Item of seating furniture, in particular an office chair

Abstract

An item of seating furniture, in particular an office chair, has a seat carrier for a horizontal seat member, and a backrest carrier for a vertical backrest. The backrest carrier is constructed in a substantially U-shaped manner with two vertically orientated U-shaped members and with a horizontal upper U-shaped member. Wherein, along at least one rotation axis which extends below the seat member, a first rotary joint and a second rotary joint are provided for the lateral tilting movability of the backrest with respect to the seat carrier. The first and second rotary joints are arranged spaced apart from each other along the rotation axis.

Claims

1. An item of seating furniture, comprising: a horizontal seat member; a seat carrier for supporting said horizontal seat member; a vertical backrest; a backrest carrier for supporting said vertical backrest, said backrest carrier constructed in a substantially U-shaped manner with two vertically orientated members and a horizontal upper member, said vertically oriented members having seat-side free ends; horizontally aligned retention arms extending from said seat-side free ends and extending below said horizontal seat member and at least partially laterally engaging around said seat carrier, said backrest carrier and said horizontally aligned retention arms produced as a unitary part from a deformable material which is elastic so as to be bendable; and rotary joints including a first rotary joint and a second rotary joint disposed along at least one rotation axis extending below said horizontal seat member, said rotary joints allowing a lateral tilting movability of said vertical backrest with respect to said seat carrier, said first and second rotary joints are disposed spaced apart from each other along the rotation axis.

2. The item of seating furniture according to claim 1, further comprising a rocker arm disposed between said vertically oriented members, said rocker arm being directed transversely relative to the rotation axis.

3. The item of seating furniture according to claim 2, wherein said rocker arm is formed from two half-shells which are stacked vertically one over the other.

4. The item of seating furniture according to claim 3, wherein said half-shells of said rocker arm are screwed to each other.

5. The item of seating furniture according to claim 4, further comprising a positioned covering shell, a screwing of said half-shells is concealed by means of said positioned covering shell.

6. The item of seating furniture according to claim 2, wherein said rocker arm is secured to said seat carrier.

7. The item of seating furniture according to claim 1 wherein: said first rotary joint is a ball joint; said horizontally aligned retention arms have a joint-socket-shaped receiving member; and said seat carrier having a joint-head-shaped continuation which engages in said joint-socket-shaped receiving member of said horizontally aligned retention arms.

8. The item of seating furniture according to claim 2 wherein: said second rotary joint is a hinge joint; said rocker arm has a groove-shaped receiving member; and said horizontally aligned retention arms each have a roller-shaped continuation which is surrounded in each case by said groove-shaped receiving member of said rocker arm.

9. The item of seating furniture according to claim 2, further comprising an actuatable blocker for impeding or blocking the lateral tilting movability of said backrest carrier.

10. The item of seating furniture according to claim 9, wherein said actuatable blocker is constructed to block a movability of said second rotary joint.

11. The item of seating furniture according to claim 9, further comprising a resiliently loaded blocking block; and wherein said actuatable blocker is disposed in said rocker arm and has a blocking pin which is coupled to said second rotary joint in a pivotably secure manner and which can be moved into in a forming-locking engagement with said resiliently loaded blocking block.

12. The item of seating furniture according to claim 1, wherein the item of seating furniture is an office chair.

13. The item of seating furniture according to claim 1, further comprising a rocker arm disposed between said horizontally aligned retention arms, said rocker arm being directed transversely relative to the rotation axis.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) Embodiments of the invention are explained in greater detail below with reference to the drawings. In the simplified and schematic drawings:

(2) FIG. 1 is a side view of an office chair as an item of seating furniture having a seat carrier for a seat member (seat face) and having a backrest carrier of a backrest which can be inclined in a lateral manner,

(3) FIG. 2 is a perspective view of the office chair in a second embodiment,

(4) FIG. 3 is an exploded view of the seat carrier and the backrest carrier,

(5) FIG. 4 is a rear view of the seat carrier and the backrest carrier of the office chair,

(6) FIG. 5 is a side view of the seat carrier and the backrest carrier,

(7) FIG. 6 is a cutout of a perspective exploded view of the seat carrier and the backrest carrier,

(8) FIG. 7 is a perspective view of the backrest carrier,

(9) FIG. 8 is a cutout of a perspective view of a retention arm of the backrest carrier,

(10) FIG. 9 is an exploded view of a rocker arm of the backrest carrier,

(11) FIG. 10 is a sectioned illustration of ball joints between the seat carrier and the retention arms,

(12) FIG. 11 is a sectioned illustration of hinge joints between the retention arms and the rocker arm, and

(13) FIG. 12a, 12b is a sectioned illustration of a blocking means of the rocker arm.

DESCRIPTION OF THE INVENTION

(14) Components and extents which correspond to each other are always provided with the same reference numerals in all the Figures.

(15) The seating furniture 2 which is constructed as an office chair in FIG. 1 comprises a seat carrier 6 which is securely connected to a supporting base (cruciform base) 4 and which is coupled by means of a backrest carrier 8 to a backrest 10. There is preferably integrated in the seat carrier 6 a so-called synchronous mechanism which carries out a synchronous movement of a seat member (seat, seat face) 12 which is arranged on the seat carrier 6 with the backrest 10 if it is redirected from the illustrated vertical starting position (upright position) into a position which is inclined toward the rear.

(16) The seat carrier 6 and consequently the seat member 12 and the backrest 10 which is connected to the seat carrier 6 via the backrest carrier 8 are rotatably connected or coupled to the supporting base 4, which has, for example, three, four or five radially extending arms 14 which have chair rollers 16 which are pivotably secured at the end side. For example, only one arm 14 and one chair roller 16 are provided with a reference numeral in the Figures.

(17) FIG. 1 shows the seating furniture or the office chair 2 as a side view when looking toward a sagittal or xz plane S, wherein a corresponding Cartesian coordinate system has an xy plane which is parallel with the seat face of the seat member 12 or transverse plane T and a z axis which is parallel with the starting position of the backrest 10. In this instance, the x axis is orientated substantially along the longitudinal sides of the seat face and the y axis is orientated substantially along the broad sides of the seat face of the seat member 12.

(18) As the side view of FIG. 1 shows in a comparatively clear manner, the backrest carrier 8 has in a projection onto the sagittal plane S substantially an Ls shaped cross-sectional shape. A horizontal retention arm 18 of the backrest carrier 8 directed along the x axis extends in this instance below the seat member 12. In the embodiment of FIG. 1, the retention arm 18 is at least partially received inside the seat carrier 6.

(19) As illustrated in FIG. 1 with dot-dash lines, the retention arm 18 is in this instance constructed and configured by means of two rotary joints 20 and 22 which are spaced apart from each other along the x axis for a lateral tilting movement of the backrest 10, that is to say, an inclination or tilting directed laterally or sideways in a front or yz plane F. Along the connection line between the rotary joints 20 and 22, consequently, a rotation axis D for a lateral tilting movement of the backrest carrier 8 or the backrest 10 is constructed.

(20) In FIGS. 2 to 11, an or the office chair 2 is shown in structurally comparatively detailed illustrations. This embodiment is explained in greater detail below with reference to FIG. 2 to FIG. 11.

(21) FIG. 2 is a perspective illustration of the office chair 2. There are secured to the seat carrier 6 of the office chair 2 in this embodiment two arm rests 24 which rise up laterally in a vertical direction with respect to the seat member 12. The backrest 10 is not illustrated in FIG. 2 so that a better view of the backrest carrier 8 is enabled. The frame-like backrest carrier 8 is in this embodiment in a projection onto the front plane F substantially U-shaped. The backrest carrier 8 comprises in this instance two vertical U-shaped members (vertical members) 26 which are orientated in the starting position along the z axis and an upper horizontal U-shaped member (horizontal member) 28 which is directed along the Y axis. The members 26, 28 of the backrest carrier 8 form in this instance substantially a securing or carrier frame for the backrest 10 which can be or is fitted thereto.

(22) In FIG. 3, the office chair 2 is shown as a perspective exploded illustration or in a partially disassembled state. The seat carrier 6 has a shell-like housing 30 in which in the assembly state a synchronous mechanism 6a is received. As can be seen comparatively clearly in the perspective exploded illustration of FIG. 3, two horizontal retention arms 18 are formed at the free ends 26a of the vertical members 26, that is to say, at the lower or seat-side member ends.

(23) The retention arms 18 and members 26, 28 form in a one-piece, that is to say, integral or monolithic manner, the backrest carrier 8. The backrest carrier 8 has in this instance an abutment face 32 which is expanded with respect to the backrest 10. As a result of the expanded abutment face 32, the retention arms 18 and members 26, 28 have in cross-section a comparatively small thickness. The backrest carrier 8 is preferably produced from a resilient spring steel or plastics material, wherein the comparatively small material thickness of the retention arms 18 and members 26, 28 enables a high resilient deformability, which is beneficial for the lateral tilting movability of the backrest 10.

(24) As a result of the U-shaped path of the members 26, 28 along the abutment face 32 which is defined by the member width in the direction toward the seat member 12, the backrest 10 which is arranged thereon (not illustrated in greater detail) moves as a result of a sideward or laterally directed force on a circular path or along a circular arc parallel with the front plane F. The radius of this circular-arc-like backrest movement, which can be adapted to the curve contour of the seat member edge which faces the backrest 10 is adjusted, sized or configured in such a manner that the laterally inclined backrest 10 neither enters the seat member 12 in a perceptible manner, nor moves away from it in a perceptible manner.

(25) As can be seen comparatively clearly in FIGS. 4 and 5, the vertical members 26 are in this embodiment slightly inclined in a projection onto the sagittal plane S (FIG. 5), wherein the vertical members 26 in the projection onto the front plane F (FIG. 4) are orientated in particular in the region of the free ends 26a so as to taper toward each other in a substantially V-shaped manner. The free ends 26a extend in this instance in a manner slightly inclined toward the rear, that is to say, away from the seat member 12, so that the backrest carrier 8 is formed in a substantially S-shaped manner in the projection onto the sagittal plane S.

(26) The upper S-shaped curve is in this instance formed by the horizontal member 24 and the vertical members 26, wherein the lower S-shaped curve is formed by the retention arms 18 and the central region which connects the curves is formed by the free ends 26a. The resilience of the backrest carrier 8, including with respect to a forward and backward tilting movement, is thereby improved.

(27) With reference to FIG. 6, the lateral tilting movability of the backrest 10 or the backrest carrier 8 is explained in greater detail. FIG. 6 is a cutout of the synchronous mechanism 6a of the seat carrier 6 and the lower portion of the backrest carrier 8 in a non-assembled state.

(28) In the region of the lower S-shaped curve, that is to say, in the transition region of the free ends 26a to the retention arms 18, in the assembled state a transverse strut 34 is fitted. The transverse strut 34 can be secured in each case at a securing location 36 of the vertical members 26 or the free ends 26a thereof so that the transverse strut 34 in the assembly state extends substantially at the height of the seat member 12 horizontally between the vertical members 26 (FIG. 4, FIG. 7).

(29) The transverse strut 34 is preferably produced from a resilient glass fiber material and has with regard to the sagittal plane S, for example, a substantially U-shaped cross-sectional shape. Additionally or alternatively, the securing of the transverse strut 34 at the securing locations 36 is carried out by means of flexible or articulated connection elements. As a result of the transverse strut 34, the stability of the frame-like backrest carrier 8 is improved, wherein at the same time the resilient deformability or torsion of the vertical members 26 is not limited in an unfavorable manner during a lateral tilting or inclination of the backrest 10.

(30) The retention arms 18 illustrated individually in FIG. 8 of the backrest carrier 8 illustrated individually in FIG. 7 have at the free-end side, that is to say, at the seat or seat carrier side, a formed-on receiving member 38. The receiving member 38 is part of the rotary joint 20 which is constructed in this embodiment as a ball joint. The joint-socket-like or ball-socket-like receiving member 38 receives in the assembled state a spherical, substantially joint-head-like continuation 40 as a counter-piece. The continuation 40 isas can be seen in particular in FIG. 6fitted so as to protrude laterally to the seat carrier 6 or the synchronous mechanism 6a thereof.

(31) The continuation 40 is formed by a spherical (joint) head 42 and a substantially pin-like (joint) neck 44 which is secured thereto.

(32) The continuation 40 and the receiving member 38 form in the assembly state the rotary joint 20, wherein, as a result of the rotary joint 20, a securing of the respective retention arm 18 to the seat carrier 6 is additionally carried out. To this end, the retention arm 18 surrounds the seat carrier 6 in the assembly state at least partially at the longitudinal sides of the seat carrier 6 (FIG. 5) so that the spherical head 42 of the continuation 40 engages in the receiving member 38 in a positive-locking manner.

(33) FIG. 10 shows a cross-section of a front plane F which extends through the rotary joint 20. As can be seen comparatively clearly in the sectioned illustration of FIG. 10, the spherical head 42 of the continuation 40 is substantially completely in the receiving member 38 of the retention arm 18. In particular, the receiving member 38 surrounds the head 42 over the equator thereof so that the ball joint 20 is constructed in particular in the manner of a socket joint. The movability of the rotary joint 20 is thereby limited, which has an advantageous effect on the stability of the securing or the retention of the retention arm 18 on the seat carrier 6.

(34) As illustrated in FIG. 10, the laterally diametrically opposed continuations 40 on the seat carrier 6 are connected to each other. In particular, the necks 44 of the heads 42 are constructed as a common pin or axial rod 46 which extends through the seat carrier 6 or the synchronous mechanism 6a. The stability of the continuations 40 is thereby improved.

(35) Between the receiving member 38 and the free end 26a, a roller-like continuation or (joint) head 48 is formed on the retention arm 18. The head 48 is consequently arranged with spacing along the x axis or in the longitudinal direction of the arm with respect to the receiving member 38and consequently with respect to the rotary joint 20.

(36) In the assembly state (FIG. 11), the roller-like head 48 is surrounded by a channel-like (joint) receiving member 50 of a rocker arm 52 which is arranged between the retention arms 18. The longitudinal roller direction of the head 48 is in this instance orientated parallel along the longitudinal arm direction of the respective retention arm 18. The head 48 and the receiving member 50 form in this instance the rotary joint 22 which is in particular constructed as a hinge joint.

(37) Consequently, both a ball joint 20 and a hinge joint 22 are arranged along each retention arm 18 so that in the longitudinal arm direction of the retention arms 18 a rotation axis D for the lateral tilting movability of the backrest 10 is formed. That is to say, the office chair 2 has in this embodiment two rotation axes D which extend below the seat member 12 and which are (horizontally) spaced apart from each other.

(38) The rocker arm 52 which is illustrated individually in FIG. 9 comprises a lower half-shell or rocker arm portion 52a and an upper half-shell or rocker arm portion 52b which can be placed vertically thereon and a cover shell 52c which can be placed at least on the upper rocker arm portion 52b and which engages at least partially around it. In the assembly state, the rocker arm 52 is arranged in the manner of a transverse strut between the retention arms 18. The rocker arm 52 is in this instance secured in a flexible or articulated manner by means of the receiving members 50 in a positive-locking manner on the heads 48 of the retention arms 18.

(39) In the assembly state, the rocker arm portions 52a and 52b are stacked vertically one above the other in a sandwich-like manner, that is to say, along the z axis. The rocker arm portions 52a and 52b have at the opposing narrow sides facing the retention arms 18 a substantially quarter-circle-like half-groove 50a or 50b, respectively. In the stacked or assembled state, the half-grooves 50a of the rocker arm portion 52a and the half-grooves 50b of the rocker arm portion 52b form the channel-like receiving member 50 for the hinge or rotary joint 22.

(40) For assembly, the rocker arm portion 52a is guided from below on the retention arms 18 so that the heads 48 are each at least partially in the half-grooves 50a. Subsequently, the rocker arm portion 52b is positioned from above so that the upper half-grooves 50b are placed on the heads 48. As can be clearly seen from the sectioned illustration shown in FIG. 11 through the hinge joints 22, the receiving members 50 formed by the half-grooves 50a and 50b surround the respective heads 48 beyond the respective (roller) equator so that a secure and positive-locking (bearing-like) securing of the rocker arm 52 on the retention arms 18 is provided.

(41) For assembly of the rocker arm 52, the rocker arm portions 52a and 52b are screwed vertically to each other. To this end, two securing screws 54 are guided from below through recesses 56 of the rocker arm portion 52a and screwed into corresponding threaded holes of the rocker arm portion 52b. Subsequently, the rocker arm 52 is secured by means of two securing screws 58 to the seat carrier 6. The securing screws 58 are to this end guided along the y axis through recesses 60 of the rocker arm portion 52b and screwed into corresponding threaded holes of the seat carrier 6 and/or the synchronous mechanism 6a. For optically attractive covering of the screw heads of the securing screws 58, the covering shell 52c is finally placed on the rocker arm portion 52b.

(42) As a result of the positive-locking retention using the hinge joint 22, during the screwing fixing operation of the rocker arm 52 on the seat carrier 12 a securing of the bearing carrier 8 on the seat carrier 12 is consequently also carried out. That is to say, the bearing carrier 8 is, on the one hand, secured by means of the ball joints 20 and, on the other hand, by means of the rocker arm 52 to the seat member 12 of the office chair 2. A reliable and operationally secure securing or retention of the backrest 10 on the seat carrier 12 is thus produced. At the same time, the resilient deformability of the backrest carrier 8 is not influenced in a disadvantageous manner so that a lateral tilting movability is thereby not limited.

(43) Preferably, an arresting or blocking means 62 is provided on the backrest carrier 8 and/or on the seat carrier 6, which in the event of an actuation by the user blocks, prevents or at least limits the lateral tilting movability of the backrest 10. An embodiment of the blocking means 62 is explained in greater detail below with reference to FIG. 12a and FIG. 12b.

(44) FIGS. 12a and 12b show as sectioned illustrations an alternative embodiment of the rocker arm 52 with a blocking means 62 which is integrated therein for blocking the movability of at least one of the hinge joints 22 of the retention arms 18 in a blocked state (FIG. 12a) and in an unblocked state (FIG. 12b). The rocker arm 52 is in this embodiment in particular constructed as a housing for the mechanism of the blocking means 62.

(45) The blocking means 62 is consequently in particular configured and constructed to block or impede the second rotary joint 22, that is to say, the rotary joint which is arranged on the retention arm 18 closer to the backrest 10. Consequently, the movability along the rotation axis D or along the retention arm 18 between the seat-carrier-side rotary or ball joint 20 and the backrest carrier 8 is blocked. The lateral tilting movability of the backrest carrier 8 is thereby blocked or at least limited.

(46) The blocking means 62 has for actuation a pulling cable 64 which is guided by means of a resilient element 66 on a lever element 68. This protrudes at least partially from the rocker arm 52 or from the covering shell 52c. The pulling cable 64 can be actuated by a user, for example, by means of a lever on the seat carrier 6. The lever element 68 which is pivotably supported at a central rotation location 70 is coupled at a free end opposite the resilient element 66 with a blocking block 72 which is guided in a linear manner along the y axis.

(47) The blocking block 72 is coupled to a resilient element 74 which is constructed in particular as a tension spring and which is relaxed in the unblocked state. The blocking block 72 has a receiving member 76 for a blocking pin 78.

(48) The blocking pin 78as can be seen in FIGS. 12a and 12bis coupled to the (joint) head 48 of the hinge joint 22 in a pivotably secure manner. This means that the blocking pin 78 is pivoted at the head side when the hinge joint 22 is rotated. The opposing blocking-block-side free end of the blocking pin 78 thereby pivots in the unblocked state along the z axis inside the rocker arm 52. The half-grooves 50a and 50b each have in this instance a recess which is not described in greater detail so that a through-opening is formed in the associated receiving member 50 for the blocking pin 78.

(49) In the blocked state, the blocking-block-side free end of the blocking pin 78 engages in the manner of a locking detent and in a positive-locking manner in the receiving member 76 of the blocking block 72. In the blocked state, the tension spring 74 is tensioned. When the pulling cable 64 is actuated again, the blockage is released so that the tension spring 74 can relax and moves the blocking block 78 out of the blocking position. The free end of the blocking pin 78 thus slides out of the receiving member 76 so that the blocking pin 78 can be moved at the free end side.

(50) With appropriate dimensions, the resilient element 66 has in this instance a greater resilient strength, that is to say, a greater resilient stiffness or spring constant, than the resilient element 74. A reliable and operationally safe actuation of the blocking means 62 is thereby achieved. In particular, the resilient element 74 is prevented from being relaxed in an undesirable manner and consequently the blocking is prevented from being released. In place of the resilient element 66, it is, for example, also possible for the pulling cable 64 to have an appropriately sized tensile resilience.

(51) The invention is not limited to the embodiments described above. Instead, other variants of the invention can also be derived therefrom by the person skilled in the art without departing from the subject-matter of the invention. In particular all individual features which are described in connection with the embodiments can also be combined with each other in another manner without departing from the subject-matter of the invention.

(52) It is, for example, conceivable that, in order to improve the restoring force with a deployed backrest carrier 8, the resilient deformability of the backrest carrier 8 is supported by means of additional resilient elements.

(53) It is also, for example, conceivable for the blocking means 62 to be constructed and configured to block or arrest both rotary joints 22 on the retention arms 18. Preferably, the rotary joints 22 are in this instance blocked or impeded in a substantially synchronous manner in the event of an actuation.

LIST OF REFERENCE NUMERALS

(54) 2 Seating furniture/office chair 4 Supporting base/cruciform base 6 Seat carrier 6a Synchronous mechanism 8 Backrest carrier 10 Backrest 12 Seat member 14 Arm 16 Chair roller 18 Retention arm 20 Rotary joint/ball joint 22 Rotary joint/hinge joint 24 Armrest 26 U-shaped member/vertical member 26a Free end 28 U-shaped member/horizontal member 30 Housing 32 Abutment face 34 Transverse strut 36 Securing location 38 Receiving member 40 Continuation 42 Head 44 Neck 46 Pin/axial rod 48 Continuation/head 50 Receiving member 50a, 50b Half-groove 52 Rocker arm 52a, 52b Rocker arm portion 52c Covering shell 54 Securing screw 56 Recess 58 Securing screw 60 Recess 62 Blocking means 64 Pulling cable 66 Resilient element 68 Lever element 70 Rotary location 72 Blocking block 74 Resilient element/tension spring 76 Receiving member 67 Blocking pin x, y, z Axis S Sagittal plane F Front plane T Transverse plane D Rotation axis