Height-adjustment device

1. Height-adjustment device for a table with three or more table legs attached in an edge region of the table, with respectively adjacent table legs being connected to one another by a horizontal, hollow-profile connecting element, comprising:

for each of the table legs, a telescopic mechanism for changing a length of a table leg, the mechanism being adjusted by rotating a rotatably mounted adjusting element, wherein the adjusting element is a vertical spindle, and a driving part connected by a rotationally fixed connection to the spindle;

a plurality of endless coupling elements which are accommodated within the hollow-profile connecting elements, wherein each said endless coupling element encircles the driving parts of two adjacent table legs and interacts therewith to respectively synchronize the adjusting elements of the table legs with each other;

a plurality of guides for the endless coupling elements, each said guide having

an external cross section which essentially corresponds to an internal cross section of a table leg,

a longitudinally oriented mount for the driving part, and

a laterally arranged openings for guiding the endless coupling elements through,

each said laterally arranged opening being of a form that, after sections of the respective endless coupling element encircle the driving part, bring together the sections to an extent that the outer sides of the endless coupling element are guided to a width that is equal to or less than an outer diameter of the driving part to within the hollow-profile connecting element,

a shape of an inner surface of each guide surrounding respective endless coupling elements is such that the respective endless coupling element is guided around the driving part by the inner surface of the corresponding guide.

2. Device according to claim 1 , characterized in that the adjusting elements interact with a telescopic element of the telescopic mechanism via a thread.

3. Device according to claim 1 , characterized in that the endless coupling elements are belts, toothed belts, or chains.

4. Device according to claim 1 , characterized by a spacer arranged in the hollow-profile connecting elements, or guiding the two opposite sections of the endless coupling elements in the hollow-profile connecting elements.

5. Device according to claim 1 , characterized in that each of the guides is formed by at least three guide bushings arranged longitudinally in contact end-to-end, with two of said at least three guide bushings having respective two said laterally arranged openings for the endless coupling elements.

6. Device according to claim 5 , characterized in that each of the guides is formed by precisely three identical guide bushings having pins on an upper side and corresponding recesses on a lower side, the pins and recesses allowing the guides to be plugged one on top of the other with different orientations of said two laterally arranged openings.

7. Device according to claim 1 , characterized in that the telescopic mechanism of one of the table legs is designed such that an actuating means for adjusting the height of the table can be coupled directly in a rotationally fixed manner to the adjusting element.

8. Device according to claim 7 , characterized in that the telescopic mechanism of each of the table legs has coupling for the optional coupling of the actuating means.

9. Device according to claim 1 , characterized in that the hollow-profile connecting elements run between the table legs and in that lateral openings for guiding the endless coupling elements through into the hollow-profile connecting elements are provided in the table legs.

10. Device according to claim 8 , characterized in that the coupling for the optional coupling of the actuator means is a plug-in connection for a crank.

11. A height-adjustable table comprising:

three or more table legs attached in an edge region of the table;

a plurality of horizontal, hollow-profile connecting elements being connected between respectively adjacent table legs;

for each of the table legs, a telescopic mechanism for changing a length of a table leg, the mechanism being adjusted by rotating a rotatably mounted adjusting element, wherein the adjusting element is a vertical spindle, and a driving part connected by a rotationally fixed connection to the spindle;

a plurality of endless coupling elements which are accommodated within the hollow-profile connecting elements, wherein each said endless coupling elements encircles the driving parts of two adjacent table legs and interacts therewith to respectively synchronize the adjusting elements of the table legs with each other; and

a plurality of guides for the endless coupling elements, each said guide having

an external cross section which essentially corresponds to an internal cross section of a table leg,

a longitudinally oriented mount for the driving part, and

a laterally arranged openings for guiding the endless coupling elements through,

each said laterally arranged opening being of a form that, after sections of the respective endless coupling element encircle the driving part, bring together the sections to an extent that the outer sides of the endless coupling element are guided to a width that is equal to or less than an outer diameter of the driving part to within the respective hollow-profile connecting element,

a shape of an inner surface of each guide surrounding respective endless coupling elements is such that the respective endless coupling element is guided around the driving part by the inner surface of the corresponding guide.

12. Method for retrofitting a table with three or more table legs attached in an edge region of the table, with respectively adjacent table legs being connected to one another by a horizontal, hollow-profile connecting element, with a height-adjustment device, characterized by the following steps:

a) replacing the table legs with height-adjustable table legs having a telescopic mechanism for changing a length of the table leg, the telescopic mechanism being adjustable by rotating a rotatably mounted adjusting element, the telescopic mechanism including

a driving part connected by a rotationally fixed connection to adjusting element;

a plurality of guides each having an external cross section which essentially corresponds to an internal cross section of the table legs, a longitudinally oriented mount for the driving part, an internal cross section shaped to guide the endless coupling element around the driving part, and a laterally arranged openings,

wherein each said laterally arranged opening is of a form that, after sections of the respective endless coupling element encircle the driving part, bring together the sections to an extent that the outer sides of the endless coupling elements are guided to a width that is equal to or less than an outer diameter of the driving part, through and within the respective hollow-profile connecting element;

b) introducing a plurality of endless coupling elements for the mechanical synchronization of the adjusting elements of adjacent table legs into the hollow-profile connecting element connecting the respective table legs, wherein each said endless coupling element encircles the driving parts of the adjusting element of adjacent table legs and therefore interact therewith; and

c) coupling the endless coupling elements to the adjusting elements, wherein the adjusting elements are spindles.