Chair

Abstract

A chair includes a deformable seat shell forming a seat part and a backrest, and further includes a frame, the seat part being connected to the frame by means of a first pivot joint and the backrest being connected to the frame by means of a second pivot joint, the pivot joints allowing a twisting of the seat part and of the backrest relative to the frame caused by a deformation of the seat shell. The second pivot joint is connected to the backrest centrally in relation to the transverse direction of the chair.

Claims

1. A chair comprising: a deformable seat shell forming a seat part and a backrest, and a frame, the seat part being connected to the frame by a first pivot joint, and the backrest being connected to the frame by a single second pivot joint, the first and second pivot joints allowing a twisting of the seat part and of the backrest relative to the frame caused by a deformation of the seat shell, wherein the second pivot joint is connected to the backrest centrally in relation to a transverse direction of the chair, and wherein the first pivot joint allows a twisting about a first axis of rotation oriented in a vertical direction of the chair, and the second pivot joint allows a twisting about a second axis of rotation oriented in a longitudinal direction of the chair.

2. The chair according to claim 1, characterised in that the first pivot joint allows a twisting about a first axis of rotation oriented in the vertical direction of the chair.

3. The chair according to claim 1, characterised in that the seat part is connected to the frame by means of at least one bearing, the bearing being formed such that it hinders a twisting of the seat part about an axis which is oriented in a longitudinal direction of the chair.

4. The chair according to claim 3, characterised in that the at least one bearing includes a first bearing and a second bearing, each arranged at a distance from the first pivot joint in the transverse direction of the chair, the first bearing and second bearing being movable towards one another in a plane extending in the transverse direction and longitudinal direction of the chair.

5. The chair according to claim 1, characterised in that a backrest support is connected to the backrest by the second pivot joint, and is rotatably connected to a seat base of the frame by a third pivot joint about an axis of rotation oriented in the transverse direction of the chair, the seat base of the frame being connected to the seat part by the first pivot joint.

6. The chair according to claim 5, characterised in that it is adjustable between at least one upright first position and a backwardly tilted second position, an angle () between the seat part and the backrest being greater in the second position than in the first position.

7. The chair according to claim 5, characterised in that the backrest support is L-shaped or arched, a first leg of the L-shaped backrest support or a first half of the arched backrest support being connected by means of the third pivot joint to the seat base and a second leg of the L-shaped backrest support or a second half of the arched backrest support being connected by means of the second pivot joint to the backrest.

8. The chair according to claim 1, characterised in that the first pivot joint allows a twisting of the seat part about an axis of rotation oriented in the transverse direction of the chair and/or the second pivot joint allows a twisting of the backrest about an axis of rotation which is oriented in the transverse direction of the chair.

9. The chair according to claim 5, characterised in that the frame is designed such that a twisting of the backrest support about the axis of rotation of the third pivot joint leads to a movement of a front edge of the seat in the vertical direction of the chair.

10. The chair according to claim 9, further comprising a lever and a rod and characterised in that the seat part is fixed to a cross beam, the cross beam being connected to the lever or the rod and the lever being rotatably connected to the seat base, whereas a rotational movement of the lever relative to the seat base is coupled by the rod to a rotational movement of the backrest support.

11. The chair according to claim 1, characterised in that the first pivot joint is arranged in the half of the seat part comprising a front edge of the seat.

12. The chair according to claim 1, characterised in that the second pivot joint is arranged above the centre of gravity of a user's body.

13. The chair according to claim 1, the frame further comprising a seat base connected to the seat part by the first pivot joint, and connected to a foot part of the frame by a foot part pivot joint.

14. The chair according to claim 1, characterised in that the seat shell comprises a seat part, a backrest and a support connecting the seat part and the backrest.

15. The chair according to claim 14, characterised in that the seat part is movably mounted on the frame in a longitudinal direction of the chair and/or the backrest is movably mounted on said frame in the vertical direction of the chair.

16. A chair comprising: a deformable seat shell forming a seat part and a backrest, and a frame, the seat part being connected to the frame by means of a first pivot joint, and the backrest being connected to the frame by means of a second pivot joint, the pivot joints allowing a twisting of the seat part and of the backrest relative to the frame caused by a deformation of the seat shell, characterised in that the second pivot joint is connected to the backrest centrally in relation to the transverse direction of the chair, a backrest support is connected to the backrest by the second pivot joint, and is rotatably connected to a seat base of the frame by a third pivot joint about an axis of rotation oriented in the transverse direction of the chair, the seat base of the frame being connected to the seat part by the first pivot joint, the frame is designed such that a twisting of the backrest support about the axis of rotation of the third pivot joint leads to a movement of a front edge of the seat in the vertical direction of the chair, and the chair further comprises: a lever and a rod, wherein the seat part is fixed to a cross beam, the cross beam being connected to the lever or the rod, and the lever being rotatably connected to the seat base, wherein a rotational movement of the lever relative to the seat base is coupled by the rod to a rotational movement of the backrest support.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1: is a side view of a first embodiment of a chair according to the invention;

(2) FIG. 2: is a view from behind of the chair according to FIG. 1 having an undeformed seat shell;

(3) FIG. 3: is a view according to FIG. 2 when the seat shell of the chair is deformed;

(4) FIG. 4: is a view from above of the chair according to FIG. 1 having an undeformed seat shell;

(5) FIG. 5: is a view according to FIG. 4 when the seat shell of the chair is deformed;

(6) FIG. 6: is a side view of a second embodiment of a chair according to the invention when the seat shell is in an upright position;

(7) FIG. 7: is a view according to FIG. 6 when the seat shell is in a backwardly tilted position;

(8) FIG. 8: is a side view of a third embodiment of a chair according to the invention when the seat shell is in an upright position;

(9) FIG. 9: is a view according to FIG. 8 when the seat shell is in a backwardly tilted position;

(10) FIG. 10: is a view from behind of a chair according to FIG. 6 to 9 having an undeformed seat shell;

(11) FIG. 11: is a view according to FIG. 10 when the seat shell is deformed;

(12) FIG. 12: is a view from above of a chair according to FIG. 6 to 9 having an undeformed seat shell in an upright position;

(13) FIG. 13: is a view according to FIG. 12 when the seat shell is deformed and in a backwardly tilted position;

(14) FIG. 14: is a side view of a fourth embodiment of a chair according to the invention in which the seat shell is in an upright position; and

(15) FIG. 15: is a view according to FIG. 14 in which the seat shell is in a backwardly tilted position.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

(16) The chair shown in FIG. 1 to 5 comprises a frame 1 and a seat shell 2 connected to the frame 1.

(17) The frame 1 is substantially rigid. Said frame is thus designed such that it does not deform functionally when the chair is used as intended. The frame 1 can be formed in one piece, for example from welded-together tubes. It forms for example four feet, as shown, by means of which the chair can be placed on a subsurface.

(18) The seat shell 2 is integrally formed such that a portion used as a seat part 3 transitions into a portion used as a backrest 4 of the seat shell 2. In this case, the seat shell 2 can be formed in one or more pieces (in particular having a then preferably one-piece seat shell upper part and a frame supporting the seat shell upper part) (cf. also FIGS. 14 and 15).

(19) The seat shell is connected to the frame 1 by means of two pivot joints 5, 6. In this case, a first pivot joint 5 is arranged near the front edge of the seat 7 of the seat shell 2. The first pivot joint 5 is positioned centrally in relation to the transverse direction of the chair and thus approximately in the sagittal plane of a user. The first pivot joint 5 allows a twisting of the portion of the seat shell 2 that is connected to this pivot joint 5, specifically substantially of the whole seat part 3, relative to the corresponding portion of the frame 1 (the seat base 8) about a first axis of rotation 9.

(20) This first axis of rotation 9 extends in the vertical direction of the chair. Specifically, it is oriented approximately vertically (when the chair is standing on a horizontal subsurface). The first pivot joint 5 can be formed such that a pin 10 that is connected to the seat base 8 (or the seat part 3) is rotatably mounted in a bushing 11 that is connected to the seat part 3 (or the seat base 8).

(21) A second pivot joint 6 connects the seat shell 2 in the region of the backrest 4 to a backrest support 12 of the frame 1. In this case, the second pivot joint 6 is arranged centrally in relation to the transverse direction of the chair and thusas in the case of the first pivot joint 5approximately in the sagittal plane of a user of the chair. The second pivot joint 6 is formed as a ball joint. This accordingly allows a twisting of the backrest 4 relative to the backrest support 12 about a plurality of axes, inter alia about at least one axis of rotation 13 extending in the longitudinal direction of the chair.

(22) The mounting of the seat shell 2 according to the invention allows a deformation of the seat shell 2 caused by a shift in weight by a user in which said seat shell is moved to one side in the transition from the seat part 3 to the backrest 4 while the front edge of the seat 7 and the edge of the backrest 14 are tilted towards the other side (cf. FIGS. 3 and 11).

(23) Furthermore, the seat part 3 of the seat shell 2 is connected to the frame 1 by means of two bearings 15. Each bearing 15 is arranged at a distance from the first pivot bearing 5 in the transverse direction of the chair. With respect to the longitudinal direction of the chair, the bearings 15 are located at the level of the first pivot bearing 5 and of the front edge of the seat 7. The two bearings 15 are formed such that they at least support, i.e. prevent, a load in the vertical direction, i.e. from above to below. As a result, a twisting of the front portion of the seat part 3 about an axis which is oriented in the longitudinal direction of the chair and consequently a sideways tipping of a user together with the seat shell 2 is prevented. In this case, the bearings 15 are formed such that a movability of the seat part 3 relative to the frame 1 in the region of the bearings 15 in a plane that extends in the longitudinal direction and the transverse direction of the chair, is possible (cf. FIGS. 4 and 5 as well as FIGS. 12 and 13). As a result, the desired deformability of the seat shell 2 is not prevented by the bearings 15. This movability of the bearings 15 can be achieved in that two respective bearing parts abut each other in a sliding manner and as a result form a corresponding slide bearing. One bearing part can be connected to the frame 1 or be formed by said frame and the other bearing part can be connected to the seat part 3 of the seat shell 2 or be formed by said seat part.

(24) If the bearings 15 are also each intended to support a load in the vertical direction, i.e. from below to above, it can be provided for one of the bearing parts of each bearing 15 to form a slot through which a guide pin of the other bearing part extends, the edge of the slot engaging at least on one side, preferably on two sides, in a groove formed in the casing of the guide pin.

(25) The chair shown in FIGS. 6 and 7 and in 10 to 13 differs from the chair shown in FIG. 1 to 5 firstly by the integration of a tilting movability of the seat shell 2. For this purpose, the backrest support 12 of the frame 1 is formed so as to be structurally separate from the seat base 8 of the frame 1 and is rotatably connected to the seat base 8 by means of a third pivot joint 16 about a third axis of rotation 17, which extends in the transverse direction of the chair. The third axis of rotation 17 extends near the first pivot joint 5. In particular, it can be provided for the third axis of rotation 17 to intersect the first axis of rotation 9 that extends in the vertical direction and is formed by the first pivot joint 5.

(26) The backrest support 12 is L-shaped, the free end of one leg being connected by means of the second pivot joint 6 to the backrest 4 of the seat shell 2 and the free end of the other leg being connected by means of the third pivot joint 16 to the seat base 8. The backrest support 12 can also, however, also be arched.

(27) In order to not impede the tilting movability of the seat shell 2, the first pivot joint 5 and the second pivot joint 6 are formed such that they allow a twisting of the corresponding portion of the seat shell 2 relative to the corresponding portion of the frame 1 in each case also about a fourth axis of rotation 18 and a fifth axis of rotation 19 respectively, which are oriented in the transverse direction of the chair. In the case of the second pivot joint 6, this rotatability results from its design as a ball joint. For the first pivot joint 5, in contrast, this rotatability results from the deformability of the seat shell, as shown in FIGS. 6 and 7. There is, however, also the possibility of forming the first pivot joint 5 as a ball joint or in another manner with two pivot joint parts movably connected to one another about the corresponding axes of rotation 9, 18. In particular, in one design of the first pivot joint 5 in which said pivot joint has a pin 10 connected to the seat base 8 (or the seat part 3 of the seat shell 2) that is rotatably mounted in a bushing 11, which is connected to the seat part 3 (or the seat base 8), it can also be provided that the pin 10 (or the bushing 11) is connected to a cross beam, at the end of which the corresponding end of the L-shaped backrest support 12 also engages. In this case, the cross beam can be mounted rotatably in the seat base 8 while the backrest support 12 and/or the pin 10 (or the bushing 11) can engage firmly on the cross beam. In this case, the cross beam that is rotatably mounted in the seat base 8 forms the third pivot joint 16 as well as part of the first pivot joint 5. It is also possible for the cross beam to be firmly integrated into the seat base 8, while the backrest support 12 and the pin 10 (or the bushing 11) are rotatably fixed to said cross beam.

(28) As a result of the distance of the third axis of rotation 17 from the fourth axis of rotation 18 formed by the first pivot joint 5 extending in the transverse direction of the chair, the (direct) distance between the fourth axis of rotation 18 and the second pivot bearing 6 changes when the seat shell 2 is tilted backwards. This leads to a deformation of the seat shell 2, where an angle formed between the seat part 3 and the backrest 4 increases (.sub.1<.sub.2).

(29) Moreover, the chair shown in FIGS. 6 and 7 and in 10 to 13 is designed as a revolving chair. For this purpose, the seat base 8 of the frame 1 is rotatably connected to a foot part 22, shown only in part, of the frame 1 by means of a fourth pivot joint 20 about a sixth axis of rotation 21 extending in the vertical direction of the chair, which is specifically approximately vertically oriented.

(30) The chair shown in FIGS. 8 and 9 and in 10 to 13 differs from the chair shown in FIGS. 6 and 7 and in 10 to 13 in particular by additional kinematics, which ensure that a backward tilting of the seat shell 2 is accompanied by a raising (in the vertical direction) of the first pivot joint 5 and thus the front edge of the seat 7.

(31) For this purpose, the third pivot joint 16, by means of which the backrest support 12 is connected to the seat base 8, is arranged further back. Moreover, two more rods 23 (one on either side of the backrest support 12) are rotatably connected to the backrest support 12 at the same end as the third pivot joint 16 and about a seventh axis of rotation 24. The seventh axis of rotation 24 is arranged at a distance from the third axis of rotation 17 formed by the third pivot bearing 16.

(32) The rods 23 each extend up to one end of a respective lever 25, to which they are rotatably connected about an eighth axis of rotation 26 extending in the transverse direction of the chair. The respective other end of the lever 25 is rotatably connected to the seat base 8 about a ninth axis of rotation 27 extending in the transverse direction of the chair. A distance is thus also produced between the eighth axis of rotation 26 and the ninth axis of rotation 27. The ninth axis of rotation 27 is approximately positioned in the manner of the third axis of rotation 17 in the case of the chair according to FIGS. 6 and 7.

(33) The first pivot joint 5 is connected to the two rods 23 near the eighth axis of rotation by means of a cross beam. Said cross beam can, however, also be connected in turn to the two levers 25, near the eighth axis of rotation. As a result of this linking of the first pivot joint 5 in conjunction with the distances formed between the third axis of rotation 17 and the seventh axis of rotation 24 on the one hand and the eighth axis of rotation 26 and the ninth axis of rotation 27 on the other, the desired height adjustment of the first pivot bearing 5 and thus of the front edge of the seat 7, which is coupled to an adjustment of the tilting of the seat shell 2, is produced.

(34) Also in the case of the chair according to FIGS. 8 and 9, a backward tilting of the seat shell 2 leads to an increase of an angle formed between the seat part and the backrest (.sub.1<.sub.2).

(35) FIGS. 14 and 15 show an embodiment of a chair according to the invention, which differs from that shown in FIGS. 8 and 9 in that the seat shell 2 is not formed integrally but rather of more than one part. Said seat shell comprises a seat part 3 and a backrest 4, which are formed as separate components at a distance from one another and are connected to one another by means of a support 28. The support 28 substantially constitutes the component of the seat shell 2 that facilitates the deformability of the seat shell 2. The support 28 is designed as a guide rail arranged centrally in relation to the transverse direction of the chair on which the seat part 3 and the backrest 4 are guided in a longitudinally movable manner. As a result of such movement and the possibility of fixing the seat part 3 and the backrest 4 in various positions by means of a locking device (not shown) in an interlocking or force-fitting manner, an advantageous adaptation of the chair to different body dimensions of users is made possible.

LIST OF REFERENCE NUMERALS

(36) 1 Frame 2 Seat shell 3 Seat part 4 Backrest 5 First pivot joint 6 Second pivot joint 7 Front edge of seat 8 Seat base 9 First axis of rotation 10 Pin 11 Bushing 12 Backrest support 13 Second axis of rotation 14 Edge of backrest 15 Bearing 16 Third pivot joint 17 Third axis of rotation 18 Fourth axis of rotation 19 Fifth axis of rotation 20 Fourth pivot joint 21 Sixth axis of rotation 22 Foot part 23 Rod 24 Seventh axis of rotation 25 Lever 26 Eighth axis of rotation 27 Ninth axis of rotation 28 Support