Telescopic column for a height-adjustable table and height-adjustable table having such a telescopic column
A telescopic column for a height-adjustable table comprises a cylindrical outer column, a cylindrical inner column at least partially arranged within the outer column, several balls, and a tube-shaped ball cage retaining the balls at positions relatively determined with respect to one another. The outer column comprises, along its longitudinal direction on its inside, an outer column running surface section configured such that the balls roll over thereon, the inner column comprises, along its longitudinal direction on its outer cross-section, an inner column running surface section configured such that the balls roll over thereon, and the inner column and the outer column are configured such that the balls, during an adjustment of a length of the telescopic column, roll over in an almost backlash-free manner on the outer column running surface section and the inner column running surface section in a predefined range of motion of the balls in order to guide the inner column in the outer column.
1 . A telescopic column for a height-adjustable table, wherein the telescopic column comprises:
a cylindrical outer column having a circular outer cross-section and a circumference,
a cylindrical inner column, having a circular outer cross-section, the cylindrical inner column being at least partially arranged within the outer column,
several balls, and
a tube-shaped ball cage configured to retain the balls at predetermined positions,
wherein
the outer column, along a longitudinal direction of the outer column on an inside of the outer column, comprises an outer column running surface section configured such that the balls roll over thereon,
the inner column, along a longitudinal direction of the inner column on an outer cross-section of the inner column, comprises an inner column running surface section configured such that the balls roll over thereon, and
the inner column and the outer column are configured such that the balls roll over in an at least almost backlash-free manner on the outer column running surface section and the inner column running surface section during an adjustment of a length of the telescopic column in a predefined range of motion of the balls in order to guide the inner column in the outer column, the outer column running surface section comprises, along the longitudinal direction of the outer column and distributed on the circumference of the cylindrical outer column, at least two longitudinal grooves respectively configured such that the balls can roll over in the longitudinal grooves during the adjustment in the range of motion,
wherein the telescopic column further comprises a tube-shaped cover element which covers the inner column running surface section of the cylindrical inner column that is partially arranged within the outer column, the cover element being combined with the ball cage and thereby being positioned between the inner and outer columns, the cover element and the ball cage being moved together when the telescopic column is in an extracted state wherein the running surfaces on the inner column are coverable by the cover element and wherein the cover element covers at least the predetermined range of motion of the balls of the inner column running surface section when in the extracted state of the telescopic column such that the inner column running surface is not visible when the telescope column is in the extracted state.
2 . The telescopic column according to claim 1 , wherein a shape and dimensions of the at least two longitudinal grooves within the predefined range of motion of the balls as well as a diameter of the balls are configured such that, during the adjustment of the length of the telescopic column, one of the balls contacts one of the at least two longitudinal grooves at two points.
3 . The telescopic column according to claim 1 , wherein the inner column comprises at least one guiding element configured such that the at least one guiding element engages into one of the at least two longitudinal grooves in an at least almost backlash-free manner during the adjustment of the length of the telescopic column along an adjustment stroke of the telescopic column in order to align the inner column with respect to the outer column.
4 . The telescopic column according to claim 3 , wherein the at least one guiding element comprises several guiding elements configured such that the several guiding elements engage into at least one of the at least two longitudinal grooves in an at least almost backlash-free manner during the adjustment of the length of the telescopic column along the adjustment stroke are provided.
5 . The telescopic column according to claim 4 , wherein the several guiding elements are integrally connected to one another, and the several guiding elements are configured to form a guiding ring.
6 . The telescopic column according to claim 5 , wherein the inner column comprises a recess, the guiding ring comprises a radial protrusion, and the recess and the radial protrusion are configured such that the recess and the first radial protrusion engage into one another.
7 . The telescopic column according to claim 6 , wherein the guiding ring comprises an at least partially circumferential, radially protruding rim, and the several guiding elements are integrated in the rim of the guiding ring.
8 . The telescopic column according to claim 7 , wherein the telescopic column is configured such that the rim of the guiding ring abuts against an end face of the inner column, and the radial protrusion comprises a snap-in nose configured such that it engages with the recess of the inner column such that the guiding ring is positively retained in the longitudinal direction of the inner column by the rim of the guiding ring and the snap-in nose.
9 . The telescopic column according to claim 8 , wherein the inner column comprises a further recess, the guiding ring comprises a further radial protrusion, and the further recess and the further radial protrusion are configured such that the further recess and the further radial protrusion engage into one another in order to positively align the guiding ring with respect to the inner column.
10 . The telescopic column according to claim 7 , wherein the telescopic column is configured such that the ball cage can abut against the rim when the length of the telescopic column is increased.
11 . The telescopic column according to claim 1 , wherein the cover element and the ball cage are formed as being an integral part.
12 . The telescopic column according to claim 1 , wherein the cover element and the ball cage are made of a same material.
13 . A height-adjustable table comprising a telescopic column according to claim 1 .
14 . The telescopic column according to claim 1 , wherein the inner column comprises at least one guiding element configured such that the at least one guiding element engages into one of the at least two longitudinal grooves in an at least almost backlash-free manner during the adjustment of the length of the telescopic column along an adjustment stroke of the telescopic column in order to align the inner column with respect to the outer column.
15 . The telescopic column according to claim 14 , wherein the at least one guiding element comprises several guiding elements configured such that the several guiding elements engage into at least one of the at least two longitudinal grooves in an at least almost backlash-free manner during the adjustment along the adjustment stroke are provided.
16 . The telescopic column according to claim 15 , wherein the several guiding elements are integrally connected to one another, and the several guiding elements are configured to form a guiding ring.
17 . The telescopic column according to claim 16 , wherein the inner column comprises a recess, the guiding ring comprises a radial protrusion, and the recess and the radial protrusion are configured such that the recess and the radial protrusion engage into one another.
18 . The telescopic column according to claim 17 , wherein the guiding ring comprises an at least partially circumferential, radially protruding rim, and the guiding elements are integrated in the rim.
19 . The telescopic column according to claim 1 , wherein the telescopic column further comprises a tube-shaped cover element provided combined with the ball cage, and which cover element is configured to move together with the ball cage half of an adjustment stroke of the inner column with respect to the outer column to cover at least the predetermined range of motion of the balls of the inner column running surface section in an extracted state of the telescopic column such that the inner column running surface is not visible also in case of the extracted telescope column.
20 . A telescopic column for a height-adjustable table, wherein the telescopic column comprises:
a cylindrical outer column having a circular outer cross-section and a circumference,
a cylindrical inner column, having a circular outer cross-section, the cylindrical inner column being at least partially arranged within the outer column,
several balls, and
a tube-shaped ball cage configured to retain the balls at predetermined positions,
wherein
the outer column, along a longitudinal direction of the outer column on an inside of the outer column, comprises an outer column running surface section configured such that the balls roll over thereon,
the inner column, along a longitudinal direction of the inner column on an outer cross-section of the inner column, comprises an inner column running surface section configured such that the balls roll over thereon, and
the inner column and the outer column are configured such that the balls roll over in an at least almost backlash-free manner on the outer column running surface section and the inner column running surface section during an adjustment of a length of the telescopic column in a predefined range of motion of the balls in order to guide the inner column in the outer column, the outer column running surface section comprises, along the longitudinal direction of the outer column and distributed on the circumference of the cylindrical outer column, at least two longitudinal grooves respectively configured such that the balls can roll over in the longitudinal grooves during the adjustment in the range of motion,
wherein the telescopic column further comprises a tube-shaped cover element which covers the inner column running surface section of the cylindrical inner column that is partially arranged within the outer column, the cover element being combined with the ball cage and thereby being positioned between the inner and outer columns, the cover element and the ball cage being moved together when the telescopic column is in an extracted state wherein the running surfaces on the inner column are coverable by the cover element and wherein the cover element covers at least the predetermined range of motion of the balls of the inner column running surface section when in the extracted state of the telescopic column such that the inner column running surface is not visible when the telescope column is in the extracted state,
wherein the inner column comprises at least one guiding element is configured such that the at least one guiding element engages into one of the at least two longitudinal grooves in an at least almost backlash-free manner during the adjustment of the length of the telescopic column along an adjustment stroke of the telescopic column in order to align the inner column with respect to the outer column.