Central unit for an office chair

Abstract

The invention relates to a central unit (10, 10a, 10b, 10c, 10d) for a chair, in particular an office chair, characterized by a multi-joint body (12, 12a, 12b, 12c, 12d, 12e, 12f) which has a seat part (14) for a seat (16), a backrest part (18) for a backrest (20), a support part (22) for a support of a base frame and a front part (24, 24a) arranged between the seat part (14) and the support part (22), wherein the multi-joint body (12, 12a, 12b, 12c, 12d, 12e, 12f) has at least three joints (26, 28, 30, 32), which each connect two of the said parts in an articulated manner.

Description

[0001] The invention relates to a central unit for a chair, in particular an office chair.

[0002] Office chairs typically have a central mechanical component, primarily made of metal. This mechanical component allows a base frame to be attached. A seat and backrest are also arranged on the central component. The central component often ensures that the backrest and seat can be moved synchronously with each other.

[0003] In the area of ​​office chairs, too, manufacturers are facing increasingly stringent demands regarding sustainability and recyclability. A conventional office chair contains numerous components that require laborious separation for recycling, some of which are not recyclable at all.

[0004] The object of the present invention is therefore to provide a central unit for a chair which is of simple construction and recyclable.

[0005] This object is achieved according to the invention by a central unit for a chair, in particular an office chair, with a multi-joint body which has a seat part for a seat, a backrest part for a backrest, a support part for a support of a base frame and a front part arranged between the seat part and the support part, wherein the multi-joint body has at least three joints, each of which connects two of the said parts in an articulated manner. Such a central unit can preferably be manufactured from only one material, for example by injection molding. If the central unit is manufactured from only one material, it can be easily recycled. The at least three joints can be of the same design, so that different joints do not have to be provided for the assembly of the central unit.

[0006] Particular advantages arise when at least one, in particular at least three, preferably four of the joints are designed as a flexural joint. A flexural joint is a region of a component that allows relative movement (rotation) between two rigid body regions through bending. A flexural joint is based on the principle of elasticity. The function of a joint is achieved by an area that has lower flexural rigidity than two adjacent regions. The reduced flexural rigidity can be created by locally reducing the material thickness. Flexural joints are often also referred to as film hinges, film hinges, or flat hinges. They are band hinges and have no mechanical parts. Flexural joints therefore eliminate the need for mechanical parts, which then do not need to be recycled.

[0007] In principle, it is conceivable to provide the flexure joints as separate components and connect them to two of the seat, backrest, support, and front sections. However, particular advantages arise when the flexure joints are formed as a single piece, particularly with a material fit, with the parts they connect. The flexure joints and the connected parts can be manufactured, for example, in an injection molding process. This eliminates the need for subsequent assembly work.

[0008] Preferably, at least the seat part, the backrest part, and the support part are rigid, and the rigid joints are flexible, particularly elastic. The seat part, backrest part, support part, and / or front part are more rigid than the rigid joints. The rigid joints preferably have a thinner material thickness than the seat part, support part, front part, and / or backrest part.

[0009] Particular advantages arise when the multi-joint body is formed as a single piece. This means that the multi-joint body can be manufactured in one piece, for example using an injection molding process. The seat part and / or backrest part can be designed in such a way that a seat, for example a seat shell, and a backrest can be attached to the seat part or backrest part. However, it is also conceivable to design the seat part and backrest part so that they already form the seat and backrest. If necessary, a seat cushion or backrest cushion can also be attached to them. This results in an (office) chair with very few separate components that can be easily separated from one another and recycled after the chair's normal service life.

[0010] If the multi-joint body is made of plastic, especially glass-fiber-reinforced plastic, preferably glass-fiber-reinforced polyamide, it can be manufactured particularly easily using an injection molding process. Such a multi-joint body is also easily recycled.

[0011] According to one embodiment of the invention, it can be provided that exactly one of the joints is designed as a hinge with a rotary pin. The multi-joint body can be injection-molded with receptacles for the rotary pin. The receptacles can then be connected to one another by the rotary pin to form a joint. The remaining joints of the central unit can be designed as solid-state joints.

[0012] According to a further embodiment of the invention, it can be provided that the front part is designed to be flexible. The other parts, in particular the seat part, backrest part and support part, can be rigid or at least more rigid. The front part can have a joint, in particular a solid-state joint, at only one end. This makes it possible to reduce the number of joints. In particular, such a multi-joint body can have only three joints. The three joints can be designed as solid-state joints. In particular, in this embodiment, the front part can have a thinner material thickness than the support part, the backrest part and the seat part, but a thicker material thickness than the solid-state joints.

[0013] In order to provide sufficient resistance for tilting the backrest backward, it may be advantageous to arrange a spring arrangement between the seat part and the support part. The spring arrangement can, for example, comprise one or more spring elements, which can be designed as leaf springs. The spring arrangement can be manufactured together with the remaining multi-joint body using an injection molding process. At least one spring element of the spring arrangement can be formed integrally, in particular by a material fit, with the seat part and the support part.

[0014] To adjust the central unit to different user weights, the spring arrangement can have at least one spring element that can be activated and deactivated. Such a spring element can, for example, be formed integrally with the seat part at one end. The other end of the spring element can be pivotally mounted on the support part. This pivoting action can be blocked by a slider. In the blocked position, the spring element exerts its spring effect, while in the position released by the slider, it is deactivated.

[0015] According to one embodiment of the invention, a limiting arrangement can be provided to limit the maximum relative movement of the seat part and the backrest part. In particular, two stops can be provided, with one stop defining the maximum opening angle between the seat part and the backrest part, and one stop defining the minimum angle between the seat part and the backrest part.

[0016] Furthermore, a manually operable locking mechanism can be provided to lock the relative position of the seat and backrest sections. This measure can be used to determine the opening angle between the backrest and seat sections.

[0017] Furthermore, a manually operable seat tilt limiter can be provided. The locking mechanism and the seat tilt limiter can be combined.

[0018] A pin can be arranged on the backrest, which is guided in a slotted guide on the support. The two ends of the slotted guide represent the stops that limit the relative movement of the seat and backrest. To ensure particularly good stability, the pin and guide can be made of metal.

[0019] A latch can be pivotally mounted on the guide part, which has both a stop for the pin and a locking receptacle for the pin. If the latch is in a position where the pin can strike the stop, the stop can limit the seat inclination. If the latch is in a position where the pin is received by the locking receptacle, the relative movement of the seat part and the backrest part is prevented.

[0020] Further advantages arise when an assembly with a mount for the support of a base frame is arranged on the support part. Particularly when the assembly is made of metal, this provides sufficient stability to accommodate the support of the base frame. The locking mechanism and seat tilt limiter can also be integrated into the assembly to ensure these functions are also implemented with sufficient stability. For recycling, the assembly can be easily detached from the multi-joint body, allowing both components to be recycled separately.

[0021] A guide for holding the seat and / or backrest can be arranged on the seat and / or backrest. This facilitates the assembly of the seat and / or backrest. The guides can be dovetail-shaped.

[0022] A plug-in connector element for attaching a seat element and / or backrest element can be arranged on the seat part and / or the backrest part. This provides a simple way to assemble the seat and backrest. The seat part and the backrest part can be part of or a central element of the seat or backrest.

[0023] Armrests can be arranged integrally with the backrest. In particular, they can be molded onto the backrest or be an integral part of it.

[0024] The scope of the invention also includes a chair, in particular an office chair, with a central unit according to the invention.

[0025] Further advantages of the invention will become apparent from the description and the drawings. Likewise, the above-mentioned and further-described features can be used individually or in combinations according to the invention. The embodiments shown and described are not intended to be exhaustive, but rather are exemplary in nature for describing the invention.

[0026] They show: Fig. 1 a multi-joint body with four film hinges in a side view; Fig. 2 a perspective view of the multi-joint body with four joints in a basic position; Fig. 3 one of the Figure 2 corresponding representation with the backrest pivoted backwards; Fig. 4 an embodiment of a multi-joint body in which a seat part and a support part are connected by a spring arrangement; Fig. 5 one of the Figure 4corresponding illustration with the backrest swivelled backwards; Fig. 6 a sectional view through a multi-joint body with a spring arrangement with several spring elements. Fig. 7 one of the Figure 6 corresponding representation with activated spring element; Fig. 8 a design of a multi-joint body with a flexible front part; Fig. 9 one of the Figure 8 corresponding representation with the backrest pivoted backwards. Fig. 10 a multi-joint body in which only three joints are designed as solid joints; Fig. 11 the multi-joint body of the Figure 10, wherein a joint has a pivot pin; Fig. 12 a central unit with a multi-joint body and a locking mechanism; Fig. 13 a central unit with a limiting arrangement; Fig. 14 the central unit with a locking mechanism; Fig. 15 the blocked locking mechanism; Fig. 16a a multi-joint body with receptacles for a seat and a backrest; Fig. 16b the multi-joint body of the Figure 16a while the seat and backrest are plugged on; Fig. 16c a backrest suitable for plugging on; Fig. 17 a further multi-joint body with plug-in connection elements for plugging on seat and backrest elements; Fig. 18 a multi-joint body with armrests arranged materially on the backrest part.

[0027] The Figure 1shows a central unit 10 of a chair, in particular an office chair, with a multi-joint body 12. The multi-joint body 12 has a seat part 14 for a seat 16, a backrest part 18 for a backrest 20, a support part 22 for a base frame, and a front part 24. The seat part 14 is connected to the backrest part 18 via a joint 26, which is designed as a solid-state joint. The backrest part 18 is connected to the support part 22 via a joint 28, which is designed as a solid-state joint. The support part 22 is connected to the front part 24 via a joint 30, which is designed as a solid-state joint. The front part 24 is connected to the seat part 14 via a joint 32, which is designed as a solid-state joint. The joints 26, 28, 30, 32 have a lower material thickness than the seat part 14, the backrest part 18, the support part 22 and the front part 24.The seat part 14, the backrest part 18, the support part 22, and the front part 24 are rigid. The joints 26, 28, 30, and 32 are less rigid, namely flexible, particularly elastic. The material thickness of the joints 26, 28, 30, and 32 can be the same or different. Two joints can also have the same material thickness.

[0028] In the illustrated embodiment, the multi-joint body 12 is designed as a four-bar linkage. The seat part 14, the backrest part 18, the support part 22, and the front part 24, as well as the joints 26, 28, 30, 32 arranged therebetween, enclose an opening 34. The multi-joint body 12 can be formed in one piece. In particular, the joints 26, 28, 30, 32 can each be formed in one piece, in particular with a material fit, with the adjoining parts. The seat 16 and the backrest 20 can be separate parts and connected to the multi-joint body 12. However, it is also conceivable for the seat 16 and the backrest 20 to be formed in one piece, in particular with a material fit, with the multi-joint body 12. In particular, the multi-joint body 12, optionally together with the seat 16 and backrest 20, can be formed from plastic and manufactured using an injection molding process.

[0029] The Figure 2shows a perspective view of the central unit 10 of the Figure 1 in a basic position. This means that no force was exerted on the backrest 20 or the seat 16 and thus the multi-joint body 12 was not deformed.

[0030] When presenting the Figure 3 a force was exerted on the backrest 20, causing it to pivot backwards. This results in a different shape of the opening 34. Because the joints 26, 28, 30, 32 are made of elastic material, they automatically return to the position of Figure 2 when no external force is exerted on the backrest 20. In the Figure 3 the backrest 20 and the seat 16 have a larger angle to each other than in the Figure 2 .

[0031] In the embodiment of the central unit 10a according to the Figure 4A spring arrangement 36 is provided between the seat part 14 and the support part 22. The spring arrangement 36 can be formed integrally, in particular materially, with the seat part 14 and the support part 22. The spring arrangement 36 can increase the resistance force for pivoting the backrest 20 back. The spring arrangement 36 essentially divides the opening 34 into two halves.

[0032] The Figure 4 shows the central unit 10a in a basic position, ie without the backrest 20 being pivoted relative to the seat 16.

[0033] The Figure 5 shows the central unit 10a after the backrest 20 has been pivoted backward relative to the seat 16. It can be seen that both the spring arrangement 36 and the opening 34 have deformed. The spring arrangement 36 can have only one spring element, which is designed like a leaf spring. However, the spring arrangement 36 can also be designed according to the Figure 6be trained.

[0034] The spring arrangement 36 of the Fig. 6 has several spring elements 38, 40. The spring element 36 is firmly connected to the seat part 14 and the support part 22, in particular formed integrally therewith. The spring element 40, in the illustrated embodiment, is only connected to the seat part 14, in particular formed integrally therewith. The support-side end 42 of the spring element 40 is rotatably mounted on the support part 22 via a pivot axis 44. Thus, when the seat part 14 moves relative to the support part 22, the end 42 can be pivoted relative to the support part 22, so that the spring element 40 has no effect. To activate the spring element 40, a slider 46 is provided, which is displaceable relative to the support part 22. The slider 46 can be pushed into the recess 48 to activate the spring element 40, as shown in the Figure 7is shown. In this case, the end 42 can no longer be pivoted about the axis 44, so that the spring element 40 exerts its effect and, when a force is exerted on the backrest 20, counteracts a relative movement of the seat part 14 and the support part 22. A spring element analogous to the spring element 38 can also be provided. In particular, the spring element 40 can be arranged between two spring elements 38.

[0035] The Figure 8shows a further variant of a central unit 10b. This embodiment has only the joints 26, 28, 32. The front part 24a is designed to be flexible. It has a material thickness that is less than that of the seat part 14, the backrest part 18, and the support part 22, but stronger than that of the joints 26, 28, 32. This design allows the rigidity of the multi-joint body 12b to be further increased. In particular, the force required to deform the multi-joint body 12 can be increased in this way compared to the design of the Figure 1 .

[0036] The Figure 8 shows the multi-joint body 12b in a basic position, ie without the backrest 20 being pivoted relative to the seat 16. The Figure 9 shows the situation after the backrest 20 has been pivoted relative to the seat 16. Here it can be seen that the front part 24a has also been deformed. In the embodiment according to the Figures 8 and 9 The front part 24a is formed integrally with the support part 22. It would also be conceivable to omit the joint 32 and connect the front part 24a directly to the seat part 14, while retaining the joint 30 between the front part 24a and the support part 22.

[0037] The Figure 10shows a further embodiment of a central unit 10c. The multi-joint body again has a seat part 14, a backrest part 18, a support part 22, and a front part 24. Seat part 14 and backrest part 18 are connected by a joint 26 designed as a solid-state joint. Support part 22 and front part 24 are connected by a joint 30 designed as a solid-state joint. Front part 24 and seat part 14 are connected by a joint 32 designed as a solid-state joint. In this case, however, the joint 28 is not designed as a solid-state joint. A pin receptacle 50 is formed on the backrest part 18, and a pin receptacle 52 is formed on the support part 22. The pin receptacles 50, 52 can be connected by a pin to form a joint 28. In this case, the multi-joint body 12c thus has only three solid-state joints. The special feature of this embodiment is that the Figure 10The multi-joint body 12c shown can be manufactured in one piece in an injection molding process.

[0038] The Figure 11 shows the multi-joint body 12c with the completed joint 28, i.e., after a pin 54 has been inserted into the pin receptacles 50, 52. In principle, it is also conceivable to design one of the other joints 26, 30, 32 as a joint with a pin. However, it is preferred that at least three of the joints 24, 28, 30, 32 be designed as solid-body joints.

[0039] The Figure 12 shows a central unit 10d with a multi-joint body 12. An assembly 60, in particular a metal assembly, is arranged on the multi-joint body 12. This assembly comprises, on the one hand, a receptacle 62 for receiving a support of a base frame (not shown here). Furthermore, a limiting arrangement, a locking mechanism, and a seat tilt limiter are formed on the assembly 60, as can be seen from the following illustrations.

[0040] The Figure 13 , in which half of the central unit 10d is hidden, it can be seen that a guide part 64 is provided, which has a guide rail 66. A pin 68 is arranged in the guide rail 66 and is fixed to the backrest part 18. The guide rail 66 limits the range of movement of the pin 68. This limits the relative movement of the seat part 14 and the backrest part 18. The two ends of the guide rail 66 represent end stops for the pin 68.

[0041] Furthermore, a latch 70 can be seen, which is pivotably mounted on the guide part 64. The latch 70 is coupled to an actuating handle 74 via a toggle lever mechanism 72. By actuating the actuating handle 74, the latch 70 can be pivoted.

[0042] In the in the Figure 14In the pivoted position of the latch 70 shown, a stop 76 blocks further movement of the pin 68 in the guide 66. This limits the mobility of the seat part 14, so that a manually operable seat inclination limitation is realized. However, further relative movement of the seat part 14 and the backrest part 18 in the sense of an increase in the angle between the seat part 14 and the backrest part 18 remains possible until the pin 68 abuts the right end of the guide 66.

[0043] The Figure 15shows a further pivoted position of the latch 70, with the pin 68 received in a locking receptacle 78 of the latch 70. Thus, a locking mechanism is realized. The relative position of the seat part 14 and the backrest part 18 is locked. The assembly 60 can be a metal assembly. However, it can also be made of another material, for example, plastic. In any case, the assembly 60 is completely detachable from the multi-joint body, thus ensuring recyclability.

[0044] Figure 16ashows a multi-joint body 12d, in which the seat part 14 has a guide 90 onto which a seat can be slid. In the illustrated embodiment, the guide 90 has a dovetail-shaped cross-section. This ensures that the slid-on seat cannot simply be removed upwards. To ensure that the seat remains in its position, the guide 90 has locking recesses 92 so that the seat can lock onto the guide 90 using corresponding locking lugs.

[0045] A guide 94 for receiving a backrest is provided on the backrest part 18. The guide 94 also has a dovetail-shaped cross-section. The guides 90, 94 can be formed integrally with the seat part 14 or the backrest part 18. In particular, the guides 90, 94 can be molded onto the seat part 14 or the backrest part 18, in particular, manufactured simultaneously with the multi-joint body 12d.

[0046] Recesses 95, 97, which can be designed as through-holes, are provided on the backrest part 18. By appropriately selecting the number, shape, and size of the recesses 95, 97, the flexural rigidity of the backrest part 18 can be adjusted.

[0047] The Figure 16b shows that the backrest 20 can be pushed onto the guide 94 in the direction of arrow 98. The seat 16 can be pushed onto the guide 90 in the direction of arrow 100. This results in a particularly simple attachment of the seat 16 and backrest 20 to the multi-joint body 12d.

[0048] The Figure 16cshows that the backrest 20 has a guide 96 on its rear side, corresponding to the guide 94, with which the backrest 20 can be pushed onto the guide 94. The guide 96 is essentially U-shaped, so that the upper horizontal web forms a stop that prevents the backrest 20 from being pushed too far onto the guide 94. The seat 16 can have a corresponding guide on its underside.

[0049] When designing a multi-joint body 12e according to the Figure 17It can be seen that both the seat part 14 and the backrest part 18 have plug-in connection elements 104, 106 designed as pin receptacles. Corresponding plug-in connection parts 104, 106 are provided on the opposite side of the seat part 14 and the backrest part 18, respectively. Seat elements 108 and backrest elements 110 can be easily inserted into the plug-in connection elements 104, 106 using corresponding plug-in connection elements 112, 114 designed as pins, in order to be easily arranged on the multi-joint body 12e. In particular, the seat part 14 and the backrest part 18 can each have four plug-in connection elements 104 and 106, respectively.

[0050] In the embodiment of the multi-joint body 12f according to the Figure 18It can be seen that armrests 120, 122 are arranged on the backrest part 18. In particular, the armrests 120, 122 are formed in a materially integral manner with the backrest part 18. They can be injection-molded onto the backrest part 18. The armrests 120, 122, together with the upper section 124 of the backrest part 18, form a U-shaped configuration. The backrest 20, which is only shown schematically here, can be attached to the section 124 of the backrest part 18.

[0051] Furthermore, it is indicated that the seat 16 can be inserted with corresponding extensions into openings 126 of the seat part 14 or can be fastened to the seat part 14 through the openings 126 by means of screws. Figure 18 a base frame 128 is also indicated, which is connected to the support part 22 via a support 130.

Claims

1. Central unit (10, 10a, 10b, 10c, 10d) for a chair, in particular an office chair, characterized by a multi-joint body (12, 12a, 12b, 12c, 12d, 12e, 12f) which has a seat part (14) for a seat (16), a backrest part (18) for a backrest (20), a support part (22) for a support (130) of a base frame (128) and a front part (24, 24a) arranged between the seat part (14) and the support part (22), wherein the multi-joint body (12, 12a, 12b, 12c, 12d, 12e, 12f) has at least three joints (26, 28, 30, 32), which each connect two of the said parts in an articulated manner.

2. Central unit according to claim 1, characterized in that at least one, in particular at least three, preferably four of the joints (26, 28, 30, 32) are designed as a solid-state joint.

3. Central unit according to one of the preceding claims, characterized in that the flexure joints are formed integrally with the parts they connect.

4. Central unit according to one of the preceding claims, characterized in that the multi-joint body (12, 12a, 12b, 12c, 12d, 12e, 12f) is formed in one piece.

5. Central unit according to one of the preceding claims, characterized in that the multi-joint body (12, 12a, 12b, 12c, 12d, 12e, 12f) is made of plastic, in particular glass-fiber-reinforced plastic, preferably glass-fiber-reinforced polyamide.

6. Central unit according to one of the preceding claims, characterized in that exactly one of the joints (28) is designed as a hinge with a rotary pin (54).

7. Central unit according to one of the preceding claims, characterized in that the front part (24a) is designed to be flexible.

8. Central unit according to one of the preceding claims, characterized in that a spring arrangement (36) is arranged between the seat part (14) and the support part (22).

9. Central unit according to claim 8, characterized in thatthe spring arrangement (36) has at least one activatable and deactivatable spring element (40).

10. Central unit according to one of the preceding claims, characterized in that a limiting arrangement is provided for limiting the maximum relative movement of the seat part (14) and the backrest part (18).

11. Central unit according to one of the preceding claims, characterized in that a manually operable locking mechanism is provided for locking the relative position of the seat part (14) and the backrest part (18).

12. Central unit according to one of the preceding claims, characterized in that a manually operated seat tilt limiter is provided.

13. Central unit according to one of the preceding claims, characterized in that a pin (68) is arranged on the backrest part (18) and is guided in a slot (66) of a guide part (64) arranged on the support part (22).

14. Central unit according to one of the preceding claims, characterized in that a latch (70) is pivotably arranged on the guide part (64), which latch has both a stop (76) for the pin (68) and a locking receptacle (78) for the pin (68).

15. Chair, in particular an office chair, with a central unit (10, 10a, 10b, 10c, 10d) according to one of the preceding claims.

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