Abstract:
A device for filling processing stations ( 16 ) with a pumpable working material guarantees a permanent and sufficient supply of working material to the processing station with the lowest possible expense and greatest possible cleanliness. The device includes a transfer chamber ( 42 ) assigned to a central tank ( 55 ) for the working material. The transfer chamber ( 42 ) is assigned to a processing station ( 16 ), in such a way that the working material can be fed at first from the central tank ( 55 ) into the transfer chamber ( 42 ) and from there to the processing station ( 16 ). An arrangement is also provided that includes such a device.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority under 35 U.S.C. §119 of European Patent Application EP 10 160 122.7 filed Apr. 16, 2011, the entire contents of which are incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention pertains to a device for filling processing stations with a pumpable working material (operating substance). The present invention pertains, furthermore, to an arrangement for filling processing stations with a pumpable working material, with a central tank for the working material and with two or more processing stations and a feed line for feeding the working material to one of the processing stations. 
       BACKGROUND OF THE INVENTION 
       [0003]    Even though the present invention is suitable for all pumpable working materials, i.e., bulk materials, gel-like or pasty substances or liquids, a concrete application of the present invention is the preparation of hot-melt adhesives for a heat-sealing means, for example, in packaging machines. The heat-sealing means is thus a processing station in this case. The hot-melt adhesive is provided as bulk material, especially in the form of granular material, also designated as pellets, and is usually stored in tanks directly at the heat-sealing means. Each heat-sealing means has its own tank with a corresponding capacity, into which the granular material is filled. The drawback in this case is that the environment of the tank is very hot, such that the personnel may be burned while filling the tank. Moreover, in the case of high-performance heat-sealing means, the tank has to be refilled very frequently, which requires a corresponding workforce. There is also the risk that sufficient granular material is not present in the tank, which may lead to defects in the bond and to production rejects as well as to production losses. Furthermore, it occurs that granular material is spilled during the refilling of the tank and the environment becomes contaminated with it. It should be taken into consideration here that spilled material is always also mixed with dust because of abrasion, which contaminates the environment as well. Moreover, spilled granular material may come into contact with hot parts of the heat-sealing means and then melt. The heat-sealing means is further contaminated as a result of this. This is always undesirable. Contaminations are especially of special concern in packaging machines for food. 
         [0004]    To avoid these drawbacks, in practice the granular material was already prepared in drums and the tank of the heat-sealing means was refilled from the drum via a corresponding refill line. Exactly one tank is assigned to each drum in this case. The workforce is reduced here, since the drum has a greater capacity than the tank. However, the personnel must still always monitor that the drums are replaced in a timely manner. Moreover, the conveying track, via which the granular material is conveyed, is highly limited in this variant, such that drums have to be set up close to the respective heat-sealing means. These drum locations are often not easily accessible sites. Moreover, it has been shown in practice that the granular material easily becomes lumpy in the drums. 
       SUMMARY OF THE INVENTION 
       [0005]    The arrangement according to the present invention includes a device with a transfer chamber that is assigned to a central tank for the working material. the transfer tank of the invention may be provided in a combination with features according to DE 20 2009 005 561 U1 which is hereby incorporated by reference in its entirety. The transfer chamber is assigned to the processing station, in such a way that the working material can be conveyed at first from the central tank into the transfer chamber and from there to the processing station. 
         [0006]    By the working material at first transferring from the central tank to a transfer chamber, i.e., a preportioning of the working material is performed so to speak, greater conveying paths can also be accommodated. For this reason, the central tank may be arranged at an easily accessible site as well, such that it can be refilled in a simple manner. Therefore and because of a greater capacity, the central tank can be refilled almost free from contaminations and arranged at a distance from the processing stations, i.e., mainly the heat-sealing stations, such that the risk of injury, especially the risk of getting burned, is avoided. Contaminations that may still possibly occur involve contaminants that pass at a distance from the processing station and can be easily removed. In this case exactly one processing station may be present that is supplied from the central tank. However, the present invention is mainly intended for supplying a plurality of the processing stations, including a heat-sealing means according to the above example, from a common central tank with the working material, granular material of the hot-melt adhesive. In this way, only one more central tank needs to be monitored, as a result of which the operating cost is considerably reduced. 
         [0007]    An object of the present invention is to provide an effective transfer chamber for an arrangement for supplying processing stations with pumpable substances, and especially for processing stations according to DE 20 2009 005 561 U1. 
         [0008]    For this purpose, a bottom surface deepening towards a sump in a funnel-like manner is provided at the bottom of the transfer chamber. The sump may be provided in the center in the bottom of the transfer chamber, but also off-center, for example, laterally. The sump should be embodied as a blind hole and have a diameter that corresponds approximately to the internal diameter of the discharge opening or of the feed tube. Also, as a result of this, the working material can be easily blown out of the transfer chamber. Conveying tracks (paths) of about 100 m and a height difference of up to 25 m can be overcome with such an equipped pilot plant. This alternative embodiment of the transfer chamber is also conceivable independent of the device and arrangement according to the present invention. 
         [0009]    The transfer chamber can be closed upwards towards the central tank by means of a ball valve. As a closing means, such ball valves have a ball provided with a passage hole. If this ball is brought into its closed position, the granular material remains behind in the passage hole, which then becomes lumpy already at room temperature and consequently clogs the passage hole even in the open position. To avoid this, provisions are made according to a variant that the closing means is also open towards the transfer chamber even in the closed position. As a result of this, granular material remaining behind in the closing means can always flow out into the transfer chamber and thus not clog the closing means. 
         [0010]    According to the arrangement according to the present invention, two or more transfer chambers may be assigned to the central tank, whereby a processing station is respectively assigned to each transfer chamber. This may result in that a particular line for the working material is always guided to a particular processing station from each of the transfer chambers. Thus, there is a star-shaped connection of the processing stations to the central tank. However, it is also conceivable that the central tank is provided with only one transfer chamber, to which two or more processing stations are then assigned. In this case, the transfer chamber is connected to a concrete processing station by means of switches in the line, respectively, such that only one concrete line is always switched between the transfer chamber and the respective processing station. This variant may be designated as a tree structure, in which, starting from the transfer chamber the trunk, a plurality of branchings arise. Of course, in the tree structure it is also possible to assign two or more transfer chambers to the central tank, such that an own tree structure then starts from each transfer chamber. It is also conceivable to provide transverse connections under the individual tree structures, such that, as an option, two processing stations arranged within the one tree structure may also at the same time be supplied with working material, if this should be necessary. As already indicated above, it is important only that at each point in time only one entirely particular path from one of the transfer chambers is always switched to an entirely defined processing station for the working material. In the simplest case, this can be embodied by a ring line that starts from a transfer chamber and ends in another transfer chamber. Then, a line from the processing station to be filled is always switched to the transfer chamber placed next to it—once around to the right and once around to the left, such that two processing stations can always be filled at the same time. 
         [0011]    According to a variant of the arrangement according to the present invention, provisions are made that the working material is fed from the transfer chamber at first to a means for separating the pressurizing means, i.e., for example, compressed air, and is conveyed from there in an unpressurized manner into the tank of the processing station. In the prior-art process mentioned in the introduction, in which the granular material of the hot-melt adhesive was conveyed from the drum by means of compressed air into the tank of the processing station, this also led to a cooling of the heat-sealing means. As a result of this, the heat-sealing means was partly cooled below the melting point of the hot-melt adhesive, which led to disturbances in the operating sequence. Since, according to the present variant, the compressed air is already separated beforehand and the working material flows into the tank in an unpressurized manner, this risk is avoided. 
         [0012]    The present invention is explained in detail below based on an exemplary embodiment shown in the drawing. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    In the drawings: 
           [0014]      FIG. 1  is a schematic lateral view showing an adhesive supply according to DE 20 2009 005 561 U1; 
           [0015]      FIG. 2  is a top view showing a transfer chamber with the features of the present invention; 
           [0016]      FIG. 3  is a vertical sectional view showing the transfer chamber according to  FIG. 2  taken in plane XI-XI; 
           [0017]      FIG. 4  is a bottom view showing a transfer chamber with the transfer chamber being according to  FIG. 2 ; 
           [0018]      FIG. 5  is a schematic lateral view showing another exemplary embodiment with a transfer chamber according to  FIG. 2  for an arrangement with the features of the present invention; 
           [0019]      FIG. 6  is a perspective view showing a ventilating means for the arrangement according to  FIG. 5 ; and 
           [0020]      FIG. 7  is a perspective top view showing a cover for a working material tank of a processing station. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    Referring to the drawings in particular, the arrangement shown in  FIG. 1  includes a central tank  10  with transfer cartridges  11  arranged under the central tank. Central tank  10  is mounted on columns  12  by means of vibration dampers  13  on a basic frame  14 . Furthermore, a control box  15  for controlling the device is assigned to the central tank  10 . 
         [0022]      FIG. 1  shows, as representative of a random number of processing stations, a processing station, in particular a heat-sealing means  16 . A working material, a granular material of a hot-melt adhesive in the present case, is fed by means of a feed line  17  at first to a ventilating means  18 , the significance of which will still be explained further below. This ventilating means  18  is located above the heat-sealing means  16 , specifically above a tank of same, so that the working material can flow in an unpressurized manner from the ventilating means  18  into the tank of the heat-sealing means  16 . The feed line  17  is connected to the transfer cartridge  11  via a feed tube  28 . 
         [0023]      FIGS. 2 and 3  show a transfer chamber  42  according to the invention, which replaces the transfer cartridge  11  in the arrangement according to  FIG. 1 . This transfer chamber  42  is embodied as a cylindrical, specifically a circular cylindrical, hollow body. The transfer chamber  42  has a bottom  43 , which forms a bottom surface  44 , which deepens towards the center in a funnel-like manner and then passes over into a central sump  45 , embodied as a blind hole in the present case. The transfer chamber  42  is closed by a cover  46 , which has a screw socket  47 , at the top, i.e., at an end opposite the bottom  43 . In the present case, the screw socket  47  is provided with a male thread  48  on its outside, but may, in addition or as an alternative, also be embodied with a nut on its inside. Furthermore, screw socket  47  has a passage hole  49 , which communicates with the internal cavity of the transfer chamber  42 . 
         [0024]    A ball valve  50 , which has for this purpose a nut  51  communicating with the male thread  48  of the screw socket  47 , is screwed onto the screw socket  47 . If the screw socket  47  should have a female thread, the ball valve  50  is, of course, provided with a corresponding male thread. All other prior-art connecting techniques, for example, a bayonet catch between the transfer chamber  41  and ball valve  50 , are also possible. Otherwise, the ball valve is embodied in the commercially available manner and is actuated via a motor actuation means  52 . 
         [0025]    At the bottom  43  of the transfer chamber  42  is arranged a discharge tube  53 , which communicates with a pressurizing means in the form of a compressed air nozzle  54 , with pressurized air source, which is arranged in the sump  45  of the bottom  43 . The compressed air nozzle  54  may be designed as a venturi nozzle and protrudes with its opening up to into the discharge tube  53 . The end  59  visible in  FIG. 2  within the sump  45  bends and extends downwards and communicates with a compressed air connection. The diameter of the sump  45  is approximately and preferably exactly as large as the internal diameter of the discharge tube  53 . 
         [0026]      FIG. 4  shows a bottom view of a central tank  55 , which is equipped with the transfer chambers  42 . In the bottom  58  of the central tank  55  there is provided a number of openings  57 , to which the transfer chambers  42  can be connected via the ball valves  50 . Furthermore, a vibrating means  60 , with which this central tank  55  is also equipped. 
         [0027]    In the variant according to  FIGS. 2 to 4  as well, the transfer chamber  42  is filled with a volume of the granular material, which corresponds to the volume that can be accommodated by the tank of the heat-sealing station  16 . For this purpose, the ball valve  50  is opened in a time-controlled manner or via corresponding filling level sensors in the transfer chamber  42 , until the respective filling level in the transfer chamber  42  is reached and the ball valve  50  is then closed again. Now, a pressurizing means is sent to the compressed air nozzle  54 . The duration of the pressure surge is again measured in a time-controlled manner, so that the transfer chamber  42  is completely emptied and the granular material is fed to the tank of the heat-sealing station  16 . Due to the pressure surge the granular material, as described above based on the transfer chambers  42 , is conveyed from the transfer chamber  42 . In this case, the flow in the transfer chamber  42  is facilitated (the material breaks down) because of the special shape of the bottom  43  in the transfer chamber  42 , so that the granular material is accelerated at a high speed. In a pilot arrangement equipped with this transfer chamber  42 , the granular material could be conveyed a distance of approximately 100 m, and a height difference of 25 m could be overcome. 
         [0028]    Ordinary ball valves have a ball provided with a passage hole as closing means. It has been shown that granular material may remain behind (in the valve) when the ball valve is closed. Therefore, in the present case, the ball valve  50  is provided with a ball, which is provided with an opening, which is open towards the transfer chamber  42  even in the closed position of the ball valve, such that the granular material can always flow from the ball into the transfer chamber  42 . For this, the ball can be provided with a corresponding groove or be embodied as a shell. 
         [0029]    The device according to the present invention and arrangement according to the present invention were described above based on the example of supplying heat-sealing means with heat-sealing granular material, i.e., a bulk material. However, the present invention is suitable for all pumpable working materials, i.e., not only for bulk materials, but also for gel-like or pasty substances and liquids. The device according to the present invention and arrangement according to the present invention are also suitable for any other type of processing stations as heat-sealing means. 
         [0030]    Furthermore, according to the above exemplary embodiments, exactly one transfer chamber  42  is always assigned to each processing station (heat-sealing station  16 ). As an alternative, it is also possible to assign two or more transfer chambers  42  to a processing station  16 . This may be sensible in very fast running processing stations  16  with only a small tank, since then the tank is refilled from one of the transfer chambers  42  from the central tank  10 . In this case, an own (dedicated) or a common ventilating means  18  may also be assigned to each transfer chamber  42  depending on the needs. It is also possible that two or more processing stations  16  are assigned to a transfer chamber  42 , which are then assigned by means of switches to the transfer chamber  42 . It is important only that only one processing station  16  is always presently assigned to the transfer chamber  42 . Such an arrangement is shown in  FIG. 5 , which is based on the central tank  55  according to  FIG. 4  and has the transfer chamber  42  from  FIGS. 2 and 3  as a transfer chamber. Specifically, two transfer chambers  42  are shown. Of course, the central tank  55  may also be provided with only one transfer chamber  42  or even three or more transfer chambers  42 . 
         [0031]    At first a main pipeline  61 , which branches into two main branches  63  and  64  at a first switch  62 , starts from the transfer chamber  42 . The switch  62  is, like all other switches still to be described further below as well, embodied as a three-two-way ball valve. That is, a total of three lines are assigned to the ball valve, whereby in the present case one inflow and two outflows are provided, respectively, and in particular in the case of switch  62  the main pipeline as inflow and the main branches  63  and  64  as outflow. 
         [0032]    The main branch  63  ends at another switch  65 . 1 , from which a branch line  66 . 1  branches off at an outflow. This in turn opens out in a switch  65 . 2 , one outflow of which ends at a branch line  66 . 2 . This goes on with a selectable number n of switches. In a similar manner, the second and possibly another other main branch  64  opens out into a first switch  67 . 1 , leads from the one first branch line  68 . 1  to another switch  67 . 2  and so forth until a selected number of m switches  67  is reached in this case as well. The respective other outflows of the switches  65  and  67  open out in a ventilating means  69 , by means of which the compressed air used for transporting the working material from the transfer  62  is removed. For this purpose, the ventilating means  69  has a tube-like, cylindrical filter  70 , whose jacket surface is made of a filter material, a screen in the simplest case. The mesh size of the screen is such that the working material cannot pass through the screen, but the air transporting the working material can. A funnel-like tapered section  71 , which opens out into a down pipe  72 , is provided under the screen  70 . The internal diameter of the down pipe  72  is smaller than the internal diameter of the filter  70  because of the tapered section  71 . As a result of this, the working material is easily retained in the area of tapered section  71 , is thus slowed down in its speed, without leading to a complete clogging. Because of the easy retaining of the working material in the area of the tapered section  71 , the compressed air escapes through the filter  70  and the working material flows in an unpressurized manner to the processing station  16 . 
         [0033]    The tanks of the processing stations  16  are usually closed with a cover. In the case of heat-sealing machines, the cover is even insulated in order to minimize the escape of heat that is used to melt the hot-melt adhesive in the tank. Also within the framework of the present invention, the tank should therefore be closed with a cover, as this is shown schematically by the cover  73  in  FIG. 5 . The cover  73  itself is shown in detail in  FIG. 7 . The cover  73  has an opening (not visible in  FIG. 7 ), through which the working material can flow. This opening is closed by a cap  74 , which in the present case is mounted pivotably about an axis  75  at the cover  73 . Another ventilating means  76 , which likewise has a cylindrical filter  77  as a jacket, similar to the ventilating means  69 , is arranged at the cap  74 . The down pipe  72  is connected to this ventilating means  76  at the top. With the cap  74  open, the ventilating means  76  is in alignment with the opening in the cover  73 , such that the working material can flow through the opening. As soon as the tank is filled, the cap  74  is pivoted into the closed position under elastic deformation of the down pipe  72 . The cap  74  now closes the opening in the cover  73 . 
         [0034]    However, vapors may escape from the tank of the processing station even with the cap  74  closed. To this end, a collecting means  78 , in which vapors are collected and are disposed of, for example, once daily by cleaning the collecting means  78 , is assigned to the cap  74  in its closed position. As an alternative, an insulating plug may possibly also be provided here, which is charged into the opening in cover  73  with cover  73  insulated from the underside and thus provides for a continuous insulation as much as possible without heat bridges. 
         [0035]    The cap  74  is actuated by a pneumatic cylinder  79  in a manner known per se. It is understood that the main branches  63  and  64  must not themselves be connected directly via the switches  65  and  67 , respectively, to processing stations  16 , but can themselves branch off into other forearms. Also, only a single main branch may be provided, which then connects directly to the transfer chamber  42 . Furthermore, it is, of course, also conceivable to mix the different concepts of the arrangement according to  FIG. 1  and  FIG. 7  with one another and to assign them to the same central tank. 
         [0036]    While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. 
         [0000]    
       
         
               
             
               
               
               
               
               
             
           
               
                 APPENDIX 
               
               
                   
               
               
                 List of Reference Numbers 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 10 
                 Central tank 
                 56 
                 Bottom 
               
               
                   
                 11 
                 Transfer cartridges 
                 57 
                 Opening 
               
               
                   
                 12 
                 Column 
                 58 
                 Bottom 
               
               
                   
                 13 
                 Vibration damper 
                 59 
                 End 
               
               
                   
                 14 
                 Basic frame 
                 60 
                 Vibrating means 
               
               
                   
                 15 
                 Control box 
                 61 
                 Main pipeline 
               
               
                   
                 16 
                 Heat-sealing means 
                 62 
                 Switch 
               
               
                   
                 17 
                 Feed line 
                 63 
                 Main branch 
               
               
                   
                 18 
                 Ventilating means 
                 64 
                 Main branch 
               
               
                   
                 28 
                 Feed tube 
                 65 
                 Switch 
               
               
                   
                 42 
                 Transfer chamber 
                 66 
                 Branch line 
               
               
                   
                 43 
                 Bottom 
                 67 
                 Switch 
               
               
                   
                 44 
                 Bottom surface 
                 68 
                 Branch line 
               
               
                   
                 45 
                 Sump 
                 69 
                 Ventilating means 
               
               
                   
                 46 
                 Cover 
                 70 
                 Filter 
               
               
                   
                 47 
                 Screw socket 
                 71 
                 Tapered section 
               
               
                   
                 48 
                 Male thread 
                 72 
                 Down pipe 
               
               
                   
                 49 
                 Passage hole 
                 73 
                 Cover 
               
               
                   
                 50 
                 Ball valve 
                 74 
                 Cap 
               
               
                   
                 51 
                 Female thread 
                 75 
                 Hinge 
               
               
                   
                 52 
                 Actuating device 
                 76 
                 Ventilating means 
               
               
                   
                 53 
                 Compressed air connection 
                 77 
                 Filter 
               
               
                   
                 54 
                 Compressed air nozzle 
                 78 
                 Collecting means 
               
               
                   
                 55 
                 Central tank 
                 79 
                 Pneumatic cylinder