Abstract
A tube holder for a tube-filling machine has a cup-shaped housing which comprises an upwardly opening tube receiving means into which a tube is insertable by way of one axial end region thereof. A clamping device, by which a clamping force can be applied to the tube, is arranged in the region of the tube wall of the tube receiving means. It can be provided in this case that that the clamping device comprises at least one magnet which is movable by at least one electric coil and/or at least one permanent magnet between a clamping position, in which a clamping force is applied to the tube, and a releasing position in which a clamping force is not applied to the tube. Alternatively, the clamping device can comprise a magnetorheological fluid, the viscosity of which is modifiable by at least one electric coil and/or at least one permanent magnet.
Claims
1. A tube holder for a tube-filling machine comprising a cup-shaped housing which comprises an upwardly opening tube receiving means into which a tube is insertable by way of one axial end region thereof, wherein a clamping device, by which a clamping force can be applied to the tube, is arranged in the region of the inner wall of the tube receiving means, wherein the clamping device comprises a magnetorheological fluid, the viscosity of which is modifiable by at least one electric coil and/or at least one permanent magnet.
2. The tube holder as claimed in claim 1, wherein the magnetorheological fluid is arranged in a fluid chamber which forms at least one portion of the inner wall of the tube receiving means with a flexible wall.
3. The tube holder as claimed in claim 2, wherein the fluid chamber is realized as a circumferential annular chamber.
4. The tube holder as claimed in claim 2, wherein the housing sits in a housing receiving means and in that the at least one electric coil and/or the at least one permanent magnet are arranged in or on the housing receiving means.
5. The tube holder as claimed in claim 4, wherein the housing receiving means is realized in an annular manner.
Description
(1) Further details and features of the invention can be seen from the following description of exemplary embodiments with reference to the drawing, in which:
(2) FIG. 1 shows a schematic sectional representation of a tube holder according to a first exemplary embodiment,
(3) FIG. 2 shows a schematic sectional representation of a tube holder according to a second exemplary embodiment,
(4) FIG. 3 shows a schematic sectional representation of a tube holder according to a third exemplary embodiment,
(5) FIG. 4 shows a schematic sectional representation of a tube holder according to a fourth exemplary embodiment and
(6) FIG. 5 shows a schematic sectional representation of a tube holder according to a fifth exemplary embodiment.
(7) A tube holder 10 shown in FIG. 1 has a cup-shaped housing 11 which tapers conically at its lower end and comprises a radially protruding, circumferential flange 11a in the upper region. A cylindrical vertical through bore, which forms a tube receiving means 12 and has an inner wall 12a, is realized in the housing 11. A circumferential chamber 21, which is filled with a clamping part 22 which consists of a soft elastic, easily deformable material, is realized in the lower region of the axial length of the tube receiving means 12, in the inner wall 12a thereof. As shown in FIG. 1, the clamping part 22 forms a portion of the circumferential boundary of the tube receiving means 12.
(8) Multiple magnets 14 distributed over the periphery are embedded in the material of the clamping part 21. The magnets 14 are connected to the material of the clamping part 22 such that movement of the magnets 114 results in deformation of the clamping part 22.
(9) The housing 11 is inserted into a receiving opening 26 of a substantially annular housing receiving means 15, the housing 11 reaching through the receiving opening 26. An electric coil 16, which is connected to an electrical voltage source in a manner not shown, is arranged in the vicinity of the receiving opening 26, in the interior of the housing receiving means 25. When the housing 11 is inserted into the housing receiving means 15, as shown in FIG. 1, the magnets 14 are located in the vicinity of the electric coil 16 and within the same. When the electric coil 16 is traversed with current, a magnetic field is formed. As long as there is no magnetic field present, the magnets 14 are displaced radially inward, i.e. in the direction of the tube receiving means 12. This results in the clamping part 22 protruding into the tube receiving means 12, as shown by the broken line in FIG. 1. As a result, a tube shown in FIG. 1 can be clamped in the tube receiving means 12.
(10) As soon as the electric coil 16 is traversed by current, a magnetic field is present and the magnets 14 together with the clamping part 22 take up their releasing position which is shown by the continuous line in FIG. 1.
(11) FIG. 2 shows an alternative design of the tube holder 10. This differs from the design according to FIG. 1 substantially as a result of a fluid chamber 24 now being provided in the inner wall 12a of the tube receiving means 12, which fluid chamber is delimited in relation to the tube receiving means 12 by a flexible wall 25, for example in the form of a film. A magnetorheological fluid 17 is arranged in the fluid chamber 24.
(12) When the tube holder 10 is inserted into the receiving opening 26 of the housing receiving means 15, as shown in FIG. 2, the fluid chamber 24, which is preferably realized as a circumferential annular chamber, is situated in the region in the interior of the electric coil 16. When a current flows through said electric coil, a magnetic field is built up, as a result of which the viscosity of the magnetorheological fluid 17 in the fluid chamber 24 changes and it becomes increasingly inviscid. An inserted tube T is fixed in the tube holder 10 on the outside as long as no magnetic field is present due to the coil 16. As soon as a magnetic field is present on account of the coil 16, the tube T is released, as shown in FIG. 2.
(13) As soon as the electric coil 16 is no longer traversed by current, no magnetic field is present and the magnetorheological fluid 17 clamps the tube T again.
(14) The embodiment shown in FIG. 3 differs from the embodiment shown in FIG. 2 in that permanent magnets 18 are now arranged in the housing receiving means 15 instead of a coil. When the housing 11 is lifted from the housing receiving means 15, the magnetorheological fluid 17 flows out of the magnetic field of the permanent magnets 18, as a result of which its viscosity increases and the tube T is held securely. When the housing 11 is then inserted with an inserted tube T into the housing receiving means 15, the magnetorheological fluid 17 flows into the magnetic field of the permanent magnets 18, as a result of which the viscosity of the magnetorheological fluid 17 drops and the tube T is released.
(15) FIG. 4 shows a modification of the design according to FIG. 1. In this case, the magnets 14 continue to be embedded in the material of the clamping part 22 but the outer coil arranged in the housing receiving means 15 is replaced by the permanent magnet 18. When the tube holder 10 is inserted into the tube receiving means 12, the magnets 14 on the one side and the permanent magnets on the other side 18 attract. As the permanent magnets 18 are held so as to be non-displaceable, this results in the clamping part 22 deforming elastically radially outward, i.e. away from the tube T, as a result of which the tube is released.
(16) FIG. 5 shows a further modification of the design according to FIG. 1. The magnets 14 are now not embedded in the material of a clamping part but are displaceable longitudinally of a guide 19, which includes bearings and in particular ball bearings 23, and are, in particular, rotatable or rotational about the longitudinal axis of the tube receiving means 12. Clamping elements 20 are provided on the inner wall 12a of the tube receiving means 12. The displacement or rotation of the magnets 14 on account of a magnetic field which is generated by the coil 16, is transmitted mechanically to the clamping elements 20, as a result of which a tube T located in the tube receiving means 12 is clamped or released.
(17) When no more current flows through the electric coil 16 and consequently no magnetic field is present, the magnets 14 return into their initial position, as a result of which the clamping elements 20 preferably clamp the tube.
