ES2268180T3 - CHAIR. - Google Patents

Abstract

Chair with a support frame (1), a seat plate (6) and a backrest (5) that is provided with an arm (7) that extends below the seat plate (6), which is articulated in a rotatable manner with the support frame (1), in which the arm (7) supports the back of the seat plate (6) by means of a swivel joint with it and the front part of the seat plate (6) it is connected to the support frame (1) by means of a bearing device (11) and at least one bending spring element (12) is provided which is held, on the one hand, in the support frame (1), and on whose upper side (14), in the area of its free end (13) that can be elastically deflected, a bearing piece (16) is supported placed on the seat plate (6), characterized in that the element (12) of bending spring supports the front part of the seat plate (6), which forms a part of the bearing device (11) for the front part of the plate (6) of seat and is connected to the support frame 1 in the area of its end directed to the backrest (5), and because a guide surface (17) arranged in the support frame (1) is provided to configure a counter bearing with which the bearing part (16) or an additional bearing part is placed in contact with the seat plate (6) placed on the surface, so that the upper side (14) of the bending spring element (12) inclined downwards towards the front side of the chair and the guiding surface (17) are angled together and run towards each other towards the rear side of the chair and, in the unturned state of the backrest (5), the bending spring element (12) is pre-tensioned with respect to the bearing part (16).

Description

Chair.

The invention relates to a chair with a support frame, a seat plate and a backrest that is equipped with an arm that extends below the plate seat, which is pivotally articulated in the frame of support, supporting the arm the back of the plate seat through a swivel joint with this and the front of the seat plate is attached to the support frame by a bearing device and the bearing device presents at least one bending spring element that is held by a side on the support frame, and at the top of which, on the area of its free end that can be tilted elastically, a bearing piece is placed on the seat plate.

In chairs of this type, when the user recline takes place a simultaneous turn of the backrest and the seating surface, however the angle of rotation of the backrest greater than that of the seat surface. These mechanisms of movement are called synchronous mechanisms.

Synchronous mechanisms have been disclosed in different embodiments. A chair of this type is known for example from document DE 196 07 136 A1. The chair described in this document has a seat plate and a backrest attached to it for common displacement that presents a section vertical and a lower arm separated laterally from it. The seat plate is attached near its leading edge so swivel by means of a swivel bearing with a support frame fixed to a base. The lower arm of the backrest protruding from under the seat plate is swivel articulated on the support frame and supports the back of the plate seat. The swivel bearing consists of the pivot shaft and an oblong hole joint that is configured so ascending in front of the backrest. The turning shaft is fixed in the lower side of the seating surface, the articulation of oblong hole instead is stationary fixed in the support frame. The back of the seat plate is articulated between the point of articulation of the arm in the frame of support and the vertical section of the backrest on the arm.

Although this chair known by the document DE 196 07 136 A1 presents a good ergonomics, the construction of this  Chair is, however, relatively expensive. Especially the axial pressure spring necessary to counteract a rotation of the backrest backing is a relatively expensive component by which the mechanism becomes more expensive.

In other known synchronous mechanisms, such as known for example from document DE 37 35 256 C2 or DE 39 16 474 C2 this problem appears more intensely since, in these mechanisms, the forces that will be applied by the Spring are clearly higher.

Other mechanisms, for example those known by WO 92/20262 and DE-PS 20 26 929 are less advantageous from an ergonomic point of view, since during the backward rotation of the backrest the seating surface leans forward with what the person sitting has the feeling that it slips from the work chair towards in front of.

A chair of the type mentioned at the beginning is known from document DE 12 97 306 B. In this chair, the element Flex spring supports the back of the plate seat, which in the zone of the end directed to the previous side of the chair, is connected to the support frame. In the zone center of its longitudinal extension is supported by an element of support frame support. To oppose a backward turn of the backrest for users with different weight with a force sufficient in each case, the previous tension of the spring element bending should be modified greatly depending on the weight of the Username. In the event that a chair is intended for use by several people with different weights, must therefore, essential changes in each case in the adjustment to allow an ergonomic seat. There is also the danger of wrong settings. In addition, the interval within which you can change the pre-tension adjustment of the spring element Flexion is limited.

For documents US 5 356 199 A and EP 0 937 326 A2 other chairs of the type mentioned at the beginning are known, which present structures similar to that of document DE 12 97 306 B.

In the case of the chair known by the document DE 43 26 609 A1, usually between the rotating frame for the backrest and the chair support frame is provided  a relatively expensive gas spring. The previous part of the seat plate is supported by a support attached to the frame of support and the back of the seat plate is attached to articulated way with the rotating frame. Between the support that supports the front part of the seat plate and the frame rotating bending spring elements are provided for Help the gas spring. Also in this chair, in the case of users of different weight, a large modification of the spring forces applied to adapt the chair to the users

The object of the invention is to facilitate a synchronous mechanism that can be manufactured very profitably and to present a simple structure, through which it is achieved also a compensation of weight for users with weight different.

According to the invention this is achieved by a synchronous mechanism with the features of the claim one.

By the bending spring element that supports the front part of the seat plate is not necessary according to the invention the use of a spring element of axial pressure However, a control system can be provided of ergonomic advantageous synchronization in which, by turning the backrest back, the leading edge of the seat plate can remain, for example, at the same height or It can move slightly upwards.

During the backrest rotation, the bending spring element deflects against the force of spring, the guiding surface forming a counter bearing. In contact with this guiding surface can be arranged the piece of  bearing placed on the upper side of the spring element of bending or an additional bearing piece placed on the plate seat. Since in the non-deflected state, the spring element of bending is previously tensioned against the bearing part that it rests on its upper side, when a user loads the plate seat, except in load peaks when sitting or when the user sit for example completely on the seat plate in the front edge area, this bearing part or the piece of Additional bearing placed on the seat plate can be maintained  adjacent to the guiding surface, which achieves a controlled synchronous development during the backrest turn towards behind.

Using the bearing part that rests on the upper side of the bending spring element inclined towards down towards the front side of the chair, when a user is sitting on the chair originates a component of directed force forward that pulls the backrest forward. Since this force component depends on the user's weight, is achieved from this way a weight compensation for users with different weight.

As a bending spring element you can advantageously use a leaf spring assembly that It has advantageous elastic characteristics and is very economic.

Advantages and details are explained below. of the invention by means of the exemplary embodiment shown in the attached drawing. In the drawing, they show:

Figure 1 a schematic side view of a chair according to the invention in a non-rotated state of the backrest, and

figure 2 the chair of figure 1 with the back turned back.

The chair according to the invention shown in the Figures 1 and 2 show a support frame 1. This may be conventionally rotatably placed around a vertical axis 2 at the top end of a central post 3 vertical supported by a cross base 4.

A backrest 5 of the chair is attached to an arm 7 extending below a seat plate 6, which is hingedly connected to the support frame 1 which can rotate about an axis 8. The arm 7 supports the part rear of seat plate 6 (including padding) by a rotating union with it around axis 9, being provided for the swivel joint of the seat plate 6 with the arm 7 a fin 10 tilted down.

The front part of the seat plate 6 is attached to the support frame 1 by means of a device 11 of bearing. The bearing device 11 has an element 12 of bending spring in the form of a leaf spring assembly that it is held, on the one hand, in the support frame 1 on the side of its end directed to the backrest 5. The other end 13 of the element 12 bending spring, free in this exemplary embodiment, can deviate in an elastic way and, in the area adjacent to this end 13, a bearing piece 16 placed in one of these fins 15 tilted down are arranged in contact with the side 14 upper inclined downward of the spring element of flexion towards the front side of the chair, so that the bending spring element 12 supports the front part of the 6 seat plate.

The bearing part 16 is arranged additionally in contact with a guiding surface 17, arranged above the bearing part 16, which configures a counter bearing up. The upper side 14 of element 12 of bending spring and guide surface 17 are arranged in this case layered together, seen in side view, and run in direction towards the back side of the chair towards each other. With the backrest rotation 5, the bearing part 16 is drag back along guide surface 17 by joining the bearing plate 6 with the arm 7, deflecting the bending spring element 12 downwards. He angle between the guiding surface 17 and the upper side 14 of the bending spring element 12 in this case influences the deflection intensity element 12 of bending spring and, by therefore, in the intensity of the spring force opposite to the deflection. The spring force opposite the deflection further increases by function of backrest deflection angle 5. To limit deflection from the backrest 5, a stop is provided which, for reasons of clarity, it is not shown in the drawing. For example, this cap could be formed by a wing tilted below the surface 17 guiding the movement of the bearing part 16 along the guiding surface 17.

To limit the backrest rotation forward in the position it adopts in the unturned state, it is also provided a cap that, for reasons of clarity, is not shown in the He drew. This unturned backrest state is also adopted when There is no user sitting in the chair.

For the support of one side of the element 12 of bending spring is provided a fastening bolt 18 that passes through the bending spring element 12 through a hole 19 The fastening bolt 18 has a thread external and is screwed into an internal thread of a part 20 rigidly attached to the support frame 1. On the opposite side of the bending spring element 12, the clamping bolt 18 it has a collar 21 that protrudes radially and is arranged in contact with the bending spring element 12 in the area around the hole 19. The spring element 12 of bending in the area of the hole 19 is separated from the support frame 1 or part 20 of support frame 1 equipped with internal threading and is previously tensioned by means of collar 21 against bearing part 16. By lever 22 of actuation this pre-tension can be adjusted by means of a bolting more or less wide of the fastening bolt 18. The tension previous causes the bearing part 16 not to rise from the guiding surface 17 either in the case of a weight load of the seat plate 6 by a user. By setting the opposite spring force can be modified from the previous tension to a backward rotation of the backrest 5.

Instead of a single bearing piece 16, which is in contact with the upper side 14 of the bending spring element 12 and with the guiding surface 17,  two bearing parts 16 may also be provided for this. independent that, for example, can be arranged in the plane of Image of figures 1 and 2 one behind the other. The piece of bearing also placed on the seat plate, in contact with the guiding surface 17 could be rigidly placed or so that it can move against the force of a spring in the seat plate or a part attached to it. To reduce the friction between the upper side 14 of the spring element 12 of bending and bearing part 16, this may be configured like a roller, especially if for contact with side 14 upper of the bending spring element 12 and for the contact With the guide surface 17, rollers are provided. rotatably separated from each other on the seat plate 6 or in a part attached to it, less wear of these is achieved surfaces 14 and 17 as well as the bearing parts.

It would also be possible and conceivable to employ several bending spring elements 12 arranged one behind  others, for example perpendicular to the drawing plane of the figures. For example, two elements 12 of bending spring in the form of a leaf spring assembly arranged on both sides of section 23 of support frame 1 extending below the anterior zone of plate 6 of seat, on whose upper sides 14 in each case a bearing part 16 configured as a rotating roller and between that runs section 23 with the intended guide surface 17 in it, in which a roller is also arranged in contact. These rollers can all be rotatably placed around of the same axis that is held on both sides by fins 15.

In the exemplary embodiment shown in the Figures 1 and 2, a part of the leaf springs of the set of leaf spring that is arranged below the leaf spring upper is set shorter than leaf spring upper and ends before the free end of the leaf spring more higher. With this, in the unturned state of the backrest, the part 16 bearing rests on a weakened area of element 12 of flexion spring with which a better elasticity is achieved of the seating surface in the unturned state of the back.

Different modifications of this embodiment example are possible. Although the guide surface 17 in the embodiment shown is approximately horizontal, an inclination of the guide surface with respect to the horizontal is also possible, preferably less than 45 °. Especially preferred is an inclination of less than 30 °. The angle between the upper side 14 of the bending spring element 12 and the guiding surface 17 is preferably in the range of 15 ° to
50th.

Instead of the fastening bolt 18 that presents an external thread could also be provided another clamping device to achieve a previous tension of the bending spring element 12. Fundamentally they would also be conceivable other bending spring elements 12 other than set of leaf spring, for example spring elements of bar-shaped flexion However, a spring assembly of sheets presents an especially good elastic characteristic to a economic price

In the turned backrest position, this one could turn for example at an angle of 24º, while the seat rotates at an angle of 8º. Preferably, the edge front seat surface remains at the same height during backrest rotation, or it rises slightly.

Legends of reference numbers

one

support frame

2

axis vertical

3

post

4

base in cross

5

back

6

license plate seat

7

arm

8

axis

9

axis

10

fin

eleven

bearing device

12

bending spring element

13

extreme

14

side higher

fifteen

fin

16

piece bearing

17

guiding surface

18

cap screw clamping

19

passage hole

twenty

part

twenty-one

necklace

22

drive lever

2. 3

section.

Claims (9)

1. Chair with a support frame (1), a seat plate (6) and a backrest (5) that is provided with an arm (7) that extends below the seat plate (6), which It is pivotally articulated with the support frame (1), in which the arm (7) supports the back of the seat plate (6) by means of a swivel joint with it and the front part of the plate (6) The seat is connected to the support frame (1) by means of a bearing device (11) and at least one bending spring element (12) is provided, which is held, on the one hand, in the support frame (1) , and on whose upper side (14), in the area of its free end (13) that can be elastically deflected, a bearing piece (16) is supported placed on the seat plate (6), characterized in that the element (12 ) of bending spring supports the front part of the seat plate (6), which forms a part of the bearing device (11) for the front part of the pl here (6) of seat and is attached to the support frame 1 in the area of its end directed to the backrest (5), and because a guide surface (17) arranged in the frame (1) of support with which the bearing part (16) or an additional bearing part placed on the surface is placed on the seat plate (6), so that the upper side (14) of the spring element (12) of bending downwardly towards the front side of the chair and the guiding surface (17) are angled together and run towards each other towards the rear side of the chair and, in the unturned state of the backrest (5) , the bending spring element (12) is pre-tensioned with respect to the bearing part (16). 2. Chair according to claim 1, characterized in that the guiding surface (17) is inclined with respect to the horizontal less than 45 °, preferably less than 30 °. 3. Chair according to claim 2, characterized in that the guiding surface (17) is approximately horizontal. 4. Chair according to one of claims 1 to 3, characterized in that the angle between the upper side (14) of the bending spring element (12) and the guiding surface (17) is in the range between 15 and 50 °. 5. Chair according to one of claims 1 to 4, characterized in that to modify the pre-tension of the bending spring element (12) with respect to the bearing part (16), a fastening bolt (18) is provided that crosses the bending spring element (12) through a through hole (19), which tensiones the bending spring element (12) towards the support frame (1), the distance of the element (12) can be modified of bending spring with respect to the support frame (1) by means of the fastening bolt (18). 6. Chair according to one of claims 1 to 5, characterized in that the bearing part (16) arranged in contact with the upper side (14) of the flexural spring element (12) is a roller rotatably positioned. 7. Chair according to claim 6, characterized in that this roller or an additional roller rotatably placed in the seat plate is arranged in contact with the guiding surface (17). 8. Chair according to one of claims 1 to 7, characterized in that the flexural spring element (12) is a leaf spring assembly. 9. Chair according to claim 8, characterized in that a part of the leaf springs arranged below the upper leaf spring is shorter than the upper leaf spring and ends before the free end of the upper leaf spring.