Device and method for beading a tube end

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of European Patent Application EP 24 162 284.4, filed on Mar. 8, 2024, the content of which is incorporated in its entirety.

TECHNICAL FIELD

The disclosure relates to a device and a method for beading a tube end. Here, the edge of a metal sheet or a tube end is bent over by means of a corresponding device or manually. In this way, for example, sharp cut edges can be prevented. It is also possible to close a tube end by means of beading.

BACKGROUND

Devices for beading a tube end are generally known. As a rule, devices of this type have a receptacle unit for the workpiece to be beaded. This receptacle unit can be rotated about a first rotational axis. Moreover, there is a tool holder, to which at least one beading roller and at least one bead roller are fastened via a common axle. The at least one beading roller and the at least one bead roller can be rotated about a second rotational axis along the longitudinal axis of the common axle. The longitudinal axis of the common axle and the rotational axis of the receptacle unit are oriented parallel to one another. A device of this type is known, for example, from U.S. Pat. No. 8,495,901 B2.

SUMMARY

The present application discloses an improved device and an improved method for beading a tube end, with the result that beading with as low wear as possible can be achieved.

The device for beading a tube end has a receptacle unit for the workpiece to be beaded, and at least one beading die which is mounted in a longitudinally displaceable manner and is aligned with the receptacle unit. A protective film is positioned between the beading die and the receptacle unit for the workpiece to be beaded. As a result of the film, merely minimum friction occurs between the beading die and the tube end to be beaded, with the result that virtually no abrasion is to be observed. Therefore, the high surface quality of the tube end to be beaded can be maintained. If a low formation of particles nevertheless occurs, the particles which are formed can stick to the protective film and thus do not pass into the critical opening region of the workpiece to be beaded. This is of great importance, in particular, in the case of cartridges for preserving and storing active pharmaceutical ingredients.

Overall, a high useful life of the individual components of the device for beading a tube end can be achieved by way of the low-wear beading, with the result that large maintenance intervals can be realized. This relates, in particular, to the beading die.

This leads to it being possible for beading dies to then also be used in a reliable and reproducible manner instead of the frequently used beading rollers. Roller bending tools of this type such as, in particular, beading dies are as a rule less expensive and simpler to handle than a beading roller. Moreover, the requirements of the edge quality of the workpiece to be beaded, in particular with regard to the cut quality, are as a rule lower than in the case of the devices which are already known in the prior art. In particular, the workpiece to be beaded can be machined in a dry state and without re-greasing.

The protective film can preferably be mounted on an endless reel. In this case, the protective film can be pulled gradually off the endless reel and wound onto an empty reel. In this way, a new piece of the protective film can be used for each beading operation. As a result, particles which adhere to the protective film can be transported away gradually and do not pass into the critical opening region of a following workpiece. In order for it to be possible for the protective film to be wound up and unwound as effectively as possible, at least one pair of transport rollers can be present between the endless reel and the empty reel. In this case, the transport rollers can preferably be positioned directly upstream of or directly downstream of the receptacle unit. This makes optimum tensioning of the protective film in the region of the receptacle unit and therefore also in the region of the workpiece to be beaded possible.

The protective film can fundamentally contain, for example, polyethylene (PE), felt, cotton or paper. Preferably, the protective film can consist of a polyvinyl fluoride or can be coated with a polyvinyl fluoride. Protective films of this type have particularly satisfactory sliding and adhesive properties.

The receptacle unit can preferably be mounted in a longitudinally displaceable manner. As a result, the beading die and the receptacle unit might be moved mutually towards one another and away from one another. The two components are therefore at a greater spacing from the protective film in their starting position, with the result that there is sufficient space for fitting the receptacle units with the workpiece to be beaded. At the same time, the protective film has to be deflected merely slightly out of its path during the beading operation.

The beading die can preferably have a conical inner contour, with the result that optimum beading results can be realized.

In the case of the method for beading the tube end, the workpiece to be beaded is first of all positioned in a receptacle unit. A protective film is positioned between this receptacle unit and a beading die which is mounted in a longitudinally displaceable manner. Subsequently, the free edge of the workpiece to be beaded is beaded inwards by means of the beading die. Here, the protective film is situated between that edge of the workpiece which is to be bent over and the beading die. In this way, considerably reduced abrasion occurs, with the result that more exact beading results can be achieved with a longer useful life of the tools, in particular of the beading die. In particular, the beading results remain identical over the entire useful life of the beading die, with the result that optimum beading results are still possible even towards the end of the planned useful life.

A primary packaging can preferably be positioned in the workpiece to be beaded. In this case, the free edge of the workpiece to be beaded is beaded around the edge of the primary packaging. In this case, in particular, the primary packaging can consist of a plastic material. In this case, for example, the workpiece to be beaded can be configured as an aluminium can or as a steel can.

The protective film can preferably be unwound from an endless reel. In this way, a new region of the protective film which is still unused can be used for each beading operation. The particles which adhere to the protective film can therefore be transported away from the critical region, with the result that subsequent contamination of the contents present in the workpiece to be beaded cannot occur.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described and explained in greater detail in the following text on the basis of the exemplary embodiment, which is shown in the drawing, in which:

FIG. 1 shows a diagrammatic side view of the device for beading a tube end before the start of the beading operation,

FIG. 2 shows a detailed view of the receptacle unit with the workpiece to be beaded and the beading die before the start of the beading operation, and

FIG. 3 shows a detailed view according to FIG. 2 after the beading of the free edge of the workpiece.

DETAILED DESCRIPTION

A diagrammatic side view of the device 10 for beading the tube end 12 of a workpiece 14 is shown in FIG. 1.

The device 10 has a receptacle unit 20, in which the workpiece 14 to be beaded is positioned. In the present example, the workpiece 14 to be beaded is a cartridge made from aluminum. In the present example, a primary packaging 22 made from a plastic material is inserted into the workpiece 14. Here, the primary packaging 22 can be filled with the desired content, as a rule with an active pharmaceutical ingredient. At its end which protrudes out of the receptacle unit 20, the primary packaging 22 has an open edge 24, with the result that the primary packaging 22 is configured substantially as an open container. At its end which protrudes out of the receptacle unit 20, the workpiece 14 has a tube end 12 in the form of a free edge. This tube end 12 of the workpiece 14 projects some way beyond the open edge 24 of the primary packaging 22 (see also FIG. 2). In contrast to the exemplary embodiment which is shown here, the primary packaging 22 might also be dispensed with. In this case, the content to be packaged would be present directly in the workpiece 14.

In the present example, the receptacle unit 20 is mounted such that it can be displaced in the longitudinal direction 26 (arrow 28).

A beading die 30 which is aligned with the receptacle unit 20 is arranged above the receptacle unit 20. The beading die 30 is mounted in a displaceable manner in the longitudinal direction 26 (arrow 32), with the result that the beading die 30 and the receptacle unit 20 can be moved towards one another during the beading operation. On its side which points towards the receptacle unit 20, the beading die 30 has a conical inner contour 34, with the result that the free edge 12 of the workpiece 14 can be bent over inwards by means of the beading die 30 (see FIG. 3). In the present example, the free edge 12 of the workpiece 14 is bent over the open edge 24 of the primary packaging 22 here.

A protective film 40 is positioned between the beading die 30 and the receptacle unit 20. The protective film 40 is mounted on an endless reel 42 and can be unwound gradually from this endless reel 42. To this end, in the present example, there are two pairs of transport rollers 44, 46. Here, the two transport roller pairs 44, 46 are positioned close beside the receptacle unit 20. The protective film 42 can be wound gradually onto an empty reel 48.

The protective film 42 can be unwound from the endless reel 42 and wound onto the empty reel 48 cyclically. As a result, a new region of the protective film can be positioned between the beading die 30 and the tube end 12 of the workpiece 14 during each beading operation. In this way, the abrasion on the workpiece 14 and on the conical inner contour 34 of the beading die 30 can be reduced considerably. This leads to a longer useful life of the beading die 30 and therefore also of the device 10. Moreover, more exact results can be achieved when beading the tube ends 12 of the workpieces 14.

Particles which possibly accrue stick to the protective film 40 and are removed from the region of the receptacle unit 20 by way of the further transport of the protective film 40. As a result, the particles cannot accidentally pass into the interior space of the workpiece 14 or the interior space of the primary packaging 22 and lead to contamination of the content there.