Tube holder for a tube filling machine

Abstract

A tube holder has a housing having an upwardly opening tube receptacle into which a tube can be inserted. A plurality of clamping elements arranged in the tube receptacle can be brought to abut an outer wall of the tube and a clamping force acting radially on the inserted tube cab be applied by at least one spring element. The clamping elements are pivotably mounted in a pivot bearing about a horizontal axis. Further clamping element are below the first group of pivot elements arranged over the tube receptacle and are under the action of the spring element and/or at least one further spring element. The clamping surface of at least some clamping elements and/or at least some further clamping elements at least in sections has a convex contour, curved about a horizontal axis, in the direction of a longitudinal central axis of the tube receptacle.

Claims

1. Tube holder for a tube filling machine, comprising a housing which has an upwardly opening tube receptacle into which one end region of a tube can be inserted, wherein first clamping elements are arranged in the tube receptacle, which can each be brought to abut with a first clamping surface to an outer wall of the tube and by which under the action of at least one first spring element a first clamping force acting radially from outside onto the inserted tube can be applied, wherein the first clamping elements are arranged and distributed over the circumference of the tube receptacle and form a first group of the first clamping elements, wherein below the first group of the first clamping elements second clamping elements are arranged at an axial distance, which are arranged and distributed over the circumference of the tube receptacle and form a second group of the second clamping elements and which can each be brought to abut with a second clamping surface to the outer wall of the tube and by which under the action of the at least one first spring element and/or at least one second spring element a second clamping force acting radially from outside onto the inserted tube can be applied, wherein the first and second clamping elements are each pivotably mounted in a pivot bearing about a horizontally extending pivot axis, wherein the first clamping surface of a plurality of the first clamping elements and/or a second clamping surface of a plurality of the second clamping elements at least in sections has a convex contour, curved about a horizontal axis, in the direction of a longitudinal central axis of the tube receptacle.

2. Tube holder according to claim 1, wherein the convex contour is formed by a section of a circle evolvent relative to the horizontally extending pivot axis.

3. Tube holder according to claim 1, wherein a trough-shaped depression is formed on each of the first and second clamping surfaces.

4. Tube holder according to claim 3, wherein the trough-shaped depression at least in sections has a concave cross-section in the direction of the longitudinal central axis of the tube receptacle.

5. Tube holder according to claim 3, wherein the trough-shaped depression at least in sections has a circular-arc-shaped cross-section in the direction of the longitudinal central axis L of the tube receptacle.

6. Tube holder according to claim 3, wherein the cross-section of the depression varies continuously at least in sections.

7. Tube holder according to claim 1, wherein the force of the at least one first spring element and/or of the at least one second spring element acts on a related one of the first and second clamping elements at a distance a from the pivot axis, wherein a ≤10 mm.

8. Tube holder according to claim 1, wherein the first group of the first clamping elements are arranged in the same axial position of the longitudinal central axis of the tube receptacle.

9. Tube holder according to claim 1, wherein adjacent clamping elements of the first group of the first clamping elements are each connected to one another.

10. Tube holder according to claim 1, wherein the first clamping elements of the first group of the first clamping elements are motion-synchronized.

11. Tube holder according to claim 1, wherein at least one of the second clamping elements is connected via a connecting part to one of the first clamping elements located thereabove.

12. Tube holder according to claim 10, wherein the at least one of the second clamping elements is motion-synchronized with the one of the first clamping elements arranged thereabove.

13. Tube holder according to claim 11, wherein the first clamping elements of the first group of the first clamping elements and/or the second clamping elements of the second group of the second clamping elements are motion-synchronized by the connecting part.

14. Tube holder according to claim 1, wherein the second clamping elements are arranged in the same axial position of the longitudinal central axis of the tube receptacle.

15. Tube holder according to claim 1, wherein adjacent second clamping elements of the second group of the second clamping elements are connected to one another.

16. Tube holder according to claim 15, wherein the second clamping elements of the second group of the second clamping elements are motion-synchronized.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further details and features of the invention are apparent from the following description of an exemplary embodiment with reference to the drawing. In the figures:

(2) FIG. 1 shows a perspective view of a tube holder according to the invention,

(3) FIG. 2 shows a longitudinal section through the tube holder according to FIG. 1 with an inserted tube of relatively small diameter,

(4) FIG. 3 shows a longitudinal section through the tube holder according to FIG. 1 with an inserted tube of relatively large diameter,

(5) FIG. 4 shows a perspective view of a clamping element,

(6) FIG. 5 shows a schematic side view of the clamping element,

(7) FIG. 6 shows the coupling of clamping elements arranged one above the other in side view together with the basic kinematic structure, and

(8) FIG. 7 shows a perspective view of two connecting parts in engagement with one another.

DETAILED DESCRIPTION OF THE DRAWINGS

(9) According to FIG. 1, a tube holder 10 has a housing 11 which preferably consists of plastic and in its interior has an upwardly open tube receptacle 12 which is adapted to the shape of a tube T to be received (see FIG. 2). A longitudinal central axis L of the tube receptacle 12 runs substantially vertically.

(10) A first group of clamping elements 14 is arranged in the upper region of the tube receptacle 12, which clamping elements are distributed over the circumference of the tube receptacle 12 and are arranged at a common axial height of the longitudinal central axis L. Since the clamping elements 14, are all configured to be constructively the same, only one of the clamping elements 14 will be explained hereinafter. The same then applies to the other clamping elements 14.

(11) The clamping element 14 is mounted pivotably in the housing 11 in a pivot bearing 20 about a horizontal pivot axis 18. All the clamping elements 14 are pre-tensioned in the direction of the longitudinal central axis L by means of a common spring element 16 which is formed by an annular spring. The spring element 16 in this case acts on the clamping element 14 at a relatively short distance a of about 3 mm to 5 mm from the pivot axis 18 (see FIG. 2).

(12) At an axial distance below the first group of pivot elements 14, there is arranged a second group of further pivot elements 14a of the same type which corresponds to the first group of pivot elements 14 in the constructive respect and comprises a plurality of further pivot elements 14a of the same type which are arranged distributed over the circumference of the tube receptacle 12. The further pivot elements 14a are under the action of a further spring element 16a, which is also configured as an annular spring and acts upon the further pivot elements 14a in the direction of the longitudinal central axis L of the tube receptacle 12.

(13) Each of the upper clamping elements 14 is connected to a lower further clamping element 14a located thereunder at an axial distance via a connecting part 19, which will be discussed subsequently in detail. All the further clamping elements 14a have the same constructive structure and correspond to the clamping elements 14 in terms of their constructive structure.

(14) One of the clamping elements 14 is shown in FIG. 4 and will be explained in the following. These explanations apply accordingly for the further clamping elements 14a. The clamping element 14 is configured to be block-shaped and is pivotable about the horizontal pivot axis 18, as is indicated by the double arrow S. The clamping element 14 is pierced by the spring element 16 and on its side facing the longitudinal central axis L of the tube receptacle 12 has a clamping surface 15 which can be brought to abut with an outer wall of the tube T. The clamping surface 15 has a convex contour, curved about a horizontal axis, in the direction of the longitudinal central axis L. The convex contour of the clamping surface 15 can be formed by a section of a circle evolvent relative to the pivot axis 18.

(15) A trough-shaped depression 17 is formed on the clamping surface 15, extends in the vertical longitudinal direction of the clamping surface 15 and has a concave cross-section in the direction of the longitudinal central axis L and in particular a circular-arc-shaped cross-section.

(16) The cross-section of the trough-shaped depression 17 is smaller at the lower end of the clamping surface 15 than at its upper end and varies continuously in the longitudinal direction of the clamping surface 15. FIG. 4 shows schematically several semicircles which each symbolize the cross-section of tubes of different diameter. As a result of the continuously varying, circular-arc-shaped cross-section of the depression 17, the clamping surface can abut against tubes of different diameter over a large area.

(17) Preferably the convex contour of the clamping surface is formed by a section of a circle evolvent relative to the pivot axis 18, as shown symbolically in FIG. 5. This has the result that for each point of the circle evolvent, a normal N to a tangent T running through the point runs at the same distance A from the pivot axis 18. This has the result that the clamping point at which the clamping surface 15 (mathematically theoretically) comes to abut with the outer surface of the tube T has the same distance from the pivot axis 18 regardless of the diameter of the tube T.

(18) As shown in FIG. 6, in each case one of the clamping elements 14 and the associated further clamping elements 14a arranged thereunder are connected to one another via a connecting part 19 and motion-synchronized, i.e. when the upper clamping element 14 pivots by an angle α, this pivoting movement is transmitted via the connecting part 19 to the lower further clamping element 14a which pivots about a corresponding angle α. The connecting part 19 is mounted in an articulated manner both at the upper clamping element 14 and also at the lower further clamping element 14a so that from a kinematic viewpoint a four-bar linkage is formed, as shown schematically on the right side of FIG. 6.

(19) The connecting part 19 is shown in FIG. 7. The connecting part 19 has an H-shaped configuration with two vertical legs 19a located at a distance next to one another. Between the upwardly pointing sections of the legs 19a of the connecting part 19, respectively one of the clamping elements 14 is mounted in an articulated manner and between the downwardly pointing sections of the legs 19a respectively one of the lower further clamping elements 14a is mounted in an articulated manner.

(20) Each connecting part 19 has a horizontal central leg 19b with horizontal projections protruding on opposite sides via which adjacent connecting parts 19 are in engagement with one another. One of the projections is configured as a fork (see FIG. 7, right side) while the projection formed on the opposite side is configured as an engaging part which can be inserted in the fork. By means of the connecting parts 19 it is achieved that both the clamping elements 14 of the upper first group of clamping elements 14 and also the lower further clamping elements 14a of the lower second group of clamping elements 14a are motion-synchronized with one another.