DE20007949U1 - Chair with adjustable seat - Google Patents

Description

Mayer Sitzmöbel GmbH & Co. KG G 1700

Mannsgereuth 02.05.2000

96267 Redwitz

Chair with height adjustable seat

The invention relates to a chair with a height-adjustable seat having the features specified in the preamble of claim 1.

A seat of this type is known from DE 195 16 841 A1 as a student chair. This is characterized by the fact that the seat plate support and the backrest support together form the shape of a V, the base of which rests on the base frame. The two telescopic supports are connected by internally arranged spindle drives, which can have different pitches.

DE 43 05 841 A1 discloses a chair with a height-adjustable seat, which has a transmission mechanism with a flexible element, such as a steel band or a rope, for adjusting the height of the backrest above the seat and the resulting limitation of the seat depth when the seat height is adjusted. The transmission mechanism acts in a correspondingly deflected direction in the pulling and/or pushing direction on a backrest support running in an inclined guide. The transmission element is attached to the base or the standpipe, while its deflection is attached to a seat support. This allows the backrest position to be continuously adjusted when the seat height is adjusted. The straight section of the backrest support is mounted so that it can be moved lengthwise in a guide in the seat support.

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CH 514 316 discloses a chair with a seat that can be adjusted in height, in which the seat height adjustment also includes a height adjustment of the backrest along a guide that runs diagonally upwards and backwards. In order to enable the coupled height adjustment, the column of the chair, the seat and the backrest are connected to one another via a deflection element in at least one direction of movement. In one version, the deflection element consists of a gear or friction wheel and two cooperating racks or rolling surfaces that are at an angle to one another, and in another version, it consists of a roller or sliding guide around which a tension element is placed.

DE 299 03 045.8 Ul discloses a chair with a seat that is adjustable in height and is attached via a holding device to the head of a column that is mounted in an extendable manner in a standpipe of a chair base. The chair also has a backrest that is adjustable depending on the seat adjustment and that is attached to a backrest support. The backrest support is mounted with a straight section so that it can move in a guide that is attached to the standpipe or to the chair base at an acute angle to the standpipe and runs in the direction of the rear area of the seat. In the lower area of the straight section of the backrest support, a pivot bearing is provided and in or on the holding device of the seat or on the column head, a pivot bearing for a coupling rod is provided, with the axes of the pivot bearings running transversely to the longitudinal axis of the column.

The invention is based on the object of providing a backrest adjustment coupled with the height adjustment of the seat, which is particularly simple in design and can be implemented inexpensively. At the same time as the height adjustment of the backrest, the seat depth relative to the backrest should also be adjustable.

The object is achieved according to the invention by the technical teachings specified in the independent claims 1 and 2. Advantageous further developments of the inventions are specified in detail in the subclaims.

Due to the positive coupling provided in claims 1 and 2, the backrest support is automatically moved to a steeper position when the seat is raised and to a more inclined position when it is lowered, so that the backrest is pivoted upwards when the seat is adjusted in height and downwards in the opposite direction when the seat is lowered. The seat depth is changed accordingly due to the radius described by the backrest support arm.

The driving lever, which is rigidly connected to the backrest support arm or, according to claim 2, to the connecting bar and extends essentially downwards beneath the seat, can be connected to the operating lever via a chain or a rod, for example. This operating lever can be extended beyond the articulation point of the coupling element and can also be made adjustable by hand, for example, or can be firmly attached to the foot of the chair or the standpipe by a coupling element, e.g. a chain or a rod.

In all cases, pivoting the operating lever causes a movement transformation to occur on the backrest support, which can be adjusted according to the seat height adjustment and, when coupled to the standpipe or the foot of the chair, is automatically adjusted with the seat height adjustment. The seat height can be adjusted in the usual way using a gas pressure spring or manually. The gas pressure spring is inserted into the standpipe for this purpose. By using two parallel brackets that form a force parallelogram, the backrest support is extremely stable.

However, a force parallelogram can also be formed here by two parallel individual backrest support arms that are arranged centrally. Likewise, instead of using a single driving lever, the invention also allows other designs, e.g. double levers or plate-shaped connecting elements, on which or at whose ends pivot bearings or fastening devices for the coupling elements are provided, which are necessary for the movement transformation of the lever movement of the lever. The operating lever can also be designed in the form of a plate or be a single lever, this depends in each case on the design of the stability of the chair and its visual design.

The operating mechanism for swivel adjustment of the backrest can also be coupled with an armrest height adjustment, as specified in claims 9 to 13. A particularly advantageous and stable embodiment is one in which supports for the armrest are provided which are guided in lateral guides and which are hinged to the coupling lever. The hinge can also be provided on the swivel bearing of the coupling element on the operating lever, in which case a coupling mechanism which acts in reverse in terms of movement is also provided in order to lock the armrest upwards when the backrest is adjusted backwards. The reversal in terms of movement does not need to be provided if the armrest is to be lowered backwards when the backrest is adjusted. Offset mounting is also possible. The insertion of an articulated connecting arm or a coupling mechanism ensures that the linear movement of the support is not hindered and that the pivoting movement of the coupling lever or the operating lever is transferred to the support in a longitudinal movement. The rigid coupling means that the height of the armrest is also adjusted at the same time as the pivoting movement is changed.

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If the guide for the armrest support is set at an angle, there is also the advantage that the depth position of the armrest can be adjusted at the same time as the backrest. A straight guide can also be used.

The invention is explained in more detail below with reference to the figures of an embodiment shown in the drawing.
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The drawings show:

FIG 1 a chair according to the invention with in section

drawn seat and backrest,
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FIG 2 is a rear view of the chair according to Figure 1 with a backrest support designed according to the invention,

FIG 3 a chair with modified height adjustment and adapted inclination of the backrest support arms depending on the height adjustment, and

FIG 4 a chair with adjustable height of the backrest and an armrest.

The chair in Figure 1 has a seat 1, which is mounted on a holding device 2 and can also be adjusted in terms of its inclination, for example. The holding device 2 is attached to the head 3 of the column 5, which is mounted in a standpipe 4 so that it is at least height-adjustable. As a rule, in office chairs or children's chairs, the columns 5 are also mounted in the standpipe so that they can rotate. The standpipe 4 is part of the chair base 6, which - as the illustration shows - has furniture castors on the chair legs that extend to the sides. Above the seat is the backrest 7, which is mounted on the

Seat 1 is pivotally articulated according to the invention. For this purpose, a backrest support 8 is provided which in the exemplary embodiment consists of two parallel backrest support arms 10 and 17 which in the specific embodiment - as can be seen in Figure 2 - are the lateral legs of two brackets and are articulated on the rear of the backrest 7 to pivot bearings 22 and 23 provided there. The distance between the pivot bearings is also provided for the attachment of the other two ends. A connecting web 18 with pivot bearings connects both cross parts of the brackets and forms a force parallelogram so that when one of the two backrest support arms is inclined accordingly, the other automatically follows and the backrest is mounted in a rotationally and tilt-proof manner. In the case of the embodiment according to claim 2, the connecting web 18 is the support arm for both articulated backrest support arms 10 and 17. The drive lever is then rigidly connected to the connecting web 18.

According to the invention, a driving lever 11 is provided either as an extension of the backrest support arm 10, firmly connected to it in the middle, or is attached to the connecting web 18, which is arranged to be pivotable about the same pivot bearing 14 as the backrest support arm 10, so that when the driving lever 11 is pivoted, the backrest support 8 automatically follows this movement upwards or downwards, whereby the backrest pivots upwards or downwards and at the same time - when pivoting upwards - the seat depth of the seat 1 increases and when pivoting downwards the seat depth decreases.

The pivoting movement of the driving lever 11 is actuated by an actuating lever 12, which is articulated on the underside of the seat 1 on the holding device 2 on a pivot bearing 13 with a pivot axis arranged parallel to the pivot bearing 14. For this purpose, a coupling

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A coupling element 15 is provided which, in the exemplary embodiment, is designed as a rigid rod in order to avoid having to provide additional locking means for fixing the inclined position of the backrest support 8 in the respective height position and to enable rigid coupling. The coupling element 15 is on the one hand pivotably connected to the driving lever 11 via the bearing 9 and on the other hand pivotably connected to the actuating lever 12 at a distance from the pivot bearing 13 so that the lever movement is translated to the backrest height adjustment device, which has been described previously. The actuating lever 12 is extended beyond the articulation point of the coupling element 15 and is connected via a pivot bearing 20 to a coupling lever 16 which is pivotally connected to a fixed pivot bearing 21 on the standpipe 5. The bearing 21 forms the abutment for the lever arrangement of the operating levers 12 and 16. The force triangle thus formed is changed by lifting the seat. An example is shown schematically in Figure 3. By adjusting the height, the articulation point of the coupling element 15 on the operating lever 12 is pivoted in the direction of the column 5. The movement is transmitted to the backrest support 8 via the drive lever 11. The drive lever 11 pivots under the seat so that at the same time the angle of inclination of the backrest support arm 10 relative to the seat surface is increased, resulting in a steeper inclination. The force parallelogram provides a uniform parallel guide upwards. It goes without saying that the lever lengths must be selected so that the height adjustment takes place in the desired manner, whereby - as already explained - a seat depth adjustment is also made possible at the same time. However, the movement transformation can also be carried out by transmitting it to the pivotably articulated backrest support arms 10 via the actuating lever 11, which is firmly connected to the connecting web 18, as is provided in the embodiment according to claim 2.

Figure 1 also shows an armrest 24 which is hinged to the lower backrest support arm 10 on the bearing 25 and is extended by means of an extension 26 beyond the parallel upper backrest support arm 17. Locking means 27 are provided on this support arm, e.g. locking bolts which can be inserted into holes in a row of holes against which the extension 25 engages, so that the angle of inclination of the armrest 24 can also be adjusted in a simple manner. It is clear from Figure 2 that the armrest 24 can be attached to the two parallel legs of the brackets which form the backrest support arms 10 and 17.

Figure 4 shows a chair according to the invention in which a height adjustment for the armrest 24 is coupled to the adjustment mechanism for the height adjustment of the backrest 7. For this purpose, the armrest 24 is mounted on the upper end of a support 31. This support 31, e.g. a tube end, is secured in a guide 30 so that it can be moved longitudinally and can be moved therein by a certain stroke. The height adjustment of the support 31 is directly coupled to the height adjustment of the backrest 7. For this purpose, as can be seen from the exemplary embodiment, a further pivot bearing 29 is provided on the coupling lever 16, at a distance from the pivot bearing 21 in the rear third. The connecting arm 28 is in turn connected to the lower end of the support 31 via a further pivot bearing 32. The pivotable arrangement of the connecting arm 28 ensures that the carrier 31 cannot become jammed in the guide 30 when the coupling lever is pivoted, e.g. in the case of the height adjustment of the seat 1 upwards or downwards.

The pivoting movement of the coupling lever 16 is transmitted directly to the carrier 31 in a longitudinal adjustment.

so that, since the coupling lever 16 pivots upwards when a new height of the seat 1 is set, as can be seen in Figure 3, the support 31 is automatically moved upwards as well, so that the armrest 24 is moved upwards in the inclined guide 30 on the one hand and further forwards on the other, so that a person-adapted depth setting of the armrest 24 is automatically achieved. Conversely, the armrest 24 is moved downwards when the seat 1 is moved to the height position shown.

List of reference symbols

1 Seat 2 Holding device 3 Head 4 Standpipe 5 pillar 6 Chair base 7 backrest 8th Backrest tüt &zgr; e 9 Swivel bearing at the end of the driving lever 10 Backrest is tender 11 Driving lever 12 Operating lever 13 Swivel bearing 14 Swivel bearing 15 Coupling element 16 Coupling lever 17 parallel backrest support arm 18 Connecting bridge 19 Swivel bearing 20 Swivel bearing 21 Swivel bearing 22 Swivel bearing 23 Swivel bearing 24 armrest 25 Pivot bearing 26 renewal 27 Locking devices 28 Connecting arm 29 Swivel bearing 30 guide 31 carrier 32 Swivel bearing

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Claims (14)

1. Chair with a seat ( 1 ) which is adjustable in height and which is fastened via a holding device ( 2 ) to the head ( 3 ) of a column ( 5 ) which is mounted in an extendable manner in a standpipe ( 4 ) of a chair foot ( 6 ), with a backrest ( 7 ) which is adjustable depending on the seat height adjustment and which is fastened to a backrest support ( 8 ), characterized in that - the backrest support ( 8 ) has at least one double-sided lever, which is articulated on the back of the seat ( 1 ), consisting of a backrest support arm ( 10 ) extending obliquely upwards over the seat ( 1 ) and a driving lever ( 11 ) extending downwards under the seat ( 1 ), which is connected to an actuating lever ( 12 ) articulated on the underside of the seat ( 1 ) or on the holding device ( 2 ), at a distance from its pivot bearing ( 13 ), with a coupling element ( 15 ), wherein at least the axes of the pivot bearings ( 13 , 14 ) for the actuating lever ( 12 ) and the driving lever ( 11 ) run transversely to the longitudinal axis of the column ( 5 ), and the actuating lever ( 12 ) pivots opposite to the direction of movement of the seat ( 1 ) during the height adjustment and the Backrest support ( 8 ) follows the movement according to the transmission ratio given by the length of the driving lever ( 11 ) and the distance of the connection of the coupling element ( 12 ) to the pivot bearing ( 13 ). 2. Chair with a seat ( 1 ) which is adjustable in height and which is fastened via a holding device ( 2 ) to the head ( 3 ) of a column ( 5 ) which is mounted in an extendable manner in a standpipe ( 4 ) of a chair foot ( 6 ), with a backrest ( 7 ) which is adjustable depending on the seat height adjustment and which is fastened to a backrest support ( 8 ), characterized in that - a double-sided lever is pivotably attached to the back of the seat ( 1 ), to the upper connecting web ( 18 ) of which, located above the seat surface and designed as a support arm, backrest supports ( 10 ) are articulated, spaced one above the other, parallel and diagonally above the rear seat section, which are articulated to the back of the backrest ( 7 ) at the same distance as to the connecting web ( 18 ) and form a force parallelogram, and to the second arm of which, extending downwards and designed as a driving lever ( 11 ), a coupling element ( 15 ) is articulated or attached at a certain distance from the pivot bearing ( 14 ), which is articulated or attached to an actuating lever ( 12 ) articulated to the underside of the seat ( 1 ) or to the holding device ( 2 ), at a distance from its pivot bearing ( 13 ), wherein at least the axes of the pivot bearings ( 13 , 14 ) for the operating lever ( 12 ) and the driving lever ( 11 ) extend transversely to the longitudinal axis of the column ( 5 ), and the operating lever ( 12 ) pivots opposite to the direction of movement of the seat ( 1 ) during the height adjustment and the backrest support ( 8 ) follows the movement according to the transmission ratio given by the length of the driving lever ( 11 ) and the distance of the connection of the coupling element ( 12 ) to the pivot bearing ( 13 ). 3. Chair according to claim 1 or 2, characterized in that the coupling element ( 15 ) is a coupling rod which is articulated on the one hand to the driving lever ( 11 ) at a distance from the pivot bearing ( 15 ) and on the other hand to the actuating lever ( 12 ) at a distance from the pivot axis ( 13 ). 4. Chair according to claim 1, 2 or 3, characterized in that the actuating lever ( 12 ) extends beyond the articulation point of the coupling element ( 15 ) and is articulated at its end to the end of a coupling lever ( 16 ), which in turn is articulated in a locally fixed manner to a pivot bearing with an axis running parallel to the pivot axis ( 13 ). 5. Chair according to one of the preceding claims, characterized in that the backrest support arm ( 10 ) is the lateral leg of a bracket, the central section of which is pivotally mounted in a bearing ( 14 ) and has a firmly connected, downwardly extending driving lever ( 11 ). 6. Chair according to one of the preceding claims 1, 3, 4 or 5, characterized in that the backrest support arm ( 10 ) is articulated on the rear side of the backrest ( 7 ) and that a second backrest support arm ( 17 ) running parallel is articulated above it at a distance therefrom, wherein both backrest support arms ( 10 , 17 ) are part of a force parallelogram and are arranged on the pivot axis ( 14 ) via a coupling element ( 18 ) so as to be pivotable relative to one another, wherein the second backrest support arm ( 17 ) is also articulated on the rear side of the backrest. 7. Chair according to claim 6 in conjunction with claim 5, characterized in that the second backrest support arm is part of an arm of a bracket running parallel to the first. 8. Chair according to claim 2 or 7, characterized in that both middle parts of the bar are coupled via a connecting plate with pivot bearings ( 14 , 19 ). 9. Chair according to one of the preceding claims, characterized in that an armrest ( 24 ) is hinged laterally to the lower backrest support arm, the angle of inclination of which can be adjusted via a locking coupling. 10. Chair according to one of claims 1 to 8, characterized in that an armrest ( 24 ) is articulated to the lower backrest support arm ( 10 ), which armrest engages with a fixing projection end under the underside of the parallel second backrest support arm ( 17 ) or can be locked thereto in various inclined positions by means of locking means ( 27 ). 11. Chair according to one of claims 1 to 8, characterized in that on the seat ( 1 ) at least on one side a stationary guide ( 30 ) is provided for a longitudinally displaceable support ( 31 ), to the upper end of which an armrest ( 24 ) is attached and to the lower end of which a connecting arm ( 28 ) is articulated, which protrudes downwards and is articulated to a pivot bearing on the coupling lever ( 16 ) at a distance from the pivot bearing ( 21 ) or a coupling rod which is articulated to the actuating lever ( 12 ). 12. Chair according to claim 11, characterized in that the guide ( 30 ) is arranged obliquely, the upper end protruding further from the backrest ( 7 ) than the lower end. 13. Chair according to claim 11 or 12, characterized in that the guide ( 30 ) is a tubular sleeve and the support ( 31 ) is a tube slidably guided therein.