Arrangement for bearing for a seat

Abstract

The mounting for a seat (3) is suitable, in particular, for a chair, but also for stools, individual seats (3) on a bench or fixed seats (3). The mounting makes it possible for the seat (3) to swing resiliently in all directions or in defined directions, in accordance with changes in the user's posture. The seat (3) rests on an underframe on which a spring element (4) is arranged, said spring element being restrained in a casing (5,6) and being capable of moving elastically, in a horizontal plane, therein. The casing (5,6) is connected to the seat (3) or forms a part thereof. The spring element (4) is preferably arranged at the top of an axially extensible push rod of a pneumatic spring (2). The outer sleeve (43) of the spring element (4) is a rubber body, while the axial through-passage (45) of the spring element (4) has a preferably metallic core (44) around it. The specific advantages of the mounting result in improved seating comfort.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a mounting for a seat, in particular a chair, but is also suitable for stools, individual seats on a bench or fixed seats in vehicles or, for example, in stadiums or parks. The invention specifically concerns a seat mounting which makes it possible for the seat to swing resiliently in all directions or in defined directions. Such seats follow the user's posture and, beyond the resilient mounting of the seat cushion, give the seat user a freer feeling of swinging action.

PRIOR ART

[0002] Mountings for seats are known in a wide range of designs. For work chairs, in particular, the capacity for height adjustment and the resilient mounting of the backrest are standard nowadays (see, for example, WO 98/16140). Many chairs are equipped with a synchronizing mechanism, as a result of which a movement of the backrest is followed by a simultaneous, synchronous movement of the seat surface. The capacity for height adjustment is brought about mostly by a pneumatic spring, while, for the synchronizing mechanisms, use is made of helical springs, pneumatic springs, torsion rods or combinations thereof (e.g. U.S. Pat. No. 5,417,473; EP 0 839 478 A1; WO 00/22961). WO 90/14031 discloses a mechanism in which the seat carrier is seated on a ball-and-socket joint, with the result that the seat can be rotated and inclined. The set rotary position and inclination can be arrested by means of a catch. In order to have resilient seat movement in the forward direction, use is also made of rubber bodies which are compressed between a fixed framework part and the moveable seat carrier as the load to which the front seat edge is subjected increases (see, for example, U.S. Pat. No. 3,863,982; U.S. Pat. No. 4,890,886).

[0003] The chair mechanisms which are relevant to the present invention make it possible for the seat to swing resiliently in all directions. Such chairs, stools and the like tend to move in the direction of the inclination or shift in the center of gravity of the user's body and extend the freedom of movement beyond the resilient mounting of the seat cushion, with the result that the seat user feels the swinging action. For this purpose, it has been practised for the central column of the seat to be divided horizontally and for a radially encircling rubber ring to be introduced (see CH 685 848; DE 43 01 734 A1) or for a planar rubber cushion to be arranged between the divided central column (see CH 678 388; U.S. Pat. No. 5,024,485). Either these designs barely provide the desired swinging effect or else the user has a certain feeling of instability and, in the case of deflection, immediately feels that it is harder to sense where the desired movement is going to stop.

[0004] FR 2 514 303 discloses, from the field of mechanical engineering, in particular of engine mounting, a vibration-absorbing arrangement in order to reduce the vibrations to which the framework is subjected. For this purpose, a damping element with a more or less insulating elastomer layer introduced therein is arranged between the vibration source and the framework side. Apart from the fact that this damping element, from a totally different field of expertise, has a quite different task--from mounting a seat--such a damping element is not suitable for mounting a swinging seat.

OBJECT OF THE INVENTION

[0005] In view of the mountings for a seat with swinging freedom of movement not being fully effective up until now, the object of this invention is to propose such a mounting which is more effective and has an improved service life. It is also the aim here for it to be possible for the mounting to be efficiently mass-produced and instooled in different seats.

SUMMARY OF THE INVENTION

[0006] The mounting for a seat which rests on an underframe has a spring element arranged on the underframe. The spring element is positioned in a casing and allows the casing to move elastically in the horizontal plane. The casing is connected to the seat or forms a part thereof.

[0007] The following features constitute advantageous embodiments of the invention: the spring element is arranged at the top of an axial column of the underframe, preferably on an extensible, axially acting spring. The spring element is intended, in particular, for being arranged at the top of an axially extensible push rod of a pneumatic spring. The spring element has an elastic outer sleeve, e.g. a rubber body. The casing has a bottom, cup-like part in which the spring element is seated. The spring element and the casing have an axial through-passage. Alternatively, the casing, in which the spring element is seated, is a cup-like part which encases the spring element from above.

[0008] The spring element comprises an inner, preferably metallic core and the elastic outer sleeve, which is arranged thereon. The core has an opening, preferably an axial through-passage, for accommodating the column. The radial, outer circumference of the outer sleeve of the spring element is preferably cylindrical or tapers conically in the upward direction or is essentially of cylindrical shape with a top and bottom reduction in diameter. The core is fixed to the outer sleeve.

[0009] In a variant of the mounting, the spring element is restrained at the top by a top molding, which is connected to the casing arranged at the bottom, the seat being fastened on the top molding. In an alternative variant, the casing, which is positioned on the spring element from above, is fixed to the outer sleeve, it being possible for the casing to have a flange for connection to the seat.

[0010] The axial through-passage preferably narrows conically. Provided in the top molding or in the casing, which is positioned on the spring element from above, coaxially with the pneumatic-spring-forming central column, is a through-opening for the purpose of actuating the triggering push rod of the pneumatic spring. In order to limit the moveability of the seat, the through-opening in the top molding or the casing, which is positioned on the spring element from above, has a defined geometry, e.g. a slot. The internal core of the spring element then has an extension which projects into the through-opening and is guided therein.

[0011] The specific advantages of the mounting according to the invention are the result of the above set object being achieved, i.e. of the improvements for the user in terms of functioning and costs and of the design-related and cost-related effects for the manufacturer.

BRIEF DESCRIPTION OF THE ATTACHED DRAWINGS

[0012] In the drawings:

[0013] FIG. 1: shows a front view of a conventional chair;

[0014] FIG. 2A: shows the view according to FIG. 1 with the moveability of the seat illustrated schematically;

[0015] FIG. 2B: shows the plan view of the chair according to FIG. 2A as a motion diagram;

[0016] FIG. 3: shows an exploded view of a first embodiment of the seat mounting according to the invention with a first variant of the spring element, in the chair according to FIG. 1;

[0017] FIG. 4A: shows a partial section of the first embodiment of the seat mounting with the first variant of the spring element according to FIG. 3, in the assembled state, in a rest position;

[0018] FIG. 4B: shows the arrangement according to FIG. 4A inclined laterally to the maximum extent;

[0019] FIG. 5A: shows a partial section of the first embodiment of the seat mounting according to FIG. 4A with a second variant of a spring element with inclination limiting, in a rest position;

[0020] FIG. 5B: shows the arrangement according to FIG. 5A inclined laterally to the maximum extent;

[0021] FIG. 6A: shows, in vertical section, the first variant of the spring element from the seat mounting according to FIGS. 4A and 4B;

[0022] FIG. 6B: shows, in vertical section, the second variant of the spring element from the seat mounting according to FIGS. 5A and 5B;

[0023] FIG. 7A: shows a side view of a further conventional chair;

[0024] FIG. 7B: shows a front view of the chair according to FIG. 7A;

[0025] FIG. 8: shows an exploded view of a second embodiment of the seat mounting according to the invention with the first variant of the spring element, in the chair according to FIG. 7A;

[0026] FIG. 9A: shows a partial section of the arrangement according to FIG. 8 in the assembled state, in a rest position;

[0027] FIG. 9B: shows a partial section of the second embodiment of the seat mounting according to the invention with the second variant of the spring element in the arrangement according to FIG. 9A, with inclination limiting, in a rest position;

[0028] FIG. 10: shows, as a basic illustration in vertical section, a third embodiment of the seat mounting according to the invention with a third variant of a spring element;

[0029] FIG. 11A: shows, as a basic illustration in vertical section, a fourth embodiment of the seat mounting according to the invention with a fourth variant of a spring element; and

[0030] FIG. 11B: shows a partial section of the arrangement according to FIG. 11A in the assembled state, in a rest position.

EXEMPLARY EMBODIMENTS

[0031] A number of exemplary embodiments of the seat mounting according to the invention are described in detail hereinbelow with reference to the attached drawings.

[0032] FIG. 1

[0033] The chair comprises an underframe 1, in this case a conventional star-shaped base, from the center of which a central column 2 extends vertically. The central column 2 may be an unalterable support or may contain an axially acting spring, e.g. a helical spring, a pneumatic spring or a combination thereof. The central column 2 has positioned on it the seat 3--in this case in the form of a seat shell--in which the user sits. It would also be possible for the seat to be designed as a, for example, angled structure or as a stool top.

[0034] FIGS. 2A and 2B

[0035] These figures illustrate the purpose of the invention schematically, namely to provide a mounting for a seat, including a chair, of which the seat allows a swinging movement in the horizontal plane, from a rest position 0, in all directions R1 to RX, the maximum movement from the rest position 0 being defined by the inclination angle .alpha.. For certain applications, the design can establish the possible directions R1 to RX--e.g. only laterally or from the front to the rear--as will be described at a later stage in the text.

[0036] FIG. 3

[0037] The underframe 1, the central column 2--typically a pneumatic spring--and a shell-like seat 3 are provided here. It is also possible to see a tubular pneumatic-spring covering 20 and a cylindrical push-rod extension 21. A triggering lever 22 fitted beneath the seat 3 is provided for actuating the pneumatic spring 2. A first embodiment of the mounting comprises a first variant of a spring element 4, a bottom, cup-like casing 5 and a top molding 6, in this case in the form of a cover plate which is intended for fastening on the top side of the base of the seat 3. Finally, a seat-cushion panel 30, which covers the top molding 6, is provided. The spring element 4 is roughly cylindrical with reduced-diameter sections 40,41 at the top and bottom, a central section 42, an outer sleeve 43, a core 44 and an axial through-passage 45, the latter running through the core 44.

[0038] FIG. 4A

[0039] In the case of the first embodiment of the mounting, in the instooled state, the first variant of the spring element 4 is accommodated, via the bottom section 41 and the central section 42, basically in a form-fitting manner by the cup part 50 of the casing 5. The top section 40 is enclosed basically in a form-fitting manner by the shaped collar 60 on the underside of the top molding 6, said collar having complementary contours. The spring element 4 is fitted, by way of its axial through-passage 45, on the pneumatic spring 2, which terminates conically at the top and has the push-rod extension 21 positioned axially on its triggering push rod 23, said extension projecting upward out of the axial through-passage 45, with the resuit that the triggering lever 22 is located thereon. Provided in the plate-like molding 6, around the emerging push-rod extension 21, is a cutout 61, which provides free space in all directions R1 to RX during swinging movement. Above the cup part 50, the casing 5 has an outwardly oriented horizontal flange 51, on which the annular flange 62 of the molding 6, said flange projecting beyond the shaped collar 60, rests and extends further outward by way of its outer border 63. The shaped collar 60 projects into the cup part 50. The flange 51 and annular flange 62, located thereon, are connected, e.g. screwed, to one another. The outer border 63 is connected, e.g. likewise screwed, to the shell-like seat 3. The seat shell 3 grips beneath the spring element 4, which is restrained between the casing 5 and the top molding 6.

[0040] FIG. 4B

[0041] In the case of the seat 3 being deflected from the rest position 0 to the maximum possible inclination angle .alpha., the elastic outer sleeve 43 of the spring element 4 is temporarily deformed in its restraint, as an increasing spring resistance develops. The deflection takes place by the action of force, namely by the user's weight shifting.

[0042] FIGS. 5A and 5B

[0043] In the case of the first embodiment of the mounting, in contrast to the previous pair of figures, FIGS. 4A and 4B, use is made of a second variant of a spring element 4. In this case, the core 44 extends axially upward as core continuation 440 and thus projects into the cutout 61. In the case of the seat 3 being deflected from the rest position 0, the core continuation 440 strikes against the border of the cutout 61 in the case of the maximum possible inclination angle .alpha.. The geometrical configuration of the cutout 61, in conjunction with the dimensions of the core continuation 440, allows the maximum possible inclination angle .alpha. to be defined or movement directions to be determined, e.g. only to the side or only from the front to the rear. This can be achieved by a correspondingly slot-like cutout 61. It would also be possible for other, crosswise or diagonal movement patterns to be formed in such a way.

[0044] FIGS. 6A and 6B

[0045] To complement the central column 2--mostly the pneumatic spring--which terminates conically at the top, the axial through-passage 45 of the spring element 4 is likewise conical. In order to optimize the movement characteristics, it has been found to be advantageous for the core 44 in the spring element 4 to be widened as a radial bead 441 in the region of the central section 42. It is thus possible, in the case of a relatively high level of deflection from the rest position 0, for material of the elastic outer sleeve 43 to be supported on the radial bead 441 and for a relatively high spring resistance to develop. In the case of the first variant of the spring element 4 (according to FIG. 6A), the core 44 terminates with the top section 40 of the outer sleeve 43.

[0046] The second variant of the spring element 4 (according to FIG. 6B) with a core continuation 440 is provided if the intention is to limit the swinging movement of the seat 3 to a maximum permissible inclination angle .alpha. or in accordance with a specific movement pattern. It would be possible for the elastic outer sleeve 43 to consist, for example, of a specifically suitable rubber mix, whereas the core 44 is preferably metallic.

[0047] FIGS. 7A to 9B

[0048] A second embodiment of the seat mounting according to the invention is illustrated here. Once again, an underframe 1, a central column 2--preferably a pneumatic spring--a seat 3, the spring element 4, the bottom casing 5' and a top molding 6' are provided for this chair. The special feature here is that, rather than being formed by a separate plate, the top molding 6' is formed by a correspondingly contoured aperture 60' in the seat carrier 6'. The aperture 60' encloses the top section 40 of the spring element 4 in the same way as the shaped collar 60. The cutout 61' is provided again in the seat carrier 6'. The casing 5' is inserted into the aperture 60' by way of its top border, is enclosed by the seat carrier 6' and is connected to the latter, the spring element 4 being more or less encapsulated in the process. The cutout 61' provides the freedom of movement as deflection from the rest position 0.

[0049] If use is made of the first variant of the spring element 4 (according to FIG. 6A), as is the case with the arrangement in FIG. 9A, the moveability of the seat 3 resting on the central column 2 is more or less unlimited. If use is made of the second variant of the spring element 4 (according to FIG. 6B) with the core continuation 440, as the arrangement in FIG. 9B shows, it is possible to limit the movement as described above (see FIGS. 5A and 5B).

[0050] FIG. 10

[0051] In the case of this third embodiment of the seat mounting, use is made of a third variant of a spring element 4, which is likewise intended for fitting onto a central column 2. The sheath-like core 44 has an axial through-passage 45 for accommodating the top end of the central column 2, preferably a pneumatic spring with a telescopically extensible lifting rod. It is advantageous if the axial through-passage 45, to complement the lifting rod, narrows conically upward.

[0052] The core 44, consisting, for example, of steel, has an encircling shoulder surface 442, which is preferably produced by an outside cone with a diameter which tapers in an upwardly sloping manner. A conical outer sleeve 43 made of elastic material, e.g. rubber, is arranged on the shoulder surface 442. The outer sleeve 43 is enclosed by a top molding 600, with the result that the latter constitutes a casing 600 for the outer sleeve 43. In order to ensure optimum functioning, the core 44 should be fixed to the outer sleeve 43 and the latter should be fixed to the top molding 600. The spring element 4 is thus a three-part component, comprising the core 44, the outer sleeve 43 and the top molding 600. A seat fastened on the top molding 600 can execute elastic movements in the horizontal plane by virtue of the elasticity of the outer sleeve 43, which is arranged between the core 44 and the molding 600. Provided in the molding 600, coaxially with the axial through-passage 45, is a cutout 61", which allows access for a triggering lever 22 to the triggering push rod 23 of the pneumatic spring (see FIG. 4A).

[0053] FIGS. 11A and 11B

[0054] In the case of the fourth embodiment of the seat mounting which is shown here, use is made of a fourth variant of a spring element 4, which, once again, is fitted onto a central column 2. Here too, the sheath-like core 44 has the preferably conical axial through-passage 45 for accommodating the top end of the central column 2. Once again, the core 44 has the shoulder surface 442 encircling the outside, and the elastic outer sleeve 43, which in this case has a basically cylindrical outer circumference, is arranged on said shoulder surface. The molding 600', which covers over the outer sleeve 43 in a cup-like manner from above, is provided with a flange 601' at the bottom. The core 44, the outer sleeve 43 and the molding 600', which constitutes the casing, form the spring element 4. Fixed connections between the core 44, outer sleeve 43 and molding 600' are more or less imperative for the functioning. A seat 3 fixed on the molding 600', preferably on the flange 601', can be moved elastically in the horizontal plane by virtue of the elasticity of the outer sleeve 43, as in the case of the previous designs. The cutout 61", once again, is provided above the axial through-passage 45 of the molding 600' in order to provide access for a triggering lever 22 to the triggering push rod 23 and/or a push-rod extension 21 of the central column 2, formed by the pneumatic spring.

Claims

1. A mounting for a seat (3) which rests on an underframe (1), having a spring element (4) arranged on the underframe (1), wherein a) the spring element (4) is positioned in a casing (5,5';6,6';600;600') and allows the latter to move elastically in the horizontal plane; and b) the casing (5,5';6,6';600,600') is connected to the seat (3) or forms a part thereof.

2. The mounting as claimed in claim 1, wherein the spring element (4) is arranged at the top of an axial column (2) of the underframe (1).

3. The mounting as claimed in claim 1 or 2, wherein the spring element (4) is arranged on an extensible, axially acting spring (2).

4. The mounting as claimed in one of claims 1 to 3, wherein the spring element (4) is arranged at the top of an axially extensible push rod of a pneumatic spring (2).

5. The mounting as claimed in one of claims 1 to 4, wherein the spring element (4) has an elastic outer sleeve (43), e.g. a rubber body.

6. The mounting as claimed in one of claims 1 to 5, wherein a) the casing (5,5';6,6') has a bottom, cup-like part (5,5') in which the spring element (4) is seated; and b) the spring element (4) and the casing (5,5';6,6') have an axial through-passage (45;61,61').

7. The mounting as claimed in one of claims 1 to 5, wherein a) the casing (600,600'), in which the spring element (4) is seated, is a cup-like part (600,600') which encases the spring element (4) from above; and b) the spring element (4) and the casing (600,600') have an axial through-passage (45,61").

8. The mounting as claimed in one of claims 1 to 7, wherein a) the spring element (4) comprises an inner, preferably metallic core (44) and the elastic outer sleeve (43), which is arranged thereon; and b) the core (44) has an opening (45), preferably an axial through-passage (45), for accommodating the column (2).

9. The mounting as claimed in one of claims 1 to 8, wherein the radial, outer circumference of the outer sleeve (43) of the spring element (4) a) is cylindrical; or b) tapers conically in the upward direction; or c) is essentially of cylindrical shape with a top and bottom reduction in diameter.

10. The mounting as claimed in one of claims 1 to 6, 8 or 9, wherein a) the spring element (4) is restrained at the top by a top molding (6,6'); b) the top molding (6,6') is connected to the casing (5,5'); and c) the seat (3) is fastened on the top molding (6).

11. The mounting as claimed in one of claims 1 to 10, wherein the core (44) is fixed to the outer sleeve (43).

12. The mounting as claimed in one of claims 1 to 5, 7 to 9 or 11, wherein a) the casing (600,600'), which is positioned on the spring element (4) from above, is fixed to the outer sleeve (43); and b) the casing (600,600') may have a flange (601') for connection to the seat.

13. The mounting as claimed in one of claims 1 to 12, wherein a) provided in the top molding (6,6') or in the casing (600,600'), which is positioned on the spring element (4) from above, coaxially with the pneumatic-spring-forming central column (2), is a through-opening (61,61',61") for the purpose of actuating the triggering push rod (23) of the pneumatic spring; and b) the axial through-passage (45) narrows conically.

14. The mounting as claimed in one of claims 1 to 13, wherein a) the through-opening (61,61',61") in the top molding (6,6') or in the casing (600,600'), which is positioned on the spring element (4) from above, has a defined geometry, e.g. a slot; and b) the internal core (44) of the spring element (4) has an extension (440) which projects into the through-opening (61,61',61") and is guided therein, as a result of which the moveability of the seat (3,3') is limited.