Method and tool for the cylindrical deformation of an al sleeve to the core dimension of the internal plastic closure, as preparation for a diffusion-proof press connection within the two components

p0001The invention relates to a method for producing a connection between the neck region of a light-metal cartridge, in particular an aluminum cartridge, and a plastic container inserted therein through a drawing process forming a connecting region and applying the wall of the light-metal cartridge to the plastic container in a manner comprising a rotating basic body of a drawing tool At least one profiled drawing roller, which is rotatable about a rotational axis, for the boundary of a tool working opening, the drawing roller being applied to the outer surface of the light metal cartridge.

p0002Furthermore, the invention relates to a drawing tool which comprises a rotatable base body with at least one profiled drawing roller which is arranged on a circular path and is rotatable about a rotational axis, the drawing roller delimiting a tool working opening and a position defining a minimum tool working opening, the diameter of the tool working opening The position defining a maximum tool working opening can be moved in a manner which increases the force of a spring.

p0003For the application of inhalable pharmaceutical active ingredient formulations, use of hand-held and manually operated inhalers is used by the patient in which the pharmaceutical active ingredient formulation is in each case contained in an inhalator cartridge which is removed from the inhaler after the consumption of the active ingredient formulation and replaced by a new inhalator cartridge Can The inhaler cartridge consists of an outer-side aluminum cartridge and a plastic container used therein, which is often a plastic container produced by the co-extrusion process, which comprises a rigid outer container and a flexible inner bag arranged therein. In order to create a pressure equalization opening between the inner bag and the outer container, an opening is introduced into the relatively rigid outer container by means of the so-called cut crack open process, for example. The plastic container is filled with the pharmaceutical active ingredient formulation and sealed and inserted into the aluminum cartridge by means of the manufacturing process for forming the inhaler cartridge. In a subsequent step, a deformed wall region is then formed in the aluminum cartridge in the upper region of the inhaler cartridge so assembled, which is applied to the outer surface of the plastic container inserted in the aluminum cartridge. In order to form the connecting region on the upper edge of the aluminum cartridge, a pulling method is used in which a rotating drawing tool with its tool working opening travels from above over the connecting region of the aluminum cartridge to be formed and thereby brings profiled drawing rollers arranged around the tool working opening into contact with the outer surface of the aluminum cartridge, To form the connecting region by an axial movement. Subsequently, the aluminum cartridge is applied gas-tight in further production steps to the outer side of the plastic container arranged therein. Subsequently, the combination of aluminum cartridge with plastic container inserted therein is fed to further processing and processing stages, at the end of which the finished, inhaler cartridge is filled with pharmaceutical active ingredient formulation.

p0004Various pulling tools are known from practice for carrying out the drawing process. Thus, there are drawing tools, in which the profiled drawing rollers are designed to be controlled so as to form the profiled connecting region. However, due to the manufacturing tolerances resulting from the manufacture of aluminum cartridges and plastic containers, drawing dies of this type can not achieve a permanently satisfactory result. Therefore, drawing tools have also been developed in which the pulling rollers are guided and moved by force-controlled means. With such drawing tools, however, only about 20000 inhaler cartridges can currently be produced in continuous operation.

p0005In a force-controlled pulling tool known from practice, on the outside a spring-loaded rocker arm is arranged parallel to the longitudinal axis of the drawing tool and can be pivoted about a pivot axis arranged perpendicular to the longitudinal axis of the drawing tool. On the side facing away from the spring, the rocker arm rests against a slide which carries a drawing roller. On account of the spring force acting on the rocker arm, when the aluminum cartridge is inserted into the tool working opening, it is pressed against the outer surface of the aluminum cartridge, and any other pulling roller of the drawing tool constructed in the same way. As a result, it is possible that when the aluminum cartridge is inserted into the tool working opening, the pulling rollers first of all deflect outwards against the force of the spring acting on the rocker arm.

p0006During the manufacturing process with this drawing tool, the stationary aluminum cartridge and the rotating drawing tool are first synchronously guided one above the other at the same speed so that the aluminum cartridge is located below the tool opening of the drawing tool. Subsequently, the drawing tool is then lowered from above onto the aluminum cartridge, whereby the pulling rollers surrounding the tool working opening come into contact with the outer surface of the aluminum cartridge and are thereby likewise brought into a rotary movement. The drawing tool is then further lowered until the drawing rollers have completely grasped the surface area to be deformed to form the connecting area. By means of this lowering movement, the drawing process is carried out by the profiled drawing rollers, and the wall of the aluminum cartridge is deformed in the connecting region in such a way that the inner side of the wall of the aluminum cartridge rests against the outer surface of the plastic container inserted therein. In order to achieve a uniform wall thickness of the aluminum cartridge and to prevent damage to the plastic container or the aluminum cartridge, the pulling rollers, as described above, can escape radially outward against the force of the pressure spring acting on the rocker arm. The minimum tool working opening set in the drawing tool is thereby set to an undersize of approx. 0.2 mm, so that when an aluminum cartridge is to be machined, the drawing rollers are always biased. With this force-controlled tool, it was not yet possible to achieve completely satisfactory results in practice due to a lack of tolerance compensation.

p0007In the case of the displacement-controlled drawing tools, the problem arises that these are not reliably able to compensate for the tolerances of the individual components of an inhaler cartridge, such as the plastic inner container, the plastic closure of the plastic inner container, the aluminum cartridge and a silicone seal. As a result, the so-called chatter marks at the neck of the formed deformation region of the aluminum cartridge are produced, for example, when there is an undersized tolerance. In the case of tolerance oversize, eg too large a closure of the plastic inner container or an aluminum cartridge with a too small diameter, the material which is deformed and displaced during the drawing process is pressed upwards and extends the neck of the aluminum cartridge in an undesirable manner. In the subsequent processing step of the inhaler cartridge, the flanging, then unsightly edges or even so-called brows are formed.

p0008The object of the invention is to provide a method and a drawing tool of the type mentioned at the outset, by means of which, on the one hand, dimensional tolerance deviations are compensated and, on the other hand, tool life times required for continuous operation are achieved.

p0009According to the invention, the rotational axis of the drawing roller is arranged on a tool-side end region of a lever which is arranged transversely to the longitudinal axis of the drawing tool and which can be pivoted in a force-controlled manner about a pivot axis on the opposite tool-side end region and the drawing roller Light metal cartridge is mounted on the drawing tool.

p0010The object, starting from a generic drawing tool solved according to the invention that the axis of rotation of the drawing roller is arranged on a tool inside end portion of an aligned transversely to the tool axis of the puller lever which at its opposite werkzeugau-βense force-controlled itigen end about a pivot axis and the respective drafting roller Is mounted on the shearing surface of the workpiece inserted into the tool working opening on the drawing tool.

p0011Advantageous and expedient refinements and refinements of the invention result from the respective subclaims.

p0012Both the method and the drawing tool are characterized by the formation of a spring-loaded lever arranged transversely to the longitudinal axis of the drawing tool and transversely to the longitudinal axis of the working area of ​​the drawing tool forming the tool working opening. The rotary axis of a rotatable drawing roller is assigned to the lever at its tool-side end, the rotation axis being displaceable about a pivot axis. In its end region on the outside of the tool, the lever is pivotally mounted about a further pivot axis, wherein a force induced by the spring engages in this end region on the tool outer side. On the other hand, the drawing roller is guided by the induced force by means of a pivoting or retracting movement for the force-controlled execution of a drawing process on the outer side of the drawing roller Of the workpiece inserted into the tool working opening. In this way, the manufacturing process of an inhaler cartridge can be applied to the outer side of the plastic container which is already arranged in the aluminum cartridge, and the connection between the inner side of the aluminum cartridge and the outer side of the aluminum cartridge is thereby made The outer side of the plastic container. The use of the drawing tool according to the invention improves the service life by the fact that the respective drawing roller, and advantageously all the drawing rollers, now no longer performs a slide-controlled, merely translatory movement in the radial direction of the tooling opening, but a movement in the radial direction due to its arrangement on the pivotable lever . On account of this movement, the deflection movement from the retraction movement and the retraction movement into the region of the tool working opening both for the respective drawing roller and the workpiece to be processed is significantly more gentle. The lever arranged transversely to the longitudinal axis of the tool working opening and / or of the drawing tool is preferably oriented essentially perpendicular to this longitudinal axis, ie, when the drawing tool is in operation, essentially horizontally.

p0013In order to ensure the force-controlled application of the respective drawing roller to the workpiece to be machined, a force induced by a spring preferably acts on the end region of the lever on the outer side of the tool, and the connecting region is pivoted by pivoting the lever, forming a pivoting movement striking a pivot angle, and a force- Pulling roller is formed on the outer surface of the light-metal cartridge, the drawing roller performing an axial movement on the basis of a further pivot axis.

p0014Since the process is preferably used for the manufacture of an inhaler cartridge for use in an inhaler for the application of active ingredient formulations by a patient himself, the plastic container is advantageously connected in a gas-tight manner to the light metal cartridge in one or more subsequent process steps and filled with a pharmaceutical formulation. Preferably, the light metal cartridge and the plastic container are then further processed into an inhaler cartridge for use in an inhaler.

p0015In the embodiment of the drawing tool, a force induced by the spring acts on the end region of the lever on the outer side of the tool, against which the lever can be pivoted about the pivot axis such that the rotation axis can be moved out of the position of the drawing roller which is assigned to the minimum tool working opening Is.

p0016In order to force the lever, and thus the pulling roller arranged on it, in a force-controlled manner, the outer side of the tool on the tool side engages on an annular disk, which is rotatably fastened to the basic body in a manner at least as far as possible Radial deflection movement of the pulling roller, the annular disc can be rotated relative to the force of the spring, and the retraction or insertion movement of the drawing roller can be effected by a return of the annular disc driven by the spring force with force transmission introduced into the region outside the tool. The annular disk offers particular advantages in the arrangement of several pulling rollers on a respective lever since in this embodiment only one spring is needed and when one lever is clamped, this lever is compulsorily displaced via the other lever associated with the ring disk. In addition, all the pulleys have the same force.

p0017In order to be able to eliminate radial play between the lever and the annular disk during adjustment or adjustment of the drawing tool, the pivot axis is formed in the center of an eccentrically mounted sleeve which engages on the annular disk in the region of the lever on the outer side of the tool. The sleeve interacts with the annular disk in the rotating direction of action of the drawing tool in a play-free manner in order to produce a defect-free workpiece reproducibly. Furthermore, the pivot axis serves for the pivotable mounting of the corresponding pivot axis of the lever.

p0018A further pivot axis is formed in the region of the drawing roller in order to produce a relatively rectilinear deflection movement of the drawing roller for tolerance compensation. In order to provide favorable lever ratios and to realize the necessary movements for the tolerance compensation, the two pivot axes are expediently laterally displaced in the longitudinal axis of the lever and the center point of the rotational axis offset with the pivot axis offset in the region of the drawing roller by, in particular, 1 mm to the rotational axis.

p0019The distance between the further pivot axis in the region of the drawing roller and the rotational axis forms a lever arm. Preferably, a lever ratio of 1: 28 exists between the lever arm and the lever.

p0020According to a further development, the further pivot axis supports the draw roller in an eccentrically adjustable manner and is rotatably mounted in bearing flanges of a bearing block which is fixed to the tool and is arranged non-rotatably on the lever. By adjusting the bearing block an adjustment of the drawing tool is performed in order to determine the size of the tool working opening and thus the outside diameter of the connecting area between the cylindrical aluminum cartridge and the plastic container inserted therein.

p0021Advantageously, the radial deflection movement of the drawing roller allows a roll stroke of 0.3 mm and the lever sweeps a pivot angle of 22 °.

p0022In order to achieve an exact shaping of the machined wall region, in particular in the case of circular cylindrical light metal cartridges, at least three pulling rollers, preferably five pulling rollers, are preferably arranged on the base body, which spacings are uniformly spaced apart from one another by the tool working opening.

p0023It goes without saying that the above-mentioned features, which are still to be explained below, can be used not only in the particular combination indicated, but also in other combinations. The scope of the invention is defined only by the claims.

p0024The invention is explained in more detail below with reference to an exemplary embodiment, with reference to the accompanying drawings. It shows:<dl id="dl0001"><dt>FIG</dt><dd>A perspective view of the drawing tool,</dd><dt>FIG</dt><dd>A representation of the drawing tool according to FIG <figref idrefs="f0001">FIG</figref> from underneath,</dd><dt>FIG</dt><dd>6 shows a perspective view of a roller unit of the drawing tool</dd><dt>FIG</dt><dd>A cross-section through the roller unit <figref idrefs="f0002">FIG</figref> and</dd><dt>FIG</dt><dd>A longitudinal section through the roller unit according to FIG <figref idrefs="f0002">FIG</figref>.</dd></dl>

p0025In order to carry out a drawing process, a tool working opening 1 is formed in the center of a rotatable drawing tool 2, said tool working opening being formed by five pulling rollers 3 surrounding the tool working opening 1 on a circular path. Only one of the pulleys 3 will be described in detail, since all pulleys 3 are constructed identically.

p0026The drawing roller 3 is rotatably mounted by means of two ball bearings 4 on an eccentric axis 6 forming an axis of rotation 5, the eccentric axis 6 being accommodated in an eccentrically rotatable manner in two bearing flanges 7 of a bearing block 8 of the drawing tool 2, A end of the eccentric axis 6 protruding beyond the bearing block 8 is arranged non-rotatably on a tool-side end region of a lever 9 by means of a transverse pin 19. The center axis of the eccentric axis 6 offset laterally relative to the axis of rotation 5 forms a pivot axis 10. At its end region opposite the drawing roller 3, the lever 9 is held pivotably about an additional pivot axis 11 by means of a sleeve 12 surrounding the latter. The two pivot axes 10, 11 are aligned in their normal position and the sleeve 12 is arranged adjustably on the lever 9 by means of an eccentric 14.

p0027The annular disk 13 is rotatably mounted on a basic body 15 of the drawing tool 2 about its longitudinal axis 16 against the force of a spring 17 designed as a ring spring. One end of the spring 17 engages in the annular disk 13 and the other end of the spring 17 is fixed to the basic body 15 of the drawing tool 2. The lever 9 is aligned transversely with respect to the longitudinal axis 16 of the drawing tool 1.

p0028To adjust the drawing tool 2, the tool working opening 1 is adjusted with a teaching mandrel to a diameter corresponding to the desired external diameter of a light metal cartridge. In this case, the bearing blocks 8 are displaced and the rotational axes 5 of the pulling rollers 3 are laterally offset. By rotating the eccentric 14, the sleeves 12 are brought into abutment in corresponding recesses of the annular disc 13, the recesses receiving the sleeves 12 with play.

p0029In the operating state, the drawing tool 2 rotates and a workpiece, that is, the light metal cartridge with a plastic container inserted therein, is introduced into the tool working opening 1. The drawing tool 2 moves downwards in the axial direction onto the workpiece, and the leading bevels 18 of the drawing rollers 3 come into engagement with the workpiece, whereupon the drawing rollers rotate about their axes of rotation. In the case of a further downward axial movement, the workpiece is tapered by the pulling rollers 3 and a shoulder is formed by the feed bevels 18.

p0030In order not to damage the workpiece but still achieve a satisfactory connection between the neck region of the light-metal cartridge and the plastic container inserted therein, each lever 9 performs a pivoting movement against the force of the spring 17, which lead to essentially radial movements of the pulling rollers 3 The diameter of the tool working opening 1 can be increased. The corresponding evasive movements are effected via the pivot axes 10, 11 of the lever 9 in the region of the twisted annular disk 13 and the rotating pulley 3. The pulleys 3 remain spring-loaded in the processing position until the drawing tool 2 is disengaged from the workpiece in an axial movement . The pulling rollers 3 are set to their adjusted positions due to the action of the spring 17. The ring disk 13 is rotated by the force of the spring 17, and the levers 9 are pivoted thereby to displace the pulleys 3.

p0031In the exemplary embodiment, five pulleys 3 are shown. However, the drawing tool 2 can also have any other number of drawing rollers 3, in particular also one or three drawing rollers 3.

p0032The lever 8 extending between the sleeve 10 bearing against the annular disc 11 and the pivot axis 10 associated with the drawing roller 3 is at a ratio of 1:28 to the lever arm which is formed between the rotational axis 5 of the drawing roller 3 and the pivot axis 10 assigned to it .

p0033The center point of the pivot axis 10 and the center point of the rotation axis 5 are arranged laterally offset relative to one another on the lever 9, wherein the center point of the rotation axis 5 is preferably 1 mm outside the longitudinal axis of the lever 9 and the center point of the pivot axis 10 on the longitudinal axis of the lever 9 Is arranged. The pivoting movement of the lever 9 in each case permits a roller stroke of the pulling rollers 3 of 0.3 mm and in this case sweeps a pivot angle of 22 °.