WO2009135617A1 - Chair having pivotable backrest - Google Patents

Abstract

In a chair, comprising a seat element (12) having a seat surface, said seat element being supported on at least one chair leg (16), and a backrest (20) that is movably fastened to a pivot arm (22) that can be  pivoted relative to the seat element (12), provision is made that the backrest (20), upon exertion of pressure onto an upper back support surface region (54) performs a deflection movement along a curved path toward the seat element (12).

Description

 Chair with swiveling backrest

The invention relates to a chair having the features of the preamble of claim 1.

Such a chair is known from practice and in particular designed as a so-called office chair, which comprises a seating surface having a seat member which is rotatably mounted in particular on a chair leg. This chair further comprises a backrest which is movably attached to a pivot arm, which in turn is pivotable relative to the seat cushion. The respective relative movements of the chair elements to each other can be locked.

Conventional office chairs of the type described above are associated with the following disadvantages. Below a lumbar region, the backrest moves away from the corresponding lower back region of the user during its pivoting back. At the same time results in a strong pressure build-up in the shoulders of the user. In addition, the pivoting back of the backrest is connected by reclining the user with the so-called Herndauszieheffekt, which results in particular in that the pivot axis of the pivot arm of the backrest is disposed below the seat surface of the seat member.

The invention is based on the object, a chair of initially mentioned, which takes account of the abovementioned disadvantages.

This object is achieved by the chair with the features of claim 1.

According to the invention, therefore, a chair is proposed, which has a sit a surface having zweisendes seat member which is mounted on at least one chair leg, and a backrest which is movably mounted on a pivot arm which is pivotable relative to the seat member. The backrest performs when exerting pressure on an upper back abutment surface area an evasive movement along a curved path in the direction of the seat element.

By the movement of the backrest along the curved path can be achieved that when the user reclines and a connected pivoting or. Tilting the backrest about the pivot axis of the pivot arm, the upper region of the backrest evades to the rear and the lower portion of the backrest moves closer to the back, so that an optimized investment behavior of the backrest can be realized on the back of the user.

The term curved track is. to understand in its broadest sense and includes both a bow line following and purely translational movements of the backrest relative to the swing arm. A translational movement can also be parallel to the pivot arm or. to the plane of the backrest, which would essentially counteract the shirt's extension effect.

The invention is particularly useful when the Swivel arm has a pivot axis which is disposed below the seat surface of the seat member. At the same time the chair according to the invention is preferably designed such that the seat is rotatable relative to the chair leg. Furthermore, the seat surface may experience misalignment or tilting with respect to the chair leg apart from the possibility of rotation when tilting the pivoting arm.

In a preferred embodiment of the chair according to the invention, the curved path is defined by at least one guide track, in which at least one guide pin is guided. The guideway may be formed from one or more mutually separate sections, wherein always at least two areas in which the at least one pin is guided, should be employed with respect to the plane of the backrest.

In a special Ausführυngsform the chair according to the invention, the guideway is fixed backrest and the pin schwenkarmfest.

It is expedient for the upper end region of the backrest, on which, in particular, the user's shoulders can rest, to be pressed in the maximum position in the direction of the user in the zero position of the backrest. The zero position of the backrest relative to the swivel arm can be held by means of a return spring, which thus biases the backrest in the direction of the zero position, ie in the direction of a first end position facing away from the seat element. The return spring may be a spiral spring, the backrest fixed at one end and connected to the other end schwenkarm- firmly. Alternatively or additionally, it is also conceivable that the return spring with a leaf spring, a rubber band or the like is formed.

The at least one guideway, which predetermines the sliding movement of the backrest relative to the swivel arm, may be formed on a carrier or bearing bracket of the backrest, via which the backrest is mounted on the swivel arm. ■

In a specific embodiment, the chair according to the invention comprises at least one upper and one lower guide track, each of which interacts with a pin and which are each set in relation to the plane of the backrest. The two guideways can then define a sliding movement, which specifies an example, approximately elliptical path of movement of the backrest.

In order to perform the movement of the backrest relative to the swivel arm as smoothly as possible, the backrest is preferably displaceably mounted on the swivel arm by means of a sliding device. The slider may comprise a guide carriage which cooperates with rollers, a needle groove bearing or the like.

The evasive movement, which executes the backrest due to the inventively designed storage, in a specific embodiment depending on the pivotal movement of the pivot arm, that is tilting of the backrest relative to the seat, a relative movement between the backrest and the pivot arm correspond, for example, between 0 and about 60 mm.

Further advantages and advantageous embodiments of the subject matter of the invention are the description, the drawings and the claims removable. Two embodiments of an office chair according to the invention are shown schematically simplified in the drawing and are explained in more detail in the following description. It shows :

Fig. 1 is a side view of a first Ausführungsfortn a Bϋrostuhls according to the invention;

Fig. 2 is a rear perspective view of the office chair after

Fig. 1;

Fig. 3a and b are side views of the office chair of FIG. 1 with upright backrest resp. pivoted backrest; and

Fig. 4 is a side view of a second embodiment of an office chair according to the invention.

In the figures 1 to 3, an office chair 10 is shown, which is provided with a trained as a seat cushion Sit zelement 12 which is rotatably mounted on a bearing bracket 14 and height adjustable on a five feet chair leg 16. The individual feet of the chair leg 16 are in each case provided with a roller 18.

The chair 10 further includes a likewise formed as a cushion element backrest 20 which is movably mounted on a pivot arm 22 which arranged by means of a Zeins 12 below the Sit, designed in the usual way pivot mechanism 24 relative to the Sit zelement 12 verschenkbar i st. The Schwenkmechani k 24 wei st a pivot axis 26 in the region of the bearing bracket 14, wherein the Sit zelements 12 is mounted on a pivot axis 28 on the pivot mechanism 24. To adjust the height of the backrest 20, the pivoting arm 22 has a sliding profile 30, which embraces a section 32 of the pivoting arm 22 formed as a flat profile, wherein the respectively set height of the backrest 20 relative to the seat element 12 can be secured by means of a locking device consisting of a Swivel tab 34 is formed with a pin which engages in detent holes 36 of the flat profile 32. The pivoting lug 34, the pivoting lug 34 is mounted on an axis formed by a bolt 40 is biased by a leaf spring 38 in the direction of its blocking position.

To mount the backrest 20 on the pivot arm 22, two bearing brackets 42A and 42B are arranged at the rear thereof, which are each provided with an upper guide track 44A and 44B and a lower guide track 46A and 46B. The guideways which define a path of movement of the backrest 20 relative to the pivotal arm 22 are respectively opposite the plane of the backrest 20, the upper guideways 44A and 44B having their upper ends towards the shoulder region of the backrest 20 and the lower guideways 46A and 46B with their lower ends in the direction of the lower end region or the lordosis area of the backrest 20.

In the guideways 44A and 44B, an upper pin 48 is mounted, which forms with its end portions guide pin and on the back of the pivot arm 22 and, of the sliding profile 30 is fixed. In the lower guide tracks 46 A and 46 B, the lower bolt 40 is slidably guided, which also forms with its end portions guide pin and which is also fixed to the back of the slide 30 of the swing arm 26. Furthermore, a bearing pin 50 is arranged between the bearing brackets 42A and 44B, to which a coil spring 52 is suspended with one end, the other end is hooked to the upper pin 48, so that the backrest 20 is biased in the direction of its substantially upright zero position so that the bolts 48 and 40 abut on the lower end surfaces of the guideways 44A, 44B and 46A, 46B, respectively.

If a user of the chair 10 now leans on the backrest 20 and exerts pressure on the shoulder region of the backrest 20 that forms an upper back abutment region, the swivel arm 22 is pivoted relative to the seat element 12. At the same time, the latter exerted against the force of the coil spring 52 relative to the pivot arm 22 in the direction of the seat member 12 by the pressure exerted on the backrest 20 in the shoulder region 54, wherein the bolts 48 and 40 in the respective associated guide tracks 44A, 44B and 46A, 46B slide. As a result, over the entire extent of the back or the backrest 20, an optimized investment behavior between the respective back and the backrest 20 can be achieved. At the same time, the shirt pull-out effect can be counteracted. The backrest 20 thus slides with respect to the swivel arm 22, resulting in a pleasant feeling of pressure on the back of the respective user in each inclination position of the backrest 20 or of the swivel arm 22. Since the action line is set up against the angle of inclination of the backrest, the backrest 20 moves against the spring force of the coil spring 52 inevitably relative to the pivot arm 22nd FIG. 4 shows a second embodiment of an office chair 10 'according to the invention, which essentially corresponds to that according to FIGS. 1 to 3, but differs therefrom in that the bearing brackets 42A' and 42B ¹ each have only one guide track 60 , in which the two bolts 40 and 48 are guided. The bolts 48 are each fixed to a bearing block 62 and 64 of the slide 30 of the swing arm 22. Incidentally, the office chair 10 'corresponds in particular also with regard to function and operation to that according to FIGS. 1 to 3.

Claims

claims A chair comprising a seat member (12) having a seat supported on at least one chair leg (16) and a seat back (20) movably mounted on a pivot arm (22) opposite the seat member (12). is pivotable, characterized in that the backrest (20) when exerting pressure on an upper Rückanlagenflächenbereich (54) performs an evasive movement along a curved path in the direction of the seat member (12). 2. Chair according to claim 1, characterized in that the curved path is defined by at least one guide track (44A, 44B, 46A, 46B, 60) in which at least one guide pin (40, 48) is guided. 3. Chair according to claim 2, characterized in that the guide track (44A, 44B, 46A, 46B, 60) backrest fixed and the guide pin (40, 48) is formed schwenkarmfest. 4. Chair according to one of claims 1 to 3, characterized in that the backrest (20) by means of a return spring (52) in the direction of a first of the seat element (12) facing away from the end position is biased. 5. Chair according to claim 4, characterized in that the return spring (52) is a coil spring, with a The backrest is fixed at the back and connected to the other end in a swivel arm. 6. Chair according to one of claims 1 to 5, characterized in that the guide track (44A, 44B, 46A, 46B, 60) on a bearing bracket (42A, 42B) of the backrest (20) is formed. 7. Chair according to one of claims 1 to 6, characterized by at least one upper and at least one lower guide track, which cooperate in each case with a pin and which in each case against the plane of the backrest (20) are employed. 8. Chair according to one of claims 1 to 7, characterized in that the evasive movement of the backrest (20) via a sliding device on the pivot arm (22) is displaceably mounted. 9. Chair according to one of claims 1 to 8, characterized in that the deflection movement in response to the pivotal movement of the pivot arm (22) is a path of 0 to 55 mm. 10. Chair according to one of claims 1 to 9, characterized in that the pivot arm (22) has a pivot axis (26) which is arranged below the seat surface of the seat element (12). 11. Chair according to one of claims 1 to 10, characterized in that the backrest (20) is height adjustable.