Chair

Abstract

The chair according to the invention has a seat, a backrest, a support frame, and at least one S-shaped leaf spring. The S-shaped leaf spring at a first section is fastened to the support frame, the seat is mounted at a second section, and the backrest is mounted at a third section. A first curvature is provided between the first and second sections, so that in a neutral position of the chair the first section and the second section are situated essentially in parallel to one another and are spaced apart, and the third section adjoins the second section via a second, opposite curvature. A compressible spacer that is displaceably guided in the longitudinal direction of the first section is provided between the first and the second section.

Claims

1. A chair having a seat (1), a backrest (2), a support frame (3), and at least one S-shaped leaf spring (4), the S-shaped leaf spring (4) at a first section (4a) being fastened to the support frame (3), the seat being mounted at a second section (4b), and the backrest (2) being mounted at a third section (4c), and a first curvature (4d) being provided between the first section (4a) and the second section (4b), so that in a neutral position of the chair the first section (4a) and the second section (4b) are situated essentially in parallel to one another and are spaced apart, and the third section (4c) adjoins the second section (4b) via a second, opposite curvature (4e), and a compressible spacer (6) is provided between the first section (4a) and the second section (4b), characterized in that the compressible spacer (6) is displaceably guided in the longitudinal direction of the first section (4a).

2. The chair according to claim 1, characterized in that only one S-shaped leaf spring (4), which is situated mirror-symmetrically with respect to the longitudinal center plane (7) of the chair, is provided.

3. The chair according to claim 1, characterized in that the compressible spacer (6) is situated in a middle area of the first section (4a), between the fastening to the support frame (3) and the first curvature (4d).

4. The chair according to claim 1, characterized in that the first section (4a) of the S-shaped leaf spring (4) has at least one recess (4f), in particular an elongated hole, extending in the longitudinal direction of the first section (4a) for displacement of the compressible spacer (6).

5. The chair according to claim 4, characterized in that the compressible spacer (6) is connected to an actuating element (8) for displacing the compressible spacer (6) along the recess (4f) and for detachably fixing the compressible spacer (6) in a desired position.

6. The chair according to claim 5, characterized in that the actuating element (8) is designed in such a way that a rotation of the actuating element (8) brings about a simultaneous displacement of the compressible spacer (6) along the recess (4f).

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

8. The chair according to claim 7, characterized in that the actuating element (8) and the elongated hole provided with the toothing (9) intermesh in the manner of self-locking lantern gear toothing.

9. The chair according to claim 1, characterized in that the S-shaped leaf spring (4) is made of steel.

10. The chair according to claim 9, characterized in that the steel has a yield strength of greater than 500 MPa.

11. The chair according to claim 1, characterized in that the compressible spacer (6) has a progressive spring characteristic curve.

12. The chair according to claim 1, characterized in that the compressible spacer (6) is formed by a coil spring made of steel and/or by a Cellasto disk.

13. The chair according to claim 1, characterized in that armrests (5) which are fastened to the seat (1) or to the second section (4b) of the S-shaped leaf spring (4) are also provided.

14. The chair according to claim 1, characterized in that the S-shaped leaf spring (4) is deflectable with regard to both bending and rotation.

15. The chair according to claim 14, characterized in that the first section (4a) of the S-shaped leaf spring (4) has at least one recess (4f), in particular an elongated hole, extending in the longitudinal direction of the first section (4a) for displacement of the compressible spacer (6), and 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 center axis of the first section (4a) is facilitated.

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

Description

[0017] Further embodiments of the invention are explained in greater detail, based on the following description and the drawings.

In the Drawings:

[0018] FIG. 1 shows a schematic side view of the chair with a spacer in a rear position,

[0019] FIG. 2 shows a schematic side view of the chair with a spacer in a front position,

[0020] FIG. 3 shows a schematic illustration of the S-shaped leaf spring with a compressible spacer in the front position,

[0021] FIG. 4 shows a schematic illustration of the S-shaped leaf spring with a compressible spacer in the rear position,

[0022] FIG. 5 shows a three-dimensional bottom view of the illustration according to FIG. 4,

[0023] FIG. 6 shows a sectional illustration in the area of the compressible spacer,

[0024] FIG. 7a-7h show schematic illustrations of the lantern gear toothing in various positions of the actuating element,

[0025] FIG. 8 shows a schematic side view of the chair according to FIG. 1 in the tilted-back position,

[0026] FIG. 9 shows a schematic side view of the chair according to FIG. 2 in the tilted-back position,

[0027] FIG. 10 shows a schematic front view of the chair according to FIG. 1 in a laterally tilted position, and

[0028] FIG. 11 shows a schematic front view of the chair according to FIG. 2 in a laterally tilted position.

[0029] The chair illustrated in FIGS. 1 through 6 is made up essentially of a seat 1, a backrest 2, a support frame 3, and at least one S-shaped leaf spring 4, with the S-shaped leaf spring 4 at a first section 4a being fastened to the support frame 3, while the seat 1 is mounted on a second section 4b and the backrest 2 is mounted on a third section 4c. A first curvature 4d is provided between the first and the second section, so that in the neutral position shown in FIG. 1, the first section 4a and the second section 4b are situated essentially in parallel to one another and spaced apart, and the third section 4c adjoins the second section 4b via a second, opposite curvature 4e.

[0030] The support frame 3 has a central column 3a and a cross-shaped base 3b with rollers 3c.

[0031] However, within the scope of the invention other support frames are conceivable, in particular those with fixed feet.

[0032] In addition, in the illustrated exemplary embodiment armrests 5 which are fastened to the seat 1 or to the second section 4b of the S-shaped leaf spring 4 are provided. Furthermore, provided between the first section 4a and the second section 4b is a compressible spacer 6 that is displaceably guided in the longitudinal direction of the first section 4a. FIG. 1 shows the compressible spacer 6 in a rear position, while a front position is illustrated in FIG. 2. The compressible spacer 6 is situated in a middle area of the first section 4a, i.e., between the fastening of the S-shaped leaf spring 4 to the support frame 3 and the first curvature 4d, the compressible spacer with a first contact surface being displaceably guided on the first section 4a, and at its opposite end having a second contact surface on which the second section 4b of the S-shaped leaf spring 4 is (loosely) supported.

[0033] Depending on the design of the compressible spacer 6, in particular as a coil spring, a guide element for the spacer 6 may be provided in the area of the second section 4b. According to an optional feature, the spacer has a progressive spring characteristic curve. The S-shaped leaf spring 6 is preferably made of steel having a yield strength of greater than 500 MPa.

[0034] It is apparent from FIGS. 10 and 11 that only one S-shaped leaf spring 4, which is situated mirror-symmetrically with respect to or in the longitudinal center plane 7 of the chair, is provided.

[0035] FIGS. 3 and 4 show the S-shaped leaf spring 4 in a three-dimensional illustration, in which it is apparent that the first section 4a of the S-shaped leaf spring 4 has at least one recess 4f, in the form of an elongated hole, which extends in the longitudinal direction of the first section 4a for displacing the compressible spacer 6. In the illustrated exemplary embodiment the compressible spacer 6 is designed as a coil spring. However, as illustrated in FIGS. 1 and 2, it may also be formed from a Cellasto disk or a combination of a coil spring and a Cellasto disk.

[0036] The compressible spacer 6 is connected to an actuating element 8 for moving the compressible spacer 6 along the recess 4f and for detachably fixing the compressible spacer 6 in a desired position. In the simplest case this may be a screw-nut connection. In the exemplary embodiment according to FIGS. 5 and 6, however, the actuating element 8 is designed in such a way that a rotation of the actuating element 8 brings about a simultaneous displacement of the compressible spacer 6 along the recess 4f. For this purpose, the recess 4f is designed as an elongated hole with toothing 9, the actuating element 8 being in operative engagement with the toothing 9, so that a rotation of the actuating element 8 brings about a simultaneous displacement of the compressible spacer 6 along the recess 4f. In the illustrated embodiment, the toothing 9 is provided on a toothed track 10 that is installed on the bottom side of the section 4a, in the area of the recess 4f. However, it is also conceivable for the recess 4f that is provided in the section 4a to already have the toothing 9.

[0037] Ideally, the actuating element 8 and the elongated hole 4f provided with the toothing 9 engage with one another in the manner of self-locking lantern gear toothing. Thus, the actuating element 8, designed as a rotary handle, may remain in any position without additional measures. FIGS. 7a through 7h illustrate the engagement of the actuating element 8 with the toothing 9 for various positions of the actuating element or of the compressible spacer 6 connected thereto. It is also apparent from FIG. 6 and FIGS. 7a through 7h that on the side of the toothed track 10 facing away from the compressible spacer 6, the actuating element 8 has a rotatably fixedly connected first disk 8a whose diameter is larger than the width of the recess 4f. Two rollers or pins 8b, 8c that come into toothing engagement with the toothing 9 are situated on the first disk 8a. In turn, a second disk whose diameter is slightly smaller than the width of the recess 4f is fastened to the two pins 8b, 8c, and is guided in the recess 4f during the displacement of the compressible spacer 6. In turn, a third disk 8e that is displaceably guided on the top side of the first section 4a is provided on the second disk 8d. The compressible spacer 6 (in this case, the coil spring) is suitably mounted on this third disk 8e, for example by means of a mounting element 8f.

[0038] The S-shaped leaf spring 4 in interaction with the compressible spacer 6 is designed in such a way that bending into a tilted-back position of the chair is made possible. The seat 1 and the backrest 2 may be inclined further rearwardly and downwardly when the compressible spacer 6 is situated farther to the front, i.e., closer to the first curvature 4d, as is the case in FIG. 9 in comparison to FIG. 8. In an extension of the central column 3a of the support frame 3, an end stop 11 may optionally also be provided which limits the movement of the S-shaped leaf spring 4 under extremely high load, as shown in FIG. 9.

[0039] When the movement of the chair into the tilted-back position according to FIGS. 8 and 9 is initiated by a person sitting on the chair, this results not only in a lowering of the second section 4b about a virtual pivot point in the area of the first curvature 4d, but also in an increase in the angle between the seat 1 and the backrest 2, as for a conventional synchronous mechanism that is implemented by a swivel mechanism. The increase in the angle between the seat 1 and the backrest 2 is apparent in FIGS. 8 and 9 from the illustration of the backrest 2 with solid lines, in comparison to the dashed-line illustration of the backrest. The angle between the seat 1 and the backrest 2 may vary by approximately 5, for example.

[0040] However, the S-shaped leaf spring 4 is designed to be deflectable not only with regard to bending into a tilted-back position according to FIGS. 8 and 9, but also preferably with regard to a rotation, so that the chair may be laterally tilted by the person sitting on the chair, as is apparent from FIGS. 10 and 11. Here as well, the position of the compressible spacer has an influence on the extent of the lateral tilting movement, so that a compressible spacer 6 situated farther to the front (FIGS. 2 and 9) allows a greater lateral tilting movement (see FIG. 11) than the compressible spacer 6 situated farther to the rear according to FIGS. 2, 9, and 12.

[0041] The rotatability of the first section 4a of the S-shaped leaf spring 4 about the longitudinal center axis 12 (FIGS. 5, 10, and 11), and thus the lateral tilting capability of the chair, is facilitated by the recess 4f which extends in the longitudinal direction of the first section 4a.