Patent Publication Number: US-6334290-B1

Title: Apparatus for producing packages

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to an apparatus for producing packages. Known apparatuses of this kind are used for making plastic cups filled with a food, such as yogurt or juice. A disadvantage of the known apparatuses is that they create a flat rim extending all the way around. This often sharp-edged rim is unpleasant to the user if the plastic cup is used as a drinking cup at the same time. For this reason, cups with a downward-drawn or rounded rim are already known. However, these cups are made either by injection molding, or if they are made by deep drawing, then the rim is formed, on an additional piece of equipment, only after the packages have been filled and separated. It is therefore an object of the invention to refine an apparatus of this generic type in such a way that packages with a downward-drawn rim region can be produced without additional, separate equipment. 
     OBJECT AND SUMMARY OF THE INVENTION 
     The apparatus according to the invention for producing packages has the advantage that by integrating the production of downward-drawn rims with the thermoforming system, the rims can be created directly in the thermodeformable strip, and the packages do not have to be separated beforehand. This makes it possible to achieve a relatively simple design of the apparatus as well as high capacity. as high capacity. 
     The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a single exemplary embodiment taken in conjunction with the drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a simplified side view of an apparatus for producing packages; 
     FIG. 2 is a side view of a forming device; 
     FIG. 3 is a side view of part of a cutting device; and 
     FIG. 4, again in side view, shows a part of a cutting device that is modified compared with FIG.  3 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An apparatus  10  for producing filled packages  1  is shown in FIG.  1 . The apparatus  10  has a heating station  11  with at least two heating plates  12 ,  13  disposed on both sides of a thermodeformable bottom strip  2 , and also has a forming station  15 , a filling station  16 , a sealing station  17  for sealing on a top foil strip  3 , and a cutting station  18 . 
     Longitudinally of both sides of the feeding path of the bottom strip  2 , feeding devices are provided, in the form of reciprocating pairs  19 ,  20 ,  21  of clamping tongs that open and close and that pull the bottom strip  2  from a roll  4  and intermittently feed the strip through the individual processing stations of the apparatus  10 . 
     The heating station  11 , filling station  16  and sealing station  17  are of known designs and will therefore not be described in further detail here. What is essential to the invention is the embodiment of the forming station  15  and the cutting station  18 . The forming station  15  has a lower part  23  and an upper part  24 , which can be moved toward and away from one another. First recesses  26  for forming the slightly conical container bodies  5  and second recesses  27 , each for forming an encompassing, downward-drawn container rim  6 , are embodied in the lower part  23 . As seen best in FIG. 2, an at least partly flat middle portion  28  is embodied between the first recess  26  and the second, annularly encompassing recess  27 . In the further course of operations, the middle portion  28  embodies the bearing surface for sealing on the top foil strip  3 . The second recess  27  is embodied obliquely, at least in the lower region  29  of the container rim, pointing in a direction away from the container body  5 . For forming the container bodies  5 , raisable and lowerable prestretching dies  31  are disposed in the upper part  24 , along with compressed air nozzles or the like, not shown. On the underside  32  of the upper part  24 , there are also encompassing protrusions  33 , which are adapted to the shape of the second recesses  27  and cooperate with them. 
     As FIG. 1 in conjunction with FIG. 3 shows, the cutting station  18  has a lower part  34  and an upper part  35 , which can both be moved toward and away from one another. Recesses  36  adapted to the shape of the container bodies  5  are embodied in the lower part  34 . What are essential are also encompassing support rims  37 , whose shape is adapted to the shape of the inside  38  of the container rims  6 , so that the support rims  37 , together with the recesses  36 , receive the container bodies  5  by positive engagement. Holding-down devices  39 , which are surrounded by sleeve-like circular stamping knives  40 , are integrated into the upper part  35 . As best seen from FIG. 3, the holding-down device  39  has a diameter which protrudes somewhat past the flat sealing region  42  on the container body  5 . In a preferred embodiment of the invention, the spacing a 1  from the sealing region  42  on the container body  5  to the stamping knife  40  is selected to be great enough that the annularly encompassing portion  43 , protruding from the sealing region  42  to the stamping knife  40 , of the top foil strip  3  can be grasped with the fingers and used as an aide in opening the package  1 . In order to make a container rim  6  as user-friendly as possible, the dimension a 2  is furthermore selected to be so great that when someone drinks out of the package  1 , the container rim  6  will not injure his lips that are contacting the edge of the package. FIG. 3 also shows that the downward-drawn container rim  6  has to be embodied in such a way that the stamping edge, indicated at  45 , can be engaged by the stamping knife  40  moving vertically from top to bottom. This means that the stamping edge  45  is spaced farther from the container body  5  than are the other points of the container rim  6 . 
     The stamping knife  40  has an encompassing cutting edge  46 . To make it simpler to sever the top foil strip  3 , it is preferably provided that the cutting edge  46  extends not in a parallel plane relative to the top foil strip  3  or the lower part  34 , but instead has at least one point with a somewhat lesser spacing. As a result, when the cutting edge  46  of the stamping knife  40  meets the top side of the top foil strip  3 , local peak tensions are created, at which the top foil strip  3  is first severed or first tears. 
     In the exemplary embodiment shown in FIG. 4, a cutting station  18   a  is employed that differs from the cutting station  18  in particular in having the presence of a second stamping knife  47 . The second stamping knife  47 , which is disposed concentrically with the first stamping knife  40   a,  is provided whenever it is undesirable to have a portion  43  of the top foil strip  3  protruding past the sealing region  42  and serving as an aide in opening the container. For that case, it is preferably provided that the second stamping knife  47  is in advance of the first stamping knife  40   a  in terms of its motion, or in other words meets the sealing region  42  before the first stamping knife  40   a  forms the stamping edge  45   a,  because in that case the second stamping knife  47 , together with the support rim  37   a  provides for additional centering of the package  1  in the cutting station  18   a.    
     Mode of Operation 
     The apparatus  10  described above functions as follows: The bottom strip  2  is advanced intermittently through the apparatus  10  by the pairs  19 ,  20 ,  21  of clamping tongs, first being heated in the heating station  11  to the temperature required for the ensuing molding process. Next, the bottom strip  2  enters the forming station  15 , where the lower part  23  and top part  24  of the station are moved toward one another, thus forming the container rims  6  in the bottom strip  2 . Next, the prestretching dies  31  move downward, in order to indent the bottom strip  2  about the first recesses  26 . The molding process is concluded by compressed air (or a vacuum applied to the first recesses  26 ), which by positive engagement presses the bottom strip  2  into the first recesses  26  (FIG.  2 ). After the ensuing feeding increment, the molded container bodies  5  have reached the region of the filling station  16 , where a certain quantity of a filling product is metered into the container bodies  5 . In the following sealing station  17 , the top foil strip  3  is sealed onto the top side of the container bodies  5  by the action of heat and pressure in the region of the sealing regions  42 . Finally, the container bodies  5 , now provided with the top foil strip  3 , enter the region of the cutting station  18 ,  18   a.    
     In the case of the cutting station  18  (FIG.  3 ), the holding-down device  39  moves in advance of the stamping knife  40 , so that the holding-down device  39 , together with the support rim  37 , centers the container body  5  in the cutting station  18 . What is also essential is that during the centering, no tensile or compressive stresses are exerted by the pairs  19 ,  20 ,  21  of clamping tongs on the composite comprising the bottom strip  2  and the top foil strip  3 . Only once the holding-down devices  39  are seated on the top side of the packages  1  does the stamping knife  40  sever the top foil strip  3  and, as operation continues, cut individual packages  1  out of the bottom strip  2 . 
     In the case of the cutting station  18   a  (FIG.  4 ), the second cutting knife  47 , as already noted, serves to center the container bodies  5  in the cutting station  18   a.  Only once the centering has been accomplished does the second stamping knife  47  sever the top foil strip  3 , while the stamping knife  40   a  is cutting the packages  1  out of the bottom strip  2 . 
     It will also be noted as a supplement that the apparatus  10  can be modified or changed in manifold ways. For instance, it is conceivable to embody the apparatus  10  as a packaging machine that operates aseptically, so that it can also be used for filling containers with foods that are critical in terms of spoilage. Furthermore, instead of single packages  1 , groups of packages  1  cohering with one another can be produced in the forming station and the cutting station. In that case, it is understood that corresponding design changes are required both in the forming station and in the cutting station. Another modification pertains to the embodiment of the stamping  40  (FIG.  3 ): Instead of a stamping knife that has a circular cutting edge and creates an annular aide (portion  43 ) in opening the container, the stamping knife can also have an embodiment such that it creates a protruding opening tab in the portion  43 , while the remainder of the top foil strip is severed directly at the portion  42 , similarly to what is shown in FIG.  4 . 
     The foregoing relates to a single exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.