Abstract:
The invention relates to a filling system for filling bottles, cans, or similar containers ( 2 ) with a liquid filling good, comprising at least one filling element ( 1, 1   a ) having at least one dispensing opening ( 7 ) for introducing the filling good into the particular container ( 2 ) in a controlled manner, means ( 10 ) for retaining and pressing the particular container ( 2 ) having a container opening ( 2.1 ) in a sealing position against the filling element ( 1, 1   a ) in the area of the dispensing opening ( 7 ), at least one pneumatic device ( 15.1, 16.1, 19 ) for producing at least one component of the press-on force, which pneumatic device can be exposed to the pressure (P 1 ) of a gaseous and/or vaporous operating medium. In order to change and/or set the press-on force, a second component of said force is produced by a further hydraulic or pneumatic device ( 15.2, 16.2, 20 ), which is exposed to a variable or settable pressure (P 2 , P 3 , P 5 ) of a liquid and/or gaseous and/or vaporous auxiliary medium preferably different from the process medium or is exposed to a vacuum (VAK).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is the national stage entry, under 35 USC 371, of PCT/EP2010/007006, filed Nov. 18, 2010, which, under 35 USC 119, claims the benefit of the priority date of German application no. 10 2010 007 288.5, filed Feb. 8, 2010. The contents of both applications are incorporated herein in their entirety. 
     FIELD OF DISCLOSURE 
     The invention relates to container filling, and in particular, to controlled introduction of liquid goods into a container. 
     BACKGROUND 
     Methods and filling systems for filling containers and in particular for the pressurized filling of containers (filling of containers under stressing or filling pressure) with a liquid filling good, for example with a carbonated filling good or drink, are known in different embodiments, including in the form of rotary filling machines in particular. Here, at least during one phase of a filling process, in particular during the actual filling phase in which the filling of the container pre-stressed with the stressing pressure or filling pressure takes place, and/or during a stress phase and/or pre-stress phase preceding the filling phase, the respective container is pressed by a press-on force with a mouth edge surrounding its container opening tightly or in sealing position up against the filling element in the region of a dispensing opening located there for the liquid filling good. 
     It is also known in particular (EP 1 520 833 B1) that the press-on force can be produced by a pneumatic device, e.g. in the form of a pneumatic piston/cylinder arrangement, which is part of a lifting device for a container carrier carrying or holding the respective container during the filling process and pressing it against the filling element and which is subjected to the pressure (clamping or filling pressure) of a gaseous and/or vaporous process medium that is used during the filling process and being in the form of an inert gas used as a purging and/or stressing and/or pre-stressing gas. The filling system and/or the corresponding filling machine exhibit a plurality of filling elements each having a container carrier and associated lifting device. 
     One basic advantage of such a filling system lies in a simplified control of the lifting devices for the container carriers and also in particular in a reduction of the number of, and/or the load on, control elements on the filling element side, for example cam rollers that, in interaction with at least one static control cam, ensure the condition of the container carriers when lowered from the filling element at the container entry as well as at the container exit of the filling machine for transferring the empty containers to the filling elements or to the container carriers located there, and for removing the filled containers from the container carriers. 
     A disadvantage of such filling systems, however, is that the pressure of the purging and/or stressing and/or pre-stressing gas is predetermined by process parameters, in particular by parameters specific to the filling good, such as its nature, its CO 2  content, and its temperature, and also by machine-related parameters, such as the throughput of the filling machine (filled containers per unit of time etc.). This pressure cannot easily be altered or can at best only be altered within certain limits. 
     If containers with different mouth diameters, for example bottles with mouth diameters of 28, 30 or 38 mm, are now to be filled on one and the same filling machine, then the pneumatic device that produces the press-on force must be designed to supply the clamping or press-on force that is sufficient for the containers with the biggest mouth diameter while taking into account the filling or stressing pressure. This also means, however, that this press-on force far exceeds the level required for containers with a smaller mouth diameter. This results in excessive press-on force exerting an unnecessarily high mechanical load on containers with a smaller mouth diameter. This can destroy or at least damage the containers, especially thin-walled containers and/or containers made from plastic. 
     SUMMARY 
     The task of the invention is to propose a method that allows a setting or alteration or adjustment of the respective press-on force while retaining the fundamental advantages offered by producing the press-on force from the pressure of the gaseous and/or vaporous process medium. 
     A gaseous and/or vaporous auxiliary medium with which the further component of the respective press-on force is produced and whose pressure acting at least in the further pneumatic device is settable and/or variable, is for example air, preferably sterile air. 
     The auxiliary medium can, of course, also be a liquid, for example, water, preferably sterile water, or in certain applications even the filling good itself. For the purpose of the present invention therefore the term “auxiliary medium” is to be understood expressly as a fluid auxiliary medium. Express reference to the possibly of liquid auxiliary medium will be dispensed with hereinbelow merely to simplify readability and without in any way limiting the scope of protection. 
     The gaseous and/or vaporous process medium is the medium with which the containers are treated and/or pressurized during the filling process, for example the purging, stressing and/or pre-stressing gas in the form of inert gas, e.g. in the form of CO 2  gas or a gaseous or vaporous medium for sterilizing the containers prior to filling. The process medium, in the sense of the invention, is, however, also a cleaning and/or sterilization medium used for cleaning and/or sterilization of the filling system, preferentially for a CIP cleaning and/or sterilization of the filling system. 
     The inventive method or inventive filling system is preferably configured so that the first component, which is produced by the pressure of the process medium, of the press-on force is greater than the component produced by the pressure of the auxiliary medium. 
     If the filling system is part of a rotary filling machine having a plurality of filling elements with attendant container carriers, then the control is effected, for example, such that the further pneumatic devices of all filling elements are constantly subjected to that pressure of the auxiliary medium that provides the desired or necessary clamping force, and that the container carriers at the container entry and at the container exit are moved by control cams into a lower lifting position against the action of the further pneumatic devices. 
     The setting and/or regulating of the pressure of both the process medium and auxiliary medium is preferentially effected by electro-pneumatic regulators, for example as a function of data or programs stored in an electronic control system (e.g. process controller) of the filling system or filling machine, or as a function of product-related and machine-related parameters. 
     Further embodiments, advantages, and possible applications of the invention arise out of the following description of embodiments and out of the figures. All of the described and/or pictorially represented attributes, whether alone or in any desired combination, are fundamentally the subject matter of the invention independently of their synopsis in the claims or a retroactive application thereof. The content of the claims is also made an integral part of the description. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The invention is explained in detail below through the use of embodiment examples with reference to the figures. In the figures: 
         FIGS. 1-4  each show different operating states of a filling element of a filling system or of a filling machine for the pressurized filling of containers; and 
         FIG. 5  shows a simplified partial view of further embodiment of a filling element. 
     
    
    
     DETAILED DESCRIPTION 
     The filling element generally identified by “ 1 ” in  FIGS. 1-4  is part of a filling system or rotary filling machine for filling containers, for example bottles  2 , under pressure with a liquid filling good, e.g. with a carbonated filling good or drink. Filling element  1  is arranged with a plurality of identical filling elements on the periphery of a rotor that can be driven to rotate about the vertical machine axis and of which a filling good tank or ring tank  3  is only very schematically shown in  FIG. 1 . During the filling operation, the latter is partly filled with the liquid filling good that is to be introduced into bottles  2  via filling elements  1 , so that a lower liquid space  3 . 1  occupied by the filling good and an upper gas space  3 . 2  are formed in the interior of ring tank  3 . This gas space is occupied by a gaseous or vaporous process medium, e.g. inert gas or CO 2  gas, to which a pressure P 1  (clamping or filling pressure) is applied. Inside a housing  4  of filling element  1 , there is configured, inter alia, a liquid channel  5  in which, inter alia, a liquid valve  6  is disposed for the controlled dispensing of the liquid filling good into respective bottle  2  and that, in the direction of flow of the filling good, is connected upstream of liquid valve  6  to a liquid space  3 . 1  of the ring tank  3  and, in the direction of flow of the liquid filling good, opens out downstream of liquid valve  6  into a dispensing opening  7  on the underside of filling element  1  or of filling element housing  4 . Dispensing opening  7  is enclosed by a ring seal  9 , which is disposed in a centering tulip  8  and concentrically encloses filling element axis FA, and against which, during filling, the respective bottle  2  arranged with its bottle axis on the same axis as axis FA lies pressed with a mouth edge  2 . 1  surrounding the bottle opening. 
     Pressure P 1  is set and regulated as a function of the nature and/or temperature of the filling good, for example as a function of the CO 2  content of the filling good, for example by an electropneumatic regulator as a function of data or programs stored in an electronic control device (process controller) of the filling machine. 
     Each filling element  1  is, moreover, associated with a container carrier  10  that, in the depicted embodiment, is designed to hold bottles  2  suspended, i.e. to hold bottles  2  by a mouth flange  2 . 2 . Container carrier  10  is attached at the lower end of two guide rods  11  that it interconnects and that, in their longitudinal extension, are arranged parallel with one another and with axis FA on either side of that axis, and can be displaced axially in filling element housing  4 . At their upper end, protruding above the filling element housing  4 , the guide rods  11  are interconnected by a bearing piece  12  on which a cam roller  13  is mounted free to rotate about an axis radial to the axis of the rotational movement of the rotor or of the ring tank  3  so as to interact with a control cam  14  that is static, i.e. that does not rotate with the rotor or with ring tank  3 . On the underside, facing away from the cam roller  13 , there acts on bearing piece  12  a piston  15  that is configured as a stepped piston having two piston sections  15 . 1  and  15 . 2 . Of the latter, piston section  15 . 1 , with the lesser diameter, is provided in a cylinder space  16 . 1  and piston section  15 . 2 , with the greater diameter, is provided in an annular cylinder space  16 . 2  that surrounds piston section  15 . 1 , both piston sections being displaceable axially, i.e. in the direction of axis FA. Cylinder space  16 . 2  is stepped in design, having a greater diameter in its upper region and having a reduced diameter in its lower region, such that within cylinder space  16 . 2  there is formed a stop or collar  17  against which piston section  15 . 2  is in contact when piston  15  is fully lowered in the direction of the filling element underside. 
     At least during the pressurized filling of respective bottle  2 , cylinder space  16 . 1  is pressurized with pressure P 1  from gas space  3 . 2  of ring tank  3  so that piston  15  moves upward and/or is pre-stressed by pressure P 1  present in cylinder space  16 . 1  and as a result respective bottle  2  is pressed with its bottle mouth  2 . 1  against ring seal  9  by piston  15 , bearing element  12 , the two guide rods  11  and container carrier  10 . Into cylinder space  16 . 1  also emerges the upper end of a gas pipe  6 . 1  arranged on the same axis as axis FA and also serving as a valve stem for the valve body of liquid valve  6 , the lower open end of the gas pipe reaching the interior of bottle  2  in sealed position with the filling element so that the latter is also pre-stressed with inert gas pressure P 1  at least during filling. 
     Pressure P 1  is predetermined by various filling and/or system parameters, for example by the temperature and/or the nature and/or the inert gas or CO 2  gas content of the liquid filling good, so that the press-on force produced by the piston/cylinder arrangement consisting of piston section  15 . 1  and cylinder space  16 . 1  is not freely variable and is, in particular, not variable for adjusting the press-on force to containers or bottles with different diameters in the region of the container or bottle mouth  2 . 1 . 
     Piston section  15 . 2  and cylinder space  16 . 2  together form a piston/cylinder arrangement that, despite the constant or generally constant pressure P 1 , permits a variation or setting of the press-on force with which the respective bottle  2  lies pressed with its mouth edge  2 . 1  against seal  9 . For this purpose, cylinder space  16 . 2  can be pressurized with a liquid, and/or gaseous, and/or vaporous auxiliary medium, for example air, preferentially sterile air, with a variable pressure P 2 , so that the press-on force is generally a function of pressures P 1  and P 2  and by changing pressure P 2  is variable and/or adaptable to particular requirements, in particular also to the respective mouth diameter D 1  of the container or of bottle  2  in the region of bottle mouth  2 . 1 . 
     Simplified control and improved operational reliability for filling elements  1  are obtained, inter alia, by the production from inert gas pressure P 1  of the press-on force with which respective bottle  2  lies pressed against ring seal  9 , at least during pressurized filling. An advantage of generating the preferentially greater component of the press-on force from pressure P 1  of the process medium (purging gas and/or stressing gas and/or pre-stressing gas), e.g. inert or CO 2  gas, is also that the respective cylinder space  16 . 1  is depressurized in the region both of the container or bottle entry and container and bottle exit, thereby reducing the load on cam rollers  13  interacting with control cam  14  with lowered container carriers  10  within the angular range of the rotary motion of the rotor between container exit and container entry. 
       FIG. 1  shows filling element  1  together with a bottle  2  that is in sealed position against it and that has a lesser mouth diameter D 1 , e.g. a bottle having a mouth diameter D 1  of 28 mm. Only the press-on force produced by pressure P 1  (stressing or filling pressure) via piston section  15 . 1  is used for pressing-on these bottles  2 , for example, at most with minimal support from the press-on force produced by piston section  15 . 2 . 
       FIG. 2  shows filling element  1  for filling bottles  2  that have a considerably greater mouth diameter D 2  at their mouth edge. For filling these bottles  2 , centering tulips  8  with seal  9  are preferentially exchanged for centering tulip  8   a  with ring seals  9   a  that (centering tulips) exhibit a somewhat larger inside cross-section. The press-on force that is produced by piston section  15 . 1  and that is additionally produced by piston section  15 . 2  is used to press bottles  2  against respective filling element  1  during pressurized filling, with cylinder space  16 . 2  being pressurized by pressure P 3  of the vaporous or gaseous auxiliary medium. Pressure P 3  of the auxiliary medium may be greater or less than pressure P 2 . In any event, pressure P 3  is set so that its force effect is sufficient to produce the necessary additional press-on force. 
       FIG. 3  shows filling element  1  in a position preparing a CIP cleaning and/or disinfection of the filling system, in which (position) sealing or purging plates  18  are seated onto the lowered container carriers  10  of the filling elements. Interaction of control cam  14  with respective control roller  13  ensures that when sealing or purging plate  18  is seated, container carrier  10  of each filling element  1  is in the lowest position in which piston section  15 . 2  is in contact against collar  17 , which acts as a stop. 
     In order to receive, at a bottle entry of the filling machine, the respective empty bottle  2  that is to be filled and to remove the respective filled bottle at a bottle exit of the filling machine, respective container carrier  10  with bottle is lowered, for example, into a position where piston  15  is lying with its piston section  15 . 2  against collar  17 . The lowered state is attained or ensured by the interaction of respective cam roller  13  with control cam  14 . Alternatively however the lowered state of respective container carrier  10  can also be attained or at least ensured by applying a vacuum VAK to cylinder space  16 . 2 . This approach places piston  15 , as shown in  FIG. 3 , in the lowest possible position. 
       FIG. 4  shows filling element  1  in a state in which, with the help of the raised container carrier  10 , the sealing or purging plate  18  lies sealed with its seal provided on the top of the plate up against the edge of centering tulip  8   a , thereby forming a purging space that is inside centering tulip  8   a  and sealed to the environment. The necessary press-on force is achieved through pressure P 4 , present in cylinder space  16 . 1 , of the medium used for the CIP cleaning and/or disinfection and in particular by pressurizing cylinder space  16 . 2  with auxiliary medium at pressure P 5 . 
       FIG. 5  shows a schematic partial view of a filling element  1   a  that differs from filling element  1  in that, to produce the component of the press-on force that results from pressure P 1 , there is provided a bellows  19  that, during the pressurized filling, is pressurized with pressure P 1  and that acts between the top of filling element housing  4  and the bottom of bearing piece  12 . As well as bellows  19 , there is provided a piston/cylinder arrangement  20  for producing the component of the press-on force resulting from the auxiliary medium pressure. In the depicted embodiment, piston/cylinder arrangement  20  consists of an annular piston  21  that concentrically encloses axis FA and the axis of bellows  19  and with which is associated an annular cylinder space  22 . The latter can be pressurized with the pressure of the auxiliary medium, for example with pressure P 2 , P 3 , P 5 , or with vacuum VAK. Instead of annular piston  21  and annular cylinder space  22  in which annular piston  21  is displaceable axially i.e. along axis FA, the piston/cylinder arrangement provided additionally to bellows  19  and also acting between the top of filling element housing  4  and bearing piece  12  can also be otherwise configured, for example comprising two circular cylinder spaces radially offset relative to bellows  19 , with an associated piston. 
     The invention has been described above by reference to embodiments. It goes without saying that numerous variations as well as modifications are possible without departing from the inventive concept underlying the invention. 
     LIST OF REFERENCE SIGNS 
     
         
         
           
               1 ,  1   a  Filling element 
               2  Bottle 
               2 . 1  Mouth edge 
               2 . 2  Mouth flange 
               3  Ring tank 
               3 . 1  Liquid or filling good space 
               3 . 2  Gas space 
               4  Filling element housing 
               5  Liquid channel 
               6  Liquid valve 
               6 . 1  Valve stem or gas pipe 
               7  Dispensing opening 
               8  Centering tulip 
               8   a  Centering tulip 
               9  Ring seal 
               9   a  Ring seal 
               10  Container carrier 
               11  Guide rod 
               12  Bearing piece 
               13  Cam roller 
               14  Control cam 
               15  Stepped piston 
               15 . 1  Piston section 
               15 . 2  Piston section 
               16  Stepped cylinder 
               16 . 1  Cylinder space 
               16 . 2  Cylinder space 
               17  Collar 
               18  Sealing or purging plate 
               19  Bellows 
               20  Piston/cylinder arrangement 
               21  Annular piston 
               22  Cylinder space 
             FA Filling element axis 
             D 1  Mouth diameter 
             D 2  Mouth diameter