EP1604589B1 - Device for adjusting the height of a table - Google Patents

Abstract

The tabletop (2) is provided with semicircular recesses for the insertion of the upper ends of the legs (3.1, 3.2, 3.3, 3.4) and surrounded by a hollow profile (4.1, 4.2, 4.3, 4.4). Each of the legs (3.1, 3.2, 3.3, 3.4) is equipped with a spindle (7.1, 7.2, 7.3, 7.4) accommodated inside and a hexagonal opening (8.1, 8.2, 8.3, 8.4) at the top. The spindles (7.1, 7.2, 7.3, 7.4) are interconnected with an endless serrated belt (9.1, 9.2, 9.3, 9.4). When one of the legs (3.1, 3.2, 3.3, 3.4) is turned all spindles (7.1, 7.2, 7.3, 7.4) are simultaneously rotated in order to lift or lower the tabletop (2).

Description

Technical area

The invention relates to a device for adjusting the height of a table with three or more arranged in an edge region of the table legs, each adjacent legs are connected by a horizontal, hollow profile-like connecting element. Each of the table legs comprises a telescopic mechanism for changing its length, which is adjustable by turning a rotatably mounted adjusting element, wherein the adjusting elements are vertical spindles and wherein a drive member is rotatably connected to each of the spindles. The invention further relates to a table with a device for height adjustment and a method for retrofitting a table with a device for height adjustment.

State of the art

Desks and desks with a table top, whose inclination and height can be adjusted to the needs of users, have long been known. But it is also often desirable for tables with non-adjustable, in particular horizontal, table tops, such as work and meeting tables and tables in the living area that the height of the table top can be adjusted. In meeting tables and dining tables for example, this allows an adaptation to the commonly used with the table, not height-adjustable seating; At work desks, together with the correct adjustment of the seat, an ergonomically correct sitting position adapted to the size of the user's body is made possible.

In such tables must be ensured in the height adjustment that the inclination of the table top remains constant, that the plate, for example, always assumes a horizontal position. This is achieved in known tables, for example, by the fact that only a single central foot is present, which is designed to be height adjustable. Also known are tables with two lateral feet whose height adjustment mechanisms are electrically or mechanically coupled.

For aesthetic reasons and thus the least possible legroom for the support structure of the table top is claimed, often tables with three or more arranged in an edge region of the table legs, especially tables with a rectangular, horizontally oriented table top and four arranged in the corners of the table legs used. This raises the problem that the height adjustment of more than two spaced support elements must be synchronized with each other.

The US 5,088,421 (Beckstead ) shows, for example, a work desk with a vertically adjustable worktop, which has at its corners four legs, which are connected laterally and on the back by plates. On the legs is a rectangular extending table frame, which carries the table top. The four table legs each have a spindle drive for height adjustment. In the corners of the frame triangular frames are fixed, each with a bearing for one of the spindles. All spindles are through a single circumferential chain, which runs along the Zargeninnenseite synchronized with each other. The chain is driven by a motor via a drive pinion.

Users of the table can, however, injure themselves on the open chain, and the chain can lead to contamination, for example by lubricant. The arrangement of the chain and the bearing for the spindles is also aesthetically unsatisfactory for modern designed tables.

The EP 0 283 103 A1 (Technical Handels Adviesbureau) relates to a table leg for a height-adjustable table with at least two, substantially juxtaposed L-shaped table legs. The table legs comprise two mutually adjustable sections, of which the upper is fixed to the table top and the lower comprises a spindle bush which cooperates with a spindle in the upper portion. An electric drive is rotatably in the lower portion of the table leg, but held displaceable and freely suspended at the lower free end of the spindle. In principle, a single equipped with the drive table leg, the spindles of several other, non-powered legs can be coupled to the driven spindle. For this purpose, toothed disks are arranged on the driven spindle, via which the toothed belt transmits the spindle movement to the spindles of the other legs.

Again, the timing belt is arranged open: compared to a chain contamination by lubricant can indeed be avoided, but there is still a risk of injury and the arrangement of the timing belt is aesthetically unsatisfactory.

This problem can be solved by providing a protective element in which the chain is received. From the FR 2 747 280 (BI 2 S SA) is for example a height-adjustable frame for furniture in the hospital known, for example, for beds or tubs. The frame is formed by a rectangular frame with two longitudinal tubes and transverse tubes arranged between them, wherein at the corners in each case a vertical, height-adjustable three-part Teleskopfuss is fixed with rollers. On the frame, a motor is arranged which drives a pinion, which cooperates with a drive chain which is guided in channels in the longitudinal and transverse tubes of the frame (page 3, lines 28-35). The drive chain interacts in the telescopic feet with a spindle at the top End of a pinion is arranged rotationally fixed. About the external thread of the spindle of the three-part Teleskopfuss is retracted or retracted.

In the EP 0 129 941 A1 (De la Haye ) discloses a height adjustable by threaded rods table with telescopic legs, the geometry and size of which can be changed by the modular design of part table tops and the number of table legs. The table legs are L-shaped with a long foot, so that a simple table without additional partial table tops can stand securely on two feet. The height adjustment of all table legs is synchronized via a rotary link, which mediates between the individual legs of the table and which is housed within a square hollow section, which is arranged between the legs of the table. The height adjustment can be done manually by means of a crank or via a motor. The threaded rods of the table legs are connected via screw elements and cardan joints with the rotary linkage.

From the DE 198 15 234 A1 (Förster ) is a workbench with several adjustable in length legs legs known. All table legs can be changed simultaneously and evenly in length via a manually or motor-operated mechanism. The height adjustment is done for example by threaded spindles. The transmission of torque between all adjustment mechanisms can be done via a cable or a wedge or toothed belt, which cooperates with corresponding pulleys on the spindles and runs in the table top frame carrying.

Chains are relatively heavy and expensive and require regular maintenance. Wedge or timing belt are lighter, cheaper and virtually maintenance-free, but prone to length changes. The circulating in the furniture frame belts are quite long, so that even a small relative change in length is sufficient so that the contact between the belt and the corresponding pulleys is no longer guaranteed or that due to the forces occurring the table frame is warped. A circulating belt can also be used in the production or retrofitting of the table only in the surrounding table frame, if the frame is designed accordingly, so can share accordingly or, for example, has a continuous longitudinal slot, or if the belt can be divided and reconnected , The longitudinal slot is not desirable for aesthetic and safety reasons, a division makes the belt more expensive and less durable.

Presentation of the invention

The object of the invention is to provide a the aforementioned technical field associated device for height adjustment, which is reliable, aesthetically unobtrusive and easy to manufacture and assemble.

The solution of the problem is defined by the features of claim 1. According to the invention, the device for height adjustment comprises a plurality of endless coupling means, which are received within the connecting elements and each mechanically synchronize two actuating elements, wherein the coupling means are arranged such that they rotate around the drive parts of the spindles of the adjacent table legs and cooperate therewith, guides are provided for the endless coupling means, which have an outer cross-section which substantially corresponds to an inner cross section of the table legs and which comprise a longitudinally oriented receptacle for the drive part and laterally arranged openings for carrying out the coupling means.

A single one of the coupling means, which synchronizes two of the adjusting elements with each other, has a smaller spatial extent than a single coupling means, which must synchronize all the adjusting elements with each other. Length changes are therefore made to a lesser extent, so that a reliable operation is ensured. The separate coupling means can also be arranged so that an installation in the Connecting elements is also easily possible if the elements are closed, that is, for example, substantially tubular.

1. a) Ersetzen der Tischbeine durch höhenverstellbare Tischbeine mit einem Teleskopmechanismus zur Änderung einer Länge des Tischbeins, wobei der Teleskopmechanismus durch Verdrehen eines drehbar gelagerten Stellelements verstellbar ist, wobei die Stellelemente vertikale Spindeln sind und wobei mit jeder der Spindeln drehfest ein Antriebsteil verbunden ist, wobei Führungen für endlose Kopplungsmittel vorhanden sind, welche einen Aussenquerschnitt aufweisen, der im Wesentlichen einem Innenquerschnitt der Tischbeine entspricht und welche eine längs orientierte Aufnahme für den Antriebsteil und seitlich angeordnete Öffnungen zum Durchführen der Kopplungsmittel umfassen;
2. b) für jeweils zwei benachbarte Tischbeine Einführen eines endlosen Kopplungsmittels zur mechanischen Synchronisation der Stellelemente der benachbarten Tischbeine in das die Tischbeine verbindende Verbindungselement, wobei die Kopplungsmittel derart angeordnet sind, dass sie die Antriebsteile der Spindeln der benachbarten Tischbeine umlaufen und damit zusammenwirken; und
3. c) Koppeln der Kopplungsmittel mit den Stellelementen.

The separate coupling means can thus also allow in particular the retrofitting of existing tables with a device for height adjustment. For this purpose, at a table with arranged in an edge region of the table table legs, each adjacent legs are connected by a horizontal, hollow-profile-like connecting element, the following steps:

1. a) replacing the legs by height-adjustable legs with a telescopic mechanism for changing a length of the table leg, wherein the telescopic mechanism is adjustable by turning a rotatably mounted adjusting element, wherein the adjusting elements are vertical spindles and wherein each of the spindles rotatably connected to a drive part, wherein guides are provided for endless coupling means, which have an outer cross-section which substantially corresponds to an inner cross-section of the table legs and which comprise a longitudinally oriented receptacle for the drive part and laterally arranged openings for carrying out the coupling means;
2. b) for each two adjacent table legs, inserting an endless coupling means for mechanically synchronizing the actuator elements of the adjacent table legs with the connecting member connecting the table legs, the coupling means being arranged to rotate and cooperate with the drive members of the spindles of the adjacent table legs; and
3. c) coupling the coupling means with the actuating elements.

A table for which the device according to the invention for height adjustment is suitable, for example, comprises a rectangular, horizontally oriented table top, in each of whose four corners a table leg is arranged. Along the edge of the table top, hollow profile-like frames run as connecting elements between the legs of the table. The frames and table legs can together form a mechanically stable table frame, on which the tabletop is merely placed. For additional stabilization, the table top can also be screwed to the frames. Alternatively, the table legs be directly connected to the table top, and the fasteners provide additional stabilization or serve in addition to the inclusion of the coupling means mainly aesthetic purposes. In each of the connecting elements, a separate coupling means is accommodated, by which the adjusting elements of the table legs adjacent to the connecting element are synchronized.

Telescope mechanisms for changing the length of table legs are known per se. They may comprise two or more telescoping telescopic elements which are adjustable relative to each other. The telescopic elements may for example have a cylindrical or another prismatic shape. From top to bottom, the telescoping elements may have a stepwise increasing or a stepwise decreasing cross section, such that the inside wall of one element can be slidably mounted on the outside wall of the corresponding adjacent element.

The adjusting elements are vertical spindles, which interact via a thread with a telescopic element of the telescopic mechanism. Such a mechanism is stable and structurally simple, by the transmitted to the actuator rotational movement is used directly for vertical displacement of the spindle or the cooperating telescopic element. The spindles can be designed both as hollow spindles with internal and / or external thread as well as full spindles with external thread.

The coupling means are endless, and with each of the spindles a drive member is rotatably connected. The coupling means are arranged so that they rotate around the drive parts of the spindles of the adjacent table legs and cooperate therewith. In this way, a purely mechanical synchronization of the telescopic mechanisms of adjacent legs is realized, which is simple, inexpensive, low maintenance and easy. The drive member may be integrally formed on the spindle, or it is screwed to the spindle, for example, riveted, welded, glued or positively attached to the spindle.

The endless coupling means are preferably belts, in particular toothed belts, or chains. Belts are lightweight, cost-effective, maintenance-free and low-maintenance. Form-fitting belts, such as toothed belts, also ensure that the synchronization between the spindles is always ensured by the positive connection with the drive parts. In addition to timing belt and V-belt or flat belt can be used, optionally together with corresponding belt tensioners, which are arranged for example in the connecting elements. When using chains of metal, plastic or a composite, the synchronization between The spindles also ensured, the risk of length change is also minimized compared to other endless coupling means.

Because a separate endless coupling means is used in each case for the synchronization of the spindles of adjacent table legs, the material-dependent possible change in length compared with a longer endless coupling means which simultaneously synchronize all spindles is reduced. In addition, the contact area between the coupling means and the driving part of the spindle is increased because, for example, in a rectangular table, the coupling means rotates about 180 ° about each driving part and not only about 90 °. Both leads to increased reliability and increased life of the device for height adjustment.

Spacers are preferably arranged in the connecting elements for guiding the two opposite sections of the endless coupling means in the connecting elements. The spacers avoid wedging the two parallel, opposing portions of the endless coupling means, which are guided in a connecting element. Depending on the shape of the connecting element they also serve to prevent wedging between the coupling means and the inner wall of the connecting element. Any clamping device for the coupling means is advantageously also formed on the spacers or attached thereto. Depending on the length of the connecting elements and the distance between the two portions of the coupling means only two spacers can be arranged at the two outer ends of the connecting element, a plurality of spacers spaced along the connecting element, or a spacer can be substantially over the entire length of the Extend connecting element. With sufficient spacing of the portions of the endless coupling means, two spacers arranged at the ends are preferred because they are easily mountable in the connector and contribute little additional weight, especially when made of a lightweight material such as plastic.

Alternatively, if the distance of the two sections of the endless coupling means, taking into account possible changes in length is large enough, can be dispensed with spacers in the connecting elements.

The device comprises guides for the endless coupling means, wherein the guides have an outer cross section which substantially corresponds to an inner cross section of the table legs. The guides comprise a longitudinally oriented receptacle for the drive part and laterally arranged openings for passing through the coupling means. Due to its shape and dimensions, the guide can be conveniently received in the table leg so that it can be easily fixed without spacers or other fixtures. Each coupling means, which cooperates with the spindle, enters through the laterally arranged opening, runs around the drive part and exits through the same or another lateral opening parallel to the incoming section. The shape of the guide is chosen so that the endless coupling means is guided exactly around the drive part. Thus, overriding or skipping of the coupling means with respect to the drive part and thus the loss of accurate synchronization between the table legs can be prevented without the need for additional tensioners for the coupling means.

The arrangement and size of the openings in the bearings may be freely selected depending on the dimensions of the coupling means, the guide and the drive member, for example, a plurality of coupling means may be passed through a single large aperture or through a plurality of smaller apertures. The openings may be shaped so that their outer edges form guides through which the coupling means is guided at the transition between the table leg and the frames. In order to simplify the assembly, it may be advantageous for the two sections of a coupling means to be guided through the same opening in each case. After the coupling means has been mounted, the opening can still be subdivided into two partial openings by an additional piece, with the additional piece simultaneously serving as spacers or being able to be formed on a spacer.

Preferably, each of the guides is formed by at least three guide bushes arranged longitudinally one behind the other, wherein two openings for the coupling means are formed at two different longitudinal ends of the guide bushes. For the coupling means so are each an opening formed at the transition between the first and the second sleeve and at the transition between the second and the third socket, wherein meh rere configurations are possible by the openings can be made either in the outer socket or in the middle socket or in both sockets. The openings are each axially closed by the adjacent bush, so that the coupling agent is securely guided by the guide and held laterally.

Advantageously, each of the guides is formed by exactly three identical guide bushes, which are plugged into each other with different orientation. In particular, with guide bushes made in a compression molding or molding process (e.g., injection molding), this has the advantage that instead of three (or more) different shapes, only a single mold has to be provided, thereby saving costs. The pluggability allows easy assembly and ensures that the sockets are fixed in their orientation to each other. The guide bushes preferably have an opening for the coupling means at one of their longitudinal ends. Two of the guide bushes are now arranged so that the corresponding openings are aligned with the male coupling means, in a rectangular table, the two openings, for example, at an angle of 90 ° to each other. The opening of the third guide bush is not used.

Alternatively, two or three different types of guide bushes may be provided, for example those without and those with an opening. The bushes can also be welded, glued or screwed together, or their relative orientation is secured by a longitudinally through all bushes pushable bolt.

Preferably, the telescopic mechanism of the table legs is designed such that an actuating means for the user for height adjustment of the table is directly rotatably coupled to the actuator. As a result, a manual adjustment of the table height is made possible in a simple manner. By synchronizing the telescopic mechanisms of the other legs a uniform height adjustment of the table height is guaranteed.

Alternatively or additionally, the device for table height adjustment may also comprise an electric drive, which either to the adjusting means of one of the telescopic mechanisms or coupled to a coupling means. An additional, manually operable drive part, which interacts with a coupling means away from the table legs, is also possible.

Advantageously, the telescopic mechanism of each of the table legs has a coupling for selectively coupling the actuating means. The coupling can be designed in particular as a plug-in connection, to which a crank can be plugged as an actuating means. The plug-in connection can be designed as a recess, e.g. be formed as hexagon socket, or as a projection in a final part of the table leg, which is rotatably mounted in the table leg and rotatably connected to the actuator. Because each of the table legs has said coupling, care must not be taken when actuating the height adjustment, where the actuating means is recognized. A recess as a plug-in connection is also particularly advantageous because when not in use the height adjustment in a simple manner, a flat lid can be placed on the final part of the leg of the table, which has, for example, a resilient projection which engages in the recess and holds the lid on the end part.

Alternatively, the coupling is provided only on one or on some of the table legs. The actuating means may also be permanently coupled to the actuating element and executed depending on the required torque, for example, as a handwheel or fold-out lever.

Preferably, the connecting elements extend between the table legs, and in the table legs side openings for passing the coupling means are provided in the connecting elements. Each coupling means, which cooperates with the adjusting element, thus passes out of the connecting element through an end-side opening of the connecting element and the corresponding lateral opening in the table leg and is mechanically coupled behind it with the adjusting element. The arrangement and the size of the openings can be chosen freely depending on the type and dimensions of the coupling means and the adjusting element, it can be provided in a table leg and a plurality of side openings for the same coupling means. The connecting elements can be arranged at the upper end of the table legs and, for example, with their upper side aligned with the upper end of the table legs, so that a circumferential Frame is formed. Such a configuration allows the tabletop to be placed on or fastened to the connectors. The connecting elements can also be arranged further below, spaced from the table top, in which case the table top is supported by the table legs.

Alternatively, the connecting elements can be placed on top of the table legs, i. H. the table legs are attached to the bottom of the connecting elements, which are assembled in the manner of a frame. In this case, the coupling elements extend completely within the connecting elements. Either mechanical connections are created to the adjusting elements of the telescopic mechanisms, or the adjusting elements pass through an opening formed at the bottom in the corner regions of the connecting elements and are thus also positioned within the connecting elements after assembly.

From the following detailed description and the totality of the claims, further advantageous embodiments and feature combinations of the invention result.

Brief description of the drawings

Fig. 1

Eine schematische Darstellung eines Tisches mit einer erfindungsgemässen Einrichtung zur Höhenverstellung in einer Draufsicht auf die Tischplatte;

Fig. 2

ein aufgeschnittenes Tischbein für die erfindungsgemässe Einrichtung zur Höhenverstellung in einer Schrägsicht;

Fig. 3

einen vertikalen Querschnitt des Tischbeins;

Fig. 4

eine detaillierte Darstellung des oberen Endes des Tischbeins in einer Schrägansicht; und

Fig. 5

eine detaillierte Darstellung des oberen Endes des Tischbeins in einem vertikalen Querschnitt.

The drawings used to explain the embodiment show:

Fig. 1

A schematic representation of a table with an inventive device for height adjustment in a plan view of the table top;

Fig. 2

a cut table leg for the inventive device for height adjustment in an oblique view;

Fig. 3

a vertical cross section of the table leg;

Fig. 4

a detailed view of the upper end of the table leg in an oblique view; and

Fig. 5

a detailed view of the upper end of the table leg in a vertical cross-section.

Basically, the same parts are provided with the same reference numerals in the figures.

Ways to carry out the invention

The FIG. 1 shows a schematic representation of a table with an inventive device for height adjustment in a plan view of the table top. For the sake of clarity, the illustration is not drawn to scale. In each of the four corners of the substantially rectangular table top 2 of the table 1, a table leg 3.1, 3.2, 3.3, 3.4 is arranged. The table legs 3.1 ... 3.4 have a circular cross section and are aligned with the two adjacent edges of the table top 2. In the corners, the table top 2 to the cross section of the table legs 3.1 ... 3.4 adapted cutouts, so that the table top. 2 between the upper ends of the table legs 3.1 ... 3.4 can be inserted. The table top 2 is mounted on hollow profile-like frames 4.1, 4.2, 4.3, 4.4 with a rectangular cross-section, which are between the table legs 3.1 ... 3.4, with respect to the outer edges of the table top 2 slightly set back.

The two frames 4.1. 4.4 adjoining one of the table legs 3.1... 3.4 each are connected to each other and to the respective table leg 3.1... 3.4 by a respective corner element 5.1, 5.2, 5.3, 5.4. The corner elements 5.1 ... 5.4 are adjacent to the frames 4.1 ... 4.4 and the respective table leg 3.1 ... 3.4 arranged on the Zargeninnenseite below the table top 2. For attachment of the corner elements 5.1 ... 5.4 are provided on the inner side of the frames 4.1 ... 4.4, adjacent to the table legs 3.1 ... 3.4 openings in which at the corner elements 5.1 ... 5.4 trained claws and cams can intervene , In addition, the corner element 5.1 ... 5.4 with the respective table leg 3.1 ... 3.4 screwed. For this purpose, it has a continuous radial opening, which is oriented in the assembled state parallel to the table top 2 and encloses to the two adjacent frames 4.1 ... 4.4 each at an angle of 45 °. A screw is passed through this opening and in a correspondingly arranged in the table leg 3.1 3.4 thread tightened. In the FIG. 1 visible are other round openings 6.1a, 6.1b, ..., 6.4a, 6.4b on the top of the frames 4.1 ... 4.4, in which a screw sleeve can be used with an internal thread for screwing the table top 2 to the frame 4.1 ... 4.4.

Each of the table legs 3.1 ... 3.4 has a vertical spindle 7.1, 7.2, 7.3, 7.4, which is coupled to a telescopic mechanism for height adjustment of the table leg, which further below, in connection with the FIGS. 2 and 3 , is described in more detail. At its upper end, each spindle 7.1 ... 7.4 has a recess 8.1, 8.2, 8.3, 8.4 in the shape of a hexagon socket. In this recess 8.1 ... 8.4, an Allen wrench or a crank with a hexagon socket connection can be used to rotate the spindle 7.1 ... 7.4 and thus adjust the height of the table leg 3.1 ... 3.4 as desired.

The spindles 7.1 ... 7.4 respectively adjacent table legs 3.1 ... 3.4 are synchronized by four endless timing belt 9.1, 9.2, 9.3, 9.4. The toothed belts 9.1 ... 9.4 are made of a flexurally elastic material, for example based on polyurethane or Neoprene, and have to reinforce and limit the elongation on a steel core. Each of the toothed belt 9.1 ... 9.4 runs in one of the frames 4.1 ... 4.4: So runs a first toothed belt 9.1 in the frame 4.1 between the first table leg 3.1 and the second table leg 3.2 and runs around the spindles 7.1, 7.2 of the two table legs 3.1, 3.2. The teeth of the belt 9.1 are directed inward and cooperate with a corresponding toothed pulley on the spindle 7.1. A second toothed belt 9.2 runs correspondingly in the frame 4.2 between the second table leg 3.2 and the third table leg 3.3 and rotates the corresponding two spindles 7.2, 7.3. In the same way, the third table leg 3.3 with the fourth table leg 3.4 and the fourth table leg 3.4 are in turn synchronized with the first table leg 3.1 by corresponding, running in the frames 4.3, 4.4 timing belt 9.3, 9.4.

With the illustrated device for height adjustment, a load of at least 50-75 kg can be raised. Conventional height-adjustable meeting and work desks offer stepless adjustability between 680 and 760 mm as standard. In the illustrated embodiment, the table legs are dimensioned so that a height adjustment in the range of approx. 680-860 mm is possible.

The FIG. 2 shows an oblique view of a cut table leg for the inventive device for height adjustment. The FIG. 3 shows a corresponding cross section along a vertical plane which extends through the longitudinal axis of the table leg and a frame. The table leg 3 is essentially formed by two telescoping, hollow cylindrical telescopic tubes 10, 11. The outer telescopic tube 10 is visible from the outside over its entire length, and two horizontal frames 4 are fixed at its upper end portion at right angles to each other (in the FIGS. 2, 3 one of them is visible). The inner telescopic tube 11 has an outer diameter which substantially corresponds to the inner diameter of the outer telescopic tube 10, and is slidably guided in a lower portion of the outer telescopic tube 10. With the uppermost portion of the outermost telescopic tube 10, an inner tube 10a is firmly connected, the material, wall thickness and diameter of the inner telescopic tube 11 match, but which is not mechanically coupled thereto. The wall thickness of the inner telescopic tube 11 is less than the wall thickness of the outer telescopic tube 10, the mechanical stability and bending stiffness of the table leg 3 is thus ensured primarily by the outer telescopic tube 10. At its lower end, the inner telescopic tube 11 is connected to a foot 12, which has an outwardly directed flange portion 12 a below the inner telescopic tube 11, the outer diameter of which corresponds to the outer diameter of the outer telescopic tube 10. In the illustrated fully retracted position, the table leg 3 thus has a closed cylindrical outer shape.

The spindle 7 is formed by a spindle part 13 and a drive part 14, wherein the drive part 14 is rotatably mounted at its lower end at the upper end of the spindle part 13. For this purpose, the two parts have matching recesses and projections; In addition, the drive part 14 is screwed to the spindle part 13 by means of a radial screw (not shown).

The spindle part 13 has an external thread and is arranged centrally in the interior of the upper section of the inner telescopic tube 11. The spindle part 13 is rotatably but non-displaceably mounted in a first, upper bearing 15 and at its lower end in a second, lower bearing 16. The first bearing 15 is above the inner telescopic tube 11 fixedly attached to the outer telescopic tube 10. The second bearing 16 slides within the inner telescopic tube 11 and prevents bending or tilting of the spindle part 13. At the upper end of the inner telescopic tube 11, an end piece 17 is arranged non-rotatably and immovably. The end piece 17 has an internal thread which cooperates with the external thread of the spindle part 13. As soon as the spindle 7 is rotated, resulting from the threaded connection, a vertical movement of the inner telescopic tube 11 relative to the spindle 7 and thus also to the outer telescopic tube 10. The inner telescopic tube 11 is thus extended at the lower end of the outer telescopic tube 11, so that the length of the table leg 3 is increased. By the ball bearings 15, 16 prevents the end piece 17 can be wedged at its lower or upper stop on the limiting elements by the stops are rotatable and thus "taken" by the tail 17, as soon as this reaches its end positions.

An anti-rotation between the inner telescopic tube 11 and the outer telescopic tube 10 is not provided in this embodiment. A rotation of the inner telescopic tube 11 but is prevented by the friction between the foot 12, which is rotatably mounted on the inner telescopic tube 10, and the ground. The friction is readily sufficient, because the foot 12 is pressed onto the ground with a considerable weight, namely a quarter of the table weight. It can be further increased by providing the underside of the foot 12 with a high coefficient of friction material. The rotatability of the inner telescoping tube 11 with respect to the outer telescoping tube 10 also allows easy leveling of the table leg length, e.g. on uneven ground. Once set length differences between the legs remain through the synchronization of the legs 3 in the common height adjustment of the legs 3 obtained.

Alternatively, a known anti-rotation between the telescopic tubes 10, 11 may be provided. In this case, the leveling can be done by appropriately adjustable feet.

The upper end of the table leg 3 is in the FIG. 4 in an oblique view as well as in the FIG. 5 shown in more detail in a vertical cross-section. The drive part 14 points in Longitudinal multiple teeth 14a, which cooperate with the teeth of two toothed belts 9.1, 9.2, which rotate the drive member 14 at different heights.

The drive member 14 is rotatably mounted at its upper end in a bearing 18 and extends to the upper end of the table leg 3. The bearing 18 is disposed inside a hollow cylindrical end piece 19, which closes the table leg 3 at its upper end and the jacket exactly in the inner tube 10a of the table leg 3 fits. The lid of the end piece 19 has a central opening for the upper end of the drive part 14. The upper end surface of the drive member 14 is aligned with the lid of the end piece 19 and has the recess 8 in the form of a hexagon socket for operating the spindle 7 by means of a crank or Allen key.

Between the upper bearing 18 for the drive part 14 and the attachment to the spindle part 13, three identically formed guide bushes 20.1, 20.2, 20.3 are arranged one above the other. They fill the intermediate space fitting, and their outer cross section substantially corresponds to the inner cross section of the outer telescopic tube 10, so that they are held immovably in the table leg 3. The guide bushes 20.1... 20.3 each have a continuous cylindrical opening along their longitudinal axes, such that the three guide bushes 20.1... 20.3 arranged one above the other form a receptacle for the drive part 14 and the sections of the toothed belts 9.1, 9.2 revolving around it. Each of the guide bushes 20.1 ... 20.3 also has at its lower end a lateral opening 20.1a ... 20.3a, which is continuous from the bush outer side to the central opening. Through the lateral opening 20.2a of the middle guide bushing 20.2, the two sections of the second toothed belt 9.2 are passed. The upper guide bush 20.3 is rotated with respect to the central guide bush 20.2 by 90 ° about its longitudinal axis, through its lateral opening 20.3a, the two sections of the first belt 9.1 are passed. The lateral opening 20.1a of the bottom guide bushing 20.1 is not used. The lateral openings 20.1 a ... 20.3a of the guide bushes 20.1 ... 20.3 have the shape of a circular ring section, wherein the outer ends of this section are formed so that they serve as guides for the smooth outer side of the timing belt 9.1, 9.2. The open angle of the openings 20.1a... 20.3a is selected such that the two sections of a toothed belt 9.1, 9.2 after the drive part 14 has been rotated be brought together again so far that they can be performed in parallel to each other within the frame 4 to the next table leg 3.

Thus, the mutual orientation of the three guide bushes 20.1 ... 20.3 is maintained, these have on their upper side pins and on its underside corresponding recesses (not shown). The pins and recesses allow both a parallel positioning of adjacent guide bushings 20.1... 20.3 as well as positions rotated by 90 °, 180 ° or 270 ° relative to each other about the longitudinal axis.

In the outer telescopic tube 10 and the inner tube 10a through openings are also provided, through which the two sections of the toothed belt 9.1, 9.2 can be performed in the frames 4 therethrough. The lateral openings 20.2a, 20.3a of the middle guide bush 20.2 and the upper guide bush 20.3 are aligned with the openings in the outer telescopic tube 10 and the inner tube 10a.

Subsequent to the table leg 3, a spacer 21 is provided in the frame 4, which guides the sections of the toothed belt 9.2 and prevents its internal teeth wedge each other, which would lead to a blocking of the synchronization mechanism. The outer shape of the spacer 21 largely corresponds to the inner cross section of the frame 4, so that the spacer 21 is displaceable only along the longitudinal axis of the frame 4. The spacer 21 has at its outer, the table leg 3 end facing a shoulder through which it is supported at the end of the frame 4 and thus precisely positioned. On the spacer 21 channel-like guides 21a are provided parallel to its longitudinal axis on both sides of the axis and on both sides of the plane of symmetry for receiving in each case a portion of the toothed belt 9.2. In each case 4 only two opposing guides 21a are used, while the others remain empty.

The spacer 21 has at its inner, adjacent to the table leg 3 end also two cams 21 b, which are guided through matching openings in the outer telescopic tube 10, in the inner tube 10a and in the guide bushes 20.1 ... 20.3. The cams 21 b prevent together with the pins and recesses on the guide bushes 20.1 ... 20.3 a rotation of the three guide bushes 20.1 ... 20.3 within the table leg 3.

The adjacent to a table leg 3 frames 4 are characterized by in the FIG. 1 shown corner element 5 on the table leg 3 and held together. The corner element 5 has claws and cams which engage through openings (not visible in the figures) on the inside of the frames 4. Together with the (above-mentioned) screwing of the corner element 5 with the table leg 3, the claws and cams ensure secure attachment of the adjacent frames 4 with each other and on the table leg 3. In the FIGS. 4 and 5 visible is also the screw sleeve 22 for screwing the table top, wherein the screw sleeve 22 is inserted through an opening 4a on the upper side of the frames 4 and extends through a receptacle 21c in the spacer 21.

The assembly of the table 1 with the inventive device for height adjustment can take place as follows. First, in the frames 4.1 ... 4.4 suitable timing belt 9.1 ... 9.4 and each at both ends a spacer 21 introduced. The frames 4.1 ... 4.4 are then attached to the table top 2, for example, screwed it.

The table legs 3.1 ... 3.4 are ready pre-assembled, with the exception of the drive parts 14, the end piece 19 and the bearing 18. The guide bushes 20.1 ... 20.3 are already aligned with each other oriented in the table leg 3.1 ... 3.4 used. Now the table legs 3.1 ... 3.4 with the help of the corner pieces 5.1 ... 5.4 can be attached to the table top 2 with the frames 4.1 ... 4.4, the ends of the timing belt 9.1 ... 9.4 through the openings of the table legs 3.1. ..3.4 and the guide bushes 20.1 ... 20.3 are introduced. When all four table legs 3.1 ... 3.4 have been mounted in this way, the drive parts 14 can be inserted into the guide bushings 20.1 ... 20.3, whereby at the same time the timing belt 9.1 ... 9.4 are stretched. This process is facilitated by the fact that the lower end of the drive parts 14 itself and a lower portion of the teeth 14a extend conically from bottom to top. Finally, the end pieces 19 can be introduced with the bearings 18 in the legs 3.1 ... 3.4.

Similarly, an existing table can be converted. The existing table legs with fixed length are made by table legs with telescopic mechanism replaced, in the existing frames straps and spacers are inserted, and the table is reassembled accordingly.

The invention is not limited to the described embodiment of a height-adjustable table. In particular, the aesthetic design of the table can be changed in various ways. For example, the frames can enclose the tabletop outside, and their top can be aligned with the top of the table top. However, the frames may also be set back further with respect to the edge of the table top, wherein the legs are also spaced from the edge of the table top.

The telescopic mechanism may also be designed differently, for example, it may include additional concentrically arranged telescopic tubes when the maximum stroke is to be increased. The mechanism may include end stops to prevent overwinding of the spindle. Depending on the dimensions and material of the spindle part can also be dispensed with that the ball bearing slides at the bottom of the spindle part inside of the inner telescopic tube. The drive member may be stored only at its lower and its upper end, while it is free, in the table leg, at the contact points with the drive means. In order for the drive part to withstand the corresponding greater mechanical load, its cross section is dimensioned larger in this case, or another material is selected. The spacers in the frames may be omitted depending on the available space or provided in other sections of the frames. As already mentioned, finally, the synchronization of the telescopic mechanisms can be realized differently, for example by friction or V-belts or chains.

In summary, it should be noted that a device for height adjustment is provided by the invention, which is reliable, aesthetically inconspicuous and easy to manufacture and assemble.

Claims (11)

1. Device for adjusting the height of a table (1) with three or more table legs (3.1...3.4) arranged in an edge region of the table, wherein respective adjacent table legs (3.1...3.4) are connected to each other by means of a horizontal, hollow section-type connecting element (4.1...4.4), comprising for each of the table legs (3.1...3.4) a telescopic mechanism (7, 10, 11) for altering the length of the table leg (3.1...3.4) and which is adjustable by rotating a rotatably supported adjusting member (7.1...7.4), the adjusting members being vertical spindles (13), a drive member (14) being connected in a rotationally secure manner to each of the spindles (13), characterized by a multiplicity of endless coupling means (9.1...9.4) which are housed within the connecting elements (4.1...4.4) and mechanically synchronise a respective two adjusting members (7.1...7.4), the coupling means (9.1...9.4) being so arranged that they extend round, and co-operate with, the drive members (14) of the spindles (13) of the adjacent table legs (3.1...3.4), guides (20) for the endless coupling means being provided which have an external cross-section corresponding substantially to an internal cross-section of the table legs (3.1...3.4) and which comprise a longitudinally oriented socket for the drive member (14) and laterally arranged openings (20.1a...20.3a) for leading the coupling means (9.1...9.4) through.
2. Device according to claim 1, characterized in that the adjusting members co-operate via a screw thread with a telescopic member (11) of the telescopic mechanism (7, 10, 11).
3. Device according to claim 1 or 2, characterized in that the coupling means are belts (9.1...9.4), especially toothed belts, or chains.
4. Device according to any one of claims 1 to 3, characterized by a spacer (20) arranged in the connecting elements (4.1...4.4) for guiding the two opposed portions of the endless coupling means (9.1...9.4) in the connecting elements (4.1...4.4).
5. Device according to any one of claims 1 to 4, characterized in that each of the guides (20) is formed by at least three guide bushes (20.1...20.3) arranged longitudinally one behind the other, two openings (20.2a, 20.3a) for the coupling means (9.1...9.4) being formed at two different longitudinal ends of the guide bushes (20.1...20.3).
6. Device according to claim 5, characterized in that each of the guides is formed by exactly three identical guide bushes (20.1...20.3) which are insertable into one another with different orientation.
7. Device according to any one of claims 1 to 6, characterized in that the telescopic mechanism (7, 10, 11) of one of the table legs (3.1...3.4) is so constructed that an actuating means for adjusting the height of the table (1) can be directly coupled to the adjusting member (7) in a rotationally secure manner by a user.
8. Device according to claim 7, characterized in that the telescopic mechanism (7, 10, 11) of each of the table legs (3.1...3.4) has a coupling (8.1...8.4) for selective coupling on of the actuating means, especially a plug-in connection for a crank.
9. Device according to any one of claims 1 to 8, characterized in that the connecting elements (4.1...4.4) extend between the table legs (3.1...3.4) and in that lateral openings are provided in the table legs (3.1...3.4) for leading the coupling means (9.1...9.4) through into the connecting elements (4.1...4.4).
10. Table (1) with three or more table legs (3.1...3.4) arranged in an edge region of the table, wherein respective adjacent table legs (3.1...3.4) are connected to each other by means of a horizontal, hollow section-type connecting element (4.1...4.4), characterized by a device for adjusting the height according to any one of claims 1 to 9.
11. Method for retrofitting a table having three or more table legs arranged in an edge region of the table, wherein respective adjacent table legs are connected to each other by means of a horizontal, hollow section-type connecting element, with a device for adjusting the height according to any one of claims 1 to 10, characterized by the following steps:

    a) replacement of the table legs by height-adjustable table legs having a telescopic mechanism for altering the length of the table leg, the telescopic mechanism being adjustable by rotating a rotatably supported adjusting member, the adjusting members being vertical spindles (13), and a drive member being connected in a rotationally secure manner to each of the spindles, guides for endless coupling means being provided which have an external cross-section corresponding substantially to an internal cross-section of the table legs and which comprise a longitudinally oriented socket for the drive member and laterally arranged openings for leading the coupling means through;

    b) for each respective two adjacent table legs, the introduction of an endless coupling means for mechanical synchronisation of the adjusting members of the adjacent table legs into the connecting element connecting the table legs, the coupling means being so arranged that they extend round, and co-operate with, the drive members of the spindles of the adjacent table legs; and

    c) coupling of the coupling means to the adjusting members.

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