Abstract:
The invention refers to a tool arrangement, in particular a sealing tool for a packaging machine, the tool arrangement consisting at least of one toolholder and one tool connected to each other by at least one releasable fixed connection. 
     The invention is characterised in that the releasable fixed connection is given by an automatically acting link.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention refers to a tool arrangement of a packaging machine, in particular formtool, deep-draw die or sealing tool for a packaging machine, the tool arrangement being formed of at least one toolholder and one tool which are connected with each other by at least one releasable fixed connection. 
         [0002]    Tool arrangements of this kind are known in particular for packaging machines. Packaging machines of this type consist of tool arrangements arranged one behind the other, for example as deep-draw dies or sealing tools. They serve either for forming (deep-drawing) the packing or for sealing, that means closing. If necessary, between the deep-drawing process, the actual packaging process and the sealing a vacuuming process is inserted. 
         [0003]    In the state of the state of the art it is known to design the known tool arrangements in such a way that there is a toolholder which is attached to the actual tool, anyway whether it is the deep-draw die or the sealing tool, with screws, clamping devices and complicated locking systems or similar fastening methods. This way of connecting toolholder and tool has a decisive disadvantage here in such a way that for a tool change often tools, usually even special tools, are required in order to be able to remove the tools of the packaging machine either manually or semiautomatically from the machine. This change is accordingly made more difficult by the fact that manual operations are required for releasing the tool from the tool holder. Furthermore, many of these parts are very heavy and unmanageable so that even suitable hoists are necessary in order to carry out this change. Another disadvantage is the fact that, exactly in the case of sealing tools, these are often heated, that means a cooling phase has to be waited for, or the parts can only be removed with suitable protective clothing. This includes the risk of accidents as rather frequently this has also lead to burns in the past. 
         [0004]    Coming from this state of the art it is an object of the invention to suggest a tool arrangement which makes a fast and easy change of the tool possible, in particular without the risk of injuries for the operating staff. 
       Short Abstract of the Invention 
       [0005]    The problem of the invention is solved by a tool arrangement, in particular a sealing tool for a packaging machine where the tool arrangement is formed of at least one toolholder and one tool, which are connected to each other at least by a releasable fixed connection which is characterised in that the releasable fixed connection is given by an automatically acting link, and the tool arrangement comprises a control controlling the automatically acting link. 
         [0006]    The fact that now an automatically acting link is available makes it possible to connect this link automatically, but also to release it automatically. The term “automatically acting” therefore comprises the characteristic to make the connection between the tool and the toolholder, and to release it again. Cleverly for that in or for the tool arrangement a control is provided acting on or controlling the automatically acting link. By means of this controllable link to the control of the tool arrangement or the machine control of a packaging machine a tool change is made considerably easier and faster. Releasing as well as attaching the tool to the tool arrangement is then done, for example, by pushing a button at the control of the tool arrangement or the machine control of the packaging machine. By means of this, first of all, manual operation and time is saved as well, secondly, the requirement of the use of tools is removed. For the operating person or the service staff who have to change the tools it is now very simple to change a tool, even if it is still hot. For that only a suitable guide is necessary, for example out of the machine on a suitable carriage, or out of the machine to a suitable hoist in order to position then the new tool again accordingly, to push it into the machine and then to activate again the automatically acting link. The tool arrangement as it is now suggested according to the invention leads to a complete removal of all disadvantages described in the state of the art, namely to reducing the required time for changing the tools of the packaging machine or the like, reducing heavy physical work, removing the risk of accidents, and, in particular reducing the stand-still times of the packaging machine during the necessary change of the tools. 
         [0007]    The way the control works is adapted in a suitable way to the design of the link. Often as control, for example, an electronic control (CNC) or software control or the like is provided. It is, of course, also possible to chose as control a pneumatic, hydraulic or otherwise mechanically acting A arrangement. 
         [0008]    In the following the invention is described in particular by means of the application case of a packaging machine, however, without limiting the tool arrangement according to the invention to this particular case of application. It is clear that the advantageous tool arrangement of the invention can be employed everywhere where a quick and easy change of the tools is required. Therefore the invention is much wider than only the case of application described here as an example in a packaging machine. The invention is just characterised by this large field of application. 
         [0009]    An essential advantage of the invention is in particular the fact that the toolholder and/or the tool can be heated, and by means of the design according to the invention even a hot tool can be changed fast and timesaving. Advantageously here the heating is provided in the toolholder fixedly attached to the tool arrangement, and heats the tool via suitable contact surfaces or the tool has its own heating. 
         [0010]    For the design of the automatically acting links according to the invention several modifications are provided as solution. Thus it is, for example, provided in a development of the invention that the automatically acting link is given by a quick coupling. 
         [0011]    An essential characteristic of the automatically acting link designed as quick coupling is that the linking process, that means the coupling process, does not bide any time, that means it is as fast as possible. 
         [0012]    In a modification according to the invention it is furthermore provided that the automatically acting link is equipped very differently, namely with mechanic, electro-mechanic, hydraulic or pneumatic means, so that all media which are usually available in a packaging machine, can also be used. By means of the quick coupling it is possible to maintain the before-described useful effects also completely. The releasable fixed connection is carried out by the quick coupling automatically and is also released again. 
         [0013]    It is a particular advantage when the automatically acting link is designed self-centering. The self-centering has the consequence that the time-consuming adjusting or setting of the tools in the packaging machine is taken over by an automatically acting link, and thus also work is made easier for the operating or service staff. Thus necessary measurement and adjusting processes are deleted which now are taken over completely by the automatically acting link. Thus the useful effect of timesaving is increased further. 
         [0014]    The automatically acting link is, as already mentioned, given by mechanic, electric, magnetic means or electro-magnetic, hydraulic, pneumatic means, or by a combination of at least two of the before-mentioned means. Of course, it is also possible to combine several of the before described means with each other in order to get to an automatically acting link equipped according to the respective tool. The invention is not limited here to one single of the mentioned means but comprises all of this means so that a general employment is possible. 
         [0015]    The invention also suggests a tool arrangement which is characterised in that the tool is provided in or at the toolholder. The tool can be attached here directly to the toolholder or indirectly via suitable connection or centering means at a carrier of the toolholder or the toolholder. It is an advantage here if the toolholder can be heated or tempered. For some packaging processes it is also convenient to cool the toolholder, so that both modifications are comprised by the invention. Of course, the tool arrangement according to the invention also comprises also a modification in which the toolholder cannot be heated or tempered. It may be, for example, provided to temper the tool itself. 
         [0016]    It is an essential advantage of the invention that the tool is provided below the toolholder. Thus the automatically acting link suggested according to the invention holds the tool in particular against the gravitation at the toolholder. If now the control controls the automatically acting link such that the link is released the gravitation helps separating the tool from the toolholder. 
         [0017]    The result is here in particular an arrangement that the tool arrangement according to the invention is employed above the good to be packaged, although the invention is not restricted to it. 
         [0018]    Another aspect of the tool arrangement according to the invention is given by the fact that the tool is a sealing plate. By means of this the tool arrangement can be employed for sealing packages which, however, does not exclude a use of a tool as deep-drawing die. It has only to be made sure that the toolholder is designed accordingly, to be connected either with the sealing plate as tool or the deep-drawing die as tool. 
         [0019]    A particularly advantageous design of the invention refers to a tool arrangement which is characterised in that as automatically acting link a magnetic holder is provided consisting of at least one magnet. By the magnetic holding device it is now provided that the tool is connected magnetically with the toolholder. Here, of course, again different modifications of a magnetic connection are possible which can be realised by the invention. Thus it is, for example, possible that the magnetic holder magnetically connects the tool with a carrier plate or the toolholder. For that purpose the electromagnetic connection is preferred. 
         [0020]    According to that a development of the invention is characterised in that the magnetic holder consists essentially of a magnet connected with the carrier plate or the toolholder and at least one magnet counterpart. It is, of course, possible here to design the tool itself as magnetic counterpart, if it is manufactured, for example, of a magnetically effective material, such as for example metal. 
         [0021]    The magnet itself can be designed according to the invention as electro-magnet or as permanent magnet. The invention comprises both modifications. 
         [0022]    Furthermore it is an advantage when the magnetic holder is integrated at least partly in the toolholder or in the carrier plate, and another part of the magnetic holder as magnetic counterpart in the tool. As already mentioned, it is also provided that the tool itself is the magnetic counterpart. For that it has to be only manufactured from magnetically active material. 
         [0023]    According to the invention it has been found to be an advantage if the magnetic holder holds the tool by a permanent magnet currentless at the carrier plate and separates it from the carrier plate by powering the electro-magnet. This design makes it possible that the tool is held even in currentless condition at the carrier plate or the toolholder, and is only separated from the carrier plate or the tool holder when the electro-magnet is powered. This generates an opposing magnetic field which is enough to separate the connection between the tool and the carrier plate or the toolholder. It is then possible to guide the tool out of the area of the toolholder and then to position there again a news or other tool. In the moment when the powering of the electro-magnet ends, the tool is attracted by the permanent magnet to the carrier plate or the toolholder, and is thus again fixedly connected with the toolholder. It is here preferred when the magnet arrangement acts at the same time centering so that adjusting and centering or measuring work for the service staff can be essentially deleted. 
         [0024]    However, the invention also comprises a solution where the magnet is designed as electromagnet and if powered, is magnetic, so that the magnetic counterpart and/or the tool is attracted, and is not attracted only in currentless state. However, this requires powering the magnet with current during the entire operation, which is, however, with packaging machines also driven by electricity no problem. In the operating condition the packaging machine has to be connected to current anyway so that also an electro-magnet or the magnetic holder can be powered permanently, at least during the complete operation. In the case of an electricity failure a safety device can be provided in the form of a mechanic, electric or electro-mechanic, hydraulic or pneumatic locking device. These media as well are connected to a packaging machine so that also here this solution can be realised with packaging machines of the kind discussed. 
         [0025]    The magnetic counterpart is, according to the invention, formed preferably of a ferromagnetic, in particular temperature stable ferromagnetic material. This guarantees a safe operation of the magnetic holder. Cleverly, also a temperature stable, ferromagnetic material is also chosen in order to realise a safe, reliable connection in application cases where heated sealing plates are used. 
         [0026]    In a development the invention suggests a tool arrangement which is characterised in that the magnetic holder, in particular its housing consists of a counter holder connected with a magnet, designed preferably T-shaped, and/or of at least one resetting element, for example a readjusting spring, arranged between the counter holder and the carrier plate or the toolholder. This arrangement makes it possible to support the magnet floating in the toolholder or the carrier plate, as it were, and at the same time to provide a readjusting spring which supports separating and/or connecting of tool with toolholder, or tool with carrier plate. It is a particular advantage here when the readjusting spring or the readjusting element acts at the same time or alternatively as centering device for the tool. This presents a particular clever modification of the invention which, on the one hand, provides a releasable fixed connection as automatically acting link, and, on the other hand, at the same time, the centering device by means of which the complete tool changing operation is clearly made easier and in particular shortened. 
         [0027]    The invention also suggests a tool arrangement where at least one magnet can be controlled by a control, preferably by the electronic control of the packaging machine itself. Thus positioning operations for the tool or separating operations for the tool and, if necessary, also its centering can be accordingly influenced and controlled by the control. 
         [0028]    For supporting and/or improving the effect of the sealing plate on the side opposite the packaging article which has to be sealed sealing struts are provided. These sealing struts achieve that the temperature of the sealing plate is not put over the complete surface to be sealed but only partially to the area of the sealing struts. 
         [0029]    A tool arrangement as described before is characterised in a modification in that the carrier plate or the toolholder can be tempered. The carrier plates can be, of course, in multiple parts, in particular in two parts, by forming, first of all, the carrier plate as basic plate, and, secondly the toolholder which then can hold the tool. 
         [0030]    The invention also provides a packaging machine, consisting of tool arrangements arranged one after the other, for example a deep-draw die or sealing tool, the tool arrangement being designed according to one or more of the before described tool arrangements. The advantages described for the tool arrangement are the same as in the packaging machine as described before. 
         [0031]    A development of the packaging machine according to the invention is characterised in that it has a preferably electronic control for triggering the automatically acting link, in particular the magnetic holder. Here also the useful effects already described with regard to the control are the same. 
         [0032]    A preferred embodiment of the packaging machine according to the invention has a conveying device, for example a conveyor belt or a chain conveyor which guarantees the transport of the goods to be packed or the packages formed of a film/foil width in the packaging machine. It is provided here that the conveying device transports the packages or the foil width or the film along a conveying path. In a modification according to the invention it is provided that at least one of the before described tool arrangements is used in the described packaging machine, and thus the invention does not comprise only the tool arrangement itself but in particular also the packaging machine altogether as the suggestion according to the invention provides in particular also in a packaging machine considerably increased rationalisation and efficiency. According to the invention it is provided in this connection that the before-described tool arrangement is arranged above this conveying device, thus the packages which have to be formed pass below the toolholder or the tool arranged in the toolholder. In an advantageous development of the packaging machine it is additionally provided that one toolholder each is arranged with a deep-draw die arranged at or in it, and/or a sealing plate arranged at or in it in the packaging machine. The arrangement can be done on both sides of a conveying device such as described above. 
         [0033]    In a modification according to the invention it is in particular provided that the packaging which has to be formed or the film is arranged below the tool arrangement. If now the tool arrangement acts on the packaging or the film as described, usually the tool faces the packaging/film, and thus the tool is arranged below the toolholder. This leads to the advantages described above during changing as the releasing process of the tool from the toolholder is supported by gravitation. 
         [0034]    It has to be mentioned in this connection that a packaging machine has a number of so-called tool stations which carry out on each side different machinings at the packing or the films forming the packing. The forming station, the deep-drawing station, the filling station or even the sealing station all are, for example, included in this. 
         [0035]    The above-mentioned single stations are usually equipped with a tool bottom part and a tool top part, the tool bottom part being located below the packing or the conveying device or the conveying plane defined by the conveying movement. The tool top part is here above the packing, the conveying device or the conveying plane. The suggestion according to the invention here refers in particular to a sealing plate serving for heating the thermally mouldable synthetic material of the packing in such a way that the packing is closed, in particular sealed. The sealing process is here carried out preferably by means of the tool top part where the tool arrangement according to the invention is preferably employed. It has to be taken into consideration here that the invention is in no way restricted to that, in a suitable and clever way it is, of course, possible to use the tool arrangement according to the invention also in a tool bottom part. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0036]    In the following the invention is described by means of embodiments. In the drawing: 
           [0037]      FIG. 1  a schematic drawing of a tool arrangement according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0038]      FIG. 1  shows a schematic drawing of a tool arrangement according to the invention. The tool arrangement is here formed by a toolholder a or a carrier plate  4 . In the embodiment shown the carrier plate  4  is at the same time the toolholder a. Below the toolholder a or on the side of the toolholder a facing the packing in operation condition there is the tool  2 . The tool  2  has in the drawing three sealing struts  2 / 1  altogether, which, however depending on the type of packing, can be provided in smaller or larger numbers. In the tool  2  a magnetic counterpart  3  is arranged which is part of the magnetic holder indicated schematically by arrow I. The magnetic holder I is furthermore formed by the magnet  1  as well as the magnetic counterpart  3 . In a modification not shown here the magnetic counterpart  3  can be the tool  2  itself, by being made of magnetizable or magnetic active material. 
         [0039]    On the left-hand side of the drawing an embodiment or an example of the tool arrangement according to the invention is shown, the magnet  1  being formed here by two coils  1 / 1  as well as an armature  1 / 3 , the armature  1 / 3  carrying an armature plate  1 / 2 . This armature plate  1 / 2  is here the connection with the magnetic counterpart  3 . The armature  1 / 3  will attract here the magnetic counterpart  3  in the powered condition and release it in currentless condition. In another embodiment, however, it is also possible to keep the magnet  1  as permanent magnet currentless at the carrier plate  4  and to separate the tool  2  from the carrier plate  4  by powering the electro-magnet. This is, for example, provided by generating a magnetic opposing field. Of course, it is enough for that to enlarge the gap between the magnetic counterpart  3  and magnet  1  so that the magnetic attraction is not enough anymore to hold the tool  2  securely. The invention also comprises a solution where the magnet is designed as electro-magnet and acts magnetically in powered condition so that the magnetic counterpart and/or the tool is attracted and not in currentless condition. 
         [0040]    The magnetic holder I consisting of the magnet  1  and the magnetic counterpart  3  is in the shown modification designed in such a way that the magnet  1  is connected with a T-shaped counter holder  5 . This counter holder  5  is carried by a resetting element  6  arranged between the carrier plate  4  or the toolholder a and the counter holder  5 . This resetting element  6  can also be here designed as a pressure or tension spring. 
         [0041]    Alternatively to the counter holder  5  shown here also simply a screw is provided on the backside of the magnet  1  which is supported by leaf springs or saucer springs as resetting element  6  at the backside of the carrier plate  4 . Of course all other holding devices can be employed. The resetting element  6  not only provides resetting or holding of the magnet in the preferred position. By means of this embodiment a floating support, as it were, of the magnet  1  is reached, and the self-centering of the tool arrangement itself is effected. The carrier plate can, as already described above, also be heated or cooled, depending on the task the tool  2  has. Of course, it is also possible to arrange the heating or cooling at the tool  2 . The invention is not limited to a single embodiment. 
         [0042]    The resetting element  6  is also provided for pushing the counter holder  5  upwards over with the magnet  1  in order to balance tolerances which may occur by thermal expansion or an inaccurate manufacturing. The magnet  1  is arranged in the carrier plate  4  in reset position slightly set back, however, maximum in zero position or congruently with the edge of the carrier plate  4 , however, never projecting. Schematically also a control  7  is indicated in the single figure which may be the control of the packaging machine itself which, however, may also form a separate control or a separate control element for the part of the tool holding device. This control  7  is connected bi-directional with the magnet  1  or the link I or magnetic holder I by the control line  7 / 1  to control the functions of the magnetic holder I, that means through the control  7  at least separating the tool  2  from the toolholder a or the connecting of these two elements is controlled. Of course, it is also possible to influence via the control  7  the heating or cooling functions in the carrier plate. The invention is not limited here. 
         [0043]    Although the invention has been described by exact examples which are illustrated in the most extensive detail, it is pointed out that this serves only for illustration, and that the invention is not necessarily limited to it because alternative embodiments and methods become clear for experts in view of the disclosure. Accordingly changes can be considered which can be made without departing from the contents of the described invention.