Height-adjustable actuation device

1. A height-adjustable actuation device, comprising:

a. a drive ( 2 ) for height adjustment of the actuation device ( 1 ; 1 a ) in a direction of extension ( 37 ) and in a direction of retraction ( 39 ) opposite to the direction of extension ( 37 );

b. a casing ( 6 ; 6 a ) having a longitudinal axis ( 5 );

c. a hollow spindle ( 7 ) arranged in the casing ( 6 ; 6 a ) for displacement of a first lid ( 8 ) arranged on the hollow spindle ( 7 ) along the longitudinal axis ( 5 );

d. an internal spindle ( 9 ) arranged inside the hollow spindle ( 7 ) for displacement of a second lid ( 10 ) arranged on the internal spindle ( 9 ) along the longitudinal axis ( 5 );

e. with the hollow spindle ( 7 ) and the internal spindle ( 9 ) being non-rotatably connected to each other in terms of a rotation about the longitudinal axis ( 5 ); and

f. with the hollow spindle ( 7 ) and the internal spindle ( 9 ) being displaceable relative to each other along the longitudinal axis ( 5 ),

wherein the hollow spindle ( 7 ) is a compound part comprising an external component ( 25 ) and an internal component ( 26 ) arranged inside the external component ( 25 ), and

wherein the internal component is a hexagonal profile pipe ( 26 ) of metal while the external component is a plastic pipe ( 25 ) injection-molded around the hexagonal profile pipe ( 26 ).

2. The actuation device according to claim 1 , wherein the internal component is a hexagonal profile pipe ( 26 ) of an aluminum alloy.

3. The actuation device according to claim 2 , wherein the hexagonal profile pipe ( 26 ) is made by extrusion molding for providing an accurate guidance for a hexagonal sliding element ( 24 ).

4. The actuation device according to claim 1 , comprising a hexagonal sliding element ( 24 ) for non-rotatably connecting the internal spindle ( 9 ) to the hollow spindle ( 7 ).

5. The actuation device according to claim 4 , wherein in order to achieve the non-rotational connection, the hexagonal sliding element ( 24 ) interacts with the hexagonal profile pipe ( 26 ) of the hollow spindle ( 7 ) and is guided in the hexagonal profile pipe ( 26 ) for displacement along the longitudinal axis ( 5 ).

6. The actuation device according to claim 1 , wherein the drive ( 2 ) drives one of the group comprising the hollow spindle ( 7 ) and the internal spindle ( 9 ) directly via a coupling element ( 17 ).

7. The actuation device according to claim 1 , wherein the casing ( 6 ; 6 a ) has a multi-part design comprising housing portions ( 32 , 33 , 34 ; 32 a , 33 a , 34 a ) which are displaceable relative to each other.

8. The actuation device according to claim 7 , comprising a design of the housing portions ( 32 , 33 , 34 ; 32 a , 33 a , 34 a ) such that the spindles ( 7 , 9 ) are arranged inside the casing ( 6 ; 6 a ).

9. The actuation device according to claim 1 , comprising a connecting unit ( 40 ) for non-rotatably connecting the drive ( 2 ) to the hollow spindle ( 7 ).

10. The actuation device according to claim 9 , wherein the connecting unit ( 40 ) comprises a profile pipe ( 41 ) with an internal profile ( 42 ) and a profile sliding element ( 44 ) with an external profile corresponding to the internal profile ( 42 ).

11. The actuation device according to claim 1 , wherein the external component ( 25 ) has several holes ( 35 ) along an outer circumferential surface for securing the internal component ( 26 ) to the external component ( 25 ).

12. The actuation device according to claim 11 , wherein the holes ( 35 ) are oriented radially regarding the longitudinal axis ( 5 ).

13. A height-adjustable actuation device, comprising:

a. a drive ( 2 ) for height adjustment of the actuation device ( 1 ; 1 a ) in a direction of extension ( 37 ) and in a direction of retraction ( 39 ) opposite to the direction of extension ( 37 );

b. a casing ( 6 ; 6 a ) having a longitudinal axis ( 5 );

c. a hollow spindle ( 7 ) arranged in the casing ( 6 ; 6 a ) for displacement of a first lid ( 8 ) arranged on the hollow spindle ( 7 ) along the longitudinal axis ( 5 );

d. an internal spindle ( 9 ) arranged inside the hollow spindle ( 7 ) for displacement of a second lid ( 10 ) arranged on the internal spindle ( 9 ) along the longitudinal axis ( 5 );

e. with the hollow spindle ( 7 ) and the internal spindle ( 9 ) being non-rotatably connected to each other in terms of a rotation about the longitudinal axis ( 5 ); and

f. with the hollow spindle ( 7 ) and the internal spindle ( 9 ) being displaceable relative to each other along the longitudinal axis ( 5 ),

wherein the first lid ( 8 ) comprises an internal thread ( 15 ) engaging into a corresponding external thread of the hollow spindle ( 7 ) causing the first lid ( 8 ) to be moved relative to the second lid ( 10 ),

wherein the second lid ( 10 ) comprises an internal thread ( 12 ) engaging into a corresponding external thread of the internal spindle ( 9 ) causing the second lid ( 10 ) to be moved relative to the drive ( 2 ),

wherein the first lid ( 8 ) is in the shape of an annular disk comprising a central opening, said opening receiving a first threaded bushing ( 14 ) comprising said internal thread ( 15 ),

wherein the first threaded bushing ( 14 ) has an undercut ( 16 ) in the shape of a hexagon head for axially securing said thread bushing ( 14 ) to the first lid ( 8 ) along the longitudinal axis ( 5 ).

14. The actuation device according to claim 13 , wherein the second lid ( 10 ) is in the shape of an annular disk with a second threaded bushing ( 11 ) comprising said internal thread ( 12 ).

15. The actuation device according to claim 13 , wherein at least one of the group of the first lid ( 8 ) and the second lid ( 10 ) comprises two parts for mounting a threaded bushing ( 11 , 14 ).

16. The actuation device according to claim 15 , wherein the two parts are identical lid halves.

17. A height-adjustable actuation device, comprising:

a. a drive ( 2 ) for height adjustment of the actuation device ( 1 ; 1 a ) in a direction of extension ( 37 ) and in a direction of retraction ( 39 ) opposite to the direction of extension ( 37 );

b. a casing ( 6 ; 6 a ) having a longitudinal axis ( 5 );

c. a hollow spindle ( 7 ) arranged in the casing ( 6 ; 6 a ) for displacement of a first lid ( 8 ) arranged on the hollow spindle ( 7 ) along the longitudinal axis ( 5 );

d. an internal spindle ( 9 ) arranged inside the hollow spindle ( 7 ) for displacement of a second lid ( 10 ) arranged on the internal spindle ( 9 ) along the longitudinal axis ( 5 );

e. with the hollow spindle ( 7 ) and the internal spindle ( 9 ) being non-rotatably connected to each other in terms of a rotation about the longitudinal axis ( 5 ); and

f. with the hollow spindle ( 7 ) and the internal spindle ( 9 ) being displaceable relative to each other along the longitudinal axis ( 5 ),

wherein the first lid ( 8 ) comprises an internal thread ( 15 ) engaging into a corresponding external thread of the hollow spindle ( 7 ) causing the first lid ( 8 ) to be moved relative to the second lid ( 10 ),

wherein the second lid ( 10 ) comprises an internal thread ( 12 ) engaging into a corresponding external thread of the internal spindle ( 9 ) causing the second lid ( 10 ) to be moved relative to the drive ( 2 ),

wherein the first lid ( 8 ) is in the shape of an annular disk comprising a central opening, said opening receiving a first threaded bushing ( 14 ) comprising said internal thread ( 15 ),

wherein the second threaded bushing ( 11 ) is axially secured to the internal spindle ( 9 ) along the longitudinal axis ( 5 ) by means of an undercut ( 13 ) in the shape of a hexagonal head, which engages into a corresponding recess of the internal spindle ( 9 ).