DE2317388A1 - DOUBLE SWIVEL JOINT FOR CHAIRS, ARMCHAIRS OR THE LIKE - Google Patents

Description

Steelcase Inc., 1120 36th Street, S.E. Grand Rapids, Michigan (USA)

Double torsion bar joint for chairs, armchairs or the like.

The invention relates to joints for chairs or the like, that is to say devices with the aid of which the seat and back of a chair or armchair or the back of the chair, etc. Like. Can be tilted relative to the chair base.

Basically, such devices have a stationary platform and carried by the chair base a tiltable platform that is tiltably attached to the stationary platform.

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In particular, the invention relates to torsion bar joints for chairs, armchairs or the like. Usually included such. Joints a torsion bar with a generally square cross-section, one end of which faces \ Rotations secured in a square opening of the stationary Platform is attached. The other end of the torsion bar is rotatably inserted in a rotatable bearing bush on the other side of the stationary platform. A lever is attached to the rotatable end of the torsion bar and so connected to the tiltable part that when this part is tilted, the movable end of the torsion bar twisted and so a torque is generated.

A disadvantage of such devices is that they must be quite long in order to use a torsion bar to be able to record a sufficiently flat spring characteristic. Therefore, such devices appear bulky and are immediately noticeable on a chair or armchair.

The problem can be greatly reduced by using a double torsion bar assembly in which one end of a bar is generally square. Cross-section in a square opening of the stationary platform and the corresponding end of a similar square rod non-rotatably in a square opening of the tiltable platform ^{: are} fastened. The free end of the first rod is rotatably inserted in a rotatable bearing bush on the other side of the stationary platform, while the free end of the second torsion bar rotatably in a similar bearing bush on the other side of the tilting platform.

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is brought. The two rods are connected at their rotatable ends by means that prevent the rotating movement of the transfer one rod to the other rod.

This results in a more compact joint that only needs to be about half as long. Such an arrangement however, it is expensive to manufacture because it has two separate rods and two separate sets of rotatable Requires bearing bushings and increases assembly costs because the rods are mounted in the bearings and openings have to. Therefore, such an arrangement does not yet represent the best solution to the problem identified.

The invention is directed to a double torsion bar joint for chairs, armchairs o. The like. Which is both cheap to manufacture, and a more compact construction than has the previous double torsion bar joints.

The more compact embodiment is achieved in that two generally U-shaped torsion bars -provided, a first leg, a second leg and a Have middle piece. The first leg of each rod sits in a plug-in bracket of the tiltable or stationary Platform. The center pieces of the torsion bars run approximately parallel to the axis from the insert brackets, around which the tilting platform tilts. The second legs both run inwards towards each other and are coupled to one another via a connecting piece that transfers the twisting of one of the two rods to the other. The middle parts of the torsion bars act as torsion springs, while the legs have a resilient one lying in series with them Deliver deflection. Although this resilient deflection

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is not necessarily essential with regard to the invention, it allows the two torsion bars shorter than the torsion bars used in the known Double torsion bar joints were used.

The economy of the production of the invention Joint is achieved by eliminating the need for rotatable bearing bushes at the rotatable ends of the torsion devices, by removing the constraint, openings in the corresponding fixed and to provide tiltable members on the rotatable ends of the torsion bars and, by eliminating the constraint, having to accommodate the rotatable ends of the torsion bars and the bushings in such openings. One achieves this in that the rotatable ends of the torsion bars are mounted directly in the connecting pieces, which transmit the rotation of one rod to the other rod. The connector itself is then free of any connection with either the tiltable or the fixed link. Thus completes the arrangement of the Connecting piece on the two torsion bars the entire chair joint.

Because the bars are generally U-shaped with bent legs at each "end, this becomes economical Manufacturing further facilitated. First, the arrangement of the connector is cheaper because the need to attach any lever to the Torsion devices for the connection to the connector are not required. Second, it is possible to have one Rod of generally circular cross-section instead

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to use a square cross-section. This is because the first legs are in pockets or Insert holders on one side of the fixed or tiltable member are included and because there is no constraint, any lever on the torsion bars assemble. A torsion bar with a circular cross-section is not only less expensive, but also has one better stress distribution in the rod. This also contributes to the compactness of the joint, since the better distribution of forces makes it possible to use a torsion bar with a smaller cross-sectional area. this leads to in turn to a flatter spring characteristic and even enables the use of shorter torsion bars.

The compactness is also achieved according to the invention in that torsion devices are provided which operatively connected to the fixed and tiltable members, and also resilient flexures may be provided in series with these torsion devices between the tiltable and stationary members are arranged so that a flatter spring characteristic can be achieved with a more compact torsion device leaves. This basic idea of the invention can also be used in connection with a chair or armchair joint Use with just a single torsion bar, but just as well with a hinge with a double torsion bar.

The invention will be explained in more detail below with reference to the drawings. These show in

1 shows an exploded perspective view of a chair or armchair joint;

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Fig. 2 is a plan view of the mounted joint; and in FIG. 3 a section along the "line III-III of FIG. 1.

In a preferred embodiment, the tilting of the tiltable platform with respect to the stationary platform is carried out 10 by a front, generally U-shaped torsion bar 50 and a rear, generally U-shaped Controlled torsion bar 60, as can be seen in FIGS. 1 and 2. One leg 51 of the front torsion bar 50 is in a bracket 20 of the fixed platform 10 mounted, while the corresponding leg 61 of the rear torsion bar 60 in the bracket 38 of the tiltable Platform 30 is housed. The opposite legs 52 and 62 of the front torsion bar 50 or the rear torsion bar 60 sit in a connecting bracket 70, which the rotation of the one Rod transfers to the other. The console 70 is free movable with respect to the tiltable platform 30 and the stationary platform 10, i.e. from any connection free to one of these platforms. The adjustment device 80 in the connection bracket 70 provides a device for adjusting the preload in the front torsion bar 50 and in the rear torsion bar 60.

The fixed platform 10 consists of a metal, a punched metal piece o. The like. _O It is generally cup shaped with a front wall 11, side walls 12 and a floor 13 formed "An inverted, cup-shaped generally lockers! Holder 14 is at the bottom 13 by Welding o, the like attached «,

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The upper part of a spindle 15 protrudes upward through an opening in the base 13 and through an opening in the spindle holder 14 and is firmly connected to the stationary platform 10 at this point.

The stationary platform 10 has an opening 19 in each side wall 12 so that the tiltable platform can be mounted there so that it can be tilted. To limit the amount of forward tilting movement of the tilting platform, a front stop 16 is provided on the upper edge of the front wall 11. It consists of a sound-absorbing or upholstery material. In order to limit the extent of the tilting of the platform 30 backwards, is a rear stop 17 made of sound-absorbing or cushioning material on a raised part 13a of the floor 13 on the Rear edge of the stationary platform 10 mounted.

To facilitate installation of the front torsion bar 50, a small curved flange is provided on the left side wall 12 (see. Fig. 1) of the stationary platform 10 welded, so that a receiving pocket or Insertion bracket 20 is created. The plug-in holder takes the left leg 51 (according to FIG. 1) of the front one Torsion bar 50 and is designed so that the leg 51 is secured against rotational movement. on this way the left end of the front torsion bar 50 is against rotation with respect to the stationary one Platform 10 fixed. Near the other side of the stationary platform 10 is a torsion bar support 18 attached both to the floor 13 and to the front wall 11. The torsion bar 18 consists of acoustically

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cushioning or cushioning material and acts as a stop, which prevents the front torsion bar 50 ge ^ - noisily on the floor 13 of the stationary platform 10 beats. By thus controlling the front torsion bar 50, the rear torsion bar 60 and the Link console 70 is controlled in a similar manner.

Finally, the stationary platform 10 contains an opening 21 in the floor 13 on the right-hand side according to FIG. 1. When the joint is fully assembled, the adjustment assembly is made 80 of the connecting bracket 70 is generally arranged above the opening 21 and the opening 21 thus gives access to the adjustment assembly 80. ~

The tiltable platform 30 also consists of a Metal casting or stamping or the like. It is generally frame-shaped with a front wall 31 and side walls 32 and a rear wall 33 are formed. At the top of the side walls 12 and. the back wall 33 is a seat mounting flange 34 with openings 39 to facilitate assembly of the seat. On the top of the front wall 31 there is a front stop flange 35, which is a short distance protrudes rearward from the front wall 31. A front stop flange 35 interacts with the front one Stop 16 on the stationary platform 10 together. The lower rear surface 38a of the pocket or Bracket 38 acts in a similar manner to the rear Stop 17 together on the stationary platform. The side walls 32 of the tiltable platform 30 have Openings 37 to facilitate the assembly of the tiltable Platform 30 on the stationary platform 10. For

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this assembly will be the openings 37 with the openings 19 is aligned and a bearing 40 is inserted through both openings. A washer 42 is over slid the end of the bearing and inserted a rivet 41 into the end of the bearing to keep the bearing on its Hold place.

The tiltable platform 30 also has one on the left side 32 to form a pocket or holder 38 welded flange. In terms of its construction and mode of operation, the pocket 38 is the same as the pocket 20 on the stationary platform 10 similarly. It takes the left end 61 of the rear torsion bar 60 and limits it so that the rear torsion bar 60 at its left end against rotation with respect to the tiltable platform 30 is fixed.

To allow access to the adjustment assembly 80 after the joint is fully assembled, the entire bottom of the tiltable platform 30 is completely open. This not only leaves room for access through the opening 21 to the adjustment assembly 80, but also facilitates the attachment of the tiltable Platform 30 to the stationary platform 10, in that the tiltable platform 30 over the upper part the stationary platform 10 can slide.

Each torsion bar 50 and 60 is generally U-shaped. The front torsion bar 50 includes one Leg 51, a leg 52 and a middle part 53. Similarly, the rear torsion bar 60 a leg 61, a leg 62 and a

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Middle part 63 on. Both rods are generally circular in cross-section. After all, the Leg 52 of the front torsion bar 50 has a groove 54 at the end to facilitate its interaction with the adjustment arrangement 80 {Fig. 3). The leg 62 of the rear torsion bar 60 includes a similar one Groove 64 to facilitate cooperation with adjustment assembly 80.

The connecting bracket 70 is generally U-shaped with a pair of side walls 71 and a bottom web 72 (Figs. 1 and 3). The floor web 72. Falls from the ends of the console 70 towards the center. In operation, the ends 74 of the bottom web 72 form pivot points, on which the legs 52 and 62 of the torsion bars rest on. The bottom web 72 falls from these pivot points so that the legs 52 and 62 have room for rotation by the adjustment device 80. In the end the bottom web 72 includes an opening 73 in the middle to facilitate attachment of the adjustment device 80. The adjustment device 80 contains a nut 82 which is screwed onto a screw bolt 81 is. The head 81 rests against the underside of the bottom web 72 and the threaded or shank portion of the screw bolt 81 extends through the opening 73 (Fig. 3). Preferably, the head of the screw bolt 81 takes a wrench to the preload on the front Torsion bar 50 and the rear torsion bar 60 can be adjusted. The mother 82 is generally T-shaped with a crossbar 83. The ends of the crossbar 83 lie over the surfaces of the legs 52 and 62 and hold them in place against the rotating

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points 74. Preferably, the cross bar includes a downwardly hanging hook 84 at each end to mate it Engagement with the grooves 54 "or 64 of the legs 52 or 62.

In the assembled state, the tiltable platform 30 is tiltable on the fixed platform 10 with the aid of Bearings mounted through aligned openings 37 and 19. The tiltable platform 30 is only over the top of the Fixed platform 10 pushed until the openings 37 and 19 are aligned. Then the bearings 10 are used and held in place in the manner previously described, it can be seen that the left side 12 of the stationary platform 10 a cutout 12a on the rear edge for receiving the pocket or holder 38 of the tiltable platform 30 has. The front torsion bar 50 is with its leg in the holder 20 of the stationary platform 10 excepted, while the rear torsion bar with its leg 61 in the pocket or holder 38 the tiltable platform rests. The middle parts 53 and 63 then extend out of the brackets 20 and 38, respectively generally parallel to the axis about which the tiltable platform 30 tilts. The other legs 52 and 62 of the Torsion bars extend inwardly towards each other and are between the profile sidewalls 71 of the connection bracket 70 comprises. The nut 82 of the adjuster 80 rests over the top surfaces the legs 51 and 62 and holds them against the pivot points 74 of the connecting bracket 70. The torsion bars are further through the hanging down Hook 84 of the nut 82 held in place, the corresponding in grooves 54 and 64 of the legs 52 and 62 to grab.

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In use, a chair or the back of a chair is attached to the tilting platform 30 in a conventional manner. if the particular chair member is tilted, the tiltable platform 30 tilts about the bearings 40 with respect to the fixed platform 10. Since the left leg 51 is fixed against rotation with respect to the stationary member 10 and there the left Leg 61 of the rear torsion bar 60 is fixed against rotation with respect to the tiltable platform 30 and the right legs 52 and 62 of the torsion bars are connected to one another by the connecting bracket 70, begin both torsion bars to twist and provide a torsion resistance against tilting the tiltable Platform 30. The presence of the torsion bar bearing 18 at the front right end of the stationary platform prevents the front torsion bar 50 from falling behind sags at the bottom and strikes against the metal floor 13 of the stationary platform 10. Because of this limitation the connecting bracket 30 and the rear torsion bar 60 are similarly subject to deflection below and prevented from generating such a striking noise. In addition to the rotating movement in the front Torsion bar 50 and in the rear torsion bar 60 there is a bend in the legs 51, 52 and 62. This Deflection occurs in series with the torsional rotation of the center pieces 53 and 63 of the torsion bars. Through this the entire torsion bar arrangement receives a flatter spring characteristic and one can therefore use shorter torsion bars use.

Because the torsion bars 50 and * 60 using their Legs can be attached, the torsion bars can be held in generally circular cross-section

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generally square cross-section like "in usual Have torsion bars. This leads to a better distribution of forces and makes the use of torsion bars possible with generally smaller cross-sectional areas. Because of the smaller cross-sectional areas are In addition, the torsion bars are not as stiff and have a flatter spring characteristic. They can even be shorter be made than it arises from this fact.

To change the preload on the torsion bars 60 and 60, use a wrench to screw them together of the screw bolt 81 in and out of the nut and thus to produce a larger or smaller Twisting of the torsion bars 50 and 60. The head of the Screw bolt 81 is through the open bottom of the tilting platform 30 and through the opening 21 in the stationary Platform 10 easily accessible. -

The present invention thus creates a chair joint that is more compact than the conventional ones Chair joints can be designed and manufactured cheaper than the usual double torsion bar chair joints is.

Claims: - 14 -

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Claims (18)

Claims 1.) Double torsion bar joint for chairs, armchairs or the like, with a stationary platform supported by the steel foot and with a tiltable platform that is tiltable on the stationary platform, so% fie 'with two torsion bars, characterized in that the first and the second Torsion bar generally U-shaped, each with a first leg (51-61), a second leg (52, 62) and a central part (53-63), on the stationary platform (10) plug-in holders (20) are attached which receive the first leg (51) of the first torsion ^ = rod (50) rotatably, a second male = holder (38) -one of the tiltable platform (30) attached _r is the first leg (61) of the second torsion bar (60 ) Drehfes.t receives _p - the middle part of the torsion bars from the insert _{brackets (2O 9} 38) in general parallel to the. "Tilting axis of the tiltable platform (30) the second leg '(52, 62) of the first and second torsion bar -to the inside and facing each other" and are enclosed by a connection bracket (70) _2, the rotary motion of a torsion bar, to the transmits to others »- · 2. Joint according to _{spoke 1 9} characterized - - geke η η · = s that the connecting bracket (70) is free ■ ■ of "any rigid connection with the stationary and movable platform» 3. Joint according to.Anspruch I ₅ thereby gek'e-nnzeich · = net that each holder "(20 _s 38) forms a pocket ₉ which holds the first leg (51» 61) »" -. . 4 * joint according to claim 3 p thereby marked- = η e t that the torsion bars have a generally circular cross-section « ■ ■ - 15 - 5. Joint according to claim 1, characterized in that the torsion bars in general have a circular cross-section. 6. Joint according to claim 5, characterized in that the connecting part (70) has a U-Prof 1 having bracket, with side walls (71) and a bottom web (72), the side walls the second legs (52, 62) of the torsion bars enclose each of the second legs from the end of the Clamp with U-profile inwards towards the other runs, each of the second legs touches the bottom web (72) at the corresponding pivot point (74), the bottom bar runs obliquely downwards from the pivot points towards the center of the clamp, an adjustment device (80) extends upwards from the center of the bottom web (72), between the Ends of the second legs (52, 62) runs and rests on the upper sides of the second legs, against them presses the corresponding support points and thus enables the pre-tensioning of the torsion bars to be adjusted, the adjustment device made of a T-shaped screw nut with a threaded shaft (82) and a transverse web (83) and is held by a screw bolt (81) which extends through an opening (73) in the bottom web of the clamp (70) extends upwards and the cross web of the screw nut rests on the second leg. 7. Joint according to claim 6, characterized in that the fixed and the tiltable Part in their bottoms contain openings through which the head of the screw bolt (81) is accessible. 8. Joint according to claim 7, characterized in that the transverse web (83) on each At the end of a downwardly hanging hook (84) and each of the second legs, a groove on the surface 30984t / 0AÜ3 - 16 - (54, 64) for mating engagement with the hooks. 9. Joint according to claim 1, characterized in that the connecting part (70) has a first Part (80) which engages with the upper sides of the two second legs (52, 62) and a second part (72) containing the undersides of the two second legs at a point near the junction touched with their middle parts (53, 63). ■ -, 10. Joint, in particular according to one or more of the preceding claims, characterized in that the torsion bars (5O ₉ 53) are connected to the stationary platform (10) and to the tiltable platform (30) that a torque occurs when the tiltable platform is tilted and a resilient bending device (51, 52, 61, 62) is arranged in series with the torsion bars between the tiltable platform and the stationary platform, which enables the implementation of a flatter spring characteristic and thus a more compact torsion device. 11. Joint according to claim 10, characterized in that the torsion device and the resilient bending device both consist of a torsion bar (50), which be_ at least one curvature sits, one end of the torsion bar is fixed in a rotationally free manner with respect to the stationary platform, the torsion bar extending from this end (51) generally parallel to the tilt axis of the tiltable platform, the torsion bar has a second leg (52) which, from the curvature, runs approximately perpendicular to the tilt axis, suitable connecting parts connected the leg to the tiltable platform so that by tilting the leg bent and at the same time the part (53) of the torsion bar, which is parallel to the tilt axis 30984S / 0403 _ runs, is twisted. 12. Joint according to claim 11, characterized in that the connecting member has a first Point of contact with the top of the end of the second leg (52) and a second point of contact with the Has underside of the second leg (52) at a point which is close to the curvature, so that the Leg between the first and second contact point tends to bend. 13. Joint according to claim 12, characterized in that two torsion bars (50, 60) are provided that one end (51) of the first torsion bar (50) rotatably fixed to the stationary platform is connected and one end (61) of the second torsion bar (60) non-rotatably with the tiltable platform, each of the two torsion bars has the curvature and a leg (52 or 62) 'and the connecting member contains a part that connects both legs so that the rotation of one of the two rods on the transmitted to others. 14. Joint according to claim 10, characterized in that the torsion device has a contains the first torsion bar (50), which with its first end (51) rotatably connected to the stationary platform is connected, a second torsion bar (60) whose first end (61) rotatably connected to the tiltable Platform is connected, a connecting member (70), the first and second torsion bars in one Connects point that is at a distance from the fixed ends and that causes the torsion of a rod the other transmits, the resilient bending device consists of at least one of the two torsion bars, ' which is capable of both resilient bends and - 18 309845/0403 Perform torsional movements, at least one of the both torsion bars has the option of moving in relation to the fixed and the tiltable platform to bend that the connecting link is sufficiently rigid and that both tilting of the tiltable platform to a bending of one torsion bar and at the same time to a twisting of both torsion bars leads. 15. Joint according to claim 14, characterized in that both torsion bars with respect to the stationary and the tiltable platform bend =. are cash; 16. Joint according to claim 15 »characterized in that each of the torsion bars has a generally U-shape ₂ eixi.es first leg (51 o. 61) _9, a second leg (52 ₉ 62) and a central part. (55" 63) , a bracket (3S ₉ 20) is provided both on the tiltable platform and on the stationary platform in order to accommodate the first legs of the first or "second torsion bar"? whereby the connecting link "connects the second legs of the torsion bars " 17. Joint according to claim 16 ₉ characterized geke η η = characterized in that the Sorsionsstäb generally circular cross-section - have «. 18. Joint according to Anspraela 17 _S characterized · gel eai ° _f that the "connecting link consists of a - generally U- £ öraig © n brackets, which has © side walls (71) and © inen bottom web" (72) * oil © side walls the second legs (52 ₉ 62) of the rods around each ^{1 of} the second bar ©! iran each end of the U ° försaigsia hammer ans to issaea on the otherji ζ, η % - © rlä «ft _p each of the touches the bottom web at the corresponding pivot point (74), this bottom web from the pivot point to the Center of the clamp runs obliquely downwards, an adjustment device (80) from the request of the bottom bar continues upwards, runs between the ends of the second legs and on the tops the second leg rests, the second leg presses against their pivot points and the setting of the Biasing the torsion bars allows the adjuster to be made from a generally T-shaped Screw nut with a threaded shaft (82) and a transverse web (83), which is on a Screw bolt (81) is located, the screw bolt through the opening (73) in the bottom web of the clamp, the cross web of the screw nut on the second Legs rests, the crosspiece has a downwardly hanging hook (84) at each end and each the second leg has a groove (54, 64) on the surface for mating engagement of the hooks. 309845/0403 i ^ί0 · »■ Read 11 e