Abstract:
A separating system for separating individual container products from a frame assembly of plastic material, particularly polypropylene, has at least one stamping device ( 36 ) that at least partially separates the respective container product from a frame waste. By the stamping device ( 36 ) including a free fall body ( 52 ) separating the respective frame waste from the associated container product from an initial position during free fall, the separation can be carried out with very high speed (free fall) and additional mechanical components for applying a constraint force on the stamping body during the creating of the separating line can be omitted.

Description:
REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a divisional application of U.S. patent application Ser. No. 12/452,283, filed Dec. 23, 2009, the entire subject matter of which is hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a separating system for separating individual container products from a frame assembly of a plastic material, particularly of polypropylene. The device has at least one stamping device which at least partially separates the respective container product from the frame waste. 
       BACKGROUND OF THE INVENTION 
       [0003]    The prior art (DE 199 26 329 A1) discloses methods and devices for producing container products of plastic, as they are supplied to a generic separating device used for separation of the pertinent individual container products from a frame assembly using a cutting or stamping device. To produce the respective container product, a tube of plasticized plastic material is extruded into a molding device, one end of the tube is sealed by welding and it is widened by producing a pneumatic pressure gradient which acts on the tube. The container is formed by being applied to the molding wall of the molding device having two opposite molding tools. By a corresponding filling mandrel, the plastic container then is filled under sterile conditions within the molding device. After removal of the filling mandrel, the container is then hermetically sealed with the formation of a definable head geometry for forming the actual plastic container in which the fluid is stored. Two container shaping jaws can be moved toward one another by hydraulic drives for obtaining the closed position and can be moved away from one another in opposite directions into one of their opening positions. To achieve very high output rates of container products, DE 103 23 335 A1 describes a multi-station arrangement. By distributing various shaping steps among different stations located in succession on an imaginary arc, a type of carousel arrangement is formed which enables very high cycle frequency for the plastic material to be outputted in the form of container products. 
         [0004]    Since the charge to be added to the respective container product is often very susceptible to ambient media, especially when it is a highly sensitive pharmaceutical, in the prior art the focus is on, for example, covering the fill opening of the container tube at least from its formation to filling of the pertinent container in a sterile space by a sterile barrier. Very good results can be achieved when, as shown in DE 10 2004 004 755 A1, a sterile medium forms the indicated barrier in the direction of the container fill opening using a medium conveyance device in order to further improve sterility. Another or additional measure for increasing sterility simply is to provide higher processing temperatures, for example, in the production of the tubing for the container products or while the charge is being added. An increased processing temperature is limited when the often used plastic material, such as polyethylene, is temperature-sensitive, which can be otherwise very easily processed in the pertinent production devices and, accordingly, is preferred. 
         [0005]    Otherwise, in addition to atmospheric oxygen, other gases can diffuse later on through the thin polyethylene wall into the interior of the container during the storage and sale of the container product which has been produced under sterile conditions and can damage the sensitive container contents or even make them unusable. 
         [0006]    In order to remedy this latter disadvantage, in the prior art, production processes for these container products have already been proposed (DE 103 47 907 A1 and DE 103 47 908 A1), which relate to so-called co-extrusion production processes in which the container is built up from several layers of plastic materials. Often at least one of the layers is used as a blocking layer. Five and more layers, for example, formed from polyethylene and low density polyethylene as well as copolymers (ethylene-vinyl alcohol copolymer) can form the multilayer container wall which in this case then forms an effective blocking layer. However, these processes are costly in practical implementation. This cost makes the respective container product correspondingly more expensive. 
         [0007]    If the individual container products come filled from the respective production machine, they are in the form of an ampule block in which several successive ampules or containers have a common wall as a block assembly or frame assembly. In order to detach the containers or ampules from the block assembly or frame assembly, they are cut out or punched out along edge zones, with a certain amount of frame waste being formed, which waste can be recycled using modern techniques. DE-PS 38 31 957 discloses a method of producing plastic hollow container products which are present first as an ampule block or frame assembly, where in one edge zone of the frame waste, an additional hollow body is molded in the frame assembly. This hollow body increases stability in the frame assembly and, among other things, helps facilitate separation from the container product of the frame waste by the separating device being used respectively. 
       SUMMARY OF THE INVENTION 
       [0008]    An object of the invention is to provide an improved separating device for separating container products at high speed, regardless of their type of plastic material, from the frame assembly with a high degree of operating reliability and relatively low production costs. 
         [0009]    This object is basically achieved by a separating device where the stamping device of the separation device has a free fall body. From the initial position, in free fall the free fall body separates the respective frame waste from the respective container product. Separation can be effected with very high speed (free fall). Additional mechanical components for applying a positive force to the stamping body in the preparation of the separation line can be omitted. Ultimately, the free fall body need only be raised again and again. This raising, for example, can take place by means of a pneumatic working cylinder, proceeds quickly and requires little energy. 
         [0010]    In particular, with the separating device according to the invention, polypropylene as the wall material can be used for container products. This plastic material is rather brittle compared to polyethylene material and can be worked only with difficulty using conventional stamping and cutting devices for container separation. If conventional separating devices are used, it has been found that with respect to the very high processing temperatures of polypropylene, it would be necessary to wait several minutes until the stamping or cutting process is possible at all. This delay necessarily leads to the requirement of very long retaining distances and/or additional cooling means for the container products to be separated to be able to effect separation without waste at all. As a result of the free fall body of the stamping device, clean separation can take place without these waiting times or ancillary cooling means. This separation is done by the respective container product being simply knocked off the still very warm or hot frame assembly with high speed by the free fall body with its projecting stamping surfaces. For one with average skill in the art in the field of such separating devices, it is surprising that with relatively bluntly kept stamping cutting edges which need not be further worked (ground) or maintained, separating stamping lines are achieved that was not possible using the devices in the prior art. 
         [0011]    The advantage of using polypropylene material instead of polyethylene or a coextruded multilayer composite consisting of LDPE/MDPE is that the polypropylene material can be autoclaved at high temperatures (121° C.). The polypropylene material from only one extrusion head can be obtained at a much lower cost than the described multilayer systems. Thus, ultimately any individual layer to be produced in a multilayer system requires its own extrusion head in the production machine. This requirement increases production cost accordingly in terms of the control side as well. 
         [0012]    If the separating device according to the invention with the stamping device and free fall body is used for polypropylene material, this application is not limited thereto. Rather, there are a plurality of possible applications here. The separating device according to the invention can also be used for other plastic materials such as polyethylene or plastic multilayer systems for separation of a container product as necessary. 
         [0013]    In one especially preferred embodiment of the separating device according to the invention, the card-shaped frame assembly with the individual container products provides for division into a head part and bottom part. Each of the pertinent parts is assigned its own stamping device which are arranged in succession along a transport line for the frame assembly. The individual separation of the head part and bottom part allows even large format cards of the frame assembly to be “worked”, with the separating device and cutting allowing the respective mass of the free fall body of the stamping device to be reduced. Another advantage in separation is keeping the stamping device for the head part unchanged for each frame assembly size, while the stamping device for the respective bottom part of the frame assembly is changed depending on how large the ampule body is in terms of its length depending on the amount of fluid to be held. In this way, adjustment efforts for the separating device can be reduced if different types or quantities of container products are to be separated from the frame waste using the separating device. Of course, the base part can also be retained and the head part changed if this is necessary. 
         [0014]    Advantageously, the material flow for the card-like frame assembly (ampule block) to the respective stamping device is improved by transfer devices located in succession in the transport line in addition to at least one pivoting device. In this way, the output rate for the separating device is increased. 
         [0015]    Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the drawings, discloses a preferred embodiment of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Referring to the drawings which form a part of this disclosure and which are schematic and not to scale: 
           [0017]      FIG. 1  is a face-side, top plan view of an actual ampule block and the frame waste of a frame assembly; 
           [0018]      FIG. 2  is a top plan view of an ampule block removed from the frame waste of the frame assembly of  FIG. 1 , in which the individual container products with intermediate wall webs are detachably connected to one another as a commercial unit; 
           [0019]      FIG. 3  is a top plan view a schematic of the transport line or conveyor line for the ampules or containers produced by a production machine with the successively arranged stations of the separating device according to an exemplary embodiment of the invention; 
           [0020]      FIG. 4  is a perspective view of a housing arrangement for holding the individual stations as shown in  FIG. 3 ; 
           [0021]      FIG. 5  is a top plan view of a first transfer device of the transport line of  FIG. 3 ; 
           [0022]      FIG. 6  is a perspective top view a pivoting device for inserting the container products into a first stamping device of  FIG. 3 ; 
           [0023]      FIG. 7  is a partial side elevational view in section of the left-hand support of a frame assembly of the pivoting device viewed in the direction of  FIG. 6 ; 
           [0024]      FIG. 8  is a perspective view of a module-like first stamping device of  FIG. 3 ; 
           [0025]      FIG. 9  is a perspective view a second form of the transfer device of  FIG. 3 ; and 
           [0026]      FIG. 10  is a perspective view of the module-like structure of another second stamping device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    The frame assembly  10  shown in the figures is formed of a plastic material, in this case, of a polypropylene material. The frame assembly  10  is composed essentially of the actual container products  12  together with the frame waste  14  which is to be separated from the actual container products  12 . When the container products  12  are separated from the frame waste  14 , an ampule block from which the frame waste  14  has been removed as shown in  FIG. 2  results for this purpose. The individual containers or individual ampules are connected to one another by way of the remaining intermediate wall webs  16  of the frame waste  14 . The intermediate wall webs  16  make it possible for the respective container product  12  to be separated from the other containers which remain in the block in the manner of a twist-off motion. 
         [0028]    The respective container product  12  is known in the prior art, and the above described ampule block solution is described, for example, in DE 38 31 957 C1. The basic shape shown in  FIGS. 1 and 2  constitutes only one type of an embodiment. In particular, the container geometries can be specified on the user side within a widely drawn scope. To release the container contents, usually in the form of a fluid which has been added beforehand, a twist-off cap  18  is used and it can be separated from the container product otherwise by way of the corresponding scoring via a grip  20 , likewise in the manner of a twist-off motion, with the result that the fluid can be removed by way of the cleared container opening. Other container opening solutions such as dropper caps can likewise be implemented. 
         [0029]    On the bottom of the frame assembly  10 , as shown in  FIG. 1 , blind holes  22  are made. Using pins of a transport device (not shown) which engage the blind holes  22  on the bottom edge of the frame waste  14 , the frame assembly  10  of the container products  12  and the frame waste  14  is removed from the tool of a production machine (not detailed). Due to the high stability of the frame waste, owing to a waste edge zone which is self-contained in its form, removal is then reliably and easily possible even when the plastic of the frame assembly  10  has not yet completely cooled. This respective configuration is conventional so that it will not be further detailed here. 
         [0030]    As  FIG. 1  furthermore shows, the frame waste  14  is divided in two along at least one separating line  24 , this division taking place in the production machine (not shown). The bottom-side frame waste  26  can be removed separately from the head-side frame waste  28  with the result that, in this embodiment, intermediate wall webs  16  between the container products  12  remain with the formation of a retail unit. The illustrated solution can, however, also be modified such that overall the frame waste  14  is removed in such a way that individual container products  12  form the respective retail unit without still being connected to one another. The configuration is chosen at the discretion of the user. 
         [0031]      FIG. 3  shows, as a schematic and in a top view, the individual stations of the separating device as a whole. Viewed in the direction of  FIG. 3 , at extreme left, the exit region  30  of a production machine for producing the frame assembly  10  is shown, this production machine, for example, being described in DE 103 23 335 A1 so that it will not be detailed here. A first transfer device  32  which is shown in  FIG. 5  in essential outlines retrieves three units of the frame assembly  10  from the production machine at the same time and transports them to a pivoting device  34  shown in  FIG. 6 . 
         [0032]    This pivoting device  34  places the three frame assemblies  10  in a first stamping device  36  as shown in  FIG. 8 . By this first stamping device  36  the bottom-side frame waste  26  is separated from the respective frame assembly  10 . Then, the respective frame assembly  10 , still including of the container products  12  and the head-side frame waste  28 , as well as the intermediate wall webs  16  as shown in  FIG. 9 , is removed by a second transfer device  38  from the first stamping device  36  and supplied to a second stamping device  40 , as is detailed in  FIG. 10 . Instead of the illustrated triple frame assembly  10 , individual ampules with the frame waste surrounding them or some other definable number of interconnected ampules could be worked with the separating device according to the invention. 
         [0033]    The second stamping device  40  then separates the head-side frame waste  28  from the remaining frame assembly, as described. The container assembly as shown in  FIG. 2  is transferred in turn in the triple arrangement by the second transfer means  38  from the second stamping device  40  for further delivery to a removal station  42  (compare  FIG. 3 ). The product, which has been obtained in this way, can then be placed in conventional packaging for commerce by suitable devices (not shown).  FIG. 3  therefore shows in rough outlines how the transport line runs, proceeding from the production machine located at left viewed in the direction of  FIG. 3  with its output region  30  which is connected to the first stamping device for bottom-side frame waste  26  and then the second stamping device  40  for the head-side frame waste  28 . For correspondingly small container products, one stamping device can also be sufficient to separate the frame waste  14  in its entirety from the respective frame assembly  10 . 
         [0034]    The stamping sequence can also be reversed such that first the head-side frame waste  28  is removed, and then the bottom-side frame waste  26  in the direction of the described transport line is removed. Only the embodiment shown in  FIG. 3  has the advantage that the length of the container product  12  and therefore the filling volume can be changed without the geometry of the head side of the container product  12  changing. Depending on the ampule length, the first stamping device  36  which is the left one viewed in the direction of  FIG. 3  can be changed on the bottom side from its stamping tools. The indicated waste products  26 ,  28  can be removed from the separating device by the corresponding removal bevels  44  on the first stamping device  36  and the second stamping device  40 . 
         [0035]    This separating device, as illustrated particularly in  FIGS. 6, 8, and 10 , is made modularly using individual modules  46  which can be easily replaced for maintenance and assembly purposes. For a production machine output with altered shapes for the frame assembly  10 , the correspondingly modular configuration of the stamping and transfer devices and of the pivoting device can be adapted to the altered product. The cabinet-shaped housing structure  48  of the separating device shown in  FIG. 4  also takes into account this modular nature, and one station is assigned to each easily accessible cabinet part. In order to enable a clear view of the respective station of the separating device, specifically that part of the housing structure  48  which is the top part, viewed in the direction of  FIG. 4 , can have glass wall segments  50 . 
         [0036]    The respective stamping device as shown in  FIGS. 8 and 10  each has a respective free fall body  52  which is intended to have a high free fall mass, for example, on the order of fifty and more kilograms. On the bottom of the respective free fall body  52  are strip-shaped separating bodies (not shown) which are kept relatively blunt and which separate the frame waste  14  from the actual container products  12  in the indicated two steps. Viewed in the directions of  FIGS. 8 and 10 , the free fall body  52  shown in its upper initial position is able to fall vertically from its initial position into the separating or stamping position, viewed in the direction of the figures. A lifting device  54 , for example, in the form of a pneumatic cylinder, is then in turn able to quickly retrieve the fallen free fall body  52  from the stamping or separating position into the initial position shown in  FIGS. 8  and  10 . For this purpose, the free fall body  52  is coupled to a falling plate  56  on which the pneumatic cylinder acts with its piston rod. 
         [0037]    As  FIGS. 8 and 10  furthermore show, the respective stamping device  36 ,  40  is provided with an angle-shaped base body  58  along whose horizontally arranged base part  60  the respective frame assembly  10  is guided and extends parallel to the free fall body  52 . Free fall body  52  is guided via at least one lengthwise guide  62  on the vertically extending part of the base body  58 . The respective base part  60  of the stamping devices  36  and  40  each has individual receivers  64  for three ampule block arrangements to be held at a time. The respective individual receiver  64  of the first stamping device  36  as shown in  FIG. 8  is designed such that the container products  12  on their head part are held with the twist-off closure in the individual receiver  64  and with the region of the actual container containing fluid as shown in  FIG. 1 , allowing the bottom-side frame waste  26  to be removed. 
         [0038]    In the other stamping device  40  as shown in  FIG. 10 , the conditions are reversed. The container product  12  is then held in the region of the actual container receiver. In the head-side region, the respective container product  12  is guided in the individual receiver  64  such that the separating body of the free fall body  52  can remove the head-side frame waste  28 . In correspondence with the number of container products  12  in the frame assembly  10 , in this embodiment there are always five pressure pads on the head or bottom side for the individual receiver  64 . The individual receivers  64  can be easily replaced so that any machine downtimes can be kept short for modification measures or in case of wear. 
         [0039]    In order to be able to ensure material transport within the transport line, as already shown, different types of transfer and pivoting devices are used. The transfer devices which are shown in  FIGS. 5 and 9  and which once vertically transport the respective frame assembly  10  and then horizontally transport the at least partially stamped out ampule block, are of conventional design and are not detailed here for that reason. The first transfer device  32  as shown in  FIG. 5  retrieves the respective frame assembly product  10  which has been completed by the production machine and moves it to the pivoting device  34  as shown in  FIG. 6 . There the product blocks  10  which have been transported by the first transfer device  32  are transferred to the pivoting device  34  and two pivotable frame parts  66  and  68  clamp the respective frame assembly  10  securely between each other and are transferred, in this case, viewed in the direction of  FIG. 5 , from the first transfer device  32  in the right travelling position, the simultaneously shown left travelling position corresponding to the removal mode on the production machine. 
         [0040]    To insert the respective frame assembly  10  into the assignable individual receivers  64  of the first stamping device  36 , with the individual working cylinder  70 , which is the lower one viewed in the direction of  FIG. 6 , the frame parts  66  and  68  can be jointly moved horizontally in order in this way to execute a horizontal feed motion to the first stamping device  36 . Furthermore, the two frame parts  66 ,  68  with the frame assembly parts clamped between them can be moved out of the acceptance position which is vertical when viewed in the direction of  FIG. 6  by two pivoting cylinders into the horizontal insertion position in which the respective frame assembly  10  is then inserted into the assignable individual receiver  64 . 
         [0041]    If the respective pivoting cylinder  72  is then retracted, the frame part arrangement  66 ,  68  viewed in the direction of  FIG. 6  is moved clockwise around the pivoting axis  76  by way of one offset pivoting lever  74  which can be assigned at a time. When the frame part  68  at least comes to rest in its horizontal position within the first stamping device  36 , the overlying frame part  66  must be pivoted back counterclockwise in order in this way to release the respective frame assembly  10  in the first stamping device  36  for free fall motion of the free fall body  52  with the stamping device strips located right at the bottom. For the pertinent resetting motion there are three working cylinders  78  and they act on a common connecting rod  80  which passes on the edge side into one transverse connecting rod  82  at a time which, thus intermeshing with teeth  84  ( FIG. 7 ), engages a gear arrangement  86  which, regardless of the actuating state of the pivoting axis  76 , allows the frame part  66  located right at the front, viewed in the direction of looking at  FIG. 6 , to pivot back. 
         [0042]    For the feed motion of the frame part  66  to the vertically positioned frame part  68  as shown in  FIG. 6 , in order to clamp the frame assembly which has been delivered with the first transfer means  32  in a triple arrangement, the working cylinders  78  jointly retract and the frame part  66  is thus pivoted counterclockwise in the direction of the frame part  68 . In the process, the common connecting rod  80  to which the working cylinders  78  are coupled on the face side with their actuating pistons entrains the two transverse connecting rods  82  which are located at a right angle on the edge side and which when viewed in the direction of  FIG. 7  are extended perpendicular to the plane of the figure in the direction of the viewer. In doing so, gear arrangement  86  moves clockwise in the pivoting direction. In the extension motion of the individual working cylinders  78 , the frame part  66  is folded back against the aforementioned pivoting direction and, accordingly, counterclockwise in the direction of the connecting rod  80  which extends transversely thereto. Furthermore, as shown in  FIG. 6 , there are damper elements  88  on the frame part  66  which damp the striking of the frame part  66  against frame part  68  and form a type of gap boundary for the clamping head-side receiver of the respective frame assembly  10 . 
         [0043]    With simultaneous retraction motion of the working cylinders  78  and of the pivoting cylinders  72 , the two frame parts  66 ,  68  then move clockwise clamped to one another toward the first stamping device  36  for the transfer process. The pertinent pivoting transfer motion can still be coupled to the axial lengthwise travelling motion of the overall carriage or frame arrangement by way of the individual working cylinder  70  which then travels in the direction of the first stamping device  36 . Essentially,  FIG. 7  shows a lengthwise section through the receiving block  90  which is the left one viewed in the direction of  FIG. 6  and which, in addition to the pivoting axis  76 , also holds the gear arrangement  86  along with the transverse connecting rod  76 . On the lower base end, block  9  separates the two frame parts  66 ,  68  from one another. The gear arrangement  86  is pivotally guided in the receiving block  90  as a pivoting sleeve and is firmly connected to the frame part  66 . 
         [0044]    The second transfer device  38  shown in  FIG. 9  then retrieves from the first stamping device  36 , as shown in  FIG. 8 , the remaining frame assembly  10  from which in this case the bottom side frame waste  26  has been removed, and inserts the pertinent parts into the assignable individual receivers  64  of the second stamping device  40  in which then the head-side frame waste  28  is removed. In the next transfer step then the finished container products  12  connected by way of intermediate wall webs  16  are deposited in the removal station  42  for packaging delivery and at the same time a new frame assembly  10  in a triple arrangement is retrieved again and the bottom-side frame waste  26  is removed from it. The second transfer device  38  as shown in  FIG. 9 , accordingly, works in the manner of a two-cycle arrangement with simultaneous operation of several stations. 
         [0045]    With the separating device according to the invention, due to the modular structure, a good spatial situation arises for use of diverse transfer and pivoting devices for individual stamping machines. Due to the modular nature, simple retrofitting is achieved by clear separation of standard parts and format parts, and there remains enough space for additional options to further expand the separating device or to be able to adapt it suitably within production lines. 
         [0046]    While one embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the claims.