Chair

Abstract

The chair according to the invention comprises a seat (1), a backrest (2), a support frame (3), and at least one S-shaped leaf spring (4), wherein the S-shaped leaf spring (4) is attached to the support frame (3) by a first section (4a), the seat (1) is held by a second section (4b), and the backrest (2) is held by a third section (4c), wherein a first curvature (4d) is provided between the first (4a) and the second section (4b) such that, in a rest position of the chair, the first section (4a) and the second section (4b) are arranged substantially parallel to each other and spaced apart, and the third section (4c) connects to the second section (4b) via an opposing second curvature (4e). A compressible spacer (6) is provided between the first (4a) and the second section (4b), which is adjustable in the longitudinal direction of the first section (4a).

Description

[0001] The invention relates to a chair with a seat, a backrest, a support frame and a seat suspension formed by at least one S-shaped leaf spring.

[0002] Synchronous mechanisms for the synchronous adjustment of the seat and backrest are known in practice, where the backrest and seat are flexibly coupled and move in a fixed ratio to each other, for example, 3:1 or 2:1. Various pivot mechanisms have been developed to implement the synchronous mechanism, through which the backrest and seat are coupled. One or more spring elements dampen the synchronous movement.

[0003] From EP 2 047 769 B1, a chair with a seat, a backrest, and a support frame is known. The seat is supported by a seat support and the backrest by a backrest support, wherein the seat support and backrest support each consist of at least one rocker spring and together form an S-shaped spring element, which has at least two sections with different spring strengths formed from separate spring elements. The effective spring length of the rocker spring can be adjusted by means of an adjustment element provided by a second element accompanying the rocker spring. Furthermore, a slider is provided that connects the rocker spring to the second element. Depending on the position of this slider, a longer or shorter portion of the rocker spring is able to deform independently of the second element.

[0004] Furthermore, US 2002 / 0000745 A1 relates to a patient chair comprising a seat, a backrest, a frame, and two S-shaped leaf springs. The S-shaped leaf springs are attached to the frame via a crossbeam with a first section, the seat is held by a second section, and the backrest by a third section. A first curve is provided between the first and second sections, such that, in a rest position of the chair, the first and second sections are substantially parallel to each other and spaced apart. The third section connects to the second section via an opposing second curve. The second section is further supported on the crossbeam by a first spring element.When the seat is tilted downwards, the first spring element is compressed and comes into contact with a second spring element located between the first and second sections. The two spring elements enable a stable, self-damping pivoting motion of the seat and backrest and limit the chair's maximum tilt angle.

[0005] The invention is based on the objective of improving the adjustability of the swivel movement.

[0006] According to the invention, this problem is solved by the features of claim 1. Further embodiments of the invention are the subject of the dependent claims.

[0007] The chair according to the invention comprises a seat, a backrest, a support frame, and at least one S-shaped leaf spring. The S-shaped leaf spring is attached to the support frame by a first section, the seat is held by a second section, and the backrest by a third section. A first curvature is provided between the first and second sections, such that, in a rest position of the chair, the first and second sections are arranged essentially parallel to each other and spaced apart. The third section connects to the second section via an opposing second curvature. A compressible spacer is provided between the first and second sections and is adjustable in the longitudinal direction of the first section.

[0008] Adjusting the compressible spacer along the first section allows for a change in the effective lever arm of the second section, thereby adjusting the firmness of the reclining movement and, in particular, adapting it to different user weights.

[0009] Preferably, only one S-shaped leaf spring is provided, arranged symmetrically to the longitudinal center plane of the chair. This reduces the number of components and also facilitates lateral swiveling of the seat and backrest. A chair designed in this way thus also enables three-dimensional dynamic sitting.

[0010] According to a preferred embodiment of the invention, the compressible spacer is arranged in a central region of the first section between the attachment to the support frame and the first curve. Furthermore, the compressible spacer can be adjustably guided with a first contact surface on the first section and can have a second contact surface at its opposite end, on which the second section of the S-shaped leaf spring preferably rests loosely.

[0011] To adjust the compressible spacer, the first section of the S-shaped leaf spring preferably has at least one recess extending in the longitudinal direction of the first section. This allows the effective lever arm of the second section of the leaf spring, and thus the spring force, to be changed easily by moving the compressible spacer.

[0012] Furthermore, the design can include a compressible spacer connected to an actuating element for moving the compressible spacer along the recess and for releasably fixing it in a desired position. Particularly simple and intuitive adjustment can be achieved if the actuating element is designed such that a rotation of the actuating element simultaneously moves the compressible spacer along the recess. This could be realized, for example, by designing the recess as an elongated slot with teeth, with the actuating element engaging the teeth so that a rotation of the actuating element simultaneously moves the compressible spacer along the recess.In this way, the actuating element and the elongated hole with the teeth can interlock, particularly in the manner of a self-locking pinion gear.

[0013] The S-shaped leaf spring is preferably made of steel. Compared to plastic or glass-fiber reinforced plastic, steel has the advantage of a significantly lower CO2 footprint. Furthermore, the spring action of steel is perceived by the user as "crisper" and thus pleasantly dynamic. Within the scope of the invention, it has proven advantageous for the steel to have a yield strength of more than 500 MPa in order to ensure elastic recovery even with higher user weights. A further reduction in the CO2 footprint can be achieved by making the seat and backrest from plywood.

[0014] To prevent the chair from feeling too soft when leaning back, it is advisable for the compressible spacer to have a progressive spring characteristic. A steel coil spring and / or a Cellasto disc, for example, could be used as a compressible spacer.

[0015] According to a further embodiment of the invention, the S-shaped leaf spring is deflectable with respect to both bending and twisting. This enables three-dimensional dynamic sitting, allowing the seat and backrest to pivot not only backward but also laterally. The compressible spacer is therefore also designed to support the lateral pivoting movement by being laterally compressible. Furthermore, the recess extending longitudinally along the first section can be configured to facilitate rotation of the first section about a longitudinal axis of the first section, thus enabling lateral pivoting.

[0016] The chair can optionally be fitted with armrests, which are attached to the seat or to the second section of the S-shaped leaf spring.

[0017] Further embodiments of the invention are explained in more detail with reference to the following description and the drawing.

[0018] The drawing shows Fig. 1 a schematic side view of the chair with a spacer in a rear position, Fig. 2 a schematic side view of the chair with a spacer in a front position, Fig. 3 a schematic representation of the S-shaped leaf spring with compressible spacer in the front position, Fig. 4 a schematic representation of the S-shaped leaf spring with compressible spacer in the rear position, Fig. 5 a three-dimensional underside view of the representation according to Fig. 4 Fig. 6 a sectional view in the area of ​​the compressible spacer, Figs. 7a to 7h schematic representations of the pinion gearing in different positions of the actuating element, Fig. 8 a schematic side view of the chair according to Fig. 1in the reclined position, Fig. 9 a schematic side view of the chair according to Fig. 2 in the reclined position, Fig. 10 a schematic front view of the chair according to Fig. 1 in a sideways tilted position, Fig. 11 a schematic front view of the chair according to Fig. 2 in a sideways tilted position.

[0019] The one in the Figs. 1 to 6 The illustrated chair essentially consists of a seat 1, a backrest 2, a support frame 3, and at least one S-shaped leaf spring 4, wherein the S-shaped leaf spring 4 is attached to the support frame 3 by a first section 4a, while the seat 1 is held by a second section 4b and the backrest 2 by a third section 4c. A first curvature 4d is provided between the first and the second section, such that the first section 4a and the second section 4b are in the Fig. 1The resting position of the chair shown is essentially parallel to each other and spaced apart, and the third section 4c connects to the second section 4b via an opposite second curvature 4e.

[0020] The support frame 3 has a central column 3a and a base 3b with casters 3c. However, other support frames are also conceivable within the scope of the invention, in particular those with fixed feet.

[0021] Furthermore, in the illustrated embodiment, armrests 5 are provided, which are attached to the seat 1 or to the second section 4b of the S-shaped leaf spring 4. A compressible spacer 6 is also provided between the first section 4a and the second section 4b, which is adjustable in the longitudinal direction of the first section 4a. Fig. 1 shows the compressible spacer 6 in a rear position, while in Fig. 2A front position is shown. The compressible spacer 6 is arranged in a central region of the first section 4a, i.e., between the attachment of the S-shaped leaf spring 4 to the support frame 3 and the first curvature 4d, wherein it is arbitrarily guided with a first contact surface on the first section 4a and has a second contact surface at its opposite end, on which the second section 4b of the S-shaped leaf spring 4 (loosely) rests.

[0022] Depending on the design of the compressible spacer 6, in particular as a coil spring, a guide element for the spacer 6 can also be provided in the area of ​​the second section 4b. According to an optional feature, the spacer has a progressive spring characteristic. The S-shaped leaf spring 6 is preferably made of steel with a yield strength of more than 500 MPa.

[0023] Figs. 10 and 11show that only one S-shaped leaf spring 4 is provided, which is arranged symmetrically to or in the longitudinal median plane 7 of the chair.

[0024] Figs. 3 and 4 Figure 1 shows the S-shaped leaf spring 4 in a three-dimensional representation, from which it can be seen that the first section 4a of the S-shaped leaf spring 4 has at least one recess 4f extending longitudinally along the first section 4a in the form of an elongated hole for adjusting the compressible spacer 6. In the illustrated embodiment, the compressible spacer 6 is designed as a coil spring. However, it can also be, for example, as shown in Figure 2. Figs. 1 and 2 depicted as being formed from a Cellasto disc or a combination of a spiral spring and a Cellasto disc.

[0025] The compressible spacer 6 is connected to an actuating element 8 for moving the compressible spacer 6 along the recess 4f and for releasably fixing the compressible spacer 6 in a desired position. In the simplest case, this can be a screw-nut connection. In the exemplary embodiment according to Figs. 5 and 6The actuating element 8 is designed such that a rotation of the actuating element 8 causes a simultaneous displacement of the compressible spacer 6 along the recess 4f. For this purpose, the recess 4f is designed as an elongated slot with a toothed section 9, with the actuating element 8 engaging with the toothed section 9, so that a rotation of the actuating element 8 causes a simultaneous displacement of the compressible spacer 6 along the recess 4f. In the illustrated embodiment, the toothed section 9 is formed on a toothed rail 10 mounted on the underside of section 4a in the area of ​​the recess 4f. However, it is also conceivable that the recess 4f provided in section 4a already has the toothed section 9.

[0026] Ideally, the actuating element 8 and the elongated hole 4f, which is provided with the toothing 9, interlock like a self-locking pinion gear. This allows the actuating element 8, designed as a rotary handle, to remain in any position without additional measures. Figs. 7a to 7h The engagement of the actuating element 8 with the toothing 9 is shown for different positions of the actuating element or the associated compressible spacer 6. Fig. 6 and the Figs. 7a to 7hIt is further evident that the actuating element 8 has a rotationally fixed first disk 8a on the side of the toothed rail 10 facing away from the compressible spacer 6. This first disk has a diameter larger than the width of the recess 4f. Two rollers or pins 8b, 8c are arranged on the first disk 8a, which engage with the toothing 9. A second disk is attached to the two pins 8b, 8c. This second disk has a diameter slightly smaller than the width of the recess 4f and is guided in the recess 4f during the displacement of the compressible spacer 6. A third disk 8e is provided on the second disk 8d and is slidably guided on the upper surface of the first section 4a. The compressible spacer 6 (here, the coil spring) is held on this third disk 8e in a suitable manner, for example, by a retaining element 8f.

[0027] The S-shaped leaf spring 4, in conjunction with the compressible spacer 6, is designed to allow the chair to bend into a reclined position. The seat 1 and backrest 2 can be tilted further backward and downward if the compressible spacer 6 is positioned further forward, i.e., closer to the first curve 4d, as shown in Fig. 9 compared to Fig. 8 This is the case. An end stop 11 can optionally be provided as an extension of the central column 3a of the support frame 3, which limits the movement of the S-shaped leaf spring 4 under extremely high loads, as shown in Fig. 9 shown.

[0028] If the movement of the chair into the reclined position is carried out according to the Figs. 8 and 9Triggered by a person sitting on the chair, not only does the second section 4b lower around a virtual pivot point in the area of ​​the first curve 4d, but the angle between seat 1 and backrest 2 also increases, as with a conventional synchronous mechanism realized by a swivel mechanism. The increase in the angle between seat 1 and backrest 2 is in the Figs. 8 and 9 This is evident from the representation of backrest 2 with solid lines compared to the dashed representation of the backrest. The angle between seat 1 and backrest 2 can change by approximately 5°, for example.

[0029] The S-shaped leaf spring 4 is not only designed to bend into a backward-leaning position according to the Figs. 8 and 9not only is it designed, but is preferably also deflectable with respect to rotation, so that the chair can be tilted sideways by the person sitting on it, as shown in the Figs. 10 and 11 This is evident. Here too, the position of the compressible spacer influences the extent of the lateral tilting movement; a compressible spacer 6 positioned further forward ( Fig. 2 and 9 ) a stronger lateral tilting movement (see Fig. 11 ) than the compressible spacer 6 located further back according to the Fig. 2 , 9 and 12.

[0030] The rotatability of the first section 4a of the S-shaped leaf spring 4 about the longitudinal central axis 12 ( Fig. 5 , 10 and 11 ) and thus the possibility of the chair tilting sideways is facilitated by the recess 4f extending in the longitudinal direction of the first section 4a.

Claims

1. Chair comprising a seat (1), a backrest (2), a support frame (3) and at least one S-shaped leaf spring (4), wherein the S-shaped leaf spring (4) is attached to the support frame (3) by a first section (4a), the seat is held by a second section (4b) and the backrest (2) by a third section (4c), wherein a first curvature (4d) is provided between the first section (4a) and the second section (4b) such that the first section (4a) and the second section (4b) are arranged substantially parallel to each other and spaced apart above each other in a rest position of the chair and the third section (4c) connects to the second section (4b) via an opposite second curvature (4e), and wherein a compressible spacer (6) is provided between the first section (4a) and the second section (4b), characterized by the fact thatthe compressible spacer (6) is adjustable in the longitudinal direction of the first section (4a).

2. Chair according to claim 1, characterized by the fact that only an S-shaped leaf spring (4) is provided, which is arranged symmetrically to the longitudinal median plane (7) of the chair.

3. Chair according to claim 1 or 2, characterized by the fact that the compressible spacer (6) is arranged in a central area of ​​the first section (4a) between the attachment to the support frame (3) and the first curvature (4d).

4. Chair according to one or more of the preceding claims, characterized by the fact that the first section (4a) of the S-shaped leaf spring (4) has at least one recess (4f) extending in the longitudinal direction of the first section (4a), in particular an elongated hole, for adjusting the compressible spacer (6).

5. Chair according to claim 4, characterized by the fact thatthe compressible spacer (6) is connected to an actuating element (8) for moving the compressible spacer (6) along the recess (4f) and for releasably fixing the compressible spacer (6) in a desired position.

6. Chair according to claim 5 characterized by the fact that the actuating element (8) is designed such that a rotation of the actuating element (8) causes a simultaneous displacement of the compressible spacer (6) along the recess (4f).

7. Chair according to claim 5, characterized by the fact that the recess (4f) is designed as an elongated hole with a toothing (9) and the actuating element (8) is in effective engagement with the toothing (9), so that a rotation of the actuating element (8) causes a simultaneous displacement of the compressible spacer (6) along the recess (4f).

8. Chair according to claim 7, characterized by the fact thatthe actuating element (8) and the elongated hole provided with the toothing (9) interlock in the manner of a pinion gear.

9. Chair according to one or more of the preceding claims, characterized by the fact that the S-shaped leaf spring (4) is made of steel.

10. Chair according to claim 9, characterized by the fact that the steel has a yield strength of more than 500 MPa.

11. Chair according to one or more of the preceding claims, characterized by the fact that the compressible spacer (6) has a progressive spring characteristic.

12. Chair according to one or more of the preceding claims, characterized by the fact that the compressible spacer (6) is formed by a spiral spring made of steel and / or a Cellasto disc.

13. Chair according to one or more of the preceding claims, characterized by the fact thatFurthermore, armrests (5) are provided which are attached to the seat (1) or the second section (4b) of the S-shaped leaf spring (4).

14. Chair according to one or more of the preceding claims, characterized by , the S-shaped leaf spring (4) is deflectable both with respect to bending and torsion.

15. Chair according to claims 4 and 14, characterized by the fact that the recess (4f) extending in the longitudinal direction of the first section (4a) is designed in such a way that a rotation of the first section (4a) about a longitudinal central axis of the first section (4a) is favored.

16. Chair according to claim 1, characterized by the fact that The compressible spacer (6) is adjustable with a first contact surface on the first section (4a) and has a second contact surface at its opposite end, on which the second section (4b) of the S-shaped leaf spring (4) is supported.

Images