangement is described in which the pivoting of two pairs of support legs is also synchronized via a joint arrangement with a coupling arm arranged approximately in the middle and two pivoting links connected to it. This solution also provides a tension spring that urges the joint arrangement and thus also the two pairs of support legs towards the normal position. The pivoting into the crossover position then takes place against the force of the tension spring.

These known joint arrangements allow the support legs to be adjusted very easily between the normal position and the cross position. However, the disadvantage is that the joint arrangement with the coupling link arrangement and the tension spring acting on it requires a considerable amount of installation space (particularly in the cross position) and therefore has a significant impact on the visual appearance of the piece of furniture. Furthermore, a considerable amount of effort is required in terms of device technology to integrate the coupling joint arrangement and the tension spring into the piece of furniture.

The DE 199 28 829 A1 discloses a seat construction designed in the manner of a lifting platform, in which an upper frame is held to a lower frame on the floor via four universal joints. This seat mechanism requires a considerable amount of technical equipment, which is accompanied by a high weight and also does not meet high aesthetic standards.

In the print FR 2 757 752 A1 A height-adjustable table with Y-shaped legs is shown. This table has the same disadvantages as the piece of furniture according to the DE 199 28 829 A1 .

In contrast, the invention is based on the object of creating a piece of furniture which enables an unobtrusive integration of the joint arrangement into the piece of furniture with little technical effort.

This object is achieved by a piece of furniture with the combination of features of patent claim 1.

Advantageous developments of the invention are the subject of the subclaims.

The joint arrangement serves for the articulated connection of support legs which are held via swivel joints on a piece of furniture according to the invention. The joint arrangement has a coupling link arrangement with a pivotable coupling arm which is mounted on a base attached to the piece of furniture. End sections of the coupling arm are articulated to swivel links, the coupling link arrangement being designed such that the support legs can be pivoted between a first position and a second position, preferably between a scissor or cross position and a normal position in which the support legs are, for example, parallel or slightly U- or V-shaped to one another. The piece of furniture also has a pre-tensioning device for pre-tensioning a support leg at least in the direction of one of the positions.

According to the invention, the coupling link arrangement and the pre-tensioning device are not arranged in one plane relative to one another, as in the prior art described at the beginning, but are offset, preferably transversely to the pivoting plane, so that the joint arrangement can be integrated unobtrusively into the design of the piece of furniture due to the resulting compact structure. The separated design with coupling link arrangement and offset pre-tensioning device, which preferably acts directly on a support leg, makes the assembly and construction of the joint arrangement significantly easier than with conventional solutions.

In a preferred embodiment of the invention, the pre-tensioning device is designed such that it has a dead center position in which a maximum pre-tension is effective. This dead center position is reached in a region between the two aforementioned positions of the support legs. This means that the pre-tensioning device acts on the support legs in the direction of the respective position (cross position, normal position) after overcoming the dead center position and thus supports the adjustment in the direction of this position.

In a particularly simple embodiment, the coupling link arrangement is designed with the coupling arm and pivoting links hinged to it, which engage directly or indirectly on a pair of support legs.

Such a structure is characterized by high stability during synchronization and a simple structure.

The joint arrangement of the piece of furniture can be made particularly compact if the coupling link arrangement and the pre-tensioning device are arranged parallel and offset on opposite sides of the base. With such a development, the base is partially immersed in the area between the coupling link arrangement and the pre-tensioning device, so that a very space-saving, compact design is achieved.

The coupling link arrangement can be designed such that the coupling arm in the second position, preferably the cross position, is arranged approximately perpendicular to a standing surface of the piece of furniture.

The aesthetic appearance of the piece of furniture can be further improved if the coupling link arrangement connects two support legs of a pair of support legs to each other, while the pre-tensioning device acts on one of the two remaining support legs. In other words, the coupling link arrangement lies approximately in the pivot plane of one of the two pairs of support legs, while the pre-tensioning device is arranged in the pivot plane of the remaining support legs arranged parallel to it. Such a solution can be integrated into the design of the piece of furniture in a much more inconspicuous way than the solution described above and also has the advantage that the weight distribution is evened out by the spacing of the coupling link arrangement and the pre-tensioning device chosen in this embodiment.

In an alternative solution, as already indicated above, the coupling link arrangement and the pre-tensioning element can be arranged in the area of the pivot plane of two support legs of the support leg pairs. The two remaining support legs, which can be pivoted in the parallel pivot plane, can then be assigned a stop that supports these support legs in the respective position.

In one embodiment, it is provided that pivot joints formed in the area of the base are offset transversely to the pivoting direction of the support legs, so that no collision occurs when pivoting into the cross-over position.

It is preferred if the base has two swivel brackets, to each of which a support leg is hinged and which are arranged on the base with the aforementioned transverse offset.

The compact design can be further improved if the coupling link arrangement and/or the pre-tensioning device are each held in sections in a recess in the base formed by the transverse offset of the swivel brackets.

In a variant of the invention, the support brackets of the base are connected by a bridge on which the coupling arm is pivotally mounted.

According to a further development of the invention, this bridge web can form a stop for the support legs in one of the positions.

In one embodiment of the invention, the coupling arm is arranged in the dead center position approximately in the height adjustment direction, so that a height offset of the articulation of the pivot struts to the coupling arm is preferably maximum.

The force applied to the support legs via the pre-tensioning device can be optimized if the pre-tensioning device acts on the lever arm according to the invention, which is designed offset from the pivot joint on the respective support leg.

This lever arm can be designed as one piece with the support leg. In principle, it is also possible to design the support leg and the elements of the swivel joint on the support leg side as one piece.

The piece of furniture according to the invention preferably has four support legs, the pivoting of which is synchronized/controlled by means of at least one joint arrangement of the previously described design.

The piece of furniture is preferably designed as seating furniture, for example as an armchair, chair, bench, sofa or as a table or sideboard.

• Figuren 1 bis 7 ein erstes Ausführungsbeispiel einer Gelenkanordnung eines erfindungsgemäßen Möbelstücks in unterschiedlichen Stellungen, jeweils in einer Vorderansicht und einer Rückansicht sowie in einer Draufsicht;
• Figuren 8 bis 11 Ansichten eines erfindungsgemäßen Möbelstücks mit einem weiteren Ausführungsbeispiel einer erfindungsgemäßen Gelenkanordnung;
• Figuren 12 und 13 eine Variante des Ausführungsbeispiels gemäß den Figuren 8 bis 11;
• Figur 14 einen Endbeschlag einer Gelenkanordnung gemäß den Figuren 12 und 13;
• Figur 15 einen Endbeschlag eines Ausführungsbeispiels gemäß den Figuren 8 bis 11;
• Figuren 16, 17 ein weiteres Ausführungsbeispiel eines erfindungsgemäßen Möbelstücks mit einer erfindungsgemäßen Gelenkanordnung;
• Figuren 18, 19 Detaildarstellungen der Ausführung eines Schwenkgelenkes einer Gelenkanordnung;
• Figuren 20, 21 ein weiteres Ausführungsbeispiel einer Gelenkanordnung;
• Figuren 22, 23 ein Ausführungsbeispiel einer Gelenkanordnung mit einer zusätzlichen Lagefixierung in den Stellungen von Stützbeinen und
• Figuren 24, 25 Ausführungsbeispiele von erfindungsgemäßen Möbelstücken mit unterschiedlich ausgebildeten Rahmen, an denen jeweils eine Gelenkanordnung gehalten ist.

Preferred embodiments of the invention are explained in more detail below with reference to schematic drawings. They show:

• Figures 1 to 7 a first embodiment of a joint arrangement of a piece of furniture according to the invention in different positions, each in a front view and a rear view as well as in a plan view;
• Figures 8 to 11 Views of a piece of furniture according to the invention with a further embodiment of a joint arrangement according to the invention;
• Figures 12 and 13 a variant of the embodiment according to the Figures 8 to 11 ;
• Figure 14 an end fitting of a joint arrangement according to the Figures 12 and 13 ;
• Figure 15 an end fitting of an embodiment according to the Figures 8 to 11 ;
• Figures 16, 17 a further embodiment of a piece of furniture according to the invention with a joint arrangement according to the invention;
• Figures 18, 19 Detailed representations of the design of a swivel joint of a joint arrangement;
• Figures 20, 21 another embodiment of a joint arrangement;
• Figures 22, 23 an embodiment of a joint arrangement with an additional position fixation in the positions of support legs and
• Figures 24, 25 Embodiments of furniture items according to the invention with differently designed frames, each of which holds a joint arrangement.

The joint arrangement described below serves to link the support legs of a piece of furniture, for example a chair, an armchair or a table, in such a way that the functional height of this piece of furniture can be pivoted by adjusting the support legs between a normal position in which the support legs are approximately parallel or U- or V-shaped to one another, into a position in which two support legs each assume a cross-over position (also called a scissor position).

The basic structure of the joint arrangement 1 is first described using a Figures 1 to 7 illustrated model of a piece of furniture in which two support legs 2, 4 are hinged to a frame, a table top or a seat by means of the joint arrangement 1. In the illustrated model, the reference number 6 stands for a table top.

Figures 1 and 2 show the joint arrangement 1 in the aforementioned normal position, in which the support legs 2, 4 are slightly inclined to each other, whereby the distance to the table top 6 decreases. A base 8 is attached to the table top 6 or to a frame supporting it, the structure of which can be seen from the Figure 3 is explained in detail. According to the presentation in the Figures 1 and 2 the base 8 extends between the two supporting legs 2, 4, which are each connected to the base 8 via a swivel joint 9, 10. In the area adjacent to the swivel joints 9, 10, the base 8 is shown in accordance with the Figures 1, 2 downwards, ie towards the indicated base 12, trapezoidal tapered, with two inclined surfaces 14, 16 of the base 8 ending in a vertex surface 18 running approximately parallel to the table top 6. In the area of the vertex surface 18, a coupling arm 22 projecting on both sides is mounted on the base 8 by means of a joint 20, which in the normal position according to the Figures 1 and 2 is set at an angle to the base 12 or the table top 6. An end section of a swivel link 24, 26 is hinged to each of the two free end sections of the coupling arm 22, which can be pivoted centrally around the joint 20. This articulation is carried out in each case by means of a coupling joint 28, 30, which allows a relative pivoting of the swivel links 24, 26 with respect to the coupling arm 22. The end sections of the swivel links 24, 26 which are remote from the coupling arm 22 are in turn hinged to the respective support leg 2, 4 via leg joints 32, 34. In the normal position shown, the coupling link arrangement 36 formed by the coupling arm 22 and the swivel links 24, 26 assumes an extended position in which the said links (22, 24, 26) are positioned approximately zigzag-shaped relative to one another, whereby they are only slightly positioned relative to the base 12 or the table top 6, preferably at an acute angle (angle of attack < 45°).

Figure 2 shows a rear view of the model according to Figure 1 In this view, the coupling link arrangement 36 is partially covered by the base 8, so that only a part of the pivot link 26 engaging the support leg 2 and the pivot link 24 engaging the support leg 4 with the end section of the coupling arm 22 pivotably connected thereto with the coupling joint 28 and the joint 20 is visible.

In this illustration, it can be seen that a lever arm 38 is formed on the support leg 4, which projects laterally towards the base 8 and projects approximately at right angles to the longitudinal axis of the support leg 4 towards the base 8 and at the end section of which a pre-tensioning device engages, via which the support leg 4 is moved into the respective position, in Figure 2 into the normal position. In the embodiment shown, the pre-tensioning device is designed as a pressure cylinder 40, the cylinder of which is articulated via a cylinder joint 42 to the end section of the lever arm 38. A piston rod 44 of the pressure cylinder 40 is articulated via a piston rod joint 46 to the base 8. In the embodiment shown in Figure 2 In the normal position shown, the lever arm 38 extends approximately parallel to the swivel link 24. The axis of the pressure cylinder 40 is set slightly obliquely to the lever arm 38, so that the support leg 4 is acted upon in the direction of the normal position. Since the lever arm 38 engages the support leg 4 at a distance from the swivel joint 9, a torque acting in the direction of the normal position is transmitted to the support leg 4 in accordance with the preload of the pressure cylinder 40, which torque is transmitted via the Coupling link arrangement 36 is connected to the other support leg 2 so that this is also pre-tensioned into the normal position. In this position, the two support legs 2, 4 each rest with their end sections 48, 50 on the table top 6 so that their secure positioning is guaranteed. As explained below, the contact area of the end sections 48, 50 on the table top 6 or on the other support area of the piece of furniture is designed in a suitable manner in order to transfer the support forces.

In the embodiment shown, the piston rod 44 engages the base 8 - of course, a reverse assembly is also possible, in which the cylinder engages on the base side and the piston rod 44 on the support leg side.

Figure 3 shows a view from the base 12 of the joint arrangement 1 according to Figure 1 , so that the underside of the table top 6 of the model is visible. As explained above, the base 8, described in more detail below, is attached to this table top 6 (or other support structure), to which the two support legs 2, 4 are hinged via the pivot joints 9, 10.

The two swivel joints 9, 10 are each formed on a swivel bracket 52, 54 of the base 8, wherein the swivel brackets 52, 54 each have three joint tabs 56, 58, 60, which are formed at a distance from each other and penetrate between the joint projections 62, 64 of the support legs 2, 4. In the illustration according to Figure 3 Only the joint brackets, joint projections of the support leg 4 or the swivel bracket 52 are provided with reference symbols. The joint connection of the joint brackets 56, 58, 60 and the joint projections 62, 64 is then made via a joint bolt 66 indicated by a dot-dash line, which is also shown in the views according to the Figures 1 and 2 is visible.

As can be seen from the illustration, the two swivel brackets 52, 54 are arranged offset from each other transversely to the swivel direction. The swivel planes of the two support legs 2, 4 run approximately perpendicular to the plane of the drawing, so that the previously described offset in the vertical of the plane of the drawing according to Figure 3 This offset is - as explained above - necessary in order to be able to move the support legs 2, 4 from the normal position shown into the cross position described below.

Between the two swivel brackets 52, 54 extends as shown in Figure 3 a bridge 68, whose Figure 3 visible side surfaces the apex surface 18 and the two inclined surfaces running obliquely towards it 14, 16. As explained above, the joint 20 is formed on this bridge web 68, which is specifically designed by a stepped joint pin 70 that is held on the bridge web 68. The coupling arm 22, which projects out on both sides, is then held on this stepped joint pin 70 in such a way that it extends parallel to the bridge web 68. The two end sections of the coupling arm 22 are connected via the coupling joints 28, 30 to the swivel links 24, 26, the end sections of which are connected via the leg joints 32, 34 to the respective associated support legs 2, 4. According to the illustration in Figure 3 The leg joints 32, 34 are each designed with a joint attachment 72 (in Figure 3 only the joint attachment 72 of the support leg 4 is provided with a reference number), to which a corresponding link attachment 74 is assigned, which in turn is mounted on a joint bolt 76 indicated by a dash-dotted line. The link attachment of the swivel link 26 hinged to the other support leg 2 has a greater length than that of the swivel link 24 due to the transverse offset. As in Figure 3 As indicated, corresponding hinge pins 78, 80 are also inserted into the coupling joints 28, 30.

The axial length of the joint projections 72 and the stepped joint pin 70 is selected such that the coupling link arrangement 36 is approximately parallel to the base 8 along the Figure 1 visible front (top in Figure 3 ) of base 8.

The pressure cylinder 40 is accordingly arranged on the rear side of the base 8. As explained above, the cylinder housing of the pressure cylinder 40 engages the lever arm 38 of the support leg 4 via the cylinder joint 42. The piston rod 44 is connected to the Figure 3 The piston rod joint 46 indicated by dash-dotted lines is hinged to the swivel bracket 54.

By arranging the pressure cylinder 40 at the rear (bottom in Figure 3 ) and the coupling link arrangement 36 on the front of the base 8, a separated design is used, which makes it possible to adapt the geometry of the coupling link arrangement 36 and the pre-tensioning device, in this case specifically the pressure cylinder 40, with the respective linkages in an optimal manner to the spatial conditions and the design of the respective piece of furniture. It is particularly advantageous that the coupling link arrangement 36 and the pre-tensioning device act separately from one another in the broadest sense on the support legs 2, 4, so that the lever ratios can also be easily adapted to the circumstances. This is a significant difference to conventional solutions in which the pre-tensioning device acts directly on the link arrangement.

As can be seen from the illustration according to Figure 3 further, the pressure cylinder 40 extends approximately in the area of a step-back 82, which is formed by the lateral offset of the pivot bracket 54 with respect to the bridge web 68. In a corresponding manner, the coupling arm 22 lies in the area of a space formed by a step-back 84 between the pivot bracket 52 and the bridge web 68. This integration of functional elements, for example the pressure cylinder 40 and the coupling arm 22, into the spaces delimited on both sides of the base 8 by the projecting pivot brackets 52, 54 enables an extremely compact, space-saving construction of the joint arrangement 1 according to the invention.

From the viewpoint of Figure 3 It can also be seen that the positioning of the lever arm 38 is such that during the pivoting process it moves along the axis shown below. Figure 3 lying rear side of the swivel bracket 52 and the bridge web 68.

The model shown only has two support legs 2, 4. In most applications, four support legs are provided for a piece of furniture, with two additional support legs being arranged parallel to the support legs 2, 4, for example. However, it is sufficient to simply design the support legs 2, 4 with the described joint arrangement 1 and to connect the two other support legs (not shown) to the respective associated support legs 2, 4, for example by means of cross braces or the like, so that these - in the Figures 1 to 7 Support legs (not shown) can be used. This will be explained using further examples.

The Figures 4 and 5 show the Figures 1 and 2 corresponding views of the joint arrangement 1 in an intermediate position between the Figures 1 and 2 shown normal position and the one in the Figures 6 and 7 shown cross-over position. This in the Figures 4 and 5 The intermediate position shown is achieved, for example, by tilting the piece of furniture or the model slightly so that it rests on the base 12 with only one support leg, for example the support leg 2, and then a torque is applied such that the supported support leg 2 pivots about its pivot joint 10 in the direction of the crossover position. Of course, this pivoting can also be initiated by hand after the piece of furniture has been lifted or turned over.

The pivoting movement of the support leg 2 is transmitted synchronously to the other support leg 4 via the coupling link arrangement 36, whereby the coupling arm 22 is guided out of the Figure 1 shown slight inclination (with reference to the base 12) is pivoted clockwise towards a vertical position via the pivoting links 26 or 24, whereby the relative pivoting of the pivoting links 24, 26 to the respective associated support leg 2, 4 is relatively small. This pivoting of the support legs 2, 4 takes place - as explained - around the pivot joints 9, 10. During this first part of the pivoting, according to Figure 5 the piston rod 44 of the pressure cylinder 40, which is supported in an articulated manner on the bridge web 68, is retracted - this pivoting movement is thus carried out against the preload of the pressure cylinder 40. This means that accidental pivoting is almost impossible. In this retracted position of the piston rod 44, the restoring force applied by the pressure cylinder 40 to the support leg 2 is at its maximum. The articulation of the pressure cylinder 40 on the support leg 2, ie the length and position of the lever arm 38 and the cylinder joint 42 as well as the position of the piston rod joint 46 on the bridge web 68 (base part 8) is selected so that the pressure cylinder 40 is in the position specified in the Figures 4 and 5 In the intermediate position indicated between the two positions mentioned (normal position, cross position) a dead center position with the previously described maximum preload force is reached.

When swiveling further into the Figures 6 and 7 In the illustrated cross position of the support legs 2, 4, the coupling arm 22 is rotated counterclockwise from the position shown in the Figures 1 and 4 shown position, so that the coupling link arrangement 36 accordingly Figure 6 shown, in which the two swivel links 24, 26 are brought from the extended position into a position in which they run almost parallel or slightly inclined to each other. In this cross position, the piston rod 44 is in accordance with Figure 7 again slightly extended from the dead center position described above, whereby the support leg 2 and the support leg 4 connected to it via the coupling link arrangement 36 are held in the cross-over position by the preload applied by the pressure cylinder 40. In this cross-over position, the support legs 2, 4 are located as shown in the Figures 6 and 7 on the inclined surfaces 14 and 16 of the base 8, which act as stops, while the two end sections 48, 50 of the support legs 2, 4 are lifted off the table top 6.

Accordingly, the position of the pressure cylinder 40 is selected so that in both positions, ie in the Figure 1, 2 shown normal position and in the Figures 6 and 7 shown cross position, the support legs 2, 4 are pre-tensioned by the pressure cylinder 40 in the direction of the respective stop position pre-tensioned and thus reliably positioned. The Figures 4 and 5 The dead center position of the pressure cylinder 40 indicated accordingly lies between these two stop positions and can only be reached by overcoming the respective pre-tension, so that accidental or unwanted adjustment with an associated change in the height of the piece of furniture is prevented.

In the embodiment described above, the base 8 and the coupling link arrangement 36 are made of a fiber-reinforced plastic material - of course, these components can also be made of metal or in a hybrid construction, for example, with the base made of plastic and the coupling link arrangement made of metal.

The Figures 8 to 11 an embodiment of a table 86 or a chair in which the joint arrangement 1 is made of metal. Figure 8 shows the table 86 in the normal position, in which the support legs 2, 4 and the two in the previously described Figures 1 to 7 not shown further support legs 2', 4' are slightly V-shaped relative to each other. The support legs 2, 2' and 4, 4' are connected to each other by cross braces not visible in these figures. The support legs 2, 4 (lying at the back in Figure 8 ) are connected to one another in the manner described above via a coupling link arrangement 36 with the coupling arm 22 and the swivel links 24, 26. The coupling arm 22 is mounted on a bridge web 68 of a base 8, similar to the embodiment described above. The latter is attached to a frame 88 of the table 86. In Figure 8 The pre-tensioning device is indicated in dash-dotted lines and can be formed, for example, by a pressure cylinder 40 or a compression spring. In the embodiment shown, this pre-tensioning device is attached to the Figure 8 The front base 8' is supported and thus engages the support legs 2' or 4'.

It is also conceivable to use a motor drive or traction elements, although the linkage would then have to be modified accordingly.

In the embodiment shown, both the bases 8, 8' and the coupling link arrangement 36 are made of sheet metal components. As in the previously described embodiment, the base 8 is designed with swivel joints 9, 10, via which the support legs 2, 4 (lying at the rear in Figure 8 ) are hinged to the frame 88. The bridge web 68 of the base 8 is designed like a strut and arches from the swivel joints 9, 10 towards the base 12. Further details are given in Figure 11 explained.

The two in Figure 8 As mentioned above, a base 8' with two swivel joints 9', 10' is assigned to the front support legs 2', 4', which has the same structure as the base of the support legs 2, 4. The support legs 2, 4, 2', 4' and the frame 88 are made of wood, with the end sections of the support legs 2, 4, 2', 4' on the coupling joint side each being provided with end fittings 90, the structure of which is also explained in more detail below. These end fittings 90 are like the joint arrangement 1 in the embodiment according to the Figures 8 and 9 constructed in metal.

In the Figure 9 The cross-over position shown can then be achieved - as explained above - by applying a force acting against the prestress of the pressure cylinder 40 indicated by dash-dotted lines to the associated support legs 2, 2'/4, 4', which force leads to an adjustment of the coupling link arrangement 36 from the position shown in Figure 8 shown stretched position into the Figure 9 not visible (see Figure 6 ) kinked position, whereby the pressure cylinder 40 indicated by dash-dotted lines is moved beyond its dead center position, so that in the cross position the four support legs 2, 2', 4, 4' are prestressed against the base 8, 8', specifically against the inclined surface 14', 16' (14, 16 not visible) of the base 8'.

Figure 10 shows this crossover position in a slightly different view than in Figure 9 , with the base 8 now shown lying at the front. It can be seen in this view that the coupling link arrangement 36 in this embodiment is arranged on the front base 8 of the support legs 2, 4. The pressure cylinder 40, on the other hand, is arranged on the rear base 8', which is assigned to the two support legs 2', 4'.

Figure 11 shows a detailed representation of this in Figure 10 rear base 8' with the linkage of the pressure cylinder 40.

As explained, the base 8' in this embodiment is designed as a bent sheet metal part, with the bridge web 68' forming the two inclined surfaces 14', 16' acting as stop surfaces and the apex surface 18' connecting them. The base 8' also has the two swivel brackets 52', 54', on which the swivel joints 9', 10' are formed for connecting the support legs 2', 4'. This base 8' is - as explained - connected to the frame 88.

The piston rod 44 of the pressure cylinder 40 is - as in the previously described embodiments - again connected to a support leg, in this case the support leg 2', via a lever arm 38. Since this support leg 2' is made of wood, the lever arm 38 is attached as a separate component. In the embodiment shown, the lever arm 38 is designed as a stamped sheet metal part and is screwed to the support leg 2'. The piston rod 44 is connected to the lever arm 38 via the piston rod joint 46.

The cylinder housing of the pressure cylinder 40 is hinged via the cylinder joint 42 to a support strut 92 which is designed as a sheet metal component and is attached to the frame 88.

In this embodiment, the coupling link arrangement 36 is assigned to the support legs 2, 4 and the pre-tensioning device, specifically the pressure cylinder 40, is assigned to the two other support legs 2', 4'. Such an even more resolved design has the advantage that the integration of these functional elements into the design of the piece of furniture is simplified and, furthermore, the introduction of force is evened out by the arrangement of the coupling link arrangement 36 and the pressure cylinder 40 on both sides. In addition, the weight distribution is also optimized compared to the solution described at the beginning.

The Figures 12 and 13 show a variant of the Figures 8 to 11 explained embodiment, wherein the joint arrangement 1 is not designed as a metal construction, but - similar to the embodiment described at the beginning - as a plastic construction. The structure of the base 8 with the bridge web 68 and the inclined surfaces 14, 16 formed thereon as stop surfaces and the basic structure of the coupling link arrangement 36 with the two swivel links 24, 26 and the coupling arm 22 as well as the arrangement of the pressure cylinder 40 with the associated joints corresponds to the embodiment according to the Figures 1 to 7 , so that further explanations in this regard with reference to the description of the embodiment according to the Figures 1 to 7 can be dispensed with.

The Figures 12 and 13 The piece of furniture shown is made of wood, so that the table top 6 or the frame 88, which can support a table top or a seat, are also made of wood or another suitable material. The support legs 2, 4 are also made of wood, the basic structure being the same as that of the embodiment according to the Figures 8 to 11 Instead of the metallic end pieces 90, the end pieces 90 placed on the ends of the support legs 2, 4 are made of plastic. The end pieces 90 are then located in the Figure 12 shown normal position with the end sections 48, 50 formed thereon to the table top 6 or the frame 88. By choosing a suitable material, it can be ensured that no wear occurs in the system area due to this system.

In this embodiment, the coupling link arrangement 36 and the pressure cylinder 40 are also arranged offset transversely to the pivoting direction on a base 8, i.e. on the base 8 assigned to the support legs 2, 4. In the case of a piece of furniture with four support legs, a single base 8' with two pivot joints 9', 10' without a coupling link arrangement 36 and without a pressure cylinder 40 would then be assigned to the other two support legs 2', 4'.

As in Figure 13 As shown, by applying force, a support leg, for example the support leg 4, can be pivoted inwards against the force of the pressure cylinder 40, whereby this pivoting is transmitted via the coupling link arrangement 36 to the other support leg 2, so that both support legs 2, 4 pivot synchronously into the crossover position. During this pivoting, the pressure cylinder 40 reaches its dead center position, so that accordingly in the two in Figure 12 and 13 In the positions shown, the piston rod 44 is extended slightly relative to this dead center position.

Figure 14 shows a detailed view of an end piece 90 of the embodiment according to the Figures 12, 13 . Accordingly, the end piece 90 is designed to be approximately cap-shaped so that it can be placed precisely on the table-top-side end of the respective support leg 2, 4.

In the area where the cap-shaped end piece 90 is placed on the support leg 2, 4, recesses 94, 96 are formed, wherein the recesses 94 are designed to pass through a fastening screw 98 (see Figure 12 ) and the other recesses 96 for the passage of the leg joint 34 (see Figure 12 ) are provided. In Figure 12 only the end piece 90 associated with the support leg 4 is provided with the corresponding reference symbol.

The two previously described tab-shaped joint projections 62, 64 of the respective swivel joint 9, 10 are formed in a corner area of the end piece 90 on the table top side. These joint projections 62, 64 engage - as can be seen for example from Figure 3 explained - between the joint plates 56, 58, 60 of the swivel brackets 52, 54 and can then be pivoted about the inserted hinge pin 66. The respective end section 48, 50 of the end pieces 90 is then each designed as a stop surface 100.

Figure 15 shows an end piece 90 in metal construction, as for example in the embodiment according to the Figures 8 to 11 This end piece is designed as a stamped and bent part and has an approximately U-shaped profile that is placed on the end of the respective support leg 2, 4. The end piece 90 according to Figure 14 corresponding reference symbols are also in Figure 15 so that with regard to the functionality of these elements, the description in Figure 14 can be referred to.

Based on Figures 16, 17 An embodiment is explained in which the attached end caps 90 are omitted in order to improve the aesthetic appearance.

In this embodiment of a piece of furniture, a frame 88 consisting of metal profiles is provided, to which pairs of support legs 2, 4; 2', 4' are each attached by means of a base 8 or 8'. The base 8, 8' has a Figures 1 to 7 corresponding structure. According to the illustration in Figure 17 , which shows a view from below of the base 8 with a support leg 4 in the normal position, the respective end piece 90 is designed with a flat stop part 104 forming the stop surface 100, on which the two joint tabs 62, 64 are formed towards the base 8, which are in joint engagement with the associated joint bracket 54. Bolts 106, 108 are inserted into the support leg 4 in a precisely fitting manner, which are diametrically penetrated by a threaded hole and into which, according to the illustration in Figure 17 To fix the support leg 2, 4 to the respective end piece 90, fastening screws 112, 114 can be screwed in from the support side in order to fix the end piece 90 to the support leg 4. In the illustration according to Figure 17 On the right, the support leg 4 is shown with the end piece 90 mounted. You can see the flush-mounted bolts 106, 108, into which the aforementioned fastening screws 112, 114 engage, so that the respective support leg 2, 4 is connected to the end piece 90 without play. This can be made of metal or plastic.

The Figures 18 and 19 show a embodiment according to the Figures 1 to 7 corresponding embodiment, in which the support leg 2 is made of metal or plastic. According to the detail in Figure 19 are on the support leg 2 The two joint projections 62, 64 are formed in one piece or by a material connection, which protrude laterally and are in joint engagement with the associated pivot bracket 52 of the base 8. As in the previously described embodiments, the joint projections 62, 64 of the respective support leg 2 and the joint brackets 56, 58, 60 are penetrated by a bore 116 (only one part of the bore is in Figure 19 provided with a reference symbol), in which the Figure 3 explained hinge pin 66 is used. In the Figures 18 and 19 Furthermore, a cross strut 118 is shown, via which the mutually associated support legs 2, 2' and 4, 4' are connected to one another, so that, for example, four support legs 2, 2', 4, 4' are connected to one another on the one hand via the coupling link arrangement 36 and on the other hand via the cross struts 118 and are thus moved synchronously.

According to the presentation in Figure 19 In the area between the two joint projections 62, 64 at the end section 48 of the support leg 2, a recess 120 is formed into which the central joint tab 58 (see Figure 18 ) when swiveling.

In this embodiment, the front surface of the end section 48 is also designed as a stop surface which rests against the frame 88 in the normal position.

The Figures 20 and 21 show a corresponding concept according to the Figures 18 and 19 executable embodiment of a piece of furniture in which four support legs 2, 2', 4, 4' are articulated to a metal frame 88 by means of an inventive joint arrangement 1. In this embodiment too, the coupling link arrangement 36 and the pressure cylinder 40 are arranged offset perpendicular to the plane of the drawing on the front and rear of the base 8, which is assigned to the two front support legs 2, 4. The rear, invisible base is only designed with the swivel joints and the stops of the two other support legs 2', 4'. In this embodiment too, the piston rod 44 of the pressure cylinder 40 engages a lever arm 38 arranged at a distance from the associated swivel joint 9, which is either integrally formed or integrally formed on the support leg 4. The base 8 in this embodiment is again made of plastic.

The Figures 22 and 23 show a possibility to further improve the positioning in the respective positions. As explained above, the pressure cylinder 40 is designed in such a way that it pre-tensions the support legs 2, 4 in the direction of the respective position (normal position, cross-over position). In addition, according to the Figures 22 and 23 A magnet or the like can also be provided in the contact area, which holds the respective support leg 2, 4 in the respective contact position. For example, in the area of the contact surface of the end section 48 of the end piece 90, a magnet 122 is provided, which can be brought into magnetic operative connection with a correspondingly designed counterpart on the frame 88, so that the associated support leg 4 is held on the frame 88 with a magnetic force acting in the direction of the arrow, which acts in addition to the preload of the pressure cylinder 40.

A corresponding magnet 124 can also be integrated into the base 8 in the area of the inclined surfaces 14, 16, in which case a corresponding magnetizable counterpart is provided on the associated support leg 4 in order to hold the support leg 4 in the cross position ( Figure 23 ) to keep.

Of course, the magnets 122, 124 shown can also be held in kinematic reversal on the other component, so that, for example, the magnet 122 is mounted on the frame side and the magnet 124 on the support leg side.

The Figures 24, 25, 26 finally show various concepts for the formation of a frame 88, to which a table top 6, a seat or another functional section of a piece of furniture can then be attached. In all of these embodiments, the frame 88 is designed as a sheet metal construction to optimize the weight and simplify production.

Figure 24 shows a variant in which the frame 88 is approximately oval with a surrounding peripheral edge 126 and an approximately elliptical support surface 128. In this, two recesses 130a, 130b are formed to optimize weight, which can also be designed with peripheral wall sections. Four support legs 2, 2', 4, 4' made of metal construction are then hinged to this oval frame 88 in the manner described above.

Figure 25 shows a variant of the embodiment according to Figure 24 , whereby instead of an approximately oval-shaped support frame 88, a double-T construction is used, which is also designed as a bent sheet metal construction. The end sections of the double-T-shaped frame 88 on the support leg side are designed as front-side U-profile bodies 132, 134, whereby the above-described bases 8, 8' are inserted into these end-side U-profile bodies 132, 134 and thus the respective base 8, 8' with its functional elements, for example the pressure cylinder 40 and the coupling link arrangement 36, are projected outwards via the respective U-wall 136, 138 is covered. In this embodiment, the support legs 2, 2', 4, 4' are again made of plastic or metal.

Figure 26 shows a variant of the embodiment according to Figure 25 , in which the support legs 2, 2', 4, 4' are designed as tapered wooden legs. Otherwise, the embodiment according to Figure 26 the one from Figure 25 , so that further explanations are unnecessary.

A piece of furniture designed with a joint arrangement is disclosed. The joint arrangement serves to connect support legs to the piece of furniture, wherein a coupling link arrangement is provided for synchronizing the pivoting movement of two associated support legs, which is arranged offset from a pre-tensioning device, via which the support legs are pre-tensioned in two positions, preferably a normal position and a cross-over position. The pre-tensioning device preferably acts directly on one of the support legs.

Claims (15)

1. A piece of furniture with support legs and with a joint arrangement for connecting the support legs (2, 4), which are held pivotably via pivot joints (9, 10), with a coupling link arrangement (36) which has a pivotable coupling arm (22) mounted on a base (8) the end sections of which are articulated indirectly or directly on the support legs (2, 4) in such a way that these can be pivoted for height adjustment between a scissor or a cross-over position and a parallel, U or V position, and with a pretensioning device for pretensioning a support leg (2, 4) at least in the direction of one of the positions, characterized in that the coupling link arrangement (36) is arranged offset approximately transversely to the pivoting plane of the support legs (2, 4) relative to the pretensioning device, one support leg (2, 4) having a laterally projecting lever arm (38) which is arranged offset with respect to the pivot joint (9, 10) and on which the pretensioning device engages.
2. The piece of furniture according to claim 1, wherein the pretensioning device has a dead center position in which a maximum pretension is effective, wherein the pretensioning device is designed to reach the dead center position between the two positions of the support legs (2, 4), so that pretension in both positions is reduced with respect to the dead center position.
3. The piece of furniture according to claim 1 or 2, wherein the coupling arm (22) is arranged approximately perpendicular to a standing surface (12) of the piece of furniture in the dead center position.
4. The piece of furniture according to any of the preceding claims, including two pivot links (24, 26) which are connected in an articulated manner to the coupling arm (22) on the one hand and in an articulated manner to one of the support legs (2, 4) on the other hand.
5. The piece of furniture according to any of the preceding claims, wherein the coupling link arrangement (36) is operatively connected to two support legs (2, 4) pivotable approximately in one plane and the pretensioning device is associated with another support leg (2, 4).
6. The piece of furniture according to any of claims 1 to 4, wherein the coupling link arrangement (36) and the pretensioning device are associated with two support legs (2, 4) pivotable approximately in one plane and the two other support legs (2', 4') are associated with stops for support in both positions.
7. The piece of furniture according to any of the preceding claims, wherein the pivot joints (9, 10) are offset transversely to the pivoting direction of the supporting legs (2, 4) pivotable approximately in a pivoting plane.
8. The piece of furniture according to claim 7, wherein the base (8) has two swivel brackets (52, 54), to each of which a support leg (2, 4) is hinged and which are arranged with the transverse offset.
9. The piece of furniture according to claim 7 or 8, wherein the coupling link arrangement (36) and/or the pretensioning device are each held approximately in a recess (82, 84) formed by the transverse offset of the swivel bracket (52, 54).
10. The piece of furniture according to claim 8 or 9, wherein the swivel brackets (52, 54) of the base (8) are connected by a bridge web (68) on which the coupling arm (22) is pivotably mounted.
11. The piece of furniture according to claim 10, wherein the bridge web (68) forms a stop for the support legs (2, 4) in one of the positions.
12. The piece of furniture according to any of the preceding claims, wherein the pretensioning device is a cylinder or a spring, preferably a compression cylinder (40) or a compression spring.
13. Piece of furniture according to any of the preceding claims, wherein the base (8) and/or the coupling link arrangement (36) are made of plastic or metal.
14. The piece of furniture according to any of the preceding claims, wherein a part of the pivot joint (9, 10) is integrally formed on the respective support leg (2, 4).
15. The piece of furniture according to one of the preceding claims, wherein the pretensioning device is arranged approximately transversely to the height adjustment direction or at an acute angle obliquely to this transverse direction.

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