Abstract:
A stamping device stamps characteristic data, especially in the form of code numbers ( 22 ), into plastic products. Such containers are preferably produced according to blowing, filling and gelling methods. At least one stamp ( 32 ), having a stamping unit ( 34 ) with interchangeable characteristic data units ( 42 ), is guided in the longitudinal direction in the frame ( 24 ) of the device. When the stamp is in an elevated position, the products to be stamped and/or have been stamped can be fed or removed. When in a lowered position, the products are stamped.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a stamping device for stamping identification data, especially in the form of code numerals, in plastic products such as containers which have been produced preferably by a blow-fill-seal process. 
   BACKGROUND OF THE INVENTION 
   Processes and molding devices for production of containers have been disclosed in the prior art (DE 199 26 329 A1). A tube of plasticized plastic material is extruded into a molding device. One end of the tube is closed by welding. A pneumatic pressure gradient acting on the hose is generated to expand the hose and is applied for the purpose of forming the container on a shaping wall of the molding device consisting of two form tools positioned opposite each other. A suitable filling mandrel is then used to fill the plastic container under sterile conditions. After the filling mandrel has been removed, the container is hermetically sealed with a definable head geometry being formed. Two container shaping jaws are moved toward each other by hydraulic or electromotive drive means to obtain a closed position and away from each other and into an open position to obtain the plastic container itself in which fluid is subsequently stored. 
   The head geometries generated by the two separately controlled jaws also generally include the neck element of the plastic container, including one in the form of an ampule. The ampule is closed by a head piece and may be opened at a separation point for removal of fluid after the head piece has been separated by a toggle element molded on it over the separation point, and thus, removed from the plastic container proper. 
   Processes and devices for execution of these processes have been disclosed in a plurality of embodiments and are widely used in packaging systems for liquid or paste products, as for example in the well-known Bottelpack® system. 
   EP 0 359 971 B1 discloses a comparable blow-fill-seal process for production of hollow containers of plastic. Two halves are molded and welded together in a tool. A frame-shaped hollow element is molded and welded in the same way as the containers themselves from a waste edge zone of the containers (ampules). The containers are configured in sequence in a strip. 
   In the above disclosed processes, the possibility exists of applying identification data, especially in the form of code numerals. Among other things, that data may indicate the place and date of production, the contents, the amount contained in the respective container and any expiration dates of the contents of a container. Placement of the data can be on the toggle element itself by which the sealing head piece is separated from the container for the process of removal of the contents or in the area of the edge waste zone surrounding the respective container and sold with the respective container as a sale unit. The respective identification data may also be present uncoded as information for end users, but are predominantly present in coded form for presentation of information content to producer and intermediate purchaser circles, and are applied in the disclosed processes in the production machine itself. The code numerals are fitted into the molding halves before the blow-fill-seal process is carried out so that the code numerals may be impressed into the respective container directly in the molding process. Since the production machines involved may easily have ten or more single-use molds, it may take several hours or even an entire day to replace the code numerals in the form of die plates or individual type which are to be fitted into the mold. Such expenditure of time is necessary in particular if one production machine is to apply different code numerals to the various molds as required by the production process. Since application of the code numerals inside the molds by hand is a very complicated process, it is also possible that a single error, such as application of an incorrect code numeral in the mold, may make it necessary to halt the production process and dispose all the containers produced up to that point by the production machine in the process. In such exchange processes the machine for producing the containers is not available, resulting in high operating costs. 
   SUMMARY OF THE INVENTION 
   Objects of the present invention are to provide improved molding processes and devices where an exchange process of the identification data for plastic containers may be carried out in a simple and cost-effective manner, and especially so that the production process itself for plastic containers is not impaired as a result. 
   These objects are basically attained by a stamping device for stamping identification data, especially in the form of code numerals, in plastic products such as containers produced by a blow-fill-seal process. A frame of the device comprises at least one stamp having a stamping unit with replaceable identification data mounted so that it may be displaced horizontally. When in a raised position, products can be moved toward and away from the stamping unit, which products are to be stamped or have been stamped. When in a lowered position, the stamping unit effects stamping of the products. 
   The stamping device is mounted outside the production machine proper for execution of the blow-fill-seal process. The containers are first fully produced, filled, and sealed before they are moved further to the stamping device for stamping of identification data. The stamping device of the present invention, with its frame structure and the stamp, permits very high rates of output of goods to be stamped. As a rule, the stamping process may basically be disconnected from the production process proper in time and space by the stamping device. In addition, because of its frame structure the stamping device is very easily accessible from the exterior, and a process of exchange of identification data for the containers (ampules) in rapid succession and with little adjustment effort may be achieved. The latter is a factor in particular if, as a result of incorrect selection of code numerals, the stamping processes must be interrupted and the incorrect code numerals, replaced with the correct ones. From the viewpoint of safety engineering the stamping device is easy to control. When supplemented by safety engineering system elements, it may help prevent hazardous conditions for operating personnel. 
   In one preferred embodiment of the stamping device of the present invention, the plastic material and/or the stamping unit is/are heated for stamping of the identification data. Thus, the residual heat of the plastic product following application of heat and pressure in the process of its production may be used for stamping by the stamping unit. It is also possible, however, to heat the stamping unit additionally to stamp the identification data required in the cooled plastic product with the heated stamping unit. 
   It has been found to be especially advantageous to deliver and remove the plastic product in the direction transverse to that of stamping with the stamp and to employ a stamp support supporting the plastic product. The stamp support is moved simultaneously with the stamp or desynchronized from it in the opposite direction of movement. This configuration makes it possible to operate the production machine at high speeds of output of plastic products safely and at the same speed of production as that of the machine. 
   In another preferred embodiment of the stamping device of the present invention, the frame has columnar guides for longitudinal movement of the plate-like stamping unit and a support plate for the stamp. The frame structure of the stamping device is reinforced by the columnar guides, so that high accuracy may be achieved in stamping processes, along with clearly recognizable identification data. In addition, the stamping forces generated by the stamping process are reliably transmitted to the frame of the stamping device by the columnar guides. Preferably, the plate-like stamping unit and the support plate are adjacent to and face each other and the piston rods of the stamping plate and the support plate engage the associated plate. Their housing element is rigidly connected to the frame. In this way, the base structure of the frame with the columnar guides may be additionally rigidified by the housing element stamp configured as an operating cylinder. Hydraulic or pneumatic cylinders, as well as electric motor operators with spindle drives, may be employed as operating cylinders for the stamp and stamp support. 
   In another preferred embodiment of stamping device of the present invention, a guide plate is connected to the frame by a columnar suspension and mounted between the plate-like stamping unit and support plate. This guide plate guides the plastic products for a stamping process within the frame. The guide plate makes certain that the plastic products to be stamped reach a precisely definable stamping position inside the stamping device and that components not provided for stamping do not inadvertently undergo the stamping process and possibly are damaged. In addition, the guide plate together with the support plate serves as a support for the plastic product during the stamping process. 
   To allow the greatest possible number of stamping processes to be carried out with the plastic products, in one preferred embodiment of the stamping device of the present invention, the plastic products in the form of ampules are configured as containers connected to each other in a strip by a (waste) edge zone, and are stamped in succession with several adjacent ampules being provided simultaneously with the stamp. 
   Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, disclose a preferred embodiment of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring to the drawings which form a part of this disclosure: 
       FIG. 1  is a side elevational view of the basic components of a stamping device according to an embodiment of the present invention, as seen in the direction of the arrow X in  FIG. 2 ; 
       FIG. 2  is a front elevational view of the stamping device of  FIG. 1 , as seen in the direction of the arrow Y in  FIG. 1 ; 
       FIG. 3  is a top plan view of a strip of (three) containers in succession with toggle elements as sealing pieces on the head side provided with identification data with the spaces identified by X provided with any desired code numerals or letters or also ones in decoded form, according to the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The plastic product shown in  FIG. 3  has three containers  10  interconnected in sequence in a strip by an edge zone  12 , also of plastic. The interior  14  of the container  10  is filled with a fluid such as one in the form of a pharmaceutical preparation or the like. A neck element  16  is sealed by a toggle seal or a toggle seal element  20 . A separation point  18  facilitates the opening of the container. The edge waste zone of flat plastic material possibly still present between edge zone  12  with neck element and the toggle seals  20  as shown in  FIG. 3  is removed, preferably by punching. The toggle seal  20  is configured to be flat and permits easy opening of the container  10  by manual separation (rotation) of the toggle seal by the separation point  18  from the associated neck element  16 . 
   Such containers  10  are produced by the above disclosed processes and molding devices (not shown), ones in which a tube of plasticized material is extruded into a molding device. One end of the tube is sealed by heat sealing. As a result of generation of a pneumatic pressure gradient acting on the tube, the tube is expanded and applied to a shaping wall of the molding device having two opposite molding tools (not shown) for the purpose of forming the container. The plastic container  10  is then filled under sterile conditions in the molding device by a suitable filling mandrel (not shown). After the filling mandrel has been removed, the tube is then hermetically sealed to form the definable head geometry illustrated in  FIG. 3 . Such processes and molding devices are of the prior art and are described, for example, in DE 199 26 329 A1 and in EP 0 359 971 B1, and accordingly, will not be discussed further here. 
   Code numerals  22  are applied to the surfaces of the toggle seal elements  20 . Crosses or the letter X are used as placeholders to indicate the spaces reserved for the identification data in the form of code numerals. In place of the placeholders indicated by X, any identification and manufacturing data can be used and may provide information as numbers or numerals in coded form to experts at large. Such information may relate to the place and mode of production, expiration dates, fluid contents, etc. The code numerals  22  may also provide information to end users in uncoded form concerning expiration dates, names of manufacturers, or the like. The possibility also exists of dying the code numerals  22  to attract the attention of the user to the display field containing the identification data. In addition, illustrations such as pictographs, for example, may be used to indicate clearly that the contents or the like are to be administered only orally. Directions for use or parts of them may also be reproduced by stamping in the identification data field. 
   The stamping device by means for applying identification data, such as code numerals  22 , to container elements will now be described with reference to  FIGS. 1 and 2 . Application of the code numerals  22  to the toggle seals  20  as shown in  FIG. 3  is presented exclusively by example. Thus, for example, the identification data may also be applied to edge zones and waste edge zones in conjunction with the containers  10 , or the identification data may be applied directly to the container  10  in areas which include the interior of the container  10  with its fluid or other medium. In the latter case, the stamping processes are to be conducted with suitable care to prevent stamping through the container  10 , something which might cause the contents of the container to be unusable. A plurality of potential container configurations can be used with the present invention, including ampules or syringes, so that the exemplary embodiment shown in  FIG. 3  represents only one option among a decidedly large number of alternatives for containers produced by the blow-fill-seal process. 
   The stamping device shown in  FIGS. 1 and 2  for stamping identification data, especially those in the form of code numerals  22 , in plastic products such as containers  10  or ampules produced preferably by a blow-fill-seal process, has a frame  24  made up of longitudinal supports  26  and transverse supports  28 . Only part of the frame elements is shown in the illustration in order that the essential components of the device may be more clearly illustrated. The frame  24  may have longitudinal supports  26  and transverse supports  28 , but may also have individual spars which are welded together, joined by a threaded connection, or riveted to each other and optionally further reinforced by crossarm braces  30  to form a kind of box-type frame in which the movable machine elements of the stamping device are received and fastened. 
   A stamp  32  with a plate-like stamping unit or stamping plate  34  is mounted in the frame  24  of the device. This stamp  32  is configured as a working cylinder and is provided with a retractable and extensible piston rod  36 . The free end of rod  36  engages the plate-like stamping unit  34 . The housing element  38  of the working cylinder (stamp  32 ) is mounted on a frame plate  40 , which, as viewed in  FIG. 2 , extends in parallel with the upper transverse support  28  and is held by the two longitudinal supports  26  a specific distance vertically from the transverse support  28 . The stamping unit  34  has, on its lower side, identification data units  42  designed to be replaceable. That is, individual code numerals  22  or letters or even pictoral symbols may be replaced as individual type or die plates as parts of the strip of identification data. The identification data may be configured as groups of information content positioned side by side or one above the other so that the stamped image is in the form of an identification data field, as is shown in  FIG. 3  for the plastic product, X identifying the empty space holders or data. 
   When the stamp  32  with stamping unit  34  and identification data units  42  has been raised, the products such as the containers  10  to be stamped are placed in position in the stamping device and/or stamped products are removed from the stamping device. The stamping process itself is carried out with the stamp  32  lowered as shown in  FIGS. 1 and 2 . The identification data units  42  are then in contact with the identification data field, in this instance with the flat parts of the toggle seal  20  as illustrated in  FIG. 3 . 
   For the purpose of stamping the identification data, the plastic product is heated as a function of production or the stamping unit  34  is heated by a heating unit (not shown). In addition, the direction of delivery and removal of the plastic product is indicated in  FIG. 1  by an arrow Z. Accordingly, unstamped products as viewed in  FIG. 1  move from the left through the stamping unit  34  in the center of the device to be stamped. After being stamped, the products move to the right from the stamping device for further handling, for example, to a packing machine (not shown). Consequently, the direction Z of delivery and removal of the plastic product is oriented transversely to the direction of stamping with the stamp  32 , which moves the stamping unit  34  vertically along the longitudinal axis  44  of the device as viewed in  FIGS. 1 and 2  (see  FIG. 2 ). 
   As shown in the illustrations, a support stamp  46  is provided, and may be moved in the opposite direction simultaneously or desynchronized from the stamp  32 . The support stamp  46  also has a working cylinder operated by hydraulic, pneumatic, or electric means and having a piston rod  48 . The free end of piston rod  48  is mounted to the support plate  50  with a support element  52  positioned on it. In addition, the support stamp  46  has a housing element  54  rigidly connected to a lower frame plate  56 . The linear movement of the support stamp  46  is also oriented in directions along the longitudinal axis  44  of the stamping device as a whole. Inside the frame  24 , four columnar guides or guide columns  58  extend in parallel with the longitudinal axis  44  of the stamping device. The free ends of columnar guides  58  are mounted in pairs in the upper frame plate  40  and the lower frame plate  56 . Both the plate-like stamping unit  34  and the support plate  50 , with their rectangular cross-sections, are mounted by guide sleeves  60  on the columnar guides  58 . When the stamp  32  and support stamp  46  are moved into and out of position, the plates move along with them, while the housing elements  38  and  54  are kept stationary in the frame  24 . 
   In  FIG. 1 , in the respective side view, the columnar guides  58  are mounted immediately adjacent to the stamp  32  and support stamp  46  so that rigidification of the stamping device as a total system is largely achieved. The plate-like stamping unit  34  and the support plate  50  are adjacent and face each other. The piston rods  36  and  48  of the stamp  32  and support stamp  46  engage the stamping unit  34  and support plate  50 . Their housing elements  38  and  54  are mounted on the frame  24  so as to be stationary. A guide plate  64  is rigidly connected to the frame  24  by a column suspension  62  having four columns. This guide plate  64  is mounted between plate-like stamping unit  34  and support plate  50  and guides the plastic products, as shown by example in  FIG. 3 , for a process of stamping with the identification data inside the frame  24 . Additional rigidification of the overall stamping device system is achieved by guide plate  64 . The containers  10  may be guided with precision through the suspended guide plate  64  so that blurred stampings or erroneous stampings may be reliably prevented. 
   The configuration of stamping unit  34  and support stamp  46  may also be reversed inside the device. Optionally, the support stamp  46  may be designed as another stamping unit if stamping of plastic products on both sides inside the stamping device is desired. The stamping temperature selected for the respective plastic product is to be one which permits a reliable stamping process without damage to the plastic material, such as by running or burning. The stamping temperatures may accordingly be varied as a function of the plastic material employed and the strength of the material used for the plastic product. 
   The stamping device illustrated in  FIGS. 1 and 2  may be connected in series to a production machine, in particular for a blow-fill-seal process with plastic products. The amounts of product obtained from the production machine may be conducted more or less continuously through the stamping station and provided with stamps. The stamping device may optionally be combined with a punching unit (not shown) which removes a possible edge waste zone from the respective plastic product. The option also exists, however, of mounting the stamping device between a production machine and a punching unit. The timing selected may be such that the plastic products produced are punched when the conveyor chain for these products is halted. Stamping of the respective plastic product is effected at the preceding or upstream station. The possibility also exists of subjecting the stamping to optoelectronic monitoring to determine if the stamp is complete and easy to read. Should this quality criterion not be met, the plastic products found not to meet it may be removed as defective elements from subsequent or downstream movement in the direction of the packaging station. 
   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 appended claims.