EP1906792A1

EP1906792A1 - Chair, especially office chair

Info

Publication number: EP1906792A1
Application number: EP06762680A
Authority: EP
Inventors: Martin Potrykus; Armin Sander
Original assignee: Koenig and Neurath AG
Current assignee: Koenig and Neurath AG
Priority date: 2005-07-27
Filing date: 2006-07-19
Publication date: 2008-04-09
Anticipated expiration: 2026-07-19
Also published as: EP1906792B1; DE502006006259D1; ATE458423T1; DE202005011725U1; ES2339151T3; AU2006274242A1; WO2007012418A1

Abstract

Disclosed is a chair, especially an office chair (1), comprising a backrest (5) that is hinged to a load-bearing frame (8) via a backrest support (10), and a sitting area (3) which is movable in synchrony with the backrest (5) and is pivotally connected to the load-bearing frame (8) in a supporting point (15) via a seat guide (9). The backrest support (10) and the seat guide (9) are rotatably fixed to the load-bearing frame (8). A connecting rod (22) movably connects the seat guide (9) to the backrest support (10) in such a way that a rearward tilting movement of the backrest (5) is translated into an upward swiveling movement of the sitting area (3) at the supporting point (15). Such a design creates an automatic weight-shifting mechanism which allows the counterforce applied by the backrest (5) to be maintained substantially regardless of the absolute inclination.

Description

description

Chair, especially office chair

The invention relates to a chair, in particular an office chair, with a synchronous mechanism.

Modern high-quality office chairs are usually equipped with a synchronous mechanism, which ensures that the seat moves synchronously with the backrest. The synchronizing mechanism is usually formed by a backrest support, which is arranged on a central support frame, is movably connected to the seat. As a result, the movements of the backrest carrier are transmitted in synchronous movements of the seat. For the design of a synchronous mechanism offer different possibilities. Thus, for example, from DE 101 22 948 C1, a floor chair can be removed, the seat surface of which inclines with a deflection of the backrest to the rear towards the backrest. From DE 42 19 599 C2, an office chair can be removed, the seat surface inclines with a deflection of the backrest to the rear opposite to the front. In both chairs shown, it is necessary to adjust the counteracting force for an inclination of the backrest according to the weight of a seated person.

US Pat. No. 6,709,058 B1 discloses an office chair in which the force of the backrest counteracting an inclination mechanically adapts to the weight of a seated person. For this purpose, the backrest support is bent over a pivot point on the support frame out up under the seat. By this bend in combination with the fulcrum, a rearward tilting movement of the backrest on the backrest support is converted into an upward movement of the seat. Since the point of contact of the backrest support acting on the seat surface makes a rotational movement, the force which opposes the seated person from the backrest is dependent on the absolute inclination position of the backrest support. It is an object of the invention to provide a chair of the type mentioned, which has an alternative mechanism for automatically adjusting the counteracting of the backrest of a force on the weight of the seated person.

This object is achieved by a chair, in particular an office chair, with a hinged to a support frame via a backrest support and a synchronous movable seat, which is connected in a Aufpunkt about a seat link pivotally connected to the support frame, the backrest support and the Seat link are each rotatably mounted on the support frame, and wherein a pull rod such that the seat link is movably connected to the backrest support, that a rearward tilting movement of the backrest is translated at the Aufpunkt in an upward pivotal movement of the seat.

The invention is based in a first step on the consideration that the weight of a seated person is directed vertically downwards. If the tilting or rotary movement of the backrest is coupled directly to the seat surface via a suitably designed backrest support, then only the component which is tangential with respect to the rotational movement in the attachment point acts from the weight force. But this is the counter-force of the backrest acting against the seated person depends on their inclination.

In a further step, the invention proceeds from the consideration of overcoming this disadvantage by movably connecting a seat link which directs the seat surface to the backrest support via a pull rod. Thus, the rotational movement of the backrest and thus of the backrest carrier is transmitted via the pull rod to a rotational movement of the seat handlebar. In contrast to a direct coupling, the coupling via the pull rod offers additional mechanical degrees of freedom which allow the inclination of the backrest to be converted into a desired upward movement of the seat surface in a certain range. Such mechanical degrees of freedom are the length of the drawbar, the location of the attachment points of the drawbar on the backrest support and the seat link and the position of the backrest support to the seat link. The basic principle acting here is based on the fact that, in the case of a coupling of a rotary movement with a movable drawbar, the movement effected per rotation angle parallel to the drawbar is again dependent on the absolute rotational position. The described Bene coupling between seat link and backrest support with a pull rod can thus be used to compensate for the described undesirable dependence of the generated per angular difference of the backrest stroke of the seat of the absolute inclination angle of the backrest.

Advantageously, the backrest support is rotatably mounted on the support frame via a pivot bearing and has a pivot bearing on which the pull rod is rotatably mounted, wherein the pivot bearing in which the pull rod is mounted, in the direction of the seat link before and in the direction of the seat over the Rotary bearing is arranged over which the backrest support is attached. This geometry ensures that a rearward tilting movement of the backrest support leads from the beginning to an offset of the drawbar. About the coupling of the drawbar to the seat handlebars steering the seat can be achieved in this way a favorable for the automatic weight increase the increase of the seat.

Advantageously, the backrest support on an angled pivot arm on which the pull rod is rotatably mounted. By means of an angled swivel arm, the angle position between the pull rod and the tangent of the rotary motion of the backrest support can be set to save material in the starting or resting state of the chair at the attachment point.

Conveniently, the seat link is rotatably mounted on the seat. This allows for a rotational movement of the seat link relative to the support frame maintaining the orientation of the seat.

In an advantageous embodiment of the invention, the seat link is designed as a joint element, in particular as a hinge plate, with a first, a second and a third pivot bearing. About the first and the second pivot bearing the seat is connected to the support frame. In the third pivot bearing the drawbar is mounted. This embodiment is cost-effective and allows a mechanically simple, movable coupling between the seat and the support frame. About the distance of the third pivot bearing of the other two pivot bearings caused by each tie rod rotation angle of the joint element can be adjusted. Again, the ratio of the angle of rotation and the tie rod offset depends on the absolute rotational position of the joint element.

In a further advantageous embodiment of the invention, the seat is guided in a spaced from the Aufpunkt further Aufpunkt by means of a support frame mounted on the support member such that at an upward pivotal movement at the Aufpunkt an overall tilt of the seat is effected to the Rückenleh- ne. In such a construction, the increasing forward inclination of the seat back pressure of the seated person is absorbed by the appropriately oriented inclination of the seat. Slipping of the seated person is thus prevented. The guidance of the seat by means of the seat guide element in a further Aufpunkt allows a great deal of freedom in the design of the desired synchronous movement of the seat with respect to the deflection of the backrest.

Expediently, the seat link and the seat guide element cooperate in such a way that the point is raised by a tilting movement of the backrest directed backwards and the additional point is pushed back upwards. Characterized in that the Aufpunkt raised in a rotational movement and the other Aufpunkt is pushed by the rotational movement, a slight embodiment of the raising of the seat with a desired inclination curve is possible.

Advantageously, the seat guide element is designed as a slotted guide. The slotted guide allows in addition to the leadership in accordance with the predetermined link shape as a further degree of freedom a rotational movement. In this way, the movement of the seat can be influenced and predetermined within certain limits in a simple manner.

Conveniently, the slide guide on a curved guide. Due to the curvature, the progression of the increase of the further point of the seat is adjustable. This can be combined with the upward pivoting As a result of the movement of the front surface, the course of movement of the seat as such is predetermined.

In another expedient embodiment, the slotted guide on a linear guide. Such leadership is low feasible. By way of interaction with the course of movement of the front point, a progression of the upward movement of the further point can also be achieved with a linear guide in such a way that the seat surface inclines when the backrest is deflected and, in addition, the more the overall height increases with increasing deflection of the backrest.

For a counteracting force which is felt to be constant by a seated person, independently of the deflection of the backrest, it is advantageous if the connecting straight line between the third rotary bearing and the first rotary bearing is connected to the connecting straight line between the third rotary bearing and the rotary bearing in which the pull rod is mounted , includes approximately a right angle and the connecting line between the pivot bearing for mounting the drawbar and the third pivot bearing with the connecting line between the pivot bearing in which the drawbar is mounted, and the pivot bearing in which the backrest support is mounted, an angle of more than 90 °, in particular more than 120 °, includes. This arrangement is space-saving and allows a favorable implementation of the tilting movement of the backrest in a desired upward movement of the seat.

In a further stable variant of the synchronization mechanism is arranged in total mirror-symmetrical to both sides of the seat. It is particularly expedient to form the joint elements as flat hinge plates.

Embodiments of the invention will be explained in more detail with reference to a drawing. Showing:

1 is a side view schematically an office chair with a weight mechanism in the rest position, wherein the seat is mounted on a seat link on a support frame and Fig. 2 in a side view schematically the office chair of FIG. 1 in the deflected position, and

3 is a side view schematically an office chair with a weight mechanism in the rest position, wherein a linear slotted guide is provided.

Fig. 1 shows a side view schematically an office chair 1, which has a seat 3 and a backrest 5. The chair 1 also has a central chair column 7, which - not shown - by a pedestal, especially a bogie with wheels, is worn. On the chair column 7, a central support frame 8 is arranged, on which the seat surface 3 and the backrest 5 are articulated via a seat link 9 or a backrest support 10.

To form a synchronous mechanism, the backrest support 10 is rotatably attached to the support frame 8 via the rotary support 11. The seat 3 is also rotatably mounted in a first pivot bearing 17 on the support frame 8 via the seat link 9 designed as a joint element 13. The joint element 13 has, in addition to the first pivot bearing 17, a second pivot bearing 18 and a third pivot bearing 19. In the second pivot bearing 18, the seat surface 3 is mounted in a Aufpunkt 15, so that the seat surface 3 can perform a total pivoting movement relative to the support frame 8.

At the third pivot bearing 19 of the joint member 9 engages a tie rod 22, whose other end is connected via the pivot bearing 23 with an angled pivot arm 25 of the back support 10. In a further Aufpunkt 27, the seat 3 is connected via a slotted guide 30 on the support frame 8.

The operation of the office chair 1 will be apparent from a comparison of FIGS. 1 and 2. While Fig. 1 - as mentioned - the office chair 1 in the idle state, the office chair 1 is shown in a deflected form in Fig. 2.

If, starting from the rest position of the office chair 1 according to FIG. 1, the backrest 5 is tilted backwards, then the pivot arm 25 is moved to the top right due to the mounting of the backrest support 10 in the pivot bearing 11. This movement will transmitted via the pull rod 22 to the joint member 13. The offset of the pull rod 22 leads due to the mounting of the joint member 13 in the first pivot bearing 17 to an erection of the joint member 13. In this case, the Aufpunkt 15 of the seat 3 moves in an upward pivotal movement. The seat 3 is thus raised overall and simultaneously moved to the right in the illustration shown. The other Aufpunkt 27 of the seat 3 moves in accordance with the curved slide guide 30 also in a kind of pivoting movement to the top right. In this case, the curvature of the slotted guide is dimensioned such that, with continuous movement, the seat surface 3 generally inclines towards the backrest 5.

If one considers the rotational or pivoting movements carried out by the joint element 9 or the end point 15, the pivot arm 25 or the pivot bearing 23 and the further point of reference in accordance with a fictitious hourly division of 12 hours, starting from the rest position of the office chair 1 of the Aufpunkt 15 initially at 9 o'clock starting in the direction of an 11 o'clock position in Fig. 2. In the beginning, the pull rod 22 engages approximately tangentially with respect to the rotational movement of the joint member 13 in the third pivot bearing 19. The angle of the pull rod 22 to the passing through the first pivot bearing 17 and the third pivot bearing 19 radius of rotation is approximately 90 °. Opposite this rotational movement of the joint element 13, the pivot arm 25 moves according to the performed tilt of the backrest 5 by about one hour. At the end of the movement, in accordance with the position of the office chair 1 assumed in FIG. 2, the pull rod 22 is oriented tangentially to the rotary movement of the swivel arm 25.

In other words, starting from the rest position of the office chair 1 shown in Fig. 1 at the beginning of the movement, the same deflection angle of the backrest 5 results in a smaller displacement of the drawbar 22 than at the end of the movement according to the deflected position of the office chair 1 in Fig. 2. In addition causes the same offset of the drawbar 22 at the beginning of the movement, a smaller angle of rotation of the Gelenkele- element 9 than at the end of the movement according to the position of the office chair 1 in Fig. 2. With the embodiment shown is a total causes a person sitting on the office chair 5 person regardless of the inclination position of the backrest 5 experiences an approximately equal back pressure. Here, a compensation of the inclination tion of the backrest 5 so possible that the case of strong inclination additionally acting on the backrest 5 weight of the seated person is taken into account. The stronger the inclination of the backrest 5, the more the seat surface 3 is raised per angular degree of inclination. The counterpressure automatically adapts to the body weight of the seated person via the synchronization mechanism.

Fig. 3 shows in a side view schematically an office chair 1 ', wherein the further Aufpunkt 27 of the seat surface 3 moves in deflection of the backrest support 10 in a linear slotted guide 30' to the right. In this case, the linear slotted guide 30 'is designed so that the seating surface 3 tends to the backrest 5 with progressive movement of the backrest and is increasingly raised overall.

LIST OF REFERENCE NUMBERS

, 1 'office chair

seat

backrest

chair column

support frame

seat link

Backrest support 1 pivot bearing

joint element

Aufpunkt first rotary bearing second rotary bearing third rotary bearing

pull bar

pivot bearing

Swivel arm further Aufpunkt, 30 'slotted guide

Claims

claims

1. chair, in particular office chair (1, 1 ^' ), with a on a support frame (8) via a backrest support (10) hinged backrest (5) and a synchronous thereto movable s seat surface (3), in a Aufpunkt (15) over one

Seat link (9) is pivotally connected to the support frame (8), wherein the backrest support (10) and the seat link (9) are each rotatably mounted on the support frame (8), and wherein a pull rod (22) the seat link (9) with the backrest support (10) so movably connects that a directed backwards tilting movement of the backrest (5) at the Aufpunkt (15) is translated into an upright pivotal movement of the seat surface (3).

2. Chair according to claim 1, wherein the backrest support (10) via a pivot bearing (11) on the support frame (8) is rotatably mounted and a pivot bearing (23), on which the drawbar

(22) is rotatably mounted, which is arranged in the direction of the seat link (9) in front of and in the direction of the seat surface (3) above the pivot bearing (11).

3. Chair according to claim 1 or 2, wherein the backrest support (10) has an angled pivot arm (25) on which the pull rod (22) is rotatably mounted.

4. Chair according to one of the preceding claims, wherein the seat link (9) is rotatably mounted on the seat surface (3).

5. Chair according to one of the preceding claims, wherein the seat link (9) as a joint member (13), in particular as a hinge plate, with a first (17) .einem second (18) and a third pivot bearing (19) is formed the seat surface (3) is connected to the support frame (8) via the first (17) and the second rotary bearing (18).

6. Chair according to one of the preceding claims, wherein the seat surface (3) in a spaced from the Aufpunkt (15) further Aufpunkt (27) by means of a support frame (8) mounted seat guide element is guided such that upon an upward pivotal movement of the seat (3) at the Aufpunkt overall an inclination of the seat (3) is effected towards the backrest (5).

7. Chair according to claim 6, wherein the seat link (9) and the seat guide element cooperate such that raised by a rearward tilting movement of the backrest (5) of the Aufpunkt (15) and the further Aufpunkt (27) is pushed backwards.

8. Chair according to claim 6 or 7, wherein the seat guide element is designed as a slotted guide (30).

9. Chair according to claim 8, wherein the slotted guide (30) has a curved guide.

10. Chair according to claim 8, wherein the slotted guide (30) has a linear guide.

11. Chair according to one of claims 5 to 10, wherein the connecting line between the third pivot bearing (19) and the first pivot bearing (17) with the connecting line between the third pivot bearing (19) and the pivot bearing (23), in which the drawbar ( 22) is mounted, approximately at a right angle, and wherein the connecting line between the pivot bearing (23) for supporting the tie rod (22) and the third pivot bearing (19) with the connecting line between the pivot bearing (23) and the pivot bearing (11) , in which the backrest support (10) is mounted, encloses an angle of more than 90 °, in particular of more than 120 °.