Method for the automated changing of devices of a forming station, and forming apparatus having a device for such automated changing

Abstract

The invention relates to methods and apparatuses for the automated changing of exchangeable devices (102, 110, 120, 130) of forming stations (4), a plurality of which are arranged in a circumferential distribution on a rotationally driven forming wheel (7). The forming wheel (7) is rotatably mounted in a machine frame (27) and can be rotationally driven by a drive device (35, 37) to move relative to the machine frame (27) and can be slowed by a braking device (39). For the automated changing, an automatic changing unit (300) is provided, which is arranged in a certain circumferential angle range of the forming wheel (7) and acts on forming stations (4) positioned into this changing region (300') and carries out the changing of the exchangeable devices (102, 110, 120, 130). The automated changing is performed outside of the forming operating mode in a changing operating mode in which the forming wheel (7) is moved cyclically by means of a drive (35, 37) and a brake (39) in order to successively position the plurality of forming stations (4) in the changing region (300'). To finely position the forming stations (4) relative to the automatic changing unit (300) in the changing operating mode, a) mechanical form-locking engagement occurs between an alignment element (31) on the forming wheel (7) and an engagement element (32) of complementary shape on the machine frame (27) or on the automatic changing unit (300), which are designed for relative movement toward one another at least partially in the radial direction, said form-locking engagement being released both in the forming operating mode and during the cyclical rotating in the changing operating mode, and / or b) a brake (39) and a drive (35, 37) are simultaneously active while the automatic changing unit (300) acts on a forming station (4) in the changing region (300'), the braking force outweighing the driving force.

Description

[0001] Method for the automated exchange of equipment of a forming station and forming device with a device for such automated exchange

[0002] The invention relates to a method according to the preamble of claim 1, in particular the invention relates to a method for the automated changing of external shapes of forming stations.

[0003] The invention further relates to a device according to the preamble of claim 6, in particular to a device for the automated changing of external shapes of forming stations.

[0004] Various methods and devices for forming preforms into containers are known in the prior art. Regardless of the medium introduced under pressure into the preform for forming purposes, the preform is expanded against an outer mold. This mold is usually and typically multi-part to allow for the insertion and removal of the preforms. Typically, the outer mold consists of two side shells and a bottom shell, thus comprising three parts. In the scope of the present invention, the multi-part and, in particular, the three-part design is considered preferred. Gases and liquids are known and commonly used as forming media in the prior art; these are hereinafter collectively referred to as the forming fluid. A typical gaseous forming fluid is, for example, compressed air.In cases involving a gaseous forming fluid, terms such as blow molding machine, and, when using a stretching bar, also stretch blow molding machine, blowing station, blow mold, blowing nozzle, etc., are known and commonly used. When using a liquid forming fluid, the material to be filled is often used as the forming medium and therefore remains in the container after the forming process is complete. The present invention is independent of the forming fluid and thus relates equally to blow molding processes and forming processes using a liquid forming fluid. The use of a stretching bar is preferred but not mandatory.

[0005] It is generally known that in forming stations where preforms are formed into containers, different components are designed to be interchangeable, allowing the same station to be used for forming different preforms into different containers. In this context, the technical term is usually "retooling" or "format change." Interchangeability can also be related to wear and tear or maintenance. In this context, interchangeability of a forming station component means that the component is part of the forming station, i.e., the entire station is not replaced, and that the component is fixed within the station, but this fixing is removable. Removing the component may require mechanical intervention, such as the use of tools. However, it can also be triggered by control commands, e.g.,Holding forces are controlled and switched on or off, e.g., via controllable electromagnets, pneumatically or hydraulically operated holding devices, or by actuating mechanically operated holding devices into or out of engagement. For the present invention, the manner in which interchangeability and releasable fastening are implemented is irrelevant, as long as the fastening is releasable and an automatic changer can perform the change.

[0006] It is generally known, and assumed within the scope of the present invention, that more than one forming station is arranged on a rotating forming wheel. This concerns devices with carousel-like rotating wheels, i.e., machines of a rotating design. During forming operation, the forming wheel is intended to rotate continuously, i.e., not intermittently. During such a rotation of the forming wheel, a preform is typically first transferred into an open forming station, then the station is closed, and with the station closed, the preform is formed into a container. After the forming process is complete, the station is opened and the finished container is removed. This process generally takes place within a single rotation, i.e.,The transfer takes place in a specific circumferential angle range of the forming wheel, and the removal takes place in another circumferential angle range spaced apart from it, while in between the station is closed, the forming process into the container is carried out, and the station is opened.

[0007] Components of a forming station that are typically interchangeable include, for example, the aforementioned molds or the mold components, such as a base or side panels. The interchangeability of the molds or the mold components is considered a typical application of the present invention. Furthermore, the drawbar, which is optional but typically included, can also be an interchangeable element. The forming nozzle, which seals against the preform or the surrounding mold for introducing the forming fluid under pressure, can also be affected. Other components of a forming station, such as those that are format-dependent, can also be affected. For instance, when switching to preforms with a different opening diameter, it is sometimes necessary to replace elements on which the preform rests within the station after the station is closed.

[0008] It is generally known to perform the replacement of format-dependent parts or the conversion of forming stations to a different preform type or to the production of a different bottle type manually. However, it is also known that so-called exchange machines are used for this purpose. These are devices, such as robots, that automatically remove the elements to be replaced from the station. Typically, these exchange machines then immediately insert the new element into the station. It is also possible, however, that the exchange machine is solely responsible for removal, with, for example, another exchange machine handling the insertion of the replacement element. As a rule, the exchange machine processes one station at a time and, after completing the exchange process at one station, processes the next station.It is also conceivable, in principle, that a changeover machine can process more than one station simultaneously. It is also conceivable that several changeover machines can perform the same changeover operations at different stations at the same time. Typically, the changeover machine is positioned at a specific circumferential angle of the forming wheel, or is permanently positioned there, for the execution of the changeover operation. The forming stations where the changeover operation is to be performed are brought into the working area of ​​the changeover machine by targeted and controlled rotation of the forming wheel. When using a changeover machine, it is necessary that the machine and the forming station are in a defined position relative to each other.This ensures that the changing machine can perform the changeover process using defined movement patterns and sequences, in particular that it can safely grasp the components to be changed and remove them from the station, and, if necessary, safely insert the components to be installed into the station. If the changing machine also needs to release the mounting of the components to be changed in the station as part of this process, it is also necessary that the changing machine and the station are positioned relative to each other in the intended manner. While it is generally possible for the changing machine to be operated in conjunction with an image recognition device, and for the changing machine to use image recognition to determine how, for example, grasping, removal, or insertion movements for the components to be changed should be performed, this is not always the case.However, it is simpler and preferred if the station to be processed is brought safely and reliably into a target position, so that the changeover machine can execute the changeover process sequence stored in the control system, for example.

[0009] In known forming wheels, the wheel is typically mounted rotatably in a machine frame. A drive for the forming wheel is provided on the machine frame, with the drive force usually transmitted via a drive gear to a toothed ring that is part of the forming wheel. A brake is also generally provided to slow the rotation of the forming wheel. In forming mode, the drive ensures continuous rotation of the forming wheel through the meshing of the drive gear with the toothed ring of the forming wheel. To stop the forming wheel, the brake is activated, reducing the wheel's rotational speed until it comes to a standstill.This drive and the aforementioned brake are fundamentally suitable for precisely moving the stations into the area where the automatic tool changer performs the exchange of interchangeable components at a station during alternating operation. However, the drive described above operates with a certain amount of play between the drive gear and the ring gear of the forming station. The brake also operates with a certain amount of play. This play cannot be reduced arbitrarily, as a certain amount of play is intentional and advantageous in order to minimize friction losses and wear. While this intentional play is beneficial and desirable for the forming process, in alternating operation it results in the station being positioned with a certain degree of inaccuracy relative to the automatic tool changer at the time of, for example, a mold change.For automated mold changes, or more generally, for automated changes of interchangeable components, and for the precise engagement of the changing machine, this play is disadvantageous because it leads to a certain degree of variation in the station's position relative to the changing machine. This play also allows the station to perform minor movements during the changeover process, movements permitted by the play. This problem also arises with drive mechanisms other than meshing gears, meaning the invention is not limited to meshing gears, although it is particularly relevant in this context. In connection with other drives, the term "slippage" is more common, but it also expresses a certain degree of positional uncertainty.

[0010] Blow molding machines with automatic changeover robots are known from the prior art, enabling the automated exchange of blow molds. These changeover robots are also known as industrial robots or industrial manipulators. Multi-axis swiveling industrial robots with grippers are used to change the blow molds of a blow molding machine, which are stored in so-called blow mold magazines. Blow molding machines with changeover robots are known, for example, from documents EP 2 878 423 B1 and DE 20 2012 013 536 U1. EP 2 878 423 discloses that either a complete blow mold or only parts of the blow mold can be exchanged. For example, it is possible that the bottom part of a blow mold is not changed, but only the side parts.

[0011] Under unfavorable circumstances, the play or slippage described above can lead to the switching machine not reliably engaging the station's components during a changeover operation and thus failing to execute the change reliably. It is also conceivable that the station might move during the changeover process due to the forces exerted on it by the switching machine, and that this movement could cause a problem.

[0012] The invention is therefore based on the objective of providing an improved solution that addresses the aforementioned problems. In particular, the objective of the present invention is to provide a method of the type mentioned in the introduction in such a way that the problems identified do not occur.

[0013] According to a first aspect of the invention, the problem is solved according to the invention by a method with the characterizing features of claim 1. As in the prior art, the method according to the invention relates to a method for the automated exchange of interchangeable components of forming stations. Other names for this would be conversion methods or format change methods. Typical components of a forming station that can be exchanged are, in particular, the outer die, especially the multi-part outer die consisting of a bottom shell and / or side shells, but also, for example, the drawing bar, the forming nozzle, or other format-dependent parts of a forming station.

[0014] Several forming stations are arranged circumferentially on a rotary forming wheel. In a forming operation mode, temperature-conditioned preforms are expanded against a surrounding die during a continuous rotation of the forming wheel by introducing a forming fluid under pressure. Preferably, a drawing bar is provided, meaning the forming is preferably carried out using a drawing bar. The forming wheel is rotatably mounted in a machine frame, which is, for example, fixed to the floor of a hall. By means of a drive device, the forming wheel can be driven to rotate relative to the machine frame. A braking device can decelerate or slow down the forming wheel in its rotational movement until it comes to a standstill.

[0015] For automated tool changes, a tool changer is provided. Alternative terms include tool changer robot or tool changer. The tool changer is positioned within a specific circumferential angular range of the forming wheel. It can be permanently installed, for example, attached to the machine frame, or it can be positioned only for the purpose of the tool change and removed again after completion. This circumferential angular range in which the tool changer is located can be referred to as the tool change range. From the tool changer's perspective, this range can be called its working range. Forming stations are positioned within this tool change range or working range, and the tool changer then acts on the forming station to change the interchangeable components, such as the outer die.This automated changeover occurs outside of the forming operation mode in a switching mode. The forming wheel is moved intermittently, meaning it alternates between rotational and stationary phases. Each rotational phase typically represents only a partial revolution of the wheel, for example, a partial revolution sufficient for a station that was located in the switching area to leave it and for the next station to take its position. It is conceivable that the switching machine could also process more than one station simultaneously, for example, two stations. In that case, for instance, during a typical rotational phase, two stations would leave the switching area and the next two stations would be positioned within it. The intermittent rotation of the forming wheel in switching mode is achieved by a drive and a brake to sequentially position the multiple forming stations within the switching area.This can involve a drive and / or a brake, provided in addition to the drive and brake devices, which continuously drive and, if necessary, brake the forming wheel in forming mode. For example, the automatic changer could have a corresponding drive and brake for the forming wheel to move it in a controlled manner. However, it is preferred that the same drive and brake are used in both forming and changing modes. In this case, the drive and brake are simply controlled differently in the two operating modes.

[0016] The problem described at the beginning is solved by performing an additional fine positioning of the forming stations relative to the changeover machine in alternating operating mode, which eliminates, for example, positional indeterminacy due to play or slippage, whereby the invention proposes two approaches for this purpose, which can also be used in combination.

[0017] In the first approach, a mechanical positive engagement occurs between an alignment element on the forming wheel and a corresponding engagement element on the machine frame or the tool changer. A corresponding alignment element is provided and arranged on the forming wheel, and the corresponding engagement element is provided and arranged on the machine frame or tool changer. These two elements are intended to engage with each other, and this engagement is intended to eliminate the play or slippage described above; that is, the engagement is backlash-free. "Backlash-free" means that the two interacting elements can engage and disengage, but that once engaged, the station is held in a fixed position relative to the tool changer.In order for the two aforementioned elements to engage, they are designed to move at least partially towards each other in a radial direction. This can mean, for example, that the form-complementary engagement element arranged on the machine frame moves towards the forming wheel and the alignment element located there. However, a reverse kinematic arrangement is also conceivable, as is a kinematic arrangement in which both elements move towards each other. The first variant is preferred. This positive engagement should be disengaged both in forming mode and during intermittent rotation in alternating mode. This excludes the possibility that the meshing gears mentioned above regarding the prior art for driving the forming wheel in the alignment and form-engagement modes, or other power transmission devices required for driving the forming wheel, are meant.

[0018] In a second approach, a brake and a drive are to be simultaneously active during the operation of the automatic changeover machine on a forming station in the changeover area, with the braking force exceeding the driving force. Preferably, this brake and drive can be, for example, the drive unit and the braking unit that continuously drive the forming wheel in forming mode. Activating the drive and brake ensures that, for example, in the case of meshing gears, the gears are moved until their flanks collide, thereby reducing or eliminating any inherent backlash. The braking force is higher than the driving force so that the drive, while allowing the gears to collide, does not cause the forming wheel to rotate further. It is conceivable, for example, that for the intermittent movement, the drive applies a continuous driving force, while the braking force is varied.If further rotation of the forming wheel is desired, the braking force can be reduced, thus allowing further rotation; to stop the forming wheel, the braking force could be increased again until it exceeds the driving force and the forming wheel comes to a standstill.

[0019] The first and second approaches can also be combined.

[0020] It is conceivable that the drive direction, and thus the direction of rotation of the forming wheel, remains the same in both the forming mode and the alternating mode. However, it is preferred that the drive direction is reversed, at least during the alternating process. This means that in the forming mode, the drive rotates the forming wheel in a first direction, while in the alternating mode, the forming wheel is driven in the opposite direction, at least temporarily, for fine positioning. In this preferred embodiment, the drive should operate in the opposite direction, at least during the alternating process. It is therefore conceivable that in the alternating mode, the drive operates in the same direction for the intermittent rotation of the forming wheel as in the forming mode. However, once the switching range of a station is reached, the drive direction reverses for the duration of the switching process to eliminate any remaining backlash.The brake is active to prevent the forming wheel from twisting due to the switching processes.

[0021] Control over the position and movement of the forming wheel can be achieved with exceptional precision by initially setting the braking force at a low level during the intermittent rotation and then continuously increasing it until the changeover point for a station is reached. Upon reaching the changeover point for the next station, the braking force should exceed the drive force, causing the forming wheel to stop. The fine positioning of the forming station relative to the changeover unit can then be performed according to the invention. Alternatively or additionally, the drive force can be changed in the opposite direction, i.e., it starts at a higher drive level and is continuously reduced until the changeover point for the next station is reached.

[0022] It is common practice in forming stations to open the station using cam-controlled mechanisms, where, for example, a cam roller runs along an external cam and this cam roller drives the station's opening mechanism. For other drive systems for opening the stations, and for the aforementioned case of cam-controlled opening, it is advantageously proposed that a gripper mounted on the machine frame or the changeover unit is moved towards a forming station and actuates the station's opening mechanism as soon as the forming station reaches the changeover area. In cam-controlled stations, this can be achieved, for example, by the gripper engaging the control roller and moving it to open the station. The gripper thus moves the control roller in the same way that the external control cam would otherwise do.

[0023] The solutions described offer the advantage that, at the time of the changeover, the forming station where the changeover is to take place is in a precisely defined position relative to the changeover machine. This means that, for example, the changeover machine does not have to compensate for potential positioning inaccuracies through image recognition or operator intervention. The changeover position assumed by the forming stations is always consistent and reproducible. Furthermore, forces and moments that arise during the changeover process are reliably and without backlash absorbed. These forces and moments can be caused, for example, by the changeover machine during the changeover or by other actions on the forming station, such as actions required to open the station or to loosen fasteners in order to change interchangeable components.

[0024] According to a further aspect of the invention, the problem is solved by a device with the features of device claim 6, namely, by a device for forming preforms into containers with several forming stations, each having interchangeable components. As explained in relation to method claim 1, this particularly concerns the exchange of outer forms, especially multi-part forms, particularly bottom forms and side shells, but also other interchangeable components of a forming station. Several forming stations are arranged circumferentially distributed on a rotary forming wheel. The device has a control unit that controls, and optionally regulates, the processes on the device. The specific design of the control unit is not essential to the invention; that is, the control unit can be of any design. Only the following control functions are essential.The control device is designed to operate the apparatus in a forming mode such that temperature-conditioned preforms are expanded against a surrounding die during a continuous rotation of the forming wheel by introducing a forming fluid under pressure. Preferably, a drawing bar is provided, and the forming process is carried out using a drawing bar. The forming wheel is rotatably mounted in a machine frame and can be driven by a drive unit to rotate relative to the machine frame and slowed down by a braking unit. The apparatus includes an automatic changer for exchanging the interchangeable components. The automatic changer is located within a specific circumferential angular range of the forming wheel; this range is hereinafter referred to as the changer range.The automatic tool changer is designed to act on the forming stations positioned within this changeover area and perform the exchange of the components; it is therefore appropriately designed and controlled. The control unit is configured to control the automatic tool changer in a changeover mode different from the forming operating mode, enabling the automated exchange of the interchangeable components. It is possible that the control unit also controls the automatic tool changer, or that the automatic tool changer has its own control system and merely communicates with the control unit of the device. In changeover mode, the forming wheel is driven into a cycle of motion by controlling a drive and a brake, such that the several forming stations are positioned sequentially within the changeover area.

[0025] According to the invention, the control unit also performs fine positioning of the forming stations relative to the changeover machine in alternating operating mode. In a first possibility, this is achieved by the control unit controlling a mechanical positive engagement between an alignment element on the forming wheel and a form-complementary engagement element on the machine frame or the changeover machine. These elements are designed to move at least partially radially towards each other, and the control unit manages or controls this movement. The positive engagement is released both in forming operating mode and during the intermittent rotation in alternating operating mode. An alignment element is arranged on the forming wheel, and a form-complementary engagement element is arranged on the machine frame or the changeover machine.The two elements are designed and configured to perform a relative movement, at least partially in a radial direction, in a manner controlled by the control unit. It is conceivable that the engagement element moves towards the alignment element or vice versa, but it is also conceivable that both elements move towards each other together.

[0026] In a second possibility, which can be implemented instead of or in conjunction with the first possibility, the control device is configured to simultaneously activate a brake and a drive for the forming wheel while the automatic changer is acting on a forming station, with the braking force exceeding the driving force. The further explanations given for method claim 1 apply mutatis mutandis and analogously to the apparatus claim, and the explanations given for the dependent method claims also apply mutatis mutandis and analogously to the apparatus claims.

[0027] It is considered advantageous to have an alignment element on the forming wheel at each forming station. This allows, for example, a single form-complementing engagement element to access an alignment element within its engagement range and perform fine positioning.

[0028] A forming wheel typically consists of a carrier wheel with forming stations mounted on it and a support wheel, which is arranged on the common axis of rotation at a distance from the carrier wheel, with the support wheel being mounted in the machine frame. In such a design, the alignment element(s) are preferably arranged on the support wheel. This ensures that neither the alignment element nor the form-complementing engagement element is located in the area of ​​the forming stations, so that these elements cannot interfere with the forming process.

[0029] Advantageously, the alignment element is fixed in position to the forming wheel and is designed, for example, as a pin. It therefore moves with the forming wheel. The engagement element should be arranged in a controlled manner, movable relative to the machine frame, either on the frame or on the tool changer, and moveable towards the alignment element of a forming station as soon as the latter is positioned within the tool changer area.

[0030] The engagement element is to be movable in a controlled manner by an actuator belonging to the engagement element, preferably designed as a pneumatic cylinder. More preferably, the engagement element has a lever that is pivotable about a rotary axis designed as a fixed bearing. Alternatively, the engagement device has a linear guide and at least one fixed bearing, preferably two fixed bearings, wherein the actuator is configured and designed to move the engagement device along the linear guide into an engagement position with the alignment element and away from this engagement position. With both of the aforementioned designs, reliable and reproducible fine positioning can be performed, leading to the desired precise relative positioning between the automatic tool changer and a forming station being processed by it.

[0031] A typical forming wheel, for example, has a carrier wheel with forming stations mounted on it. Spacing from this carrier wheel along the axis of rotation, the forming wheel has a support wheel mounted in the machine frame. This support wheel may, for example, have an outer toothed ring to mesh with a drive gear. If a support wheel is present, the alignment element(s) should be located on it. This arrangement offers advantages because the alignment elements are positioned away from the forming stations and therefore do not interfere with access by the automatic tool changer.

[0032] In principle, the alignment element could be moved towards a stationary engagement element. It is also conceivable that both the alignment element and the engagement element could be moved towards each other. However, it is advantageous for the alignment element to be fixedly connected to the forming wheel, for example, in the form of a pin, an alignment notch, or another alignment structure, which rotates with the support wheel or the forming wheel but does not move relative to it. Instead, the engagement element should be arranged on the machine frame or the changeover machine in a controlled manner and be movable relative to it. It should be able to move towards the alignment element of a forming station as soon as the latter is positioned within the changeover area. In this way, for example, the movement of the alignment element cannot cause a disruptive movement of the forming wheel. Moreover, it is structurally simpler to integrate movable devices and, if necessary,whose actuators are to be arranged in the area of ​​the stationary machine frame rather than in the area of ​​a rotating forming wheel.

[0033] The engagement device should be movable in a controlled manner and therefore includes an actuator. Preferably, this actuator is designed as a pneumatic cylinder. This offers an advantage because compressed air is required in forming devices anyway, for example, for switching valves or for other control tasks. If compressed air is used as the forming fluid, a compressed air supply must be provided regardless. Another advantage of a pneumatically operated actuator is that it exhibits a certain degree of compliance or elasticity and movement tolerance for engagement with the alignment element. Alternatively, the actuator could also be designed as an electric or linear motor.

[0034] For a reliable, stable design that allows for fine positioning, it proves advantageous if the engagement device has a lever that pivots about a rotary axis designed as a fixed bearing. At the free end of the lever, an engagement contour could be provided, which is shaped to be complementary to the alignment element. The lever allows a short actuator movement to be converted into a larger movement of the engagement contour. The fixed bearing ensures a reliable and stable movement sequence, reliably absorbing the forces exerted by the forming wheel.

[0035] A similarly reliable, stable design that allows for fine positioning is achieved when the engagement device has a linear guide and at least one fixed bearing, preferably two fixed bearings, wherein the actuator is configured and designed to move the engagement device along the linear guide into an engagement position with the alignment element and away from this engagement position. The linear guide ensures consistent movement, and the fixed bearings ensure reliable force absorption.

[0036] Advantageous embodiments of the device and the method are specified in the respective dependent claims. The preferred embodiments of the method discussed can also be provided in the device in a mirror image. Conversely, the preferred embodiments of the device discussed can also be provided in the method in a mirror image. The advantages of the method and the device specified in each case are also advantages of the device and the method, respectively, in a mirror image. A device according to the invention can, for example, be designed and configured to carry out one of the methods specified in the method claims. A device according to the invention is preferably used in the specified methods.

[0037] The invention is explained in more detail below with reference to preferred embodiments and the accompanying figures. The drawings are not necessarily to scale. In the figures, identical or essentially functionally identical or similar elements are designated by the same reference numerals. They show:

[0038] Fig. 1 shows a schematic top view of a forming device as it is known in its basic structure and in principle in the prior art;

[0039] Fig. 2 shows a schematic representation of a forming wheel with drive device and brake device in a sectional view along a vertical section plane through the wheel center;

[0040] Fig. 3 perspective views of a typical forming station with a multi-part outer form; Fig. 4 a schematic diagram of a changer and a changer operation performed by it;

[0041] Fig. 5a, b Illustrations of a first embodiment of a device for the fine positioning of a forming wheel and a changer:

[0042] Fig. 5a: in a top view,

[0043] Fig. 5b: in a perspective view;

[0044] Fig. 6 shows a schematic representation in a top view of a second embodiment of a device for the fine positioning of a forming wheel and a changing machine;

[0045] Fig. 7 shows a flowchart for an embodiment of a method according to the invention.

[0046] Fig. 1 is a simplified schematic top view illustrating the basic structure of a device for forming preforms 2, using the example of a stretch blow molding machine 1, which produces finished containers 3 from preforms 2. The basic structure of a stretch blow molding machine does not differ substantially from other forming machines in which forming fluids are introduced under pressure, preferably using a stretching bar, into preforms to expand the preform 2 against an external mold until it rests against the inner contour of the external mold. Therefore, the following description is representative and generalizable for other forming machines to which the present invention also relates. The stretch blow molding machine 1 shown is enclosed in a machine housing 10 and comprises several sections. Sections S1, S2, S3, S4, S5, S6, S7, and S8 are shown by way of example.In other embodiments, fewer or more sections may be provided. Within the sections, transfer devices (e.g., transfer wheels) T1 to T9 are arranged for transporting the preforms 2 or the containers s. In some sections, for example, treatment devices are provided. In section S5, for example, a forming wheel 7 is provided with several forming stations 4 arranged circumferentially on it, in this case stretch blow molding stations, while in section S3, for example, a heating device 11 is provided for heating the preforms 2.

[0047] The preforms 2 are fed to the stretch blow molding machine 1 via a feeder 5, which is designed, for example, as a feed rail or an air conveyor, and first pass through the first section S1, through which they are conveyed by means of the transfer devices T1, T2, and T3 (transfer wheels). In this section, the preforms can be inspected, for example, for defects in the opening area and the sealing surfaces for the subsequent sealing of a forming nozzle. Other properties can also be inspected, for example, for possible foreign bodies in the preforms. A cleaning step can also be carried out in this area, for example, blowing out the preforms to remove dust or other deposits from their interior.

[0048] The second section S2 follows the first section S1 in the transport direction of the preforms 2 and is traversed by the preforms 2 essentially by means of the transfer device T4. There, the preforms 2 are exposed to a sterilizing fluid, for example, for the purpose of sterilization. The sterilizing fluid is applied to the preforms 2, for example, from the inside and outside, in a known manner.

[0049] On the further transport path, the preforms 2 pass through the transfer device T5, which transfers them to the third section S3, where the heating device 11 is located. There, the preforms 2 are heated (tempered) to a temperature suitable for a forming process using heating devices (e.g., radiant heaters) in a known manner. If desired, a temperature profile is also generated in the preforms 2. This is also sufficiently known from the prior art, so no detailed description is necessary.

[0050] From the heating device 11 in section S3, the preforms 2 pass via the fourth section S4 and the transfer device T6 arranged in this section to the forming wheel 7 with the several stretch blow molding stations 4 (also known as forming stations) arranged on it and rotating with the forming wheel 7. As a rule, one preform 2 is transferred to each forming station 4, although double or multi-cavity stations are also known. Without loss of generality, however, this document focuses on forming stations 4 that can each receive one preform 2 and form it into a container 3. In the stretch blow molding station 4, the heated preforms 2 are formed into finished containers 3 in a known manner by the application of a forming fluid, e.g.,Compressed air is fed into the preform 2 via a forming nozzle, and a stretching rod 12 moves into the preform, comes into contact with the closed bottom of the preform 2, and then stretches the preform 2 axially, so that the preform 2 is stretched or elongated axially and expanded radially until the resulting container bladder comes into contact with the inner contour of a surrounding mold (110, 120, 130). The forming process is controlled by a control unit 50 of the forming device 1, as are other processes described above and below. This control unit 50 can be designed in any way and, for example, can also consist of several sub-control units. The design and function of the control unit 50, insofar as they are relevant to the invention, will be discussed later.

[0051] The finished containers s are removed from the forming wheel 7 in the area of ​​the transfer device T7 and pass through the sixth section S6. Subsequently, they are transferred to further transfer devices T8 and T9 and pass through sections S7 and S8, for example, to feed the containers s in the direction of arrow 8 to another device for further processing of the containers 3, such as a labeler, a filler, or another device. During their passage through sections S6, S7, and / or S8, the container 3 can, for example, be cooled, inspected, and / or measured. This is also generally known in the prior art and therefore requires no further description.

[0052] Reference numeral 25 designates an area in which, for example, the wall thickness of the containers 3 is measured, e.g., distributed over the length of the containers at several height levels, in order to compare these measured values ​​with target values, in order to then use the comparison result in the control of the heating device 11, as is already known from the prior art.

[0053] Partition walls 30 are provided in some areas to separate sections. This is particularly useful where, for example, sterilizing agents are used or where there is a risk of contamination. It can also be useful where, for example, sections are supplied with sterile gas, such as sterile air, and / or where sections need to be kept under positive pressure relative to the environment. However, these partition walls 30 are optional.

[0054] Figure 1 schematically depicts a tool changer 300. Viewed from the forming wheel 7, this tool changer 300 is located within a specific circumferential angle range 300'. The tool changer 300 is designed and configured to process forming stations 4 arranged within this circumferential angle range 300'; the circumferential angle range can therefore also be referred to as the working range 300' of the tool changer. The processing consists of removing interchangeable components from the forming station 4 and, if necessary, inserting a new component into the station 4. It is also conceivable that another tool changer performs the insertion of the new component within a different circumferential angle range. Furthermore, it is conceivable that not only one forming station 4 is arranged within the working range 300' of the tool changer 300, but, for example, two stations 4, and that the tool changer 300 processes two stations 4 simultaneously.It is also possible that several changing machines 300 are arranged in different circumferential angle ranges 300' and simultaneously perform the same changing process at different stations 4.

[0055] Fig. 2 shows a schematic diagram of how the forming wheel 7 shown in Figure 1 is driven into a rotary motion and how this motion is stopped. The forming wheel 7 has a central axis of rotation 26, which is rotatably mounted in a machine frame 27 of the stretch blow molding machine 1. For example, a ball bearing slewing ring can be provided in the machine frame on which the forming wheel is mounted. The forming wheel 7 has a support wheel 28 in the area of ​​the machine frame 27 and, at a vertical axial distance from this and further away from the machine frame 27, a carrier wheel 29, on which the forming stations 4, also shown in Figure 1, are arranged circumferentially spaced. A motor 35 drives the forming wheel 7. The motor transmits the power to the intermediate wheel 37, which is also considered part of the drive system.The intermediate gear 37 transmits the drive force provided by the motor 35 to a spherical rotary joint (not shown) in the machine frame 27, on which the forming gear 7 is mounted, e.g., by the intermediate gear 37 being designed as a gear and the support gear 28 having an external toothed ring meshing with it. Additionally, alignment bolts 31, rigidly connected to the support gear 28, are shown, which interact, as will be explained later, with engagement devices arranged on the machine frame 27.

[0056] In the illustrated embodiment, the drive 35, 37 performs different functions. In a forming mode, the drive is intended to drive the forming wheel 7 to a continuous rotation. For this purpose, the motor can be controlled accordingly by the control unit 50. Furthermore, in an alternating mode, the drive 35, 37 is intended to drive the forming wheel 7 in a manner different from the forming mode, e.g., also controlled by the control unit 50. In the illustrated embodiment, the drive is intended, for example, to move the stations 4 sequentially into the working area 300' of the changeover machine 300 and, after the exchange of the interchangeable components, to move the processed station 4 out of the working area 300' and simultaneously move the next forming station 4 into the working area 300'. In addition to the drive 35, 37, a brake 39 is also used for this purpose.

[0057] The drive 35, 37 is intended, and optionally also in a setup mode, to drive the forming wheel 7 in a manner suitable for setting up the forming device 1. The setup mode is intended, for example, for adjustment and calibration work. In setup mode, the forming wheel 7 of the forming machine 1 rotates, for example, only at a low speed. Often, the machine 1 is controlled with a handheld operating device in setup mode. Figure 3 shows a perspective view of a typical forming station 4 in an open position. Some elements of the forming station 4 are not shown; in particular, the forming die and the drawing bar are not shown, but these are also fundamentally interchangeable components within the scope of the invention. Also not shown are a valve block for the valve-controlled supply of the forming fluid and the controlled discharge of the forming fluid.Other components typically found in a forming station are missing, such as a pull-rod drive or a drive for the forming die. The kinematics of opening and closing the station are also not shown. However, none of these details are essential to the invention.

[0058] In the illustrated case, the side shells 110 and 120 of the three-part outer form, which is a typical example of an interchangeable device, have already been removed from the opened station 4 in the direction of the arrow, so that only the side shell supports 330 of station 4 surround the station cavity 350. The bottom form 130 has not yet been removed and is still held by a bottom form support 340. In a later step, the bottom form 130 can be removed from station 4 in the direction of the arrow shown. The side shells 110 and 120 have gripping pins 140 for grasping them. It is also conceivable to provide other means by which they can be gripped. The side shells 110 and 120 are held in the form supports 330 in a manner not shown. It is conceivable that the outer form is removed in a closed state, i.e., the side shells 110, 120 and the bottom shell 130 are removed together.It is also possible to remove only the base tray 130 and not replace the side trays 110 or 120. It is also conceivable to replace only the side trays 110 and 120.

[0059] Figure 4 shows a schematic diagram of a changeover machine 300, which is fixedly mounted on the machine frame 27 and can, for example, be permanently arranged on this machine frame 27. It is shown that a forming station 4 is located and being processed within the working area 300' of the changeover machine 300. It is also conceivable to place the changeover machine on a factory floor where the stretch blow molding machine 1 is also located, and to position the changeover machine in a defined orientation relative to the stretch blow molding machine. The changeover machine 300 could therefore also be moved to the stretch blow molding machine 1 as needed and, for example, coupled to the machine frame 27 of the stretch blow molding machine 1 in a defined position.

[0060] In the illustrated embodiment, the changeover machine 300 has two working arms 305 and 306 to allow the side shells 110, 120 and the bottom mold 130 to be removed separately. It would also be possible to use the first working arm 305 to remove the outer mold 102 located in the forming station 4 and the second working arm 306 to hold the new outer mold 102 ready for insertion, so that it can be replaced with the new outer mold 102 after the first outer mold 102 has been removed. For this purpose, the two working arms 305 and 306 can, for example, be rotated about the pivot joint 307. After removal of the mold elements 110, 120, 130, they can, for example, be placed in a storage device 200. This storage facility 200 also contains new forming elements that are to be inserted into the forming stations 4 by the changing machine 300 after the forming elements previously held there have been removed. This is indicated by the dashed arrow.The forms 102 are held in a holder 100 of the storage device 200.

[0061] Figures 5a and 5b show illustrations of a first embodiment of how fine positioning between a forming station 4 and a changeover machine 300 can be implemented. For this purpose, an alignment pin 31 is provided on the upper side of the support wheel 28, which is arranged in a defined position relative to a forming station 4, which is not shown in Figures 5a and 5b. Alignment with this alignment pin is therefore equivalent to alignment with respect to the forming station 4. The alignment with the alignment pin 31 is achieved with the aid of an alignment partner, namely an engagement element 32, which can be moved towards the alignment pin 31 and is arranged in a defined position on the machine frame 27. In the illustrated embodiment, the engagement device 32 is part of an assembly 33 that is fixedly connected to the machine frame 27.For positive engagement with the alignment bolt 31, a shaped piece 36 is arranged at the end of a pivotable lever arm 34. The lever arm 34 is pivotable about a fixed bearing 41, and the pivoting movement is controlled by a pneumatic cylinder 38, which is pressurized with compressed air in a controlled manner to bring the shaped piece 36 into engagement with the alignment bolt 31 or to release the engagement and return it to a starting position. This can be done, for example, in a manner controlled by the control device 50. In addition, the illustrated assembly 33 optionally has an actuating arm 40 to move the forming station 4 to be processed into the open state, for example, so that the changeover machine 300 has access to the interchangeable components, such as the base form 130, the side shells 110, 120, the blow nozzle, or the drawing bar.Since, in the embodiment shown in Figure 5a, station 4 can be opened and closed by cam control, in the present case a gripper 42 is servomotor-driven and engages the cam roller 44 of the forming station 4, which would be guided along an external control cam in forming mode. In the illustrated example, the force exerted by the control cam in forming mode is applied by the servomotor-driven gripper 42. Thus, as soon as, for example, the forming part 36 engages with the alignment pin 31, and fine positioning has taken place between the forming wheel 7 (i.e., the forming station) and the assembly 33 (i.e., the machine frame 27 and the changeover machine 300), the servomotor 43 moves the gripper 42 towards the cam roller 44 of the forming station 4 and moves the control roller 44 to open station 4.Simultaneously, or possibly with a short delay thereafter, the automatic changer 300 can grasp the device to be replaced and remove it from station 4. The necessary release of a fastening of the device in station 4 can, for example, occur during the execution of fine positioning; however, it is also possible that the automatic changer 300 releases the fastening if necessary. Alternatively, the control unit 50 can send a control command to the station to effect a controlled release of the fastening.

[0062] The embodiment shown in Figures 5a and 5b assumes that several alignment pins 31 are arranged circumferentially on the forming wheel 7, and that the fine positioning described above is performed after each rotation of the forming wheel 7. For example, if the automatic changer 300 processes two stations 4 simultaneously, the forming wheel 7 would be rotated two stations 4 further, and one alignment pin 31 would be provided for each pair of stations. If the automatic changer 300 processes only one station 4 at a time, one alignment pin would be provided for each station 4. In the illustrated embodiment, the alignment pin is fixed in position on the forming wheel 7, and the engagement element 32, which is fixedly connected to the machine frame 27, is moved towards the alignment pin 31. In principle, this kinematics could also be reversed, i.e.,An alignment bolt 31 could be arranged in a fixed position on the machine frame 27, and an engagement device 32, similar to that described above, could be arranged on the forming wheel 7.

[0063] Figure 6 shows a simplified schematic diagram in a top view of a second embodiment of a device for the fine positioning of forming wheel 7 and changer 300. For this purpose, an alignment bolt 31 is again arranged on the support wheel 28 of the forming wheel 7. A shaped piece 36, which can be moved towards the alignment bolt 31, is driven by a pneumatic cylinder 38 and guided by a linear guide 45 in the direction of the alignment bolt 31 until a recess 46 in the shaped piece 36, which is complementary in shape to the bolt 31, engages in a positive-locking engagement with the alignment bolt 31, as shown in Fig. 6.Simultaneously, the forming piece 36, with two bearing notches 47 arranged symmetrically on both sides of the form-complementing recess 46, engages with fixed bearings 48, so that the forming piece 36 is in a defined position by the two fixed bearings 48, and thus the aligning bolt 31 is also in the position specified by the forming piece 36, so that the forming wheel 7, to which the aligning bolt 31 is fixedly arranged, is also held in a defined position. In this way, and in the alternative ways shown for the first embodiment, any possible play and any possible degree of rotational freedom of the forming wheel 7 are eliminated or significantly reduced, and the forming wheel 7 is secured against rotation, so that the automatic changer 300 finds a forming station 4 in its working area 300' in a defined relative position to the automatic changer 300.

[0064] With reference to the schematic sequence shown in Figure 7, a third embodiment of fine positioning will be presented. The sequence shown in Figure 7 can be predefined, for example, by the control unit 50, e.g., in a switching operating mode of the forming device 1; that is, this control unit 50 can send corresponding control commands to the participating devices.

[0065] First, in step 205, the forming wheel 4 is set in rotation by activating a drive 35, 37, which drives the forming wheel 7. After a short delay, a brake 39 is activated in step 210, bringing the forming wheel 7 to a standstill within the working area 300' of the automatic changer 300. In this state, fine positioning has not yet occurred, as, for example, in the case of meshing gears, some play still exists. To eliminate this degree of freedom, fine positioning is performed in process step 215. This fine positioning could, in principle, be achieved by using and controlling the exemplary devices shown in Figures 5a, 5b, and 6. However, in the present example, fine positioning will be carried out according to a third embodiment.

[0066] According to this third embodiment, the forming wheel 7 is driven in the opposite direction after reaching its working range, while the brake remains active. Due to the applied drive force, the forming wheel can rotate until it mechanically hits a stop, for example, until the tooth flanks of the meshing gears collide. To prevent further rotation of the forming wheel 7, the braking force is selected to exceed the drive force. Both the drive force and the braking force are maintained, but they can be reduced to a necessary minimum level, and in step 220, the changeover machine 300 can be activated to begin the changeover process. For example, in step 225, a connection can first be released that links a device to be exchanged with the forming station being processed.A connection between the outer form and the form carriers of the station can be released, e.g., for the base form. In step 230, the station to be processed can, for example, be moved into the open state. In the example of Figures 5a and 5b, the gripper could, for example, be moved towards the cam roller of the station, which is responsible for the opening movement of the station. Once the station is in the open state, the changeover machine 300 can grasp the component to be replaced and remove it from the station; this would correspond to step 235. Step 240 could, for example, consist of inserting a new component into the station. Subsequently, the gripper of Figures 5a and 5b could be retracted to its starting position, thereby moving the cam roller back to its starting position and closing the station. Before or simultaneously, step 245 could be performed, and the newly inserted component could be secured in the station, e.g.,by the control unit 50 transmitting a corresponding control command to a fastening element in the forming station. In step 250, for example, the drive and the brake are activated to further rotate the forming wheel, namely to move the processed station out of the working area of ​​the changeover machine and to move the next forming station to be processed into the working area. In the case of the embodiments shown in Figures 5 and 6, for example, in step 250 the forming piece would be moved away from the alignment bolt to release the positive engagement and to free the forming wheel for further rotation.

[0067] In step 255, the changeover machine could place the removed component, e.g., removed forming elements such as a removed base mold, in a storage unit and pick up a new component to be used in the next forming station. In step 260, the changeover machine could return to its starting position, allowing the process described above to be repeated.

[0068] List of reference signs

[0069] 1 Forming device, stretch blow molding machine

[0070] 2 Preform

[0071] 3 finished containers

[0072] 4 Conversion station

[0073] 5 Feeder, feed rail for preforms

[0074] 6 Mouth section of the preform 100 Mold holder

[0075] 7 Conversion wheel 102 outer shape

[0076] 8 Direction of further processing of the 110, 120 side trays container 130 bottom tray

[0077] 9 Sterilization unit for transport equipment from T8 200 storage unit

[0078] 10 machine housings

[0079] 11 Heating device 205-260 Process steps

[0080] 26 rotary axis 300 automatic changer

[0081] 27 machine frame 300' working area

[0082] 28 Support wheel 305, 306 Working arm

[0083] 29 Carrier wheel 307 Swivel joint

[0084] 30 partition walls between sections, 330 side shell supports

[0085] 31 alignment bolts 340 base form carriers

[0086] 32 intervention unit 350 station cavity

[0087] 33 Assembly

[0088] 34 lever arm S1 -S8 sections of the

[0089] 35 Motor Stretch Blow Molding Machine

[0090] 36 molded piece

[0091] 37 Intermediate gear T1-T9 transfer device,

[0092] 38 pneumatic cylinders, transfer wheel, singulation wheel,

[0093] 39 Brake feed wheel, discharge wheel

[0094] 40 Actuating element

[0095] 41 fixed camps

[0096] 42 grippers

[0097] 43 Servomotor

[0098] 44 Control roller

[0099] 45 linear guide

[0100] 46 Exclusion

[0101] 47 bearing notches

[0102] 48 fixed storage

[0103] 50 Control unit

Claims

Claims 1. Method for the automated exchange of interchangeable devices (102, 110, 120, 130) of forming stations (4), which are arranged circumferentially distributed on a rotary forming wheel (7), and in which, in a forming operating mode, temperature-conditioned preforms (2) are expanded against a surrounding outer form (102) during a continuous rotation of the forming wheel (7) by introducing a forming fluid under pressure, preferably using a drawing bar, wherein the forming wheel (7) is rotatably mounted in a machine frame (27) and can be driven by a drive device (35, 37) to a relative movement with respect to the machine frame (27) and can be slowed down by a braking device (39), wherein an automatic exchanger (300) is provided for the automated exchange, which is arranged in a specific circumferential angular range of the forming wheel (7), the exchange range (300'),and acts on forming stations (4) positioned within this exchange area (300') and performs the exchange of the interchangeable devices (102, 110, 120, 130), wherein the automated exchange is carried out outside the forming operating mode in an exchange operating mode in which the forming wheel (7) is moved intermittently by means of a drive (35, 37) and a brake (39) in order to successively position the several forming stations (4) in the exchange area (300'), characterized in that in the exchange operating mode a fine positioning of the forming stations (4) relative to the exchanger (300) takes place by a) a mechanical positive engagement between an alignment element (31) arranged stationary on the forming wheel (7) or stationary relative to the forming wheel (7) and a form-complementary engagement element (32) on the machine frame (27) or on the exchanger (300), which is a relative movement is carried out at least partially in a radial direction towards each other,wherein this positive locking engagement is released both in the forming mode and during the intermittent turning in the alternating mode, and / or b) during the action of the changing machine (300) on a forming station (4) in the changing area (300') a brake (39) and a drive (35, 37) are simultaneously active, wherein the braking force and the drive force are dimensioned relative to each other in such a way that are that during the action of the changing machine (300) on the forming station (4) the forming station (4) is held in a defined changing position, in particular by the braking force exceeding the driving force.

2. Method according to claim 1 and according to feature b) of claim 1, wherein the brake (39) and / or the drive (35, 37) that are active during the action of the changer (300) are the braking device (39) and / or the drive device (35, 37) that drive or brake the forming wheel (7) in forming mode.

3. Method according to claim 1 or 2 and according to feature b), wherein the drive (35, 37) drives the forming wheel (7) in a first direction of rotation in the forming operating mode and the forming wheel (7) is driven at least temporarily in the opposite direction in the alternating operating mode for fine positioning.

4. Method according to claim 1 or 2 and according to feature b), wherein the braking force of the brake (39) is slowly increased during the rotation of the forming wheel (7) until the changeover range (300') is reached, until a forming station (4) reaches the changeover range (300'), wherein the braking force is then higher than the driving force.

5. Method according to one of the preceding claims, characterized in that a gripper (42) arranged on the machine frame (27) or the changer (300) is moved towards a forming station (4) and actuates the opening mechanism (44) of the station (4) as soon as the forming station (4) has reached the changer area (300').

6. Device (1) for forming preforms (2) into containers (3) with several forming stations (4), each having interchangeable devices (102, 110, 120, 130) and arranged circumferentially distributed on a rotary forming wheel (7), with a control device (50) configured to control the device (1) in a forming operating mode such that temperature-conditioned preforms (2) are expanded against a surrounding outer form (102) during a continuous rotation of the forming wheel (7) by introducing a forming fluid under pressure, preferably using a drawing bar, wherein the forming wheel (7) is rotatably mounted in a machine frame (27) and can be driven by a drive device (35, 37) to a relative movement with respect to the machine frame (27) and can be slowed down by a braking device (39).wherein the device (1) has a changer (300) for changing the interchangeable devices (102, 110, 120, 130), which is arranged in a certain circumferential angle range of the forming wheel (7), the changer, The control unit (50) is designed and controlled in a switching area (300') and acting on forming stations (4) positioned in this switching area (300') and performing the switching of the devices (102, 110, 120, 130), wherein the control unit (50) is designed to control the switching machine (300) in a switching operating mode different from the forming operating mode to perform the automated switching of the interchangeable devices (102, 110, 120, 130), wherein in the switching operating mode the forming wheel (7) is controlled to move in a cycle by means of a drive (35, 37) and a brake (39) in order to position the several forming stations (4) in the switching area (300') one after the other, characterized in that the control unit (50) is designed such that in the switching operating mode fine positioning of the forming stations (4) relative to the switching machine (300) is also possible. is feasibleby the control device (50) a) controlling a mechanical positive engagement between an alignment element (31) on the forming wheel (7) and a form-complementary engagement element (32) on the machine frame (27) or changer (300), which are designed to move at least partially towards each other in a radial direction for a relative movement, wherein this positive engagement is released both in the forming operating mode and during the intermittent rotation in the changer mode, wherein preferably the alignment element (31) is arranged on the forming wheel (7) and a form-complementary engagement element (32) is arranged on the machine frame (27) or on the changer (300), which are preferably configured and designed to perform a relative movement at least partially in a radial direction in a manner controlled by the control device (50),and / or b) during the action of the changeover machine (300) on a forming station (4) in the changeover area (300') to simultaneously activate a brake (39) and a drive (35, 37) for the forming wheel (4), wherein the braking force and the driving force are dimensioned relative to each other such that during the action of the changeover machine (300) on the forming station (4) the forming station (4) is held in a defined changeover position, in particular by the braking force exceeding the driving force.

7. Device according to claim 6 and according to feature a) of claim 6, wherein an alignment element (31) is arranged on the forming wheel (7) for each forming station (4), which preferably projects vertically upwards or downwards.

8. Device according to claim 6 and feature a) or according to claim 7, wherein the forming wheel (7) has a carrier wheel (29) with forming stations (4) arranged thereon and a support wheel (28) spaced apart from the axis of rotation, which is mounted in the machine frame (27), wherein the alignment element (31) or alignment elements (31) is / are arranged on the support wheel (28).

9. Device according to claim 6 and feature a) or according to claims 7 to 8, wherein the alignment element (31) is fixedly connected to the forming wheel (7) and wherein the engagement element (32) is arranged in a controlled manner relative to the machine frame (27) or relative to the changer (300) and can be moved towards the alignment element (31) of a forming station (4) as soon as the latter is arranged in the changer area (300').

10. Device according to claim 6 and feature a) or according to claims 7 to 9, characterized in that the engagement device (32) can be moved in a controlled manner by an actuator (38) which belongs to the engagement device (32) and is preferably designed as a pneumatic cylinder (38).

11. Device according to claim 6 and feature a) or according to claims 7 to 10, wherein the engagement device (32) has a lever (34) which is pivotable about a pivot axis designed as a fixed bearing (37).

12. Device (1) according to claim 10, wherein the engagement device (32) has a linear guide (45) and at least one fixed bearing (48), preferably two fixed bearings (48), wherein the actuator (38) is configured and designed to move the engagement device (32) along the linear guide (45) into an engagement position with the alignment element (31) and away from this engagement position.

Images