WO2018007200A1

WO2018007200A1 - Base for an item of seating furniture

Info

Publication number: WO2018007200A1
Application number: PCT/EP2017/065816
Authority: WO
Inventors: Peter Wagner
Original assignee: Topstar Gmbh
Priority date: 2016-07-04
Filing date: 2017-06-27
Publication date: 2018-01-11
Also published as: EP3478129B1; EP3478129A1; DE202016103557U1

Abstract

The invention relates to a base (1) for an item of seating furniture (10), particularly for a stool, comprising on its underside (3), which faces the floor (20), a plurality of elastic elements (6) that project from said underside (3). Said elastic elements (6) allow both lateral (P1) and vertical (P2) movements and can preferably be deformed and/or move independently of one another.

Description

Foot for a chair

The invention relates to a foot for a chair, in particular for a chair, stool or stool, which is connected via a single, usually height-adjustable leg with the foot.

It is now known that especially office chairs should be movable so that the back muscles are stabilized and strengthened to prevent back complaints. The known movable seating uses different principles: in the Applicant's model "Sitness 20", for example, the foot consists essentially of an air-filled tire.

DE 20 2014 000 079 U1 discloses a movable stool which has an annular base, the inwardly leading profile of which tapers continuously downwards in diameter, and continuously merges from the vertical position at the top to a horizontal position at the bottom and thus with increasing load an increasing restoring behavior developed. This should enable automatic weight adjustment.

Although the known movable pedestal or feet allow a tilting movement of the seat, but smaller micro-movements, eg in the lateral direction, only limited. However, it is precisely these minimal movements that train the back muscles the most, without consciously occupying the seated person and thus distracting from the work. The invention thus has the task of providing a foot for a chair, which also allows small movements and / or vibrations of the seat. Another object of the invention is to provide a foot for a chair, which is also easy and inexpensive to produce.

This object is achieved by a foot for a chair according to claim 1 and a chair according to claim 18. According to the invention, the foot rests on several, protruding from the bottom, elastic elements. By "protruding" is meant in particular that the elastic elements protrude from the plane of the underside or protrude from it, in particular downwards towards the floor.

During a movement of the seated person, the elastic elements execute micro movements, which lead to a particularly advantageous oscillation of the seat surface. Preferably, especially small movements, i. Vibrations of low amplitude, possible in different directions. Overall, the foot according to the invention allows a tilting security of the furniture with simultaneous mobility.

According to a preferred embodiment, the elastic elements allow both lateral and vertical movements. In particular, it is advantageous if the individual elastic elements allow a slight displacement of the foot parallel to the floor, preferably in all directions, and thus allow lateral movements. In addition, the elastic elements in advantageous embodiments in the vertical direction, ie perpendicular to the floor, elastic, for example, elastically compressible. As a result, both a vertical movement, as well as a tilting movement of the seat surface is made possible, the latter in particular when the elastic elements are shortened elastically only on one side of the foot ßes. In particular, the foot here acts like a fitness sole of a sneaker, which allows both a movement around the fitness sole and a movement of the fitness sole itself. In advantageous embodiments, the elastic elements are made of an elastic material, in particular polyurethane (in particular TPU) or polyethylene. Also possible is rubber or rubber. Preferably, the elastic-see elements are part of a foot base, which forms the bottom of the foot and z. B. is made by injection molding. In advantageous embodiments, the entire underside of the elastic material is formed in the manner of a fitness sole, for example, the entire foot base. Advantageously, the elastic material has a Shore A hardness of 50 to 70. The elastic elements are z. B. elevations of elastic material, which may have a round or square longitudinal or cross-section. In preferred embodiments, the elastic members have a height and / or width of over 10mm, preferably 15 to 50mm, more preferably 20 to 40mm, even more preferably 25 to 35mm. The elastic elements may have their base above the bottom, so that they protrude only slightly (for example 1 -5 mm) from the bottom, despite greater height.

In advantageous embodiments, elastic elements are arranged on the underside of the foot between 6 and 70, preferably between 20 and 40. The number of elements is related to the spring constant or to the hardness / elasticity of the elastic elements. However, it has been found that an advantageous seat dynamics can be achieved in particular by more than 6 elastic elements. The underside is typically curved slightly outwards (ie toward the floor), so that when sitting still, all the elastic elements make contact with the floor, and preferably only the elastic elements. In advantageous embodiments, the foot also allows a tilting, in which this is no longer the case, for example, by a "rolling" of the foot base to the outside.This happens, for example, in a deliberate tilting movement of the sitter preferably absorbed by the elastic elements so that they do not lose contact with the floor. Preferably, the elastic elements are independently movable or deformable. This distinguishes the novel foot from the models, for example, with air-filled tires, as this represents a single oscillating object. As a result, it has entirely different amplitudes and natural frequencies than the elastic elements according to the invention, which oscillate at a lower amplitude and at a higher frequency. It is also possible to arrange various elastic elements on the underside, so that some elastic elements allow different movements (eg with greater amplitude or in other directions) than the others. Movements in all directions, both translational and rotational movements, are advantageously possible, in particular, these each have a comparatively small amplitude.

In a preferred embodiment, the ratio of the projecting areas of all elastic elements to the projecting area of the underside is between 10% and 30%, preferably between 15% and 22%. Thus, projecting the underside of the foot onto the floor results in an area which is set in proportion to the sum of the corresponding projecting areas of the elastic elements. The projected area of an elastic element may also correspond to its bearing surface on the floor, but this is not necessarily the case, since the elastic elements partly still have a certain texture on their underside, in any case they do not necessarily rest on the floor over the entire surface. The projecting area of a single elastic element can thus be between 0.2 and 2% of the total area of the underside, all elastic elements together, for example, amount to 10 to 30%. This results in a particularly advantageous interaction of mobility of the seat on the one hand and stability and stability on the other hand.

Preferably, in each case the two elastic elements which are furthest apart are at least 23 cm apart (measured from the center to the middle of the elastic elements), more preferably at least 25 cm. This also helps to improve the tip resistance of the foot, but without restricting the freedom of movement of the sitter.

The foot preferably has a round base, i. the projecting area of the underside is round. Alternatively, however, polygonal shapes, e.g. 5-, 6- or 8-sided conceivable. Advantageously, radially outward of the outermost elastic elements there is still an edge of the foot, which is advantageously made of elastic material, or a part of e.g. one-piece foot-lower part of the elastic material is. As a result, the seating and thus the foot can be tilted without losing the grip on the floor. This allows a particularly flexible, mobile sitting and working, especially in a stool.

Preferably, the elasticity and mobility of the foot is determined by the material properties (elasticity, hardness, etc.) and the shape of the elastic elements or of the foot base - in contrast to stools according to the prior art which work with pneumatic tires. The foot or base of the invention preferably does not include pneumatic tires or other air-pressure elements.

In a particularly advantageous embodiment, the elastic elements are designed as profile blocks which are each surrounded by tread grooves. The tread grooves can be narrow or so wide that they are referred to as cutouts. Preferably, at least some of the tread blocks and tread grooves are formed from a single piece of the above elastic material. In particular, the foot has a lower foot part of the above-described elastic material, for example polyurethane, in which the tread blocks and tread grooves are formed. The tread grooves are in an advantageous embodiment as deep (and thus the tread blocks so high) that the tread blocks can swing individually or relatively independently. In particular, in some embodiments, the ratio of the largest diameter of a tread block (as viewed from the underside) to its height is between 0.6 and 1.0. This ratio determines - in conjunction with the hardness and other properties of the material and the shape of the tread blocks - the vibration characteristics of the foot. It has been found that by means of such a ratio, preferably between 0.75 and 0.9, a particularly pleasant lateral mobility and tilting movement of the seat surface is achieved. This also contributes to the depth of the tread grooves, which, for example, between 15 and 45 mm, in particular 22 to 33 mm. This dimensioning of the tread blocks and tread grooves ensures that the seat performs micro-movements that strengthen the back muscles of the seated person without having to perform disturbing compensatory movements so as not to lose his balance.

Moreover, in some embodiments, the elastic material also has suitable damping properties. It is desirable that the seat is indeed to be movable, but this movement does not rock or lead to a continuous and therefore unsettling vibration. Instead, the said micro-movements should be allowed, but then also dampened to allow a quiet work. In addition to the material properties from which the tread blocks are made, it is advantageous in terms of damping if at least some of the tread blocks are at least partially hollow. The thus trapped air leads to an advantageous vibration damping.

Seen from the bottom (or in cross-section, ie in section parallel to the floor), at least some of the tread blocks in some embodiments, a round or hexagonal shape. These approximately circular-symmetrical shapes have the advantage that lateral movements / vibrations are uniformly allowed in all directions. Of course, however, other shapes are conceivable, such as rectangular, square or octagonal. Likewise, it is also conceivable to provide a slat profile, it being advantageous if the slats are aligned in different areas of the bottom in different directions. Advantageously, at least some of the tread blocks on a rectangular longitudinal section. As a result, a particularly advantageous vibration and movement behavior is generated. A more damped oscillation would be achieved for example by a trapezoidal longitudinal section, which is also advantageous. Alternatively, the tread blocks can also be designed to be round downwards.

In an advantageous embodiment, the profile blocks each have at least one elevated area on their side facing the floor. As a result, the adhesion to the floor is improved, thus ensuring the slip resistance. Alternatively, the tread blocks may also have a different texture on their side facing the floor, in particular a non-slip texture, e.g. Grooves or a flat profile. In a preferred embodiment, the floor facing side of the tread blocks is flat, so at a height, with the underside of the foot. However, the said elevated areas are then present accordingly, so that only the raised areas have contact with the floor. In some embodiments, multiple raised areas are provided per tread block. The height of the raised areas over the underside is for example 1 to 4 mm, in particular 1, 5 to 2.5 mm. In other words, the elastic elements preferably project by about this amount from the underside.

Preferably not projecting areas of the underside are provided between the tread blocks, which in particular also consist of the elastic material. In the case of a tilting movement of the foot, these can also partially touch the floor and thus support the resilient and damping effect of the foot.

As already mentioned, the tread blocks and tread grooves are preferably formed in a foot bottom of an elastic material. So if the foot base is relatively soft, this is advantageously connected to a stable support. In some embodiments, this is formed by a foot top, which preferably has recesses or openings. Preferably exists the foot shell of a harder material, in particular plastic, z. B. polyamide. The recesses may be punctiform or elongated cuts or breakthroughs. Advantageously, the recesses form a desired pattern / picture element or lettering. Through these recesses can advantageously be seen from above the elastic material of the foot base, and even easily penetrate with appropriate movement of the foot in the recesses. This leads to a pleasant design effect, especially if foot base and foot top have a different color. The elastic material of the foot base is color-dyed in advantageous embodiments, for example in yellow or green. In particular, in the embodiments in which recesses are present in the foot top, this results in an innovative design effect. To ensure movement in all directions, it is advantageous if the elastic elements are evenly distributed over the underside of the foot. In particular, a point-symmetrical and / or mirror-symmetric distribution is possible. In this case, for example, be arranged in each 30 ° segment of the bottom between 1 and 5 elastic elements.

The invention is also directed to a corresponding seating furniture having a foot according to the invention, in particular it is connected via a single leg with one foot. Advantageously, the leg is height adjustable, for example via a gas spring. In some embodiments, such a high level of height adjustment is achieved that the seat can be used sitting and standing, so it is a stand-up stool. On the other hand, the foot can also be used for children's and young people's chairs and stools, as it provides a great resistance to tipping with simultaneous mobility. The foot can be used for a chair with back and / or armrests as well as for a stool (ie without backrest) as well as for a saddle-like seat. Particularly preferably, the seating is a work chair / stool, especially office chair / stool. The invention will now be explained in more detail by means of embodiments with reference to the accompanying drawings. In the drawings show:

1 is a perspective view of a chair with a foot according to an embodiment of the invention.

Fig. 2 is a partial longitudinal section through a foot according to an embodiment of the invention;

Fig. 3 is an enlarged detail of Fig. 2;

Fig. 4 is a central longitudinal section through a foot according to another embodiment of the invention;

Fig. 5 is a simplified bottom plan view of a foot according to an embodiment of the invention;

6 is a simplified plan view of a foot according to another embodiment of the invention;

Fig. 7 is a bottom plan view of a foot according to an embodiment of the invention;

Fig. 8 is a section along the line A-A in Fig. 7;

Fig. 9 is a longitudinal section taken along the line B-B in Fig. 7;

10 is a top plan view of a foot according to one embodiment of the invention. Identical or corresponding elements are indicated in the drawings with the same reference numerals.

Figure 1 shows a perspective view of a chair 10 with a foot 1 according to an embodiment of the invention. The foot 1 is connected via a pillar or a single leg 12 with a seat 2. In the example shown is still missing the actual seat, which can be placed and fixed on the base 2 shown. The height adjustment of the chair is realized by a conventional gas spring 1 1.

The leg 12 extends centrally from the foot 1 upwards, which has approximately the shape of a circular disc in the example shown. The top of the disc is provided in this example with star-shaped elongated recesses 5, through which the underlying foot base 13 shimmers through. On the underside 3 are different tread grooves 4, which will be explained in more detail below.

Figure 2 shows a foot according to an embodiment of the invention in a central longitudinal section. Therein, first, the gas spring 1 1 can be seen. At the lower end of the gas spring 1 1 and the leg 12 of the foot 1 is attached, which rests with its bottom 3 on the floor 20 partially. In particular, the chair leg 12 is attached to a foot top 15, which is made of a hard material such as plastic or metal, for example. On the underside of this upper foot part 15, an annular element 13 made of elastic material is attached, which is referred to below as foot base 13. In the foot base, the elastic elements 6 are formed in the form of tread blocks, which are each surrounded by tread grooves 4. The tread blocks 6 protrude beyond the underside 3 of the foot, so that the foot rests exclusively on the sides 16 of the tread blocks facing the floor. There are also non-elevated areas 7 between the tread blocks. The diameter d of the foot is, for example, more than 30 cm, in particular more than 32 cm, in order to ensure adequate tipping safety. FIG. 3 shows an enlargement of the profile blocks 6 in order to be able to explain their function in more detail. The tread blocks 6 are formed integrally with the foot base 13, which consists for example of polyurethane. Due to the elastic properties of this material, the tread blocks 6 can move or deform in different ways: on the one hand, they can oscillate laterally about their base points M1, which is symbolized by the arrow P1. The distance between the base M1 and the support surface on the floor 16 is r, where in preferred embodiments r can be between 20 and 40 mm, preferably 25 to 35 mm. This height of the tread blocks, which is particularly pronounced for a rubber profile, leads to freedom of movement of the foot, which permits small lateral micro movements of the seat surface. In particular, adjacent tread blocks oscillate synchronously. Furthermore, however, the tread blocks can also be compressed along the radius r. This allows for a height suspension of the foot. In particular, however, this allows a tilting movement, namely, when, for example, the profile block 6a shown on the left is compressed, while the profile block 6b shown on the right is not compressed, or even stands out easily from the floor. This corresponds to a tilting movement about the point M2, which is symbolized by the arrows P2.

It is understood that the illustrated lateral movements (P1) and tilting movements (P2) can also be arbitrarily combined with each other. Various elastic elements 6 may also participate in different types of vibrations and movements at the same time. In particular, by the lateral mobility of the elastic elements 6 shown with reference to the arrows P1 results in a back-enhancing mobility of the chair equipped with the foot.

FIG. 4 shows another embodiment of the foot 1. This foot also has a foot top 15. This is followed, however, by a differently staltetes foot base 22 at. This has recesses 23. In each of the recesses is a spring element 24, in this case a coil spring. In the example shown, connects to the lower ends of the

Coil springs 24 a stopper element 25 which rests on the floor 20 and is connected via the coil spring 24 to the foot 1. In this case, the elastic elements 6 are thus essentially formed by a spring element 24 with a corresponding display surface to the floor, wherein the spring element is typically made of metal and thereby requires a further rubber element 25 as a non-slip footing on the floor. The functionality of this embodiment according to Figure 4 is similar to that of Figure 3. Here, lateral and rotary oscillations can be allowed, the strength of the vibration and its amplitude depends on the spring constant. Figure 5 shows a bottom view of a bottom 3 of a foot, which in turn is provided with tread blocks 6 and tread grooves 4. In the center 18 is the connection to the gas spring 1 1, so that this area is recessed. The dotted areas project respectively from the bottom to the front and are part of the elastic elements or tread blocks 6. Various types of tread blocks are shown, in particular round and quadrangular. These are each surrounded by tread grooves 6, wherein some tread grooves are also directed radially outwards and do not directly enclose a tread block.

The profile grooves 4 are for example about 2 to 6 mm wide, preferably 3 to 5 mm. This allows sufficient lateral movement of the tread blocks.

Furthermore, Figure 5 shows a round profile block 6, which has three round raised portions 8, which rest in use on the floor. That is, not the entire profile block protrudes over the bottom 3, but only the raised areas 8. This leads to an optimized support and adhesion to the floor. Figure 6 shows an advantageous embodiment in which the profile elements 6 are hexagonal in plan view from below. This has the advantage that they can be arranged honeycomb. This allows a comparatively dense packing / arrangement of the tread blocks while maintaining a sufficient distance (in the form of tread grooves 4) between adjacent tread blocks 6. In the example shown, 12 tread blocks are provided.

Here too, additional profile grooves 4a are arranged in the elastic material 13 of the foot part 13. This supports the movement possibilities of the foot.

Figure 7 shows a plan view from below of a foot according to an advantageous embodiment of the invention. Here you can see the foot base 13, which is fastened by means of screws 14, in this case Ejot screws on the foot top. In the center of the round foot, the foot upper part can be seen in its central region 18, on which the gas spring is plugged.

The lower foot part 13 is preferably made of TPU (thermoplastic polyurethane), although other thermoplastic elastomers are conceivable. Preferably, it is a super-soft plastic with hardnesses below 75 Shore A. The foot base has a profiling, which is described in more detail below: The elastic elements are here formed by hexagonal tread blocks 6 having a maximum diameter of 24 to 28 mm (preferably 26 mm) and are each surrounded by tread grooves, which a width of 4 mm and a depth (measured from the bottom 3) of about 28 mm. The tread blocks 6 are arranged honeycomb-shaped, with five tread blocks each forming an outwardly open semicircle in each 60 ° segment.

The tread blocks do not protrude as a whole from the bottom 3, but each have centrally oriented raised areas 8, which also have a hexagonal base, but a slightly smaller diameter of only about 20 mm. These are shown in FIG. 7 with thick borders. Only the Surfaces of the raised areas have contact with the floor 20 in use. In addition to the tread grooves 4 surrounding the tread blocks 6, there are also radially extending additional tread grooves 4a which in this example have the same depth and width as the other tread grooves 4. These are radially aligned incisions increase the compressibility of the foot base and thus lead to a greater flexibility in the circumferential direction. It can z. B. 4-10 radially oriented tread grooves may be provided. The pattern of the honeycomb profile grooves 4 continues in some places, even without a profile block 6 is completely surrounded by tread grooves, such as the tread extensions 4b. This partially additional profile blocks 19, which are not completely surrounded by tread grooves 4. In this example, the tread blocks 19 have no elevated areas 8 and thus have no contact with the floor; however, in other embodiments, this could be provided. However, it is advantageous if all the profile blocks at least substantially the same dimensions, dimensions and material properties, so that they can swing together with the same frequency. The natural frequency of the lateral movement P1 of the tread blocks is in some embodiments, for example between 0.2 and 3 Hz.

Figure 8 shows a longitudinal section along the line AA in Figure 7. Here, the first gas spring 1 1 can be seen, which is inserted into the foot top 15 and held by this. The cut passes through one of the above-mentioned radial recesses 5 of the foot top 15, so that the elastic material of the foot base 13 extends in this area to the top of the foot. Further, one of the screws 14 is cut, with which the foot base is attached to its holder (here the foot top). In the section you can see very well the longitudinal section of the two profile blocks 6 with their elevations 8, which protrude about 2 mm from the bottom 3. The bottom 3 is a total of slightly convex, so that in normal sitting, although all elevated Areas 8 have contact with the floor, but still a tilting of the seat is possible, for example, when the sitter leans forward or otherwise moves. The cut is also through the here radially oriented tread grooves 4, so that their pronounced depth is clear. The tread blocks are approximately the same height as wide at this location, resulting in optimum vibration and compression performance (particularly in the vertical direction), thus ensuring that the foot can perform the beneficial lateral micro-movements and light micro-tilts To allow sitting in motion.

FIG. 9 shows the longitudinal section, which does not go through the center, along the line B-B in FIG. As a result, the fine structure of the foot upper part 15 and the foot bottom part 13 is visible in this exemplary embodiment. In particular, both parts are not solid but have an inner rib structure. This leads to stabilization while saving material, especially in the case of the foot shell made of plastic. This has inwardly directed ribs 29 which surround corresponding cavities 28. The foot base of a softer, elastic material also has cavities 26 which extend partially into the tread blocks 6. As a result, an advantageous damping of vibrations of the tread blocks 6 is achieved in order to ensure a stable sitting feeling. Between the cavities are also ribs 30, which protrude upwards and partially into the cavities 28 of the foot shell. This also has a favorable influence on the vibration behavior. The exact design with ribs / cavities in FIG. 9 is merely an example, and a solid foot base 13 may also be advantageous.

FIG. 10 shows a plan view from above of the foot of FIGS. 7 to 9. In the center, the gas spring 12 can be seen, and otherwise the foot upper part 15 with its radially oriented, elongate recesses 5. Through these openings, the underlying elastic Material of the foot base visible, which with a corresponding colored coloring of this material a gives a pleasing visual effect, especially when the seating 10 is used. The movement of the foot is then reflected in the movement of the elastic material, which presses dynamically at changing points against the openings 5.

Claims

claims

Foot (1) for a seat (10), in particular for a stool, which has on its bottom (3) facing the bottom (3) a plurality of the underside (3) projecting elastic elements (6).

Foot (1) according to claim 1, wherein the elastic elements (6) allow both lateral (P1) and vertical movements (P2).

Foot (1) according to claim 1 or 2, wherein the elastic elements (6) made of an elastic material, in particular polyurethane or polyethylene, are formed.

Foot (1) according to one of the preceding claims, wherein on the bottom (3) facing the bottom (3) between 6 and 70, preferably between 20 and 40, elastic elements are arranged.

Foot (1) according to one of the preceding claims, wherein the elastic elements (6) are independently deformable and / or movable.

Foot (1) according to any one of the preceding claims, wherein the ratio of the projecting areas of all elastic elements (6) to the projecting surface of the underside (3) is between 10% and 30%, preferably between 15% and 22%.

7. foot (1) according to any one of the preceding claims, wherein the elastic elements (6) are formed as profile blocks.

Foot (1) according to claim 7, wherein the tread blocks (6) are each surrounded by tread grooves (4, 4a).

9. foot (1) according to claim 7 or 8, wherein at least a portion of the tread blocks (6), seen from the bottom, has a round or hexagonal shape.

10. foot (1) according to any one of the preceding claims 7 to 9, wherein the ratio of the largest diameter of a tread block (6) to its height between 0.6 and 1, 0 is.

1 1. Foot (1) according to one of the preceding claims, wherein the elastic elements or profile blocks (6) have a height and / or width of about 10mm, preferably 15 to 50mm, more preferably 20 to 40mm.

12. foot (1) according to any one of the preceding claims 7 to 1 1, wherein at least some of the profiled blocks (6) are at least partially hollow.

13. foot (1) according to any one of the preceding claims 7 to 12, wherein at least some of the profiled blocks (6) have a rectangular longitudinal section.

14. foot (1) according to any one of the preceding claims 7 to 13, wherein the profiled blocks (6) each have on their side facing the floor at least one raised portion (8).

15. foot (1) according to any one of the preceding claims 7 to 14, wherein the tread blocks (6) and possibly tread grooves (4) in a foot base (13) are formed from an elastic material.

16. foot (1) according to any one of the preceding claims, wherein the elastic elements (6) are evenly distributed over the underside (3) of the foot, in particular point-symmetrical and / or mirror-symmetrical.

17. foot (1) according to any one of the preceding claims, which has a Fuß- upper part (15) with recesses (5).

18. Seating furniture with one foot (1) according to one of the preceding claims, in particular stool, stool or standing stool.