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(11) | EP 0 539 377 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
HIGH DENSITY STACKING FLEX CHAIR MIT HOHER DICHTE STAPELBARER UND KIPPBARER STUHL CHAISES SOUPLES EMPILABLES EN NOMBRE |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
BACKGROUND
Field of the Invention
[0001] The present invention relates to chair design, more specifically, to a design for a high density stacking chair with a tilting back.
Discussion of the Prior Art
[0002] The use of low-cost, stacking chairs is well-known in the art. However, such chairs are designed not with comfort or ergonomics in mind, but rather to provide a large quantity of temporary seats for occasional use which can ordinarily be stored and take up minimal storage space. Such chairs may have some limited flexibility in the seat back portion, but provide no ergonomic benefits.
[0003] Considerable attention has been focused in recent years on better ergonomic designs, resulting in home and office chairs which demonstrate a wide variety of designs which include the ability to recline and provide lumbar support. See, for example, U.S. Patent No. 4,732,424 (EP-A-0 173 372). Such ergonomic designs do not, however, provide low cost seating. Thus, it would be desirable to combine the benefits of ergonomic design into a low cost, stackable chair.
SUMMARY OF THE INVENTION
[0004] The chair of the invention is defined by the features of claim 1, further embodiments are defined by the dependent claims.
[0005] A chair with a tiltable back portion is presented, wherein a single frame is provided, having a seat portion attached thereto, and a back portion pivotally attached thereto. In use ergometric adjustment of the chair is accomplished by tilting of the back portion and flexure of the frame, and flexure of the frame urges the back portion into a normal upright position for stacking and uniform appearance. The back portion may be curved and hollow, and engages the frame at upper and lower curved sections of the frame, which sections preferably have radii of curvatures less than that of the back portion and which sections are positioned at a downward angle such that the effective horizontal radii of the sections in the upright position is shorter than the actual radii, causing the back portion to rest against the curved sections and limit forward tilting of the chair back. Therefore when the back portion is tilted, the radial movement disengages the back portion from the curved sections due to the preferred difference in radii, until the angle of tilt is such that the effective radii are again equal and the back portion again rests against the curved sections of the frame and limits tilting backward.
[0006] A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description of the invention and accompanying drawings which set forth an illustrative embodiment in which the principles of the invention are utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figs. 3-5 are views taken across section 3-3 of Fig. 1 and showing the chair extending through its range of backward tilt.
[0010] Fig. 6 is a view taken across Section 6-6 of Fig. 4 and represents a plan view of the chair according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Referring now to Fig. 1, a first embodiment of a chair according to the present invention is shown. There are three major portions of the chair: a frame 10, a seat portion 20, and a back portion 30. The back portion is curved to adapt to a user's back and is composed of a front section 32 and a rear section 34, each of which has a lip 33, 35 or other spacer which creates a hollow interior space between sections when they are attached.
[0013] The frame 10 is ideally a continuous structure, constructed of solid rod or tubular steel or the like. Alternatively, it may consist of welded or otherwise connected sections. The frame 10 has an upper curved section 12 which is enclosed within the back portion 30 with cylindrical bearing sections 12a at either end and which extends through the middle of the back portion and is angled downward. The frame 10 then extends from each end of the upper curved section 12 outward from the hollow interior, the back portion 30 being pivotally attached thereto at the cylindrical sections 12a. This pivotal attachment can be accomplished by bearings attached to the front section 32, but is preferably accomplished by providing bearing surfaces 12b formed on plastic molded front and back sections 32 and 34.
[0014] The frame 10 has a pair of rear support legs 16 which extend downward and rearward to a floor surface and forwardly along the floor. A pair of front support legs 18 then extend upward and rearward to the front of the seat portion 20, then rearward supporting the seat portion 20, then slightly inward, then upward into the back portion 30, then inward, where the back portion is again pivotally attached in a manner similar to the pivot connection 12a and 12b. The frame 10 continues to a lower curved section 14 which is enclosed within the back portion and which extends through the back portion having a downward angle. The distance d1 between the opposing legs of the frame 10 as it sits on the floor is lesser than the width d2 of the seat portion 20, so as to facilitate stacking a plurality of such chairs.
[0015] In the preferred embodiment of Fig. 2, the seat supporting portion of the frame 10 is positioned inwardly from the edges of the seat portion 20 and connected by welded struts 22 to improve the support of the seat portion and lateral stability of the frame. In Fig. 7, such lateral stability can be provided by a pair of stabilizers 50, 52. Additionally, clips 24 are attached to the bottom surface of the seat portion 20 in order to easily attach/detach the seat portion to frame 10.
[0016] The back portion 30 is a one-piece molded unit, having openings or clips 40 which are adapted to pivotally engage the rear support legs 16 at cylindrical sections 12a. Openings or clips 42 are likewise adapted to pivotally engage the front support legs 18. In this way, the back portion 30 may be easily and securely fitted to frame 10. The curved sections 12 and 14 remain in a fixed position relative to frame 10 to provide pivotal limits, as will be next described.
[0017] Referring now to Figs. 3-5, the tilting action of the back portion 30 is illustrated. When the chair is in its upright position, as in Fig. 3, the rear support legs 16 of the frame 10 are inclined at a forward angle so as to provide a natural spring-type action which holds the back portion 30 forward.
[0018] The curved sections 12 and 14 of frame 10 are parallel, each extending outward and downward from the back of the front section 32 at a twenty-two and one-half degree angle. The radii of curvature for both curved sections 12 and 14 is lesser than that of the back portion. But, the radius of curvature of section 12 projected at a plane inclined to the plane of section 12 by an angle of 22.5 degrees equals the radius of curvature of the back portion 30, such that the inside of the front section 32 is in contact with the curved sections 12 and 14 at points 36 and 37 as a result of the effective radius of the curved sections 12 and 14 being equal to the radius of the back portion 30.
[0019] As a user leans back on the chair, the front section 32 pivots about point 50 on the upper curved section, causing the upper half of the front section to rotate backwards, and the lower half to rotate forward about point 50. Note also that the seat portion 20 will be lifted by the forward rotation of the lower curved section 14. Since the back portion 30 has a greater radius of curvature than both curved sections, the back portion lifts away from the curved sections as it is tilted, reengaging the curved sections at points 38 and 39, located further down the back portion, where the effective radii of the back portion is again equal to the radii of the curved sections after the back portion has tilted 45 degrees.
a seat (20) adapted to engage a user's seat;
a back (30) generally perpendicular to said seat and adapted to engage a user's back and having upper and lower regions; and
a frame (10) for holding and supporting said seat (20) and back portions (30), said frame comprising
a pair of support legs (16, 18) one at each side of the seat (20) with each support leg having a back leg portion (16) pivotally attached by first connection means (12a, 42) to the upper region of said back (30), a front leg portion (18) extending upwardly to the front of said seat (20) to support said seat (20), a bottom leg portion for extending along a floor surface between said back leg portion (16) and said front leg portion (18),
second connection means (12a, 40) pivotally connecting the rear of the seat (12) to the lower region of said back (30) at a location below the attachment (12a, 42) of the back leg portions (16) to the upper region of said back (30), whereby the flexibility of the frame (10) permitting the back (30) to resiliently tilt toward a reclining position while the user's weight is suspended from the second connection means (12a, 40).
wherein said back (30) has a curved surface.
characterized further by limited relative pivotal movement of the back (30) in both directions with respect to the support legs between an upright position determined by the stop means and a reclined position with the back (30) held in the upright position by the resiliency of the support legs.
characterized further by a curved rod (12) connected between the back leg portions (16) for pivotal movement with respect to the back (30) as the back (30) pivots with respect to the legs with the curved rod (12) having a radius of curvature less than the radius of curvature of the back (30) whereby the curved rod (12) limits pivotal movement of the back (30) in both directions.
characterized further by a first curvilinear section (12) attached to each of said back leg portions (16) at the upper region of said back (30) and extending across the upper region at a downward angle, wherein said first curvilinear section (12) has a radius of curvature less than that of said back (30), and wherein said back (30) is pivotally attached to said back leg portions (16) and first curvilinear section, and a second curvilinear section (14) attached to said connecting means at the lower region of said back (30) and extending across the lower region at said downward angle, wherein said second curvilinear section (14) has a radius of curvature less than that of said back, and said downward angle is equal to about twenty-two and one-half degrees.
characterized further by said bottom leg portions being spaced apart by more than the width of the seat in order to facilitate stacking.
further characterized by the second connection means (12a, 40) being located above the bottom of the back (30).
further characterized by the first connection means (12a, 42) being located below the top of the back (30) and the second connection means (12a, 40) being located above the bottom of the back (30) and below the first connection means (12a, 42).
further characterized by the second connection means (12a, 40) being located above the seat (20).
further characterized by said front leg portions (18) extending rearwardly along the seat (20) to couple with said second connection means (12a, 40).
further characterized by said front leg portions (18) extending rearwardly along the seat to form said second connection means.
ein Sitz (20), der das Gesäß eines Benutzers aufnehmen kann,
eine zum Sitz im wesentlichen senkrechte Lehne (30), die mit dem Rücken eines Benutzers in Berührung kommen kann und obere und untere Bereiche aufweist,
ein Rahmen (10) zum Halten und Stützen der Sitz- (20) und Lehnenabschnitte (30), wobei der Rahmen folgende Merkmale umfaßt:
ein Paar Tragbeine (16, 18) an jeder Seite des Sitzes (20), wobei jedes Tragbein einen hinteren Beinabschnitt (16), der schwenkbar mittels einer ersten Verbindungseinrichtung (12a, 42) mit dem oberen Bereich der Lehne (30) verbunden ist, einen vorderen Beinabschnitt (18), der nach oben zur Vorderseite des Sitzes (20) verläuft, um den Sitz (20) zu stützen, und einen unteren Beinabschnitt aufweist, der entlang des Fußbodens zwischen dem hinteren Beinabschnitt (16) und dem vorderen Beinabschnitt (18) verläuft,
eine zweite Verbindungseinrichtung (12a, 40), die die Rückseite des Sitzes (12) schwenkbar mit dem unteren Abschnitt der Lehne (30) an einer Stelle verbindet, die sich unterhalb der Verbindungsstelle (12a, 42) befindet, an der die hinteren Beinabschnitte (16) mit dem oberen Bereich der Lehne (30) verbunden sind, wodurch die Flexibilität des Rahmens (10) ermöglicht, daß die Lehne (30) elastisch in eine verstellbare Position gekippt werden kann, während das Gewicht des Benutzers an der zweiten Verbindungseinrichtung (12a, 40) aufgehängt ist.
dadurch gekennzeichnet, daß die Lehne (30) eine gekrümmte Fläche aufweist.
ferner gekennzeichnet durch eine begrenzte relative Kippbewegung der Lehne (30) in beide Richtungen mit Bezug auf die Tragbeine, und zwar zwischen einer aufwärts gerichteten Stellung, die durch eine Anschlageinrichtung festgelegt ist, und einer verstellten Stellung, wobei die Lehne (30) durch die Elastizität der Tragbeine in der aufrechten Stellung gehalten wird.
ferner gekennzeichnet durch einen gekrümmten Stab (12), der zwischen den hinteren Beinabschnitten (16) befestigt ist, für eine Kippbewegung der Lehne (30), wenn die Lehne (30) mit Bezug auf die Beine gekippt wird, wobei der gekrümmte Stab (12) einen Krümmungsradius besitzt, der kleiner ist als der Krümmungsradius der Lehne (30), wodurch der gekrümmte Stab (12) die Kippbewegung der Lehne (30) in beide Richtungen begrenzt.
weiter gekennzeichnet durch einen ersten krummlinigen Abschnitt (12), der mit jedem hinteren Beinabschnitt (16) an dem oberen Bereich der Lehne (30) verbunden ist und sich über den oberen Abschnitt unter einem abwärts geneigten Winkel erstreckt, wobei der erste krummlinige Abschnitt (20) einen Krümmungsradius hat, der kleiner ist als der Krümmungsradius der Lehne (30), und wobei die Lehne (30) schwenkbar mit den hinteren Beinabschnitten (16) und dem ersten krummlinigen Abschnitt verbunden ist, und
durch einen zweiten krummlinigen Abschnitt (14), der mit der Verbindungseinrichtung am unteren Bereich der Lehne (30) verbunden ist und sich über den unteren Bereich unter dem abwärts geneigten Winkel erstreckt, wobei der zweite krummlinige Abschnitt (14) einen Krümmungsradius hat, der kleiner als der Krümmungsradius der Lehne ist und wobei der abwärts geneigte Winkel etwa 22,5° beträgt.
weiter dadurch gekennzeichnet, daß die unteren Beinabschnitte einen Abstand zueinander aufweisen, der größer ist als die Sitzbreite, um das Stapeln zu erleichtern.
weiter dadurch gekennzeichnet, daß die zweite Verbindungseinrichtung (12a, 40) oberhalb des unteren Bereichs der Lehne (30) angeordnet ist.
dadurch gekennzeichnet, daß die erste Verbindungseinrichtung (12a, 42) unterhalb des oberen Bereichs der Lehne (30) angeordnet ist und die zweite Verbindungseinrichtung (12a, 40) oberhalb des unteren Bereichs der Lehne (30) und unterhalb der ersten Verbindungseinrichtung (12a, 42) angeordnet ist.
dadurch gekennzeichnet, daß die zweite Verbindungseinrichtung (12a, 40) über dem Sitz (20) angeordnet ist.
dadurch gekennzeichnet, daß die vorderen Beinabschnitte (18) entlang des Sitzes (20) nach hinten verlaufen und mit der zweiten Verbindungseinrichtung (12a, 40) verbunden sind.
dadurch gekennzeichnet, daß die vorderen Beinabschnitte (18) entlang des Sitzes nach hinten verlaufen, um die zweiten Verbindungseinrichtungen zu bilden.
un siège (20) adapté à engager le fessier d'un utilisateur ;
un dossier (30) généralement perpendiculaire audit siège et adapté à engager le dos d'un utilisateur et comportant des régions supérieure et inférieure ; et
un châssis (10) pour maintenir et supporter lesdites parties formant siège (20) et dossier (30), ledit châssis comprenant
une paire de pieds de support (16, 18), un de chaque côté du siège (20) avec chaque pied de support comportant une partie de pied arrière (16) fixée de manière à pivoter par des premiers moyens de connexion (12a, 42) à la région supérieure dudit dossier (30), une partie de pied avant (18) s'étendant vers le haut jusqu'à l'avant dudit siège (20) pour supporter ledit siège (20), une partie de pied inférieure pour s'étendre le long d'une surface du sol entre ladite partie de pied arrière (16) et ladite partie de pied avant (18),
des deuxièmes moyens de connexion (12a, 40) reliant avec possibilité de pivotement l'arrière (12) du châssis à la région inférieure dudit dossier (30) à un emplacement en dessous de la fixation (12a, 42) des parties de pied arrière (16) à la région supérieure dudit dossier (30), de manière que la flexibilité du châssis (10) permette au dossier (30) de s'incliner élastiquement vers une position inclinée tandis que le poids de l'utilisateur est porté par les deuxièmes moyens de connexion (12a, 40).