EP0584620B1 - Chair - Google Patents

Abstract

A chair, in particular office chair, is provided with a foot stand (1), with a seat support (4) which is supported thereon by means of a chair column (3) and has a front and a rear seat-support part (12, 13) connected to one another via a pivot pin (20), with a seat (5) supported on the seat-support parts (12, 13), with a back (7) fixed to the rear seat-support part (13) and with an energy storing device (gas spring 27) which is articulated on the seat-support parts (12, 13) at a distance from their pivot pin (20), is adjustable in length and is intended for mutual adjustment of back (7) and seat (5), one seat-support part (12) being equipped with a receptacle (bearing block 47) for the upper end of the chair column (3). The receptacle (bearing block 47) on the seat-support part (12) is articulated via an articulation pin (49) arranged parallel to the pivot pin (20) of front and rear seat-support parts (12, 13). In order to lock and release various inclinations of the seat support (4) with respect to the chair column (3), the seat-support part (12) is provided with a locking device which is operative between the seat-support part (12) and the receptacle (bearing block 47). <IMAGE>

Description

The invention relates to a chair, in particular an office chair according to the preamble of patent claim 1.

Such chairs are known from DE-PS 27 33 322 (corresponding to US-PS 4,200,332). Due to the mutual assignment of the seat support parts, the articulated seat, the backrest fastened to the rear seat support part and the gas spring inserted between the seat support parts, such chairs have a so-called synchronous mechanism, in which a pivoting of the seat is accompanied by a pivoting of the seat. In this respect, the seat adapts ergonomically to the swivel position of the backrest in its inclined position in such a way that when the backrest is pivoted by e.g. 10 ° to the rear, the seat with its rear area tilts down by about 5 ° around its front edge.

Basically, the angle of inclination of the seat and the backrest, which are jointly adjustable due to the synchronous mechanism, are fixed in these known chairs. In this context, it is felt to be disadvantageous that the inclination of the seat and backrest, particularly in their extremely upright working position or extremely reclined relaxing position, cannot be changed.

Proceeding from this, the object of the invention is to further develop a chair of the generic type in such a way that the seat together with the backrest can also be adjusted in its inclination independently of the given inclination adjustment due to the synchronous mechanism and can be ascertained in different inclined positions, so that the synchronous mechanism to be able to change the given angle of inclination of the seat and backrest within an adjustment range.

This object is achieved by the features specified in the characterizing part of patent claim 1. Accordingly, one of the seat support parts not directly and rigidly attached to the chair column, but connected to it via an additional joint. To fix a certain base tilt position, from which the seat and the backrest can be pivoted within certain limits due to the synchronous mechanism, a locking of the seat is additionally provided with the aid of a locking device which is effective between the seat support and the bearing part. This enables a continuous inclination adjustment of the seat support part articulated on the chair column.

Claim 2 characterizes an advantageous development of the receptacle on the seat carrier, which enables a structurally favorable attachment of the joint axis to the receptacle.

According to claim 3, the locking device is designed as a disk pack locking device. Such disk pack locking devices are basically from the prior art - e.g. known from EP 0 394 784 or DE 30 30 009 C2 - for releasably locking two parts of seat support structures which can be pivoted relative to one another.

Due to the measures specified in claim 4, the locking device is spaced particularly far from the hinge axis, so that the locking acts with a large lever arm with respect to the hinge axis. With a given clamping force of the disk pack locking device, the locking effect is thus optimized.

The claims 5 to 7 characterize advantageous configurations of the disk pack locking device, which are characterized by structural simplicity, compactness and simple operability.

In this context, claims 9 and 10 teach an advantageous embodiment of the actuating mechanism of the disk pack locking device. The locking device is released by simply pivoting an actuating lever, which is particularly user-friendly.

Fig. 1

eine perspektivische Darstellung eines Bürostuhls gemäß der Erfindung,

Fig. 2

eine Seitenansicht der Sitzteil-Unterkonstruktion,

Fig. 3

einen Querschnitt der Unterkonstruktion entlang der Schnittlinie III-III nach Fig. 2 und

Fig. 4

einen Schnitt durch die Unterkonstruktion entlang der Schnittlinie IV-IV nach Fig. 3.

Further features of the invention are the subject of the remaining dependent claims. In the following description, an embodiment is explained in more detail with reference to the accompanying drawings. Show it:

Fig. 1

a perspective view of an office chair according to the invention,

Fig. 2

a side view of the seat part substructure,

Fig. 3

a cross section of the substructure along the section line III-III of FIG. 2 and

Fig. 4

a section through the substructure along the section line IV-IV of FIG. 3rd

An office chair shown in Fig. 1 has a base frame 1, which is supported by rollers 2 against the floor. Attached to the base frame 1 is a height-adjustable chair column 3, covered by a bellows 3a, at the upper end of which a seat support 4 is detachably fastened, on which in turn a padded seat 5 is attached. Attached to the seat support 4 is an essentially upward-extending backrest support 6, to the upper end of which a backrest 7 is attached. The height of the chair column 3 is adjusted by means of an operating lever 8. To change the inclination of the backrest 7 with the backrest support 6 while simultaneously changing the inclination of the seat 5, a further actuating lever 9 is mounted on the seat support 4. The seat support 4 can be partially or largely covered by a panel 10 attached to the underside of the seat 5. In Fig. 1 it can be seen that the backrest support 6 is covered by a bellows 11 for optical reasons.

The basic structure of the office chair described is generally known. The height-adjustable chair column 3 is known for example from DE-PS 19 31 012 (corresponding to US Pat. No. 3,711,054) or DE-PS 18 12 282 (corresponding to US Pat. No. 3,656,593). The structure of the seat support 4 including the described pivoting possibilities of the backrest 7 and seat 5 is known for example from EP-PS 0 179 185 (corresponding to ZA-PS 85/6126).

As can be seen from FIGS. 2 and 3, the seat support 4 is of split design. It consists of a front seat support part 12 and a rear seat support part 13, which have an essentially U-shaped cross section that is open at the bottom. It follows that they each have two side walls 14, 15 and 16, 17, which are each connected to one another by floors 5 facing floors 18 and 19. The two seat support parts 12, 13 are connected to one another by a pivot axis 20 arranged adjacent to their bottoms 18, 19.

At the front end of the seat support 4, a seat holder 21 is attached so as to be pivotable about a pivot axis 22, the seat holder 21 being supported by a transverse to the main plane of symmetry of the chair, i. 2 is formed transverse to the plane of the drawing. The seat 5 is supported on this seat holder 21 via spacers 23.

The seat 5 is further supported and fastened on the floor 19 of the rear seat support part 13 by means of elastic buffers 26.

At the rear end of the rear seat support part 13, ie in the area where the backrest support 6 is fastened to the rear seat support part 13, a length-adjustable energy store in the form of a length-adjustable gas spring 27 is articulated about a pivot axis 28 which runs parallel to the pivot axes 20 and 22. This pivot axis 28 faces the housing 29 of the gas spring 27, from the other end of which a piston rod 30 is led out. An actuating pin 31 protrudes from the piston rod 30, by means of which a valve located in the gas spring can be actuated for length adjustment. The piston rod 30 is connected by a thread to an actuating device 32, to which the actuating lever 9 belongs. This actuating device is pivotably mounted between the side walls 14, 15 of the front seat support part 12 parallel to the pivot axes 20, 22, 28. The operating lever 9 is led out through an elongated hole 33 in the associated side wall 16 of the rear seat support part 13, this elongated hole being curved such that its center coincides with the pivot axis. With corresponding length adjustments of the gas spring 27, the front and rear seat support parts 12 and 13 about the pivot axis 20 against each other pivoted, which on the one hand changes the inclination of the seat 5 and on the other hand the backrest support 6 is pivoted with the backrest 7 at the same time. Such devices are referred to as so-called synchronous mechanisms. If the actuating pin 31 is not only briefly inserted into the piston rod 30 of the gas spring 27 to achieve a change in length of the gas spring 27 and thus a change in the position of the seat 5 and the backrest 7, but when the actuating pin 31 for a longer time in the Piston rod 30 is inserted, then the seat 5 can be rocked together with the backrest 7.

The structure of the seat support 4 with the seat 5 is - insofar as it has been described so far - known from EP-OS 0 179 185 (corresponding to ZA-PS 85/6126). Structure and arrangement of the actuating device 32 and the gas spring 27 is known from EP-OS 0 179 216.

A spring abutment 34 is pivotally mounted about the pivot axis 20 of the front and rear seat support part 12 or 13, which is designed in cross section like an angle lever. One abutment lever 35 extends rearward from the pivot axis 20, i.e. in the direction of the backrest support 6, specifically below the floor 19 of the rear seat support part 13.

In the area of the free end of the abutment lever 35, an adjusting screw 36 is arranged by means of its external thread 37 in an internal thread 38 on the lever 35. The threads 37, 38 are self-locking. The free end of the set screw 36 is supported against the bottom 19 of the rear seat support part 13.

The other, approximately perpendicular to the lever 35 from the pivot axis 20 downward abutment lever 39 rests against a spring 40 which is formed by a block of elastic material, for example a neoprene foam. This spring rests with its other end against a stationary but pivotable abutment 41, which is formed by a rear wall opposite the lever 39 of the bearing part 46, which will be explained in more detail below. The spring 40 is on a pin-like Protrusion 42 of the lever 39 attached so that it can not fall down from the area between the lever 39 and the abutment 41.

Neoprene is the common, non-trademarked name for chloropren, a chlorinated hydrocarbon.

If - as shown in Fig. 2 - the external thread 37 of the adjusting screw 36 is completely screwed through the internal thread 38 of the spring abutment 34, then the abutment lever 39 is in its position closest to the abutment 41, i.e. the spring 40 is most biased. The abutment 41 is - which is repeated here - arranged in the front seat support part 12.

If the backrest 6 is pivoted backwards when the gas spring 27 is unlocked, the front and rear seat support parts 12 and 13 are pivoted towards each other in their area below the pivot axis 20, i.e. the spring is compressed more with progressive damping of this backward pivoting movement of the backrest 7. This counterforce of the spring 40 thus progressively counteracts the pivoting back movement of the backrest 7. When the backrest 7 is relieved, its forward pivoting is supported by corresponding relaxation of the spring 40, this supporting force decreasing with increasing forward pivoting movement of the backrest 7.

If the set screw 36 is screwed out of the abutment lever 35 so far that its front end 43 is approximately flush with the lever 35, then the spring 40 does not come into effect during the entire possible pivoting range from the front and rear seat support part 12, 13 , ie it is not compressed between the abutment 41 and the abutment lever 39 to generate a corresponding counterforce.

At intermediate positions of the adjusting screw 36, the spring 40 comes in each case with correspondingly different pivoting positions of the rear seat support part 13 relative to the front seat support part 12, that is to say at different positions Backward inclinations of the backrest 7 and thus also the seat 5 for engagement. In addition, the block-like spring 40 first comes into contact with the abutment 41 in these intermediate positions only with an edge 44 and only gradually comes to rest against the abutment 41 with a further pivoting movement. Here too, a certain progression in the spring action is achieved.

So that the spring abutment 34 is inherently rigid, the levers 35, 39 are stiffened with one or more intermediate webs 24. So that the set screw 36 is not accidentally unscrewed from the internal thread 38, its external thread is squeezed in the area of the end 43 in the usual way. In order to enable easy actuation of the adjusting screw 36, it is provided with a rotary handle 25 at its end which projects downward from the seat support 4. The set screw 36 is offset from the gas spring 27. The gas springs 27 are customary on the market and generally known in terms of structure and mode of operation, for example that from DE-PS 18 12 282 (corresponding to US Pat. No. 3,656,593).

For additional inclination adjustment of the entire seat 5 with the synchronous mechanism, the front seat support part 12 is connected in an articulated manner to the upper end of the chair column 3, which is designed as a bearing cone 45, via a bearing part designated as a whole as 46. The bearing part 46 is seated with an inner-conical bearing block 47 on the bearing cone 45 of the chair column 3. The bearing block 47 is fastened in a longitudinally oriented rectangular tube 48 which, on its side located behind the bearing block 47, has an articulated axis 49 running parallel to the center of gravity 20 in the form of a simple screw with mother wears. The front seat support part 12 is articulated on this hinge axis 49.

To lock the seat 5 in a certain inclination position, the front seat support part 12 is provided with a plate pack locking device which is effective between it and the bearing part 46 and is arranged in front of the bearing block 47. It has a plate pack 50 fastened to the bearing part 46, consisting of plates 52 arranged parallel to one another with the interposition of frictional engagement elements 51. The latter are in side view (dashed lines in Fig. 2) formed approximately triangular and sit with their downward-facing corner area on an axis 53 on the bearing part 46, which is held between the two side walls 54, 55 of the U-shaped profile part 56 which is open towards the front. The elongated oval-shaped frictional engagement elements 51 in side view are fixed in the disk pack 50 by a further retaining bolt 57, which loosely holds the frictional engagement elements 51 and the disks 52 together.

The disk pack locking device furthermore has a releasable clamping device 58, which essentially consists of a clamping bolt 59, a helical compression spring 60 and an actuating lever 61. The clamping bolt 59 is arranged parallel to the swivel 20 or articulated axis 49 and passes through the plate pack 50 and the two side cheeks 54, 55 of the bearing part 46 via the elongated holes 62 shown in dashed lines in FIG. 2 so that there is play when the front seat support part is tilted 12, on which the clamping bolt 59 is guided so as to be longitudinally axially displaceable in the clamping direction K, movement of the clamping bolt 59 relative to the slats 52 is possible. At one end 63, the clamping bolt 59 has a thread 64 with a nut 65 seated thereon, which serves as a stop for the loading sleeve 66 placed on the clamping bolt 59, which is provided with a flange 67 at its end facing the slats 52.

Between the side wall 15 facing away from the end 63 of the front seat support part 12 and the slats 52, an abutment sleeve 68 is further arranged on the clamping bolt 59, which has an abutment flange 69 at its slat-side end. At its opposite end, the abutment sleeve 68 is supported on the side wall 15. With its second end 70, the tensioning bolt 59 is guided out of the front seat support part 12 via a bore 71 in the side wall 15 and ends within a guide tube 72 designed as a square tube, which is attached coaxially with the tensioning bolt 59 on the outside of the side wall 15 (FIG 4). The lead-out end 70 of the clamping bolt 59 is provided with an approximately cuboid actuating head 73, which is formed from an inner hexagon 74 with a circumferential groove 75 and a support 76 molded thereon.

Between the outside of the side wall 15 of the front seat support part 12 and the actuating head 73, with the interposition of a washer 77, the helical compression spring 60 is inserted, which acts on the clamping bolt 59 in the clamping direction K.

On the outside in front of the actuating head 73 of the clamping bolt 59, the actuating lever 61 is mounted on the free end of the guide tube 72 so as to be pivotable about a pivot axis 78 running at right angles to the clamping direction K. It is in contact with the actuating head 73 via a cam-like pivot bearing part 79. The latter has stop surfaces 80, 81 arranged within the guide tube 72 for limiting the swivel angle, which in each case form obtuse-angled wedge surfaces on the sides of the swivel bearing part 79 facing away from one another to limit the swivel angle V of the actuating lever 61. On the side of the pivot bearing part 79 facing the actuating head 73, the cam region 82 of the pivot bearing part 79, which is formed from a flat and convexly curved part, is provided between the stop surfaces 80, 81.

Fig. 3 shows the disk pack locking device in the locked state. By acting on the helical compression spring 60, the clamping bolt 59 clamps the plate assembly 50 relative to the abutment sleeve 68 via the loading sleeve 66, so that a movement of the clamping bolt 59 and thus the front seat support part 12 connected to it relative to the plate assembly 50 and thus again with respect to the this connected bearing part 46 is not possible. The seat 5 is thus locked in the tilt position shown.

To release the locking, the actuating lever 61 is pivoted counterclockwise with respect to FIG. 3, whereby the eccentric, convexly curved cam region 82 of the pivot bearing part 79 of the clamping bolt 59 is displaced counter to the clamping direction K and counter to the action of the helical compression spring 60. This releases the clamping handle around the plate pack 50, as a result of which the clamping bolt 59 and thus the entire seat support 4 together with the backrest support 6 relative to the plate pack 50 and to the bearing part 46 within the limits determined by the elongated holes 62 can be moved, which leads to a common inclination adjustment of the seat 5 and the backrest 7 by the same angular amount. By resetting the actuating lever 61 into the position shown in FIG. 3, the disk pack locking device is brought back into its locked state.

Claims (12)

1. Chair, in particular office chair, comprising a pedestal (1), a seat support (4) supported on the pedestal (1) by means of a chair column (3), which seat support (4) comprises a front and a rear seat support element (12, 13) interconnected via a pivot axle (20), a seat (5) supported on the seat support elements (12, 13), a backrest (7) secured to the rear seat support element (13), and a longitudinally adjustable energy storing device (gas spring 27) articulated to the seat support elements (12, 13) at a distance from their pivot axle (20) for mutually adjusting the backrest (7) and the seat (5), a seat support element (12) being provided with a receptacle (bearing block 47) for the upper end of the chair column (3), characterized in that the receptacle (bearing block 47) is articulated on the seat support element (12) via an articulated axle (49) arranged parallel to the pivot axle (20) of the front and the rear seat support element (12, 13), and in that the seat support element (12) is provided with a locking device effective between the seat support element (12) and the receptacle (47) for the purpose of locking and releasing, respectively, different inclinations of the seat support (4) in relation to the chair column (3).
2. Chair according to claim 1, characterized in that the receptacle (bearing block 47) comprises a bearing element (46), on which the articulated axle (49) is arranged.
3. Chair according to claim 1 or 2, characterized in that the locking device is a lamellar pack locking device.
4. Chair according to claim 2 or 3, characterized in that referred to the longitudinal direction of the seat, the receptacle (bearing block 47) is arranged between the articulated axle (49) and the locking device.
5. Chair according to claim 3 or 4, characterized in that the lamellar pack locking device comprises a lamellar pack (50) secured to the bearing element (46), which lamellar pack (50) consists of lamellas (52) arranged parallel to each other with frictional resistance elements (51) being positioned between them, as well as a releasable clamping device (58), arranged on the seat support element (12), for the lamellar pack (50), which clamping device (58) together with the seat support (4) is displaceable in its released condition in relation to the lamellar pack (50) for the purpose of an adjustment of inclination.
6. Chair according to claim 5, characterized in that the clamping device (58) comprises a clamping bolt (59) penetrating with play the lamellar pack (50) in the transverse direction to its lamellas (52) and guided on the seat support element (12) to be longitudinally axially displaceable in this transverse direction, which clamping bolt (59) drives with its one end (63) the lamellar pack (50) for its locking in the clamping direction (K) and for this purpose is subject to spring loading action (helical compression spring 60) in this direction, the clamping bolt (59) being displaceable against the clamping direction (K) by means of an actuating lever (61) for releasing the locking.
7. Chair according to claim 6, characterized in that the bearing element (46) with the lamellar pack (50) is arranged within the box-type seat support element (12), the clamping bolt (59) with its end facing away from the lamellar pack (50) being extended out of the seat support element (12) and being guided in a guide tube (72) secured to the seat support element (12), in which guide tube (72) a compression spring (helical compression spring 60) is arranged for spring-loading the clamping bolt (59) and on which guide tube (72) the actuating lever (61) is supported.
8. Chair according to claim 7, characterized in that the extended end (70) of the clamping bolt (59) is provided with an actuating head (73), the compression spring (helical compression spring 60) supporting itself between the actuating head (73) and an external side of the seat support element (12).
9. Chair according to claim 7 or 8, characterized in that the actuating lever (61) is supported on the free end of the guide tube (72) to be pivotable about a pivot axle (78) extending at right angles to the clamping direction (K) and contacts the extended end (70) of the clamping bolt (59) via a cam-like swivel bearing element (79) in such manner that the clamping bolt (59) is displaceable against the clamping direction (K) by a pivoting movement of the actuating lever (61).
10. Chair according to claim 9, characterized in that the swivel bearing element (79) comprises stop faces (80, 81) arranged within the guide tube (72) for limiting the pivot angle (V) of the actuating lever (61).
11. Chair according to one of claims 7 to 10, characterized in that the clamping bolt (59) is provided with a driving element (driving sleeve 66) on its end driving the lamellar pack (50) and with an abutment element (abutment sleeve 68) in its central region between the lamellar pack (50) and the internal side of a wall (side wall 15) adjacent to the guide tube (72), via which abutment element (abutment sleeve 68) the lamellar pack (50) supports itself on this internal side in its lock condition.
12. Chair according to one of claims 1 to 9, characterized in that the bearing element (46) and the locking device are connected with the front seat support element (12) of the seat support (4).

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