Chair, especially, office chair

Abstract

A chair, especially an office chair, includes a seat that is fastened on a base support unit, a backrest that includes a back lower region and an upper shoulder region and is fastened to a back support, the back support being supported by the base support unit in a manner permitting rotation about an inclination axis. The shoulder region is connected to the back support in a manner permitting inclination about a shoulder axis and is hinge-connected to a back lower region at a lumbar region, and the back lower region further extends along a chair element so that when the shoulder region is inclined about the shoulder axis, an angle of the shoulder region relative to the back lower region is changed.

Claims

1. A chair comprising: a seat that is fastened on a base support unit; and a backrest that includes a back lower region and an upper shoulder region and is fastened to a back support, the back support being supported by the base support unit in a manner permitting rotation about an inclination axis, wherein the shoulder region is connected to the back support in a manner permitting inclination about a shoulder axis and is hinge-connected to the back lower region at a lumbar region, wherein the back lower region further extends along a chair element so that when the shoulder region is inclined about the shoulder axis, an angle of the shoulder region relative to the back lower region is changed, wherein the backrest includes a center region and a side region sharing a boundary with the center region and oriented frontward as a side guide, wherein when the shoulder region is inclined, the orientation of the side region relative to the center region is forcedly change, and wherein the side region is rotatable about a perpendicular axis toward the center region.

2. The chair according to claim 1, wherein the back lower region is hinge-connected to the seat.

3. The chair according to claim 1, wherein the seat includes a seat rear part hinge-fastened to a seat front part.

4. The chair according to claim 1, wherein the shoulder region is continuous to a back upper region for supporting the head and, in particular, the back upper region is hinge-connected to the shoulder region.

5. The chair according to claim 1, wherein a spring element for acting between the back support and the backrest is arranged and applies a restoring force to the shoulder region so as to allow hinge connection thereof to the back support.

6. The chair according to claim 1, wherein the backrest includes a frame upholstered therearound with cloth and the frame includes a frame upper part located in the shoulder region and a frame lower part located in the back lower region.

7. The chair according to claim 6, wherein the frame includes a lower crossbar and an upper crossbar and the upper crossbar is hinge-connected to the back support.

8. The chair according to claim 6, wherein the frame includes an upper crossbar and a lower crossbar, which are respectively hinge-connected to the frame upper part and the frame lower part, and wherein the hinge connection is such that when the shoulder region is inclined about the shoulder axis, frame side parts respectively rotate inward and outward.

9. The chair according to claim 6, wherein a lumbar support is arranged connected to a lower crossbar mechanically in a non-rotatable manner.

10. The chair according to claim 8, wherein the hinge connection is realized through a notch.

11. The chair according to claim 1, wherein the backrest includes a plurality of back elements fastened to each other in a freely rotatable manner, wherein the plurality of back elements includes at least a main back element for limiting the shoulder region and a lower back element hinge-fastened to a lower end of the main back element and forming the back lower region.

12. The chair according to claim 11, wherein side-part elements are respectively hinge-fastened in a side part to the main back element and the lower back element and the side-part elements are also hinge-fastened to each other.

13. The chair according to claim 11, wherein the back elements individually have a wedge-shaped surface or a trapezoidal surface and mutually adjacent back elements are supported by each other.

14. The chair according to claim 11, wherein the back elements are hinge-connected to each other by a film hinge method.

15. The chair according to claim 11, wherein the plurality of back elements are fabricated from a member of one-piece form, and wherein the individual back elements are connected to each other by a film hinge formed as a material bridge or, alternatively, the back elements are formed as plates of separate form and then connected to each other selectively either by an elastic hinge strip or by an elastic cover of large area, in particular, covering the entire surface of the back elements.

16. A chair comprising: a seat that is fastened on a base support unit; and a backrest that includes a back lower region and an upper shoulder region and is fastened to a back support, the back support being supported by the base support unit in a manner permitting rotation about an inclination axis, wherein the shoulder region is connected to the back support in a manner permitting inclination about a shoulder axis and is hinge-connected to the back lower region at a lumbar region, wherein the back lower region further extends along a chair element so that when the shoulder region is inclined about the shoulder axis, an angle of the shoulder region relative to the back lower region is changed, wherein the backrest includes a frame upholstered therearound with cloth and the frame includes a frame upper part located in the shoulder region and a frame lower part located in the back lower region, and wherein the frame includes an upper crossbar and a lower crossbar, which are respectively hinge-connected to the frame upper part and the frame lower part, and wherein the hinge connection is such that when the shoulder region is inclined about the shoulder axis, frame side parts respectively rotate inward and outward.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Embodiments of the present invention are described below in detail with reference to the drawings. The contents of the drawings are as follows.

(2) FIG. 1 is a perspective front view of an office chair according to a first implementation variation.

(3) FIG. 2 is a rear view of an office chair shown in FIG. 1.

(4) FIG. 3 is a side view of an office chair shown in FIG. 1 in a state that a backrest is at a standard upright position.

(5) FIG. 4 is a side view of an office chair shown in FIG. 1 in a state that a backrest is inclined.

(6) FIG. 5 is a perspective side view of a cut-out part of an office chair according to a second implementation variation.

(7) FIG. 6 is a perspective side view of an office chair shown in FIG. 5 in a state that the shoulder region alone of the backrest is slightly inclined rearward.

(8) FIG. 7 is a perspective side view of an office chair shown in FIG. 5 in a state that in comparison with the situation shown in FIG. 5, a backrest in its entirety is inclined rearward about an inclination axis so that a shoulder region of the backrest is supplementarily inclined rearward about a shoulder axis.

(9) FIG. 8 is a perspective side view of an improvement implementation variation of an office chair in which an auxiliary lumbar support is arranged supplementarily to the implementation variation shown in FIG. 5.

(10) In the figures, components having an identical function are designated by an identical reference numeral.

DESCRIPTION OF EMBODIMENTS

(11) In each of both implementation variations, an office swivel chair shown in the figure includes abase support unit 2, to which a seat 4 and a back support 6 are fastened. The back support 6 is supported (befestigen ist) by the base support unit 2 in a manner permitting rotation about an inclination axis A1. The base support unit 2 receives a synchronous mechanism not shown in detail in the figure here. This includes also a mechanism for weight adjustment. This may be formed as an automatic weight adjustment device or, alternatively, may be formed as an important adjustment device of manual adjustment type.

(12) A backrest 8 divided into a plurality of partial regions is fastened to the back support 6. Thus, this includes an upper shoulder region 10 and a back lower region 12. Further, continuously to the shoulder region 10, a back upper region 14 for forming a head region is further provided in both embodiments.

(13) In its entirety, the backrest 8 includes a center region 16, which is continuous to side regions 18 individually in a transverse direction.

(14) The shoulder region 10 and the back lower region 12 share a boundary with each other in a lumbar region 20 and are fastened to each other through a hinge joint by a hinge method. Thus, these can be inclined relative to each other about a common axis (referred to as a lumbar axis A2, hereinafter) so that the relative azimuthal angle can be changed.

(15) The shoulder region 10 also is connected to the back support 6 by a hinge method through an additional hinge joint for allowing the shoulder region 10 to be inclined about a horizontal axis (referred to as a shoulder axis A3, hereinafter). Supplementarily, perpendicular axes in a transverse direction running substantially perpendicularly, that is, upper perpendicular axes B2, are formed in the shoulder region 10. Further, lower perpendicular axes B2 are formed in the back lower region 12. The perpendicular axes B1 and B2 allow the side regions 18 to perform inward rotation in a frontward direction toward the seat 4.

(16) In both embodiments, the backrest 8 is mechanically connected directly to the seat 4. Thus, in addition to indirect connection through the back support 6 and the base support unit 2, direct connection is formed between the backrest 8 and the seat 4. Further, the seat 4 includes a plate-shaped seat rear part 22 mechanically connected to the back lower region 12. This connection is achieved especially through a hinge joint and at least one to-a-certain-extent rotational movement about a connection axis A4 is allowed. The seat rear part 22 itself is fastened through an additional hinge joint to a seat front part 24 such that rotation about a seat axis A5 is allowed. Here, both seat parts 22 and 24 are fabricated in plate shapes or shell shapes and, in particular, form a seat support of two-piece form so as to finally support a cushion.

(17) A spring element 26 (see FIGS. 3 and 4) acting between the back support 6 and the backrest 8 applies a restoring force to the shoulder region 10 so that inclination adjustment about the shoulder axis A3 is allowed for the shoulder region 10.

(18) In the embodiment shown in FIGS. 1 to 4, the backrest 8 forms a plurality of back elements of plate shape or shell shape, that is: a main back element 28 for forming a center region of the shoulder region 10; a lower back element 30 for forming a center part of the back lower region 12; and an upper back element 32 for forming a center part of the back upper region 14. These three back elements 28, 30, and 32 are respectively connected to each other through hinge joints running horizontally. The main back element 28 and the lower back element 30 are connected to each other by a hinge method through the lumbar axis A2. The upper back element 32 is connected to the main back element 28 in a manner permitting inclination about head axis A6 together with the main back element 28.

(19) Each of these back elements 28 to 32 is continuous to a side-part element (wangenelement) 34 on the side and is connected to each adjacent side-part element (wangenelement) 34 by a hinge method. As seen especially from the side views of FIGS. 3 and 4, the side-part element (wangenelement) 34 extends frontward from the side toward the seat 4 and then is oriented at an angle toward the back elements 28 to 32 of the center region 16.

(20) Each of the back elements 28 to 34 has a basic surface of trapezoidal shape, wedge shape, or triangular shape and extends from the longer side toward the shorter side in a narrow width manner or a tapering manner. The individual back elements 28 to 34 are arranged such as to support (befestigen) each other. Thus, mutually adjacentwhen viewed from a perpendicular directionback elements 28 to 34 are in contact with each other on the longer-side side or the shorter-side side. By virtue of this, a waist is formed in the lumbar region 20. At the same time, here, the side-part element (wangenelement) 34 is pulled frontward from the side.

(21) Operation of the chair according to the first implementation variation shown in FIGS. 1 to 4 is as follows.

(22) When the shoulder region 10 is inclined rearward (mainly) about the shoulder axis A3, since this is hinge-connected to the back lower region 12, the back lower region 12 is pulled approximately upward and, at the same time, protrudes also frontward toward the seat 6 so that desired support is achieved in the lumbar region 20. At the same time, by virtue of the mechanical connection between the side-part elements (wangenelemente) 34 and further by virtue of the special trapezoidal shape of each of the back elements 28 to 34, the side-part elements (wangenelemente) 34 are bent frontward toward the seat. Thus, the upper part of the body is held satisfactorily and further the sides of the body are also guided satisfactorily. Since the backrest 8 protrudes frontward in the lumbar region 20, length correction is necessary within the limits of the back lower region 12.

(23) This is achieved by the hinge connection of the back lower region 12 with the seat rear part 22 and the hinge connection with the seat front part 24. When the shoulder region 10 is inclined rearward, in the seat rear part 22, the region of connection with the back lower region 12, that is, the region of connection axis A4 is pulled upward in an approximately perpendicular direction. At the same time, the seat rear part 22 performs rotational movement with facing the seat front part 24. Thus, once the shoulder region 10 is inclined about the shoulder axis A3, the seat rear part 22 is moved obliquely upward. Here, in general, the shoulder axis A3 is formed in an approximately upper one-third portion of the shoulder region.

(24) Usually, inclination adjustment of the shoulder region 10 is achieved at the time that the entire backrest 8 is inclined with facing the base support unit 2, that is, at the time that the back support 6 is inclined about the inclination axis A1. The situation of such complex inclination is shown in FIG. 4 in comparison with FIG. 3. With starting at the initial position that the back support 6 is at the basic upright position as shown in FIG. 3, when inclination adjustment is to be performed, the individual elements perform rotating motion about the individual axes A1 to A6 as indicated by arrows 36 in FIG. 4.

(25) By virtue of the inclination of the backrest 8 about the inclination axis A1, the shoulder region 10 is pulled obliquely rearward along the shoulder axis A3. As a result, the backrest is elongated in comparison with the initial situation shown in FIG. 3. That is, the shoulder region 10 is inclined frontward toward the seat 4 about the shoulder axis A3 so that the angle between the shoulder region and the back lower region 12 becomes large. Thus, in its entirety, the seat rear part 22 is pulled downward toward the back support 6. The angle between the seat rear part 22 and the back lower region 12 which is approximately the right angle in the initial situation shown in FIG. 3 becomes slightly smaller.

(26) Thus, in its entirety, what is formed by the individual axes A1 to A6 is a hinge chain or a link chain, which causes the contour of the backrest 8 to fit forcedly to the desired shape at the time of inclination adjustment.

(27) By virtue of the elongation of the backrest, that is, when the lumbar region 20 is shifted rearward toward the back support 6, at the same time, forced correction is caused in side regions 8. As a result, the individual side-part elements (wangenelemente) 34 are bent frontward about the perpendicular axes B1 and B2 and, supplementarily, also bent frontward about a third perpendicular axis B3 in the back upper region 14.

(28) When the backrest 8 is to return to the upright position, the movement is performed in the reverse sequence. Here, the spring force of the spring element 26 is oriented such as to be against the elongation movement at the time that the backrest 8 transits from the upright position to the inclined position shown in FIG. 4.

(29) Also in a second embodiment shown in FIGS. 5 to 8, the operation is basically the same. Thus, what is formed here is also a hinge chain or a link chain for guiding forcedly the contour of the backrest at the time of inclination so as to forcedly achieve fitting. Anyway, the back elements 28 to 34 formed separately are absent here. Instead, the backrest 8 is constructed from one frame 38, that is, a frame 38 constructed from: a frame lower part 40 of the back lower region 12; a frame upper part 42 of the shoulder region 10; a lower crossbar 44; and an upper crossbar 46. In the present embodiment, the upper crossbar 46 simultaneously forms the lower crossbar of the head frame 48 within the limits of the back upper region 14. The head frame 48 includes side parts 50 facing each other and continuous to the frame upper part 42; and an upper crossbar 52 located yet above. In particular, the upper crossbar 46 and the upper crossbar 52 located yet above are each fabricated in a form warped rearward here. Since, the frame parts 40 and 42 are arranged with an angle relative to each otherwhen viewed from a transverse direction, the lumbar region 20 is warped frontward.

(30) In its entirety, the frame 38 is upholstered with cloth 54. In order to form the lumbar axis A2, a notch, that is, a material taper 56 is added to the frame 38. In order to form both perpendicular axes B1 and B2, suitable notches 56 in a perpendicular direction are added to a transitional region from the frame upper part 42 to the upper crossbar 46 and added to a transitional region from the frame lower part 40 to the lower crossbar 44.

(31) The upper crossbar 46 is connected to an edge on the front side of the back support 6 and then rotational movement between the upper crossbar 46 and the back support 6 is allowed at this connection site. By virtue of this, the shoulder axis A3 is limited.

(32) In the implementation variation of FIG. 8, further, supplementarily, a lumbar support 58 is arranged that is connected through a holding web to the lower crossbar 44 in a non-rotatable manner.

(33) FIG. 5 shows the initial position of no-load condition in which the backrest 8 stands upright. FIG. 6 shows a position that with starting at the no-load initial position, the shoulder region 10 is inclined mainly about the shoulder axis A3 (no inclination about the inclination axis A1). That is, the head frame 48 has first been inclined frontward and then the head frame 48 has been inclined rearward anew so as to be located at an approximately upright position at present. Thus, in its entirety, the cloth 54 is slightly pulled upward. Necessary length correction is achieved when the seat rear part 22 is pulled upward about the seat axis A5. At the same time, here, the angular position between the seat rear part 22 and the back lower region 12 preferably elastically held by each other about the connection axis A4 can be changed. In the present embodiment, at the time of this movement from the position shown in FIG. 5 to the position shown in FIG. 6, no change occurs in the angular position between both frame parts 40 and 42. That is, rotation about the lumbar axis A2 is not yet performed.

(34) FIG. 7 shows a multi-functional and complex inclination adjustment in which at last, the shoulder region 10shown in FIG. 6is inclined rearward about the shoulder axis A3 and, at the same time, the entirety of the backrest 8 also is inclined rearward about the inclination axis A1. Similarly to the first implementation variation shown in FIG. 4, also here, the backrest 8 is elongated downward and then the seat rear part 22 rotates downward in comparison with the initial situation shown in FIG. 5. At the same time, the shoulder region 10 is inclined rearward. By virtue of this elongation, in its entirety, the side frame parts 40 and 42 rotate inward about the perpendicular axes B1 and B2 so as to serve as side guides more effectively.

(35) In the implementation variation shown in FIG. 8, supplementarily, the lumbar is supported (befestigen ist) by the additional lumbar support 58 in the lumbar region 20.

DESCRIPTION OF REFERENCE NUMERALS

(36) 2 Base support unit 4 Seat 6 Back support 8 Backrest 10 Upper shoulder region 12 Back lower region 14 Back upper region 16 Center region 18 Side region 20 Lumbar region 22 Seat rear part 24 Seat front part 26 Spring element 28 Main back element 30 Lower back element 32 Upper back element 34 Side-part element (wangenelement) 36 Arrow 38 Frame 40 Frame lower part 42 Frame upper part 44 Lower crossbar 46 Upper crossbar 48 Head frame 50 Side part 52 Additional crossbar 54 Cloth 56 Notch 58 Lumbar support A1 Inclination axis A2 Lumbar axis A3 Shoulder axis A4 Connection axis A5 Seat axis A6 Head axis B1 Upper perpendicular axis B2 Lower perpendicular axis