EP3659467B1 - Height-adjustable device - Google Patents

Description

The invention relates to a height-adjustable device with at least two synchronously height-adjustable lifting devices, each of which has a stand element and a lifting element that is adjustable in height relative to it, the height adjustment being carried out by pulling elements which are formed by deflection devices for lifting each lifting element relative to the associated stand element; each tension element being non-positively or positively attached to two lifting devices and an elongation in the area of the first lifting device causes a synchronous shortening in the area of the second lifting device; and each tension element is designed for lifting only one lifting element relative to the associated stand element.

Height-adjustable devices of the type mentioned at the beginning, in particular so-called lifting tables, are known and are used, for example, in the office area or in aircraft, in particular VIP aircraft. Such lifting tables regularly have two lifting columns. When adjusting the height of such a device, it can be problematic to synchronize the lifting movement between two or more lifting devices and to lock it at the desired height without tilting or other problems occurring. It can be problematic in particular with corresponding tables in VIP aircraft, in which the height adjustment is usually carried out by flight attendants from the end of the table. Included there is regularly an uneven application of force to the lifting columns.

A lifting device of the type mentioned is from EP 1 987 734 B1 , or from DE 20 2006 012 066 U1 known. Proceeding from this, the present invention is based on the object of creating a lifting device of the type mentioned at the outset, which facilitates synchronous height adjustment, enables secure locking at the desired height, and is simply constructed.

This object is achieved in that a locking device is provided for locking each tension element by means of non-positive and / or positive engagement on this tension element and the locking device is also designed to synchronize the movement of the tension elements.

First, some terms used in the context of the invention will be explained. According to the invention, a height-adjustable device can in particular comprise a piece of furniture or furnishings, tables, worktops or the like may be mentioned by way of example.

With the stand elements, the device stands on the installation surface. It can, for example, be table legs or their parts that are immovable relative to the installation surface.

A lifting element is height-adjustable relative to each stand element. The lifting elements carry, for example, a table top or the like.

Tension elements in the sense of the invention can transmit the tensile forces required for the height adjustment, it can for example, preferably flexible belts, bands, chains or the like. By means of deflection devices, they are designed to lift each lifting element relative to the associated stand element. The deflection devices, preferably deflection pulleys, can serve both to deflect the force of the pulling elements and to support the lifting process in the sense of a pulley. For example, according to the invention, a deflection device can be arranged in the lower region of a lifting element; this deflection device is used to raise it in the sense of a pulley system by means of a tension element deflected around it by approximately 180 °.

Each tension element is attached to two lifting devices in a force-fitting and / or form-fitting manner. The fastening is preferably carried out with one end of a tension element on each of the static areas (stand element) of a lifting device. The kinematics are designed in such a way that an elongation in the area of the first lifting device causes a synchronous shortening in the area of the second lifting device. As will be shown in more detail below, this synchronizes the lifting movements of two lifting devices.

Each tension element is designed to lift only one lifting element relative to the associated stand element. According to the invention, two lifting devices are connected to one another by at least two pulling elements, each of these pulling elements is designed (preferably via deflection rollers) to raise only one lifting element by shortening it in the area of this lifting element. The two pulling elements work together by moving in opposite directions, causing the lifting movement of both lifting elements and the synchronization of this movement.

According to the invention it is provided that a locking device is provided for locking each tension element by means of non-positive and / or positive engagement on this tension element. By locking each tension element, the further movement of these tension elements and thus also the lifting movement of the lifting device are blocked or locked.

In the device according to the invention, the pulling elements thus have the double function of synchronizing the lifting movement on the one hand and locking the set height position on the other hand by blocking these pulling elements themselves by the locking device according to the invention. According to the invention, separate and often failure-prone locking devices in the lifting devices themselves are not required.

The locking device according to the invention is also designed so that the movement of the tension elements takes place synchronously. This means that the locking device kinematically couples the usually opposing movements of, for example, two tension elements through corresponding devices in this locking device in such a way that a movement of a tension element in one direction causes a preferably opposite synchronous movement of the second tension element. This synchronization by the locking device is preferably provided in addition to the synchronization by the kinematics of the connection of the tension elements with standing elements and lifting elements and improves the operation and, in particular, the uniform lifting movement of the device according to the invention. In particular, such a synchronization can be provided by the locking device if it is designed to drive the pulling elements.

According to the invention, it is preferred that each tension element is frictionally connected at each end to one stand element; and that it is guided in the area of a lifting device via a pulley block arranged on the lifting element. The shortening of the pulling element in the area of the lifting element with pulley lifts the corresponding lifting element, the synchronous elongation of the pulling element in the area of the second lifting device is preferably used in the manner shown below in the exemplary embodiments via pulleys arranged in the upper area of the lifting element of the second lifting device and synchronized with it inevitably also the lifting movement of this second lifting element, in that it prevents excessive lifting of this second lifting element, since an additional elongation of the tension element would then be required.

According to the invention, it is preferred if the locking device is designed for non-positive and / or positive engagement on each tension element in the area of the guidance of these tension elements between the lifting devices. In particular, according to the invention, it can be designed as a central unit which can lock all tension elements in an area centrally between the lifting devices (table legs). The locking in only one central unit significantly facilitates handling and operation. In particular, according to the invention, it is not necessary to provide separate locking devices in the individual lifting devices and, if necessary, complex devices for distributing a locking signal to several locking devices in these lifting devices. A central locking system also ensures that the force is evenly distributed to the various lifting devices.

The locking device can also be designed to drive the tension elements. It can therefore be used for manual or Motorized drive of at least one, preferably all of the pulling elements can be designed so that a height adjustment takes place by actuating the drive. In this embodiment of the invention, the tension elements therefore not only serve to synchronize the lifting movement, while the lifting force is applied, for example, by pushing or pulling on the table top. Instead, they also serve directly to actuate the lifting devices.

According to the invention, the locking device has a shaft (preferably with a toothed wheel, friction wheel or the like placed thereon) for non-positive and / or positive movement, locking and synchronization of the tension elements. The term wave denotes an element which, through rotation, can bring about a corresponding longitudinal movement of the tension element or the tension elements. Between the shaft (or gearwheel or friction wheel) and the tension element there can be a force fit or friction fit, but a form fit is preferred according to the invention for the synchronization of the movements.

It is therefore particularly preferred according to the invention that the tension elements have toothed belts and the shaft have toothed wheels meshing with them. It can be provided according to the invention that the locking of the tension elements takes place by blocking a rotational movement of the shaft. Gear wheels or friction wheels placed on the shaft can be connected to the shaft, for example, by means of a feather key connection.

According to the invention, additional deflection rollers are provided to secure the frictional connection and / or positive connection between the shaft and the tension elements in the area of the leading and / or trailing edge of the tension elements relative to the shaft. These pulleys can, for example, cause the toothed belt to have a sufficient length large circumferential section of the shaft and thus a secure form fit and / or force fit results. The deflection rollers can be mounted freely rotating on an axis, ie not kinematically coupled to the shaft described above. Alternatively, they can be connected to the shaft in a rotationally fixed manner. The non-rotatable connection is preferably not only made via the tension elements, for example toothed belts, but also by means of a suitable kinematic connection such as, for example, toothed wheels or the like.

The tension elements are preferably designed in such a way that they do not experience any significant elongation during operation under the intended operating conditions. No significant elongation means that any elongation / elongation does not affect the operation of the lifting device and the synchronicity of the lifting movement. The tension elements can be made of a material with corresponding tensile strength or they can have reinforcing elements. For example, toothed belts can be provided with steel cords.

The device according to the invention can be provided with two lifting devices, for example as a table with two lifting columns. Such a configuration can be used, for example, as a table in vehicles or aircraft, for example VIP aircraft. The device according to the invention can preferably be designed as a table, regardless of the number of lifting devices.

In the embodiment as a table, the locking device is preferably designed as a central unit below the table top between the lifting devices (table legs or lifting columns).

The device according to the invention can have at least one device for receiving lifting loads. For example, gas pressure springs can be arranged in the lifting devices, which for example largely compensate for the weight of the height-adjustable part of the device, or overcompensate somewhat. This facilitates manual height adjustment and / or allows height adjustment by means of driving the tension elements with the application of lower forces.

Reference is made to the above statements to explain the device according to the invention.

Figur la, 1b:

eine schematische Darstellung des Grundprinzips der Höhenverstellung wie es in der erfindungsgemäßen höhenverstellbaren Vorrichtung genutzt wird;

Figur 2:

eine schematische Darstellung eines Ausführungsbeispiels einer erfindungsgemäßen Vorrichtung;

Figur 3:

eine schematische Darstellung eines Ausführungsbeispiels einer Arretierungseinrichtung;

Figur 4:

eine schematische Darstellung eines Ausführungsbeispiels einer Umlenkrichtung in einer Hubeinrichtung;

Figuren 5- 7:

schematische Darstellungen eines Ausführungsbeispiels einer Spanneinrichtung zum Spannen der Zugelemente.

The invention will now be described by way of example on the basis of advantageous embodiments with reference to the accompanying drawings. Show it:

Figure la, 1b:

a schematic representation of the basic principle of height adjustment as it is used in the height-adjustable device according to the invention;

Figure 2:

a schematic representation of an embodiment of a device according to the invention;

Figure 3:

a schematic representation of an embodiment of a locking device;

Figure 4:

a schematic representation of an embodiment of a deflection direction in a lifting device;

Figures 5-7:

schematic representations of an embodiment of a tensioning device for tensioning the tension elements.

With the help of Figures 1a and 1b the basic principle of a height adjustment, as used in accordance with an exemplary embodiment of a device 1 according to the invention, is illustrated below. The explanation takes place according to the exemplary embodiment with a first lifting device 2 and a second lifting device 3. The first lifting device 2 comprises a first standing element 4 and a first lifting element 5, which can be moved into and out of the first standing element 4, and also a first tension element 6 Analogously, the second lifting device comprises a second standing element 7, a second lifting element 8 and a second pulling element 9. The first pulling element 6 is connected in the first lifting device 2 to the first standing element 4 at the first connection point 17 and is guided vertically upwards and via a first front deflection roller 10 of a first deflection device 11 guided horizontally to a second front deflection roller 12 of a second deflection device 13 of the second lifting device 3 and there guided vertically downwards via the second front deflection roller 12 and upwards again via a lower deflection roller 14 and with the second standing element 7 on the second connection point point 16 connected. Analogous to the first tension element 6, the second tension element 9 is connected to the second stand element 7 at the second connection point 16 and is guided vertically upwards to a second rear deflection roller 18 and from there horizontally to a first rear deflection roller 19. In the first lifting device 2, the second tension element 9 is guided vertically downwards from the first rear deflection roller 19 to a first lower deflection roller 15, from there upwards and connected to the first stand element 4 at the connection point 17.

A height adjustment takes place via a movement of the first and / or the second tension element 6, 9. The movement is triggered by the application of force to the tension elements 6, 9. Two variants are possible. In one variant, a force is applied to a tension element. This leads to a movement of the tension element and the sequence of movements described below. According to a second variant, the force is applied to both tension elements simultaneously, in such a way that an opposing movement of the tension elements is triggered synchronously. The movements of the tension elements 6, 9 described below then run synchronously.

A movement of the second tension element 9 to the left leads to a lifting of the second lifting element 8 due to the connection of the second tension element 9 with the second standing element 7 first connection point 17 and a synchronous shortening between the second connection point 16 and the second lower roller 14 and the first lower deflection roller 15 of the first lifting device 2, the first lifting element 5 being pulled upwards by the first pulling element 6, that is to say being lifted, due to the shortening of the distance 23. Moving the first tension element 6 to the right would result in an analogous sequence of movements.

A movement of the second tension element 9 to the right leads to a lowering of the first and second lifting elements 5, 8, there in this way the distance 20 in the first lifting device is shortened. The shortening of the distance 20 has the consequence that the first lifting element 5 is pulled back into the first support leg 4 by the second tension element 9, that is to say is lowered. Synchronously, the path 23 in the first lifting device 2 is lengthened. The lengthening of the path 23 leads to the path 22 being shortened, which in turn pulls the second lifting element 8 into the second standing element 7, that is, it is also lowered. It is also true here that a movement of the first tension element 6 to the right results in an analogous movement sequence of the lifting devices 2, 3.

A first exemplary embodiment for a height-adjustable device 1 according to the invention is shown in FIG Fig. 2 shown. The device shown comprises a first lifting device 2 with a first stand element 4 and a lifting element 5. Furthermore, the device comprises a second lifting device 3, which consists of a second stand element 7 and a second lifting element 8. With both lifting devices 2, 3, the lifting elements 5, 8 can be moved in and out of the standing elements 4, 7 and vice versa. Arranged on the lifting devices 2, 3 is a traverse 25 which connects the lifting devices 2, 3 to one another.

In addition to the schematic representation of the basic principle, the device 1 according to the exemplary embodiment has a locking device 26 through which both tension elements 6, 9 are guided and which is designed such that the movement of the tension elements 6, 9 can be locked. The locking device 26 is arranged centrally on the cross member 25 between the two lifting devices 2, 3. Due to the central arrangement of the locking device 26 between the lifting devices 2, 3, the path lengths are between the lifting devices of the same length, whereby a synchronous transmission of the tensile forces occurring to the lifting devices 2, 3 is achieved, which in turn has the consequence that the lifting elements 5, 8 are moved up or down at the same time and tilting is avoided. Even in the locked state, when the load is on one side, tilting can be reliably avoided through the synchronous transmission of the tensile forces.

the Fig. 3 shows a possible embodiment for a locking device 26 according to the invention. The locking device 26 consists of a cover plate 27, via which the locking device 26 can be attached to the cross member 25 and two side parts 28 and second central deflection roller 29, 30 guided through the locking device 26. The central deflection rollers 29, 30 are connected in a rotationally fixed manner to a central shaft 31. In addition, for each tension element 6, 9, in front of and behind the central deflection rollers 29, 30, lateral deflection rollers 32, 33, 34, 35 are provided, with the side deflection rollers 32, 34 and 33, 35 lying next to one another each loosely mounted on a common axis 36, 37 are arranged. In order to enable the required opposite direction of movement of the tension elements 6, 9, the first tension element 6 is guided over the underside of the first central deflection roller 29 and the second tension element 9 is guided over the upper side of the second central deflection roller 30. The guidance through the lateral deflection rollers 32, 33, 34, 35 is adapted accordingly. The tension elements 6, 9 are preferably moved by rotating the central shaft 31, which for this purpose can be connected to an electric motor or a crank (both not shown).

The central shaft 31 can be blocked in various positions. In the illustrated embodiment, a locking disk 38 is attached to the central shaft 31, on the circumference of which various bores are provided, into which a spring-loaded locking bolt 39 can be guided for locking purposes. The locking bolt is fastened in a side part 28 of the locking device 26 and, due to the spring force, settles into the next hole. Using a Bowden cable or a rod system, it is possible to release or set the locking bolt 39 from other positions (e.g. the front of the table top).

The tension elements 6, 9 can be designed as toothed belts. As a toothed belt z. B. Toothed belts from the manufacturer Mädler GmbH, which are provided with the HTD profile, can be used. This profile is characterized by its use in high-performance belts and ensures a belt drive with little play. A TPU belt (thermoplastic polyurethane) with steel tension cord was chosen (see: http://www.maedler.de/product/1643/ 1616/945 / zahnriemen-meterware-pu-profil-htd). The pulleys are designed accordingly as toothed belt wheels.

In the Figure 4 an exemplary embodiment for a deflection device 11, 13 in a lifting device 2, 3 is shown, in which case the second lifting device 3 with the deflection device 13 is involved. The first lifting device 2 with the deflecting device 11 is designed analogously to this. The deflection device 13 comprises a second front and rear deflection roller 12, 18, both of which are loosely arranged on an axle 40. The axis 40 is preferably rotatably arranged on the lifting element 8 via a bushing 42 and is fixed in place via an adjusting ring 43. Alternatively, the axis 40 can also be rotationally fixed, preferably by means of a transition fit be connected to the lifting device 3; deflection pulleys are then rotatably mounted via bushings on the non-rotatable axle 40. The second tension element 9 is deflected via a second lower pulley 14, guided upwards again and fastened together with the first tension element 6 to the second stand element 7 via a belt clamping plate consisting of an auxiliary plate 44, a spacer 45 and a clamping plate 46.

Due to the positive connection of the tension elements 6, 9 to the central shaft 31, which is locked, it is necessary to tension all four sections of the tension elements 6, 9 individually. An embodiment of a possible tensioning device 60 can be the Figures 5 , 6th and 7th which show the clamping device 60 on a second lifting device 3. For the first lifting device 2, the design of the clamping device 60 is correspondingly analogous. In the Figure 5 the second lifting element 8 of the second lifting device 3 is shown. On the second lifting element 8, the second deflection rollers 12, 18 are arranged on the axis 40, over which the tension elements 6, 9 are guided. The second lifting element 8 is attached to the cross member 50. The traverse 50 connects the first and second lifting devices 2, 3 to one another. In addition, the locking device 26 is also attached to the cross member 50. In the Fig. 6 it is shown that the traverse 50 has an opening above the fastening with the second lifting device 3, in which the clamping device 60 is arranged. As in Figure 7 Shown in more detail, the tensioning device 60 comprises tensioning blocks 70 which are connected to the upper deflection rollers 12, 18 (not shown). The clamping blocks 70 are received in clamping plates 71 and connected via retaining screws 73. The clamping plates 71 are displaced via adjusting screws 72, the clamping plates having short elongated holes 74 in which the retaining screws 73 are guided. When adjusting to the locking device 26 inward, the belt tension is reduced; when adjusting outward, the belt tension is increased.

Claims (13)

1. Height-adjustable apparatus (1), with at least two synchronously height-adjustable lifting devices (2, 3) which in each case have a stand element (4, 7) and a lifting element (5, 8) which is height-adjustable relative to the former, the height adjustment taking place by way of flexible drive elements (6, 9) which are configured by way of deflection devices (11, 13) to raise each lifting element (5, 8) relative to the associated stand element (4, 7);

   each flexible drive element (6, 9) being fastened in a non-positive and/or positively locking manner to two lifting devices (2, 3), and lengthening in the region of the first lifting device (2) bringing about synchronous shortening in the region of the second lifting device (3); and

   each flexible drive element (6, 9) being configured to raise only one lifting element (5, 8) relative to the associated stand element (4, 7);

   a locking device (26) being provided for locking each flexible drive element (6, 9) by means of a non-positive and/or positively locking action on the said flexible drive element (6, 9), and the locking device (26) additionally being configured for the synchronization of the movement of the flexible drive elements (6, 9);

   the locking device (26) having a shaft (31) for the non-positive and/or positively locking movement, locking and synchronization of the flexible drive elements (6, 9), and characterized in that deflection rollers (32, 33, 34, 35) for securing the non-positive connection and/or positively locking connection of the flexible drive elements (6, 9) to the shaft (31) are provided in the region of the forerun and/or backlash of the flexible drive elements (6, 9) relative to the shaft (31).
2. Apparatus according to Claim 1, characterized in that each flexible drive element (6, 9) is connected by way of each end in a non-positive and/or positively locking manner to in each case one stand element (4, 7), and in that it is guided in the region of a lifting device (2, 3) via a pulley which is arranged on the lifting element (5, 8).
3. Apparatus according to Claim 1 or 2, characterized in that the locking device (26) is configured for the non-positive and/or positively locking action on each flexible drive element (6, 9) in the region of the guide of the said flexible drive elements (6, 9) between the lifting devices (2, 3).
4. Apparatus according to one of Claims 1 to 3, characterized in that the locking device (26) is additionally configured for driving the flexible drive elements (6, 9).
5. Apparatus according to one of Claims 1 to 4, characterized in that the flexible drive elements (6, 9) have toothed belts, and the shaft (31) has gearwheels which mesh with the said toothed belts.
6. Apparatus according to one of Claims 1 to 5, characterized in that the locking of the flexible drive elements (6, 9) takes place by way of blocking of a rotational movement of the shaft (31).
7. Apparatus according to one of Claims 1 to 6, characterized in that the deflection rollers (32, 33, 34, 35) are preferably mounted rotatably on an axle (36, 37).
8. Apparatus according to one of Claims 1 to 7, characterized in that the connection of friction wheels and/or gearwheels to the shaft (31) takes place via a feather key connection.
9. Apparatus according to one of Claims 1 to 8, characterized in that the flexible drive elements (6, 9) are configured in such a way that they do not experience any substantial lengthening during operation under provided operating conditions.
10. Apparatus according to one of Claims 1 to 9, characterized in that it has two lifting devices (2, 3).
11. Apparatus according to one of Claims 1 to 10, characterized in that it is configured as a table.
12. Apparatus according to Claim 11, characterized in that the locking device (26) is configured as a central unit below the tabletop between the lifting devices (2, 3) .
13. Apparatus according to one of Claims 1 to 12, characterized in that it has at least one device for absorbing lifting loads.

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