WO2008000207A1 - Back rest for a stool or a chair, and stool or chair provided with such a back rest - Google Patents

Abstract

The invention relates to a back rest for a stool or a chair, comprising two adjacent, spring-mounted back supports (3.1), each of which is fixed to a separate carrier part (4.1). Said back rest is characterised in that each carrier part (4.1) forms the first limb of an essentially L-shaped carrier (4), and the second limb (4.2) of each carrier (4) is fixed beneath the stool or chair seat in such a way that it can be pivoted about a horizontal axis against an elastic force.

Description

 Backrest for a chair or armchair and chair or armchair equipped with such a backrest

The invention relates to a backrest for a chair or chair with two laterally juxtaposed, resiliently held backrests, each of which is attached to a separate support member.

In such a backrest described in DE 90 06 316 Ul each back support is attached to a separate support member. The support members are V-shaped to each other, and the lower ends of these support members are attached to the rear end of the seat on the chair frame. Although the backrests have some flexibility due to the resilient properties of the two support members to adapt to different seating positions of a seated person, it has been shown that this construction is unable, the spine of a seated person both during prolonged sitting in itself changing seat positions, as well as to greatly relieve the individual persons in greatly varying physique.

The invention has for its object to design a backrest for a seat or armchair so that the seated person is optimally supported in a variety of seating positions in the area of the back or the spine. To achieve this object is provided according to claim 1, that each support member forms the first leg of a substantially L-shaped support, and that the second leg of each carrier is pivotable below the chair or armchair seat against spring force about a horizontal axis. In this way, it is ensured that each back support optimally follows the back movement, depending on the different movements or sitting positions of a seated person, without losing their support function.

In order to ensure that the seated person is optimally supported even in the case of laterally or laterally rearward movements, it is provided according to a further invention that the carriers are connected to one another by a guide rod oriented essentially perpendicular to the carriers in the rest position mounted in or on a seat substructure and connected to the carrier, that when moving a back support forward or backward, the other back support is displaced in opposite directions, to avoid a "jump" between the two back supports this preferably resiliently to the Straps are attached, such that there is a substantially uniform, stepless backrest.

The guide rod is preferably articulated with its ends to the carriers and also mounted between their articulation points on the carriers hinged to the seat or the seat base.

Further preferred embodiments of the invention are treated in subclaims.

The invention will be described below with reference to the accompanying drawings.

Figure 1 shows a view of a backrest which is attached to a stand of an otherwise not shown armchair or chair.

Figure 2 shows a view of a modified embodiment of a backrest;

FIG. 3 shows a view of a further modified embodiment of a

Backrest;

Figure 4 shows an embodiment of the manner of attaching a back support to its support member; FIG. 5 shows an exploded view of the embodiment according to FIG. 4;

Figure 6 shows an embodiment of the manner of attachment of the

Backrest support on the stand of a chair or chair;

Figure 7 shows an isometric view of a chair;

Figure 8 is a fragmentary isometric view of the column stand of the chair with attached seat chassis to which the backrest supports are pivotally mounted;

Figure 9 is an isometric view of a top view of a seat base attached to the seat chassis;

FIG. 10 shows a schematic for explaining the principle according to the invention

Partial view of the backrest construction in association with the seat base.

FIG. 7 shows an isometric view of an armchair comprising a base 1.1 equipped with rollers, a column 1 supported by the base, a seat 100 and a backrest 3 with two laterally spaced back supports 3.1, which are attached to L-shaped straps 4 are attached, which consist of a substantially vertically oriented support member 4.1 and a substantially horizontally oriented support member 4.2. Each back support 3.1 is attached to a support member 7 which is lockable along the associated support member 4.1 in different height positions. Each support member 7 includes rubber members, such that the single back support is movable relative to the support member 4.1. The support members 4.1 are interconnected by an elastically deformable cross member 9, the spring stiffness is designed so that the free mobility of the individual back support is maintained relative to the other back support to a limited extent.

According to Figures 1 to 3, the support members 4.2 are pivotally mounted about a horizontal pivot axis 5 by means of a support unit 2. The supporting parts 4.2 of the carrier 4 are designed as two-armed lever, acting on the free lever ends 4.3 a substantially vertically aligned spring element 6, the force acting on the carrier force is variable. This spring element 6 may be a tension spring, a pneumatic or hydraulic spring element or the like.

In the region of the support members 4.1 Einrastöffhungen 8 illustrated that the support members 7 are height-adjustable attached to the support members 4.1. According to Figure 2, the back braces 3.1 are connected approximately at their center by means of an elastically deformable crossbar 3.2, whose strength is designed so that the back braces 3.1 keep their function as individual supports, the free mobility of a back support relative to the other back support to a limited extent preserved.

According to FIG. 3, the two back supports 3.1 are likewise fastened individually on their own holding parts 4.1 of carriers 4, each by themselves. In this backrest, the support members 7 are designed so that the upper ends of the support members 4.1 project upwardly beyond the support members 7. The free ends of the holding parts 4.1 are interconnected by an elastically deformable cross member 9.

Figure 6 shows a modified embodiment of the pivotable about a horizontal axis carrier. In or on the support unit 2 is provided with opposing threads horizontal shaft 20 is mounted on which the second leg 4.2 of the carrier 4 are pivotally mounted. Each leg 4.2 is designed as a two-armed lever, the free lever end 4.4 is bent upwards, on which a substantially horizontally oriented tension spring 22 engages. The tension springs 22 are fixed with their ends on a variable relative to the horizontal axis at different distances detectable adjusting member 23 for varying the force acting on the carrier force, the e.g. a nut 24 carries, in which a rotatable by means of a knurled wheel 26 threaded pin 25 engages. Each leg 4.2 carries in the region of its bearing on the shaft 20 a threaded bushing 27, such that by turning the shaft 20 due to the opposing threaded portions of this shaft, the two legs 4.2 can be laterally adjusted relative to each other, whereby the distance between the back supports 3.1 in accordance Figures 1 and 3 can be adjusted.

Figures 8 and 9 show a detail of a fixed at the upper end of the stand column 1 seat chassis 38 to which the two supports 4 in the region of the free ends of the support members 4.2 are pivotally mounted about the pivot axis 39 shown schematically. On the seat chassis 38, a substantially box-shaped seat base 40 is fixed, for example by means of screws 41 which are guided in slots 42, such that the seat base 40 relative to the seat frame 38 is displaceable forward and backward. The inventive principle of this construction will be described below with reference to the schematic representation of FIG.

A core idea of this teaching according to the invention consists essentially in coupling the two backrests 3.1 with one another in such a way that, when the person sitting on the chair (chair) is displaced, a displacement of the backrest, e.g. to the rear inevitably has a movement of the other back support forward. Due to the resilient suspension of the back supports on the straps 4, the two back braces 3.1 are able to assume such a position that a substantially uniform, continuous backrest is created when the user of the chair or armchair when leaning back more against the one In Figure 9 right backrest 3.1 shown leaning or stronger presses against this as against the other back support 3.1. This positive coupling of the two back supports 3.1 to oppositely directed movements is effected by means of a in the rest position substantially perpendicular to the straps 4 guide rod 43, which is mounted in such or in the seat base 40 and connected to the support members 4.2, that at a backward movement of a back support 3.1 the other back support in the opposite direction, ie moved to the front, is. In Figure 9, the deflection angle of the guide rod 43 is shown with respect to the center position to illustrate the principle oversubscribed; In reality, the deflection angle is only very small, so that when pivoting the ends of the guide rod 43 perform only very small movements, which are in the range of tenths of a millimeter and are thus absorbed by the tolerance play of the construction.

The ends of the guide rod 43 are articulated to the respective support parts 4.2, for example by means of ball joints 44 shown schematically in FIG. 8b, which are preferably mounted in elastically deformable sleeves 44.1. The guide rod 43 is also mounted in the middle between its articulation points on the support parts 4.2, preferably by means of the ball joint 45 shown in Figure 9a in or on a longitudinal member 40.2 of the seat base 50 articulated.

The support members 4.2 are supported by means mounted in the seat base 40 helical compression springs 46 such that the two back braces 3.1 in the unloaded rest position the have the same distance from the seat base 40 and the guide rod 43 occupies a rest or middle position.

According to Figure 8, the support members 4.2 are provided with upwardly directed lugs 47 on which the guide rod 43 is articulated. To the lugs 47 include pressure plates 48 which are supported by means of the frame 40.1 of the box-shaped seat base 40 guided plunger 49 on the helical compression springs 46 which are aligned perpendicular to the pivot axis 39 housed in the seat base 40. The helical compression springs 46 are supported on longitudinally displaceable blocks 50, which in turn are supported on cams 52 of a rotatable by means of the handle 53 camshaft 51 to change the biasing force of the spring 46 by turning the cam 52 can.

The guide rod 43 is guided in the frame 40.1 of the seat base 40 in arcuate guide grooves 54 whose ideal axes are parallel to the pivot axis 39 of the carrier 4 and are curved relative to the front of the chair from top to back and down.

The guide grooves 54 allow the tilting or pivoting movement of the guide rod 43 in the region of the ball joint 45, such that upon pivoting of the support member 4.2 to the rear of this support member is also pivoted down at the same time opposite movements of the opposite support member 4.2.

Figure 8 shows a position of the two support members 4.2 in a central, substantially mutually parallel position when the two back rests 3.1 are either unloaded or evenly loaded.

If a user leans backwards under uniform load both back braces 3.1, the guide rod 43 follows this rearward movement, which due to the articulated support of the guide rod 43 in or on the side rail 40.2 of the entire seat base 40 pulled back on the one hand and on the other hand at the same time is pivoted downwards or lowered in its rear region, in accordance with a seat storage with synchronous mechanism described in DE 299 08 599 Ul, which, as known, is not the subject of the present invention. Such a synchronous mechanism is used when pivoting the backrest forward or to pivot back and the seat according to a predetermined angular ratio.

The rearward movement of the seat base 40 is against the force of compression springs 60 which are supported between a support plate 61 forming part of the seat chassis 38 and thus stationary, and a support surface 62 forming part of the movable seat base 40.

Figures 4 and 5 show how the support member 7 is attached to a back support to allow pivotal movements of this back support 3.1 relative to the support member 7 both about a vertical axis and about a horizontal axis: A top and bottom open, box-shaped main body 10 is at its the support member 7 facing the end provided with two spaced preferably triangular wall sections 10.1, which have opposite Lageröffhungen 10.11. On the support member 7, a horizontally oriented bearing bushing 11 is fixed, so that after passing through an axle pin 12 by the brought with the bearing bush 11 in the alignment position bearing openings 10.11 of the main body 10 is pivotally attached to the support member 7. In the space between the main body 10 and the support member 7, a rubber buffer 14 is placed according to Figure 5, which is provided with a corresponding shape of the bearing bush 11 recess 14.1. The spring stiffness of the rubber buffer 14 is designed so that a controlled pivoting movement of the main body 10 around the defined by the axle 12 horizontal axis 2 allow.

The main body 10 is provided on its side facing away from the retaining ring member 7 with an upper and lower bounded by wall sections 10.2 opening. The wall sections 10.2 are provided with Lageröffhungen 10.21. A fixable at the back of each back support 3.1 fastener 13 has a vertically oriented bearing bush 13.1, which carries a radially outwardly projecting partition 13.2. When the bearing bush 13.1 is brought into alignment with the Lageröffhungen 10.21, an axle pin 14.2 can be inserted through these Lageröffhungen 10.21 and the bearing bush 13.1, whereby the main body 10 is pivotally mounted about a vertical axis on the fastening element 13. The partition wall 13.2 bounded within the sleeve-shaped main body 10 two Aufhahrnräume for spring elements 15, preferably cylindrical rubber buffers whose Dimensions and spring stiffness are designed so that a limited relative movement between the fastening element 13 and the main body 10 is possible about the vertical axis defined by the axle pin 11.

Claims

claims 1. A backrest for a chair or armchair with two laterally juxtaposed, resiliently supported back supports (3.1), each of which is attached to a separate support member (4.1), characterized in that each support member (4.1) the first leg of a substantially L shaped support (4), and that the second leg (4.2) of each support (4) below the chair or armchair seat against spring force about a Hotizontalachse (5 or 39) is pivotally mounted. 2. backrest according to claim 1, characterized in that the carrier (4) by a in the rest position substantially perpendicular to the supports (4) aligned guide rod (43) are in communication in such or in a seat base (40) mounted and connected to the carrier (4), that when moving the one back support (3.1) forward or backward, the other back support (3.1) is moved in each opposite direction. 3. Backrest according to claim 2, characterized in that the ends of the guide rod (43) on the supports (4) are preferably articulated by means of a ball joint (44) which is mounted in an elastically deformable sleeve (44.1). 4. Backrest according to claim 2 or 3, characterized in that the guide rod (43) between its articulation points on the supports (4) is articulated to the seat or seat base (40) is mounted. 5. Backrest according to claim 4, characterized in that the guide rod (43) by means of a ball joint (45) is mounted. 6. Backrest according to one of claims 2 to 5, characterized in that the guide rod (43) in in or on the seat base (40) mounted arcuate guide grooves (44, 54) is guided whose ideal axes parallel to the pivot axis (39). the carrier (4) lie and are curved with respect to the front of the chair from top to back and down. 7. Backrest according to one of claims 2 to 6, characterized in that the guide rod (43) on the second legs (4.2) of the L-shaped support (4) is articulated. 8. Backrest according to claim 7, characterized in that the second leg (4.2) each have an upwardly directed projection (47), and that the lugs (47) are supported by springs (46) which in the rest position of the L- shaped support (4) are evenly loaded with pressure. 9. Backrest according to claim 8, characterized in that the springs (46) are coil springs whose longitudinal axes are perpendicular to the pivot axis (39) of the carrier (4) and in the region of the seat base (40) are arranged. 10. Backrest according to claim 9, characterized in that on the lugs (47) pressure plates (48) are mounted, which are supported on plungers (49) on the springs (46). 11. Backrest according to one of claims 8 to 10, characterized in that the biasing force of the springs (46) is variable. 12. A backrest according to claim 11, characterized in that the springs (46) abut with their pressure plates (48) opposite ends against slidable in the spring longitudinal direction blocks (50) on cams (52) of an externally rotatable camshaft (51) are. 13. Backrest according to one of claims 2 to 12, characterized in that the guide rod (43) on the means of springs (60) supported seat base (40) is fixed such that this seat base (40) upon pivoting of the carrier (4) relative to the seat chassis (48) is displaceable forward or backward. 14. Backrest according to one of claims 1 to 13, characterized in that the back supports (3.1) are resiliently fixed to the support parts (4.1). 15. Backrest according to one of claims 1 to 14, characterized in that the back supports (3.1) are mounted to substantially vertically aligned axis lines pivotally mounted on the support parts (4.1). 16. Backrest according to one of claims 1 to 15, characterized in that the back supports (3.1) along the support members (4.1) are positionable in different height positions. 17. Backrest according to one of claims 1 to 16, characterized in that the back supports (3.1) are attached to the support members (4.1) displaceable support members (7). 18. Backrest according to one of claims 1 to 17, characterized in that the two backrests (3.1) by means of an elastically deformable transverse web (9) are interconnected, whose strength is designed so that the two backrests (3.1) their function as a single support retain the mobility of a back support relative to the other back support to a limited extent. 19. armchair or chair, characterized in that it is equipped with a backrest according to one of claims 1 to 18. 20. Backrest according to claim 1, characterized in that each carrier part (4.2) is aligned substantially vertically. 21. A backrest according to claim 20, characterized in that on the carrier (4) acting spring force is mutually variable. 22. Backrest according to one of claims 20 to 21, characterized in that the two supports (4) along their common horizontal pivot axis at different distances from each other can be fixed. 23. Backrest according to one of claims 20 to 22, characterized in that each back support (3.1) relative to its support part (4.1) about a horizontal axis is pivotable. 24. Backrest according to claim 23, characterized in that each back support (3) on a support member (7) is fixed, which along the associated support member (4.1) can be determined in different height positions. 25. A backrest according to claim 24, characterized in that each back support (3) with the interposition of at least one elastically deformable suspension element is attached to its support member (7). 26. A backrest according to claim 24, characterized in that attached to each support member (7) against spring force about a horizontal axis (12) pivotable body (10) which in turn against spring force about a vertical axis (14) pivotally mounted on a back support (3). is attached. 27. Backrest according to one of claims 20 to 26, characterized in that the two backrests (3) by means of an elastically deformable transverse web (3.2) are interconnected, whose strength is designed so that the two backrests (3) their function as individual supports retain the mobility of a back support relative to the other back support to a limited extent. Seating furniture in the form of a chair, armchair, or the like, equipped with a backrest (3) according to one of claims 20 to 27, the seat surface of which is fastened to a stand (1) by means of a support unit (2), characterized in that the second limb (4.2) of each carrier (4), which can be fastened so as to be pivotable about the horizontal pivot axis, is designed as a two-armed lever, onto whose free lever end (4.3 or 4.4) the spring force acts. 29. Seating furniture according to claim 28, characterized in that the spring force is effected by a substantially vertically aligned spring element (22). 30. Seating furniture according to claim 28, characterized in that the second leg (4.2) in the region of its free end of the lever, an upwardly or downwardly directed bend (4.4) has, acts on a substantially horizontally oriented spring element (22). 31. Seating furniture according to claim 28, characterized in that the Abkröpfüng (4.4) is directed upward and the spring element as a tension spring (22) is formed, and that the tension springs (22) of both carriers to change the force acting on the carrier force with their Ends are fixed to a relative to the horizontal axis at different distances detectable adjusting member (23).