A chair base, a chair frame and a chair

Abstract

A chair base includes a central opening configured to receive and support a post essentially vertical in an operating position of the chair base, and at least three, preferably five, arms which project radially from the opening. At least one of the arms has a substantially U-shaped profile or a substantially O-shaped profile along its longitudinal direction starting from an outer arm end, and the at least one of the arms also has a substantially I-shaped profile or a substantially T-shaped profile along the longitudinal direction which differs from the U-shaped profile or O-shaped profile.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a chair base for a chair, wherein the chair base comprises a central opening designed to receive and support a post which is essentially vertical in the operating position of the chair base. The chair base has at least three, preferably five, arms which extend radially from the opening, and at least one of the arms has a substantially U-shaped profile or a substantially O-shaped profile along its longitudinal direction starting from an outer arm end. Furthermore, the invention relates to a chair frame and a chair with such a chair base.

[0002] Such chair bases are generally known from the prior art. As is customary, as can be seen, for example, from documents CN 2508626 Y and DE 19841225 A1, the arms of such chair bases have an essentially continuous, uniform cross-sectional profile with relatively solid cross-sectional wall thicknesses. On the one hand, this is usually due to the desire to achieve the simplest possible manufacturing process, which is why the basic cross-section along the longitudinal axis of the arms hardly changes. On the other hand, the focus in the design of chair bases is usually exclusively on constructing very stable chair bases, which often results in overdimensioned chair bases. All in all, such state-of-the-art solutions result in an unnecessarily high use of material.SUMMARY OF THE INVENTION

[0003] The task of the present invention is therefore to provide a chair base that is an improvement on the state of the art, with an optimized support structure, in particular where the support structure requires as little material as possible while meeting all necessary stability requirements.

[0004] This task is solved by providing a chair base of the type mentioned at the beginning, wherein the at least one arm of the chair base has a profile along the longitudinal direction that differs from the U-shaped profile or O-shaped profile and is substantially I-shaped or substantially T-shaped.

[0005] This design differs advantageously from conventional approaches, by using an innovative way to make a specifically optimized support structure. The chair base according to the invention naturally meets all standard requirements, such as BIFMA X5.1 “Footrest Static Load Test” and / or BIFMA X5.1 “Footrest Durability Test” and / or the safety requirements of DIN EN 1335.

[0006] A first major advantage of the invention is that the wall thicknesses of the arms can be significantly smaller than those of the chair bases of the prior art. This allows a significant amount of material to be saved, which can result in both lower manufacturing costs and a reduced carbon footprint.

[0007] Low material requirements also mean that the chair base is lighter, which is of course very practical when handling a chair equipped with this chair base.

[0008] Another advantage is that the design of the chair base according to the invention can result in a slimmer construction, which in turn enables a visually appealing design.

[0009] The opening is preferably circular cylindrical and / or geometrically designed to match the post, in particular a gas pressure spring, of the chair.

[0010] The opening can also be designed as a blind hole so that the post can be inserted from above when in the operating position.

[0011] The opening is designed to accommodate the post in a substantially vertical orientation, which means in particular that the orientation of the post may deviate from an exact vertical orientation, e.g. due to unevenness of a ground and / or due to manufacturing tolerances.

[0012] The profiles mentioned are substantially U-, 0-, I-, and / or T-shaped, which means in particular that the at least one arm consists of a main supporting structure in at least a U-, 0-, I-, and / or T-shape.

[0013] The cross-sectional shape of the profiles may deviate from an exact U, O, I, and / or T shape. However, the U, O, I, and / or T shapes are clearly recognizable.

[0014] The arms extending radially from the opening are preferably arranged at regular intervals from one another.

[0015] The arms may also be inclined downwardly from the opening and / or may also be bent and / or curved along their longitudinal direction, in particular downwardly toward a floor. This means, in particular, that the longitudinal axis may be inclined and / or bent, whereby a respective profile cross-section along the longitudinal axis changes only insignificantly or slightly.

[0016] The central opening is positioned centrally relative to the arms. This means, in particular, that the opening is positioned in the center of the chair base, preferably with the arms all being of the same length.

[0017] The I-shaped profile can basically also be regarded as an H-shaped profile, in particular a rotated one.

[0018] The U-shaped profile can basically also be regarded as a C-shaped profile, in particular a rotated one.

[0019] Preferably, the I-shaped profile or the T-shaped profile has a substantially vertically aligned web and furthermore a lower flange and / or an upper flange in the operating position. This ensures, for example, optimum load transfer via the arms.

[0020] In a preferred embodiment, the I-shaped profile has a vertically aligned web, an upper flange, and a lower flange.

[0021] In a preferred embodiment, the T-shaped profile has a vertically aligned web and an upper flange.

[0022] In a further embodiment, the T-shaped profile has a vertically aligned web and a lower flange.

[0023] The alignment of the web may deviate from a perfectly vertical alignment, e.g. due to unevenness of the surface and / or varying wall thicknesses, in order to improve the flow of force.

[0024] Preferably, the I-shaped profile or the T-shaped profile has stiffening ribs, preferably extending between the web and the lower flange and / or the upper flange, in particular symmetrically to a vertical plane of symmetry through the I-shaped profile or the T-shaped profile. This can, for example, increase the rigidity, in particular the torsional rigidity, of the at least one arm.

[0025] The alignment of the vertical symmetry plane may deviate from an exact vertical alignment, e.g. due to unevenness of a ground.

[0026] In a particularly preferred embodiment, the I-shaped profile has stiffening ribs, preferably extending between the web and the lower flange and the upper flange, in particular symmetrically to the vertical plane of symmetry through the I-shaped profile.

[0027] In one embodiment, the T-shaped profile has stiffening ribs, preferably extending between the web and the lower flange and / or the upper flange, in particular symmetrically to the vertical plane of symmetry through the T-shaped profile.

[0028] The stiffening ribs can be designed, for example, in a honeycomb shape and / or a zigzag shape and / or a cross shape.

[0029] The lower flange and / or the upper flange can have a concave, preferably V-shaped in the operating position, particularly preferably inverted V-shaped, indentation. This may be advantageous, for example, in order to save additional material.

[0030] It is particularly preferred that the U-shaped profile is substantially inverted in the operating position, with the legs of the U-shaped profile being substantially vertical and with a side of the U-shaped profile located between the legs forming an upper side.

[0031] It is also possible that one side of the O-shaped profile forms the top.

[0032] The alignment of the legs may deviate from a perfectly vertical alignment, e.g. due to unevenness in the ground and / or varying wall thicknesses.

[0033] Sides of the U-shaped profile or the O-shaped profile, in particular the legs of the U-shaped profile, may have concave recesses. This may be advantageous, for example, in order to save additional material.

[0034] The recesses can, for example, taper to a point and / or be rounded toward the outer end of the arm and / or correspond to stress distribution in the arm. This means, in particular, that areas in the cross-section or profile with low stresses have recesses.

[0035] Preferably, the U-shaped profile or the O-shaped profile has stiffening ribs, preferably in a cross-shaped configuration when viewed from below.

[0036] It is particularly preferred that the upper side of the U-shaped profile or one upper side of the O-shaped profile and the upper flange of the I-shaped profile or the T-shaped profile merge into one another. This ensures, for example, a continuous flow of force in the arm, which advantageously prevents stress peaks.

[0037] It is particularly preferred that a wall is arranged between the U-shaped profile or the O-shaped profile and the I-shaped profile or T-shaped profile, preferably with the wall forming a transition between the legs of the U-shaped profile and the web of the I-shaped profile or T-shaped profile. This ensures, above all, an advantageous continuous flow of force in the arm.

[0038] In particularly preferred embodiments, the wall is arranged between the U-shaped profile and the I-shaped profile, preferably with the wall forming a transition between the legs of the U-shaped profile and the web of the I-shaped profile.

[0039] In preferred embodiments, the wall is arranged between the U-shaped profile and the T-shaped profile, preferably with the wall forming a transition between the legs of the U-shaped profile and the web of the T-shaped profile.

[0040] Preferably, the I-shaped profile or the T-shaped profile extends along the longitudinal direction over between 50 and 80%, preferably over between 60 and 70%, of a length of the at least one arm. This can mean that the at least one arm is I-shaped or T-shaped in the vicinity of the opening and transitions directly or indirectly into a U-shaped or O-shaped profile toward the arm ends. This allows an efficient and material-saving support structure to be achieved.

[0041] It is particularly preferred that the at least one arm has a support area at the outer arm end for supporting the chair base. Preferably, the support area has a bearing opening, in particular a blind hole-shaped bearing opening, for receiving an insertable extension.

[0042] The support area can be designed to rest on a floor, on a castor, on a stopper, on a sliding element, or similar.

[0043] The bearing opening can be designed to accommodate an extension of a castor, a stopper, a sliding element, or the like.

[0044] It is preferable for the support area to have an outer wall that is closed circumferentially, preferably with stiffening struts arranged between the bearing opening and the outer wall, in particular struts that are aligned radially to the bearing opening. This allows a support force to be transferred particularly well across the support area.

[0045] Preferably, the outer wall merges into the O-shaped profile or the U-shaped profile, in particular into the legs and the top of the for U-shaped profile. This allows, example, advantageous continuous force transmission.

[0046] It is particularly preferred that the inner ends of the arms facing the opening form an area that is essentially concentric with the opening and has a reinforced double wall. This allows the chair's post to be supported securely and stably by the chair base.

[0047] The shape of the concentric area may deviate from a precisely concentric arrangement, e.g. due to varying wall thicknesses to improve the flow of force within the chair base.

[0048] Preferably, the concentric area toward the opening has radial stiffening struts, preferably spaced evenly apart, which advantageously further increase the rigidity.

[0049] However, the stiffening struts within the double wall can also be shaped differently, for example in a zigzag and / or cross shape.

[0050] It is possible that the concentric area is open at the bottom in the operating position, particularly to save additional material.

[0051] Preferably, an outer wall of the double wall merges into the I-shaped profile or the T-shaped profile, in particular into the web and the upper flange and / or the lower flange. This allows, for example, advantageous continuous force transmission.

[0052] In a preferred embodiment, the outer wall merges into the I-shaped profile, in particular into the web, the upper flange, and the lower flange.

[0053] It is also conceivable that the concentric area has a vertical extension when in operation. This can serve, for example, to stabilize the post.

[0054] The vertical extension can extend downwards and / or upwards in the operating position.

[0055] It is possible for the arms to be formed separately from each other and preferably connected to the opening and / or to each other, preferably in a detachable manner. This allows for a modular design of the chair base, which, for example, enables individual defective arms to be easily replaced.

[0056] It is particularly preferred that the chair base consists at least in part and / or proportionally, preferably completely, of plastic.

[0057] The plastic is preferably a thermoplastic, in particular an engineering plastic such as polyamide.

[0058] The plastic may comprise glass fibers, with a glass fiber content preferably between 20% and 40%.

[0059] The chair base, in particular the at least one arm, may be, for example, an injection molded part.

[0060] It is conceivable that the chair base has connecting elements to which additional components, such as cover elements for protection and / or improved visual design, can be attached.

[0061] Protection is also sought for a chair frame for supporting a seat, comprising a chair base according to the invention, a post inserted into the opening, in particular a gas pressure spring, and a connecting element attached to the post for attaching the seat.

[0062] Furthermore, protection is sought for a chair, in particular an office or work chair, comprising a chair frame according to the invention, a seat attached to the connecting element, and castors, stoppers, sliding elements, and / or the like attached to the arms.

[0063] A chair base according to the invention can also be used with already known chair frames or chairs of the prior art and can also be retrofitted.BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Further advantages and details of advantageous embodiments of the invention can be seen from the figures, in which:

[0065] FIG. 1 shows a first embodiment of a first chair base according to the invention,

[0066] FIGS. 2-6 show an arm of a second embodiment of a second chair base according to the invention,

[0067] FIGS. 7-10 show a third embodiment of a chair base according to the invention, and

[0068] FIG. 11 shows a fourth embodiment of a chair base according to the invention.DETAILED DESCRIPTION OF THE INVENTION

[0069] FIG. 1 is a perspective top view of a first embodiment of a chair base 1 according to the invention for a chair, wherein the chair base 1 comprises a central opening 2 which is designed to receive and support a post 3, for example a gas pressure spring, which is essentially vertical in an operating position of the footrest 1, and wherein the chair base 1 has at least three, preferably five, arms 4 which project radially from the opening 2, wherein at least one of the arms 4 has, along its longitudinal direction 5 starting from an outer arm end 6, a substantially U-shaped profile 7 or a substantially 0-shaped profile 7, wherein the at least one arm 4 has, along the longitudinal direction 5, a profile 8 that is different from the U-shaped profile 7 or O-shaped profile 7 and is essentially I-shaped or essentially T-shaped.

[0070] FIGS. 2-6 are views and sections of an arm 4 of a second embodiment of a chair base 1 according to the invention, wherein the at least one arm 4 has a substantially I-shaped profile 8 along the longitudinal direction 5, which differs from the U-shaped profile 7.

[0071] Alternatively, instead of the U-shaped profile 7, an O-shaped profile 7 could be provided and / or instead of the I-shaped profile 8, a T-shaped profile 8 could be provided.

[0072] FIG. 2 shows at least one arm 4 from a perspective view from below. In this particularly preferred embodiment, the I-shaped profile 8 has a substantially vertically aligned web 9, a lower flange 10 and an upper flange 11 in the operating position.

[0073] In the event that a T-shaped profile 8 is provided instead of the I-shaped profile 8, the T-shaped profile 8 may have a lower flange 10 or an upper flange 11.

[0074] It is also conceivable that the T-shaped profile 8 along the longitudinal direction 5 has at least one area with a lower flange 10 and at least one area with an upper flange 11.

[0075] The view shown in FIG. 2 reveals that the at least one arm 4 has a support area 20 at the outer arm end 6 for supporting the chair base 1. Preferably, the support area 20 has a bearing opening 21, in particular a blind hole-shaped bearing opening, for receiving an insertable extension, e.g. castors, a stopper, a sliding element or the like.

[0076] Preferably, the support area 20 has an outer wall 22 that is closed on the opposite side, preferably with stiffening struts 23 arranged between the bearing opening 21 and the outer wall 22, in particular those that are aligned radially to the bearing opening 21.

[0077] FIG. 2 also shows sections of the concentric area 24 with a double wall 24 with an outer wall 26. However, these features are shown more clearly in FIG. 11.

[0078] In the side view shown in FIG. 3 and in the section shown in FIG. 4, it can be seen that the I-shaped profile 8 or the T-shaped profile 8 preferably extends along the longitudinal direction 5 over between 50 and 80%, preferably over between 60 and 70%, of a length 19 of the at least one arm 4.

[0079] FIG. 3 also shows that it is preferable for the outer wall 22 to merge into the U-shaped profile 7, in particular into the legs 15 and the upper side 17 of the U-shaped profile 7.

[0080] The section shown in FIG. 5 shows that the lower flange 10 and / or the upper flange 11 may have a concave, preferably V-shaped in the operating position, particularly preferably inverted V-shaped, indentation 14.

[0081] The indentation 14 can be provided both in an I-shaped profile 8 and in a T-shaped profile 8.

[0082] The cutaway view shown in FIG. 6, it can be seen that the U-shaped profile 7 is preferably oriented in a substantially inverted manner in the operating position, wherein the legs 15 of the U-shaped profile 7 are oriented substantially vertically and wherein a side 16 of the U-shaped profile 7 arranged between the legs 15 forms an upper side 17.

[0083] It is preferred that the upper side 17 of the U-shaped profile 7 and the upper flange 11 of the I-shaped profile 8 merge into one another.

[0084] If an O-shaped profile 7 is provided, it is preferable that the upper side 17 of the O-shaped profile 7 and the upper flange 11 of the I-shaped profile 8 or, alternatively, of the T-shaped profile 8 merge into one another.

[0085] In this embodiment, a wall18 is arranged between the U-shaped profile 7 and the I-shaped profile 8, preferably with the wall 18 forming a transition between the legs 15 of the U-shaped profile 7 and the web 9 of the I-shaped profile 8. This can be seen particularly well in FIGS. 2 and 4.

[0086] In the following descriptions of the embodiments shown in the following figures, in order to avoid repetition, the differences from the first two embodiments are primarily discussed. Otherwise, the above descriptions of the first and second embodiments also apply to the embodiments described below, where applicable.

[0087] FIGS. 7-10 are views and sections of a third embodiment of a chair base 1 according to the invention. In this embodiment, the I-shaped profile 8 or the T-shaped profile 8 has stiffening ribs 12, in particular those which are zigzag-shaped.

[0088] The stiffening ribs 12 extend preferably between the web 9 and the lower flange 10 and / or the upper flange 11.

[0089] The perspective top view shown in FIG. 7 shows that the arms 4 are preferably formed separately from one another and are preferably connected to the opening 2 and / or to one another, in particular in a detachable manner.

[0090] FIG. 8 shows essentially the same aspects as FIG. 7, but in a side view.

[0091] The cross-section through the I-shaped profile 8 shown in FIG. 9 reveals that the stiffening ribs 12 extend preferably symmetrically to a vertical plane of symmetry 13 through the I-shaped profile 8 or the T-shaped profile8.

[0092] FIG. 10 shows essentially the same aspects as shown in FIG. 6 with reference to the second embodiment.

[0093] FIG. 11 shows a bottom view of a fourth embodiment of a chair base 1 according to the invention. This view clearly shows that the inner ends of the arms 4 facing the opening 2 preferably form an area 24 that is essentially concentric with the opening 2. The concentric area 24 has a reinforced double wall 25.

[0094] In this embodiment, the concentric area 24 has radial stiffening struts 23 facing the opening 2, which are preferably spaced apart at regular intervals.

[0095] Furthermore, the concentric area 24 is open at the bottom in the operating position.

[0096] In this embodiment, the outer wall 26 of the double wall 25 merges into the I-shaped profile 8 or the T-shaped profile 8, in particular into the web 9 and the upper flange 11 and / or the lower flange 10.

[0097] In all of the embodiments shown, the arms 4 are slightly bent downward along their longitudinal axes 5. However, the arms 4 can also generally be designed to be straight.

[0098] In all the embodiments shown, the inner arm ends of the arms 4 are connected in the operating position essentially horizontally to the opening 2, in particular to the concentric area 24. However, the arms 4 can also protrude and / or be connected at an angle from the opening to the side and / or downward.REFERENCE LIST1 Chair base

[0100] 2 Opening

[0101] 3 Post

[0102] 4 Arm

[0103] 5 Longitudinal direction

[0104] 6 Outer arm end

[0105] 7 U-shaped or O-shaped profile

[0106] 8 I-shaped or T-shaped profile

[0107] 9 Web

[0108] 10 Lower flange

[0109] 11 Upper flange

[0110] 12 Stiffening ribs

[0111] 13 Symmetry plane

[0112] 14 Indentation

[0113] 15 Leg

[0114] 16 Side between the legs

[0115] 17 Upper side

[0116] 18 Wall

[0117] 19 Length

[0118] 20 Support area

[0119] 21 Bearing opening

[0120] 22 Outer wall

[0121] 23 Stiffening struts

[0122] 24 Concentric area

[0123] 25 Double wall

[0124] 26 Outer wall

[0125] 27 Connection point

Claims

1. A chair base for a chair, the chair base comprising:a central opening configured to receive and support a post which is essentially vertical in an operating position of the chair base, andat least three, preferably five, arms which project radially from the opening, wherein at least one of the arms has a substantially U-shaped profile or a substantially O-shaped profile along its longitudinal direction starting from an outer arm end,wherein the at least one of the arms also has a substantially I-shaped profile or a substantially T-shaped profile along the longitudinal direction which differs from the U-shaped profile or O-shaped profile.

2. The chair base according to claim 1, wherein the I-shaped profile or the T-shaped profile has, in the operating position, a substantially vertically aligned web and a lower flange and / or an upper flange.

3. The chair base according to claim 1, wherein the I-shaped profile or the T-shaped profile has stiffening ribs, preferably extending between the web and the lower flange and / or the upper flange, in particular symmetrically to a vertical plane of symmetry through the I-shaped profile or the T-shaped profile.

4. The chair base according to claim 1, wherein the lower flange and / or the upper flange has or have a concave, preferably V-shaped in the operating position, particularly preferably inverted V-shaped, indentation.

5. The chair base according to claim 1, wherein the U-shaped profile is essentially inverted in the operating position, wherein legs of the U-shaped profile are essentially vertically aligned and wherein a side of the U-shaped profile arranged between the legs forms an upper side.

6. The chair base according to claim 1, wherein the upper side of the U-shaped profile or an upper side of the O-shaped profile and the upper flange of the I-shaped profile or of the T-shaped profile merge into one another.

7. The chair base according to claim 1, wherein a wall is arranged between the U-shaped profile or the O-shaped profile and the I-shaped profile or T-shaped profile, preferably wherein the wall forms a transition between the legs of the U-shaped profile and the web of the I-shaped profile or T-shaped profile.

8. The chair base according to claim 1, wherein the I-shaped profile or the T-shaped profile extends along the longitudinal direction over between 50 and 80%, preferably over between 60 and 70%, of a length of the at least one arm.

9. The chair base according to claim 1, wherein the at least one arm has a support area at the outer arm end for supporting the chair base, preferably wherein the support area has a bearing opening, in particular in the form of a blind hole, for receiving an insertable extension, e.g. from castors.

10. The chair base according to claim 9, wherein the support area has an outer wall closed circumferentially, preferably wherein stiffening struts are arranged between the bearing opening and the outer wall, in particular which are aligned radially to the bearing opening.

11. The chair base according to claim 9, wherein the outer wall merges into the O-shaped profile or the U-shaped profile, in particular into the legs and the upper side of the U-shaped profile.

12. The chair base according to claim 1, wherein the inner arm ends of the arms facing the opening form an area which is substantially concentric with the opening and has a reinforced double wall, preferably wherein the concentric area has radial stiffening struts which are preferably spaced apart from one another and / or is open at the bottom in the operating position. preferably regularly spaced stiffening struts and / or is open at the bottom in the operating position.

13. The chair base according to claim 12, wherein an outer wall of the double wall merges into the I-shaped profile or the T-shaped profile, in particular into the web and the upper flange and / or the lower flange.

14. The chair base according to claim 1, wherein the arms are formed separately from one another and are preferably connected to the opening and / or to one another.

15. The chair base according to claim 1, wherein the chair base consists at least in part and / or proportionally, preferably completely, of plastic.

16. A chair frame for supporting a seat, the chair frame comprising:the chair base according to claim 1,a post inserted into the opening, in particular a gas pressure spring, anda connecting element attached to the post for attaching the seat.

17. A chair, in particular office or work chair, comprising:the chair frame according to claim 16,a seat attached to the connecting element, andcastors, stoppers, sliding elements or the like attached to the arms.

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