Abstract:
A filling machine includes a filling element that has a liquid channel, a liquid valve, controlled gas paths, and a probe having a channel and an opening. The channel connects to a tank of filling material. A filter in a gas path traps contaminants. During filling, the liquid valve introduces filling material into a container, the first gas path connects to an interior space of the container, and the probe&#39;s position determines a fill level in the container.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims is the national stage under §371 of PCT/EP2012/004288, filed on Oct. 12, 2012, which claims the benefit of the Oct. 20, 2011 priority date of German application DE 102011116469.7, the contents of which are herein incorporated by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    The invention relates to filling containers, and in particular, to filling containers with the correct amount of liquid filling material. 
       BACKGROUND 
       [0003]    Two methods are known for setting a precise target fill level inside a container during filling. These are: the Trinox method and the vacuum filling method. Common to both methods is that a pipe-shaped probe is used on the filling element to determine fill level. The probe includes a gas return pipe and extends into the container during the filling with at least one lower probe opening. In both methods, the container is initially overfilled so that, during a filling phase, the lower probe opening is submerged below the filling material level. After the filling phase, which ends with the closing of the liquid valve of the filling element, a fill-level correction phase begins. During this phase, overfilled filling material is removed from the container through the probe and returned to the filling material tank. 
         [0004]    In the Trinox method, to remove the overfilled filling material in the fill level correction phase, a sterile inert gas, for example CO2, at a pressure lying above the filling pressure or the pressure prevailing in the filling material tank, is released into a headspace of the container. This pressure forces filling material through the probe back into the filling material tank until the probe opening is outside the filling material. At this point, the target fill level is reached. A disadvantage of the Trinox method, therefore, is the additional costs due to the inert gas. 
         [0005]    In vacuum filling, which is mainly used in the filling of still products, i.e. for filling products that do not contain CO2, a negative pressure prevails in the filling material tank. After closing the liquid valve, the container is removed from its sealed seat or sealed position on the filling valve so that, in the fill-level correction phase, the filling material is returned, by suction through the probe, into the filling material tank due to the pressure difference between the pressure in the filling material tank and the pressure of the ambient air until the probe opening is outside the filling material and thus the target fill level is reached. 
         [0006]    A disadvantage of the vacuum filling method is that ambient air, and with it also possibly dirt, microorganisms, and pathogens, such as mold, and bacteria, inevitably enters the container&#39;s headspace and is thus placed into contact with the filling material. 
       SUMMARY 
       [0007]    The invention includes a method with which an exact filling of containers without filling material losses or substantially without filling material losses and of optimum quality and/or at a reduced cost is possible with a high level of operational reliability. 
         [0008]    As used herein, “container” includes cans and bottles, whether made of metal, glass and/or plastic. 
         [0009]    The phrase “container in a sealed position with the filling element” means that the container to be filled is pressed with its container mouth tight on the filling element or on a seal there, surrounding a discharge opening of the filling element. 
         [0010]    As used herein, the term “headspace” means the space within the container interior under the container opening that is not taken up by the filling material. 
         [0011]    As used herein, the terms “substantially” and “approximately” mean deviations from exact values in each case by +/−10%, and preferably by +/−5% and/or deviations in the form of changes not significant for functioning. 
         [0012]    Further developments, benefits and application possibilities of the invention arise also from the following description of examples of embodiments and from the figures. In this regard, all characteristics described and/or illustrated individually or in any combination are categorically the subject of the invention, regardless of their inclusion in the claims or reference to them. The content of the claims is also an integral part of the description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    These and other features and advantages of the invention will be apparent from the following detailed description and the accompanying figures, in which 
           [0014]      FIG. 1  is a simplified schematic representation in plan view of a filling machine according to the invention; 
           [0015]      FIG. 2  is a simplified representation of one of the filling positions of the filling machine in  FIG. 1 ; and 
           [0016]      FIG. 3  shows the filling position of  FIG. 2  in more detail. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Referring to  FIG. 1 , a filling machine  1  fills containers, such as bottles  2 , with a liquid product or filling material. The filling machine  1  comprises a rotor  3  that can be driven to rotate around a vertical machine axis 
         [0018]    MA. On the circumference of the rotor are filling positions  4 . The bottles  2  to be filled are supplied to the rotor  3  or the filling positions  4  individually by a container inlet  5 . The filled bottles  2  are removed from the rotor  3  or the filling positions  4  by a container outlet  6 . 
         [0019]      FIG. 2  shows, in more detail, one of the filling positions  4  together with an annular top rotor element  7 , concentrically enclosing the machine axis MA. On the rotor element  7  is an annular tank  8  that is common to all the filling positions  4  and that likewise concentrically encloses the machine axis MA. During the filling operation, liquid filling material partially fills the annular tank  8  up to a filling material level. The filling material level divides the annular tank  8  into a gas space  8 . 1  above the filling material level and a liquid space  8 . 2  below it. The liquid space  8 . 2  contains the liquid filling material. 
         [0020]    Each filling position  4  has a filling element  9  and a container carrier  10  arranged below the filling element  9 . In the illustrated embodiment, the container carrier  10  is a bottle plate that is coaxial with a vertical filling element axis FA. The bottle plate is moveable upwards and downwards in a controlled manner in the direction of the filling element axis FA. This movement raises and lowers a bottle  2  relative to the filling element  9 . 
         [0021]    A liquid channel  12  is formed within a housing  11  of the filling element  9 . A product pipe  13  connects a top end of the liquid channel  12  to the liquid space  8 . 2  of the annular tank  8 . On the underside of the filling element, in the area of a centering bell  14 , a bottom end of the liquid channel  12  forms a discharge opening  15  through which liquid filling material flows into a bottle  2  during the filling. Between the connection of the product pipe  13  and the discharge opening  15  is a liquid valve  16 . The liquid valve  16  can be opened and closed in a controlled manner to control the filling of the particular bottle  2  by an actuation device  17 , such as a pneumatic cylinder. 
         [0022]    The liquid valve  16  comprises a valve body  18  that is provided on a gas return pipe  19  acting as a valve plunger. The gas return pipe  19  interacts with the actuation device  17  and opens with its top open end into a gas space  20 . The gas space  20  is part of a controlled first gas path that is made in the housing  11  and connects the gas return pipe  19  to an annular channel  22  through a second control valve  21 . The latter is provided on the rotor element  7  jointly for all the filling positions  4  or filling elements  9  of the filling machine  1 . The gas return pipe  19 , which is arranged on the same axis as axis FA, projects with its lower open end above the underside of the filling element  9  so that it extends slightly into the headspace of the bottle  2 , which, for filling, is pressed with an edge  2 . 1  of its opening by the container carrier  10  into a sealed position against the filling element  9  or against an annular seal enclosing the discharge opening. 
         [0023]    Each filling element  9  comprises a height-adjustable probe  23  that can be moved in the direction of the axis FA. The height-adjustable probe  23  is formed by a length of pipe that is open at both ends, that is arranged on the same axis as axis FA, and that extends through the gas return pipe  19  and the gas space  20 , which is sealed by the top face of the housing  11 . The height-adjustable probe  23  is enclosed by the gas return pipe  19 , but at a distance from it. The resulting space forms an annular gas return channel between the inner surface of the exhaust gas pipe and the outer surface of the height-adjustable probe  23 . This annular gas return channel, which is open at both ends, opens into the gas space  20 . 
         [0024]    The height-adjustable probe  23  forms a probe channel, which is open at both ends. At its lower end, the probe channel has a lower probe opening  23 . 1 . The lower end is above the discharge opening  15  and the lower end of the gas return pipe  19 . By adjusting the height of the height-adjustable probe  23 , the target fill level of a bottle  2  can be adjusted. 
         [0025]    The end of the height-adjustable probe  23  that projects above the top of the housing  11  is connected to a first control valve  24 , which is connected by a flexible pipe  25  to the gas space  8 . 1  of the annular tank  8 . 
         [0026]    In the embodiment shown in  FIG. 2 , the filling machine  1  is made for a negative-pressure or vacuum filling method. In this method, the gas space  8 . 1  of the annular tank  8  is connected to a vacuum pump  26  so that a pressure below the ambient pressure prevails in the gas space  8 . 1  at least during the filling operation. The ring channel  22 , which is common to all the filling positions  4 , is connected to the environment by a filter unit  27 , such as an air filter. The filter unit  27  reliably removes dirt, microorganisms and pathogens, such as e.g. mold and bacteria, from the environment. 
         [0027]    It is also possible to implement a vacuum method with the filling machine  1 . 
         [0028]    The vacuum method starts with the container carrier  10  raising a bottle  2  that has been transferred to a filling position  4  so that it lies with its mouth edge  2 . 1  in a sealed position against the filling element  9  and so that the probe  23  extends into the bottle by a length corresponding to the target fill level. The first control valve  24  is then opened to evacuate the bottle  2  and to equalize pressure between the inner space of the bottle  2  and the gas space  8 . 1  of the annular tank  8 . Following this, with the first control valve  24  still open, the liquid valve  12  is opened. This begins the filling phase. 
         [0029]    During the filling phase, liquid filling material flows through the discharge opening  15  into the inner space of the bottle  2  due to the height difference between the bottle  2  and the filling material level in the annular tank  8 . The discharge opening  15  is, moreover, preferably designed so that the filling material is fed in an umbrella-like pattern from the discharge opening  15  onto the inner wall of the bottle. The gas forced out of the interior of the bottle by the filling material exits through the probe  23  or its probe channel and by through the open first control valve  24  into the gas space  8 . 1  of the annular tank  8 . 
         [0030]    The filling phase is ended by the closure of the liquid valve  16 . This closing occurs by a corresponding control of the actuation device  17 , for example by a timer. Other events can trigger closure of the liquid valve  16 . For example measuring signals from a flow-meter that measures the quantity of filling material quantity that has flowed into the bottle can be used to close the liquid valve  16 . In either case, the closing of the liquid valve  16  occurs when the level of the liquid filling material in the bottle  2  is above the probe opening  23 . 1  that is located at the bottom end of the probe  23 . 
         [0031]    After the end of the filling phase, which ends with the closure of the liquid valve  16 , the fill level correction phase begins. With the first control valve  24  still open, the second control valve  21 , which has, until now, been closed, is opened. As a result, the headspace of the bottle  2 , which is still in a sealed position against the filling element  9 , becomes connected to the environment by the gas return pipe  19 , the gas space  20 , the open second control valve  21 , the ring channel  22 , and the filter unit  27 . Superfluous filling material is then sucked out of the headspace of the bottle  2  through the probe  23 , until the probe opening  23 . 1  emerges from the liquid filling material. Once this occurs, the desired target fill level in the bottle  2  will have been reached. 
         [0032]    The first control valve  24  is then closed, and with the second control valve  21  still open, the headspace of the filled bottle  2  is depressurized to atmospheric or ambient pressure. After this depressurization, and after closing the second control valve  21 , the container carrier  10  lowers the filled bottle. The bottle  2  is then removed from the filling machine  1  through the container outlet  6 . 
         [0033]    The prescribed vacuum filling method is suitable for both filling still drinks, such as wine and spirits, and also for filling drinks or wines containing a slight amount of CO 2 . In contrast to conventional vacuum filling systems or vacuum filling methods, the suction or return of the overfilled filling material from bottle  2  occurs while the bottle  2  is in a sealed position on the filling element  9 . As a result, during the fill level correction phase, no unfiltered air enters the headspace of the bottle  2 . 
         [0034]    The filling machine  1  can also be used to implement a filling method based on the Trinox method. In this case, at the end of the filling phase, which is after the closing of the liquid valve  16 , the fill level correction phase begins. During this phase, filling material is forced out of the overfilled bottle  2  while it is in a sealed position against the filling element, or returned to the annular tank, through the probe  23  and the open first control valve  24  until the probe opening  23 . 1  is above the filling material level in the bottle  2 . This return is driven by subjecting the headspace of the bottle  2  to a pressurized and filtered pressure medium, such as gas and/or vapor, from the ring channel  22 , to which pressure medium is supplied by the filter unit  27 . The pressure in the ring channel  22  is greater than the pressure in the gas space  8 . 1 . 
         [0035]    A suitable pressure medium is, for example, an inert gas, such as nitrogen, or, in the simplest case, filtered ambient air. If the pressure medium is ambient air, this air is preferably sucked up by a pump, which is not shown, compressed to a higher pressure, and filtered by at least one filter unit  27  on the way to the ring channel  22 . 
         [0036]    At the start of the filling process, the container carrier raises the bottle  2  so that the bottle  2  lies with its mouth edge  2 . 1  in a sealed position against the filling element  9  and the probe  23  extends into the bottle by a length corresponding to the target fill level. The first control valve  24  is then opened to evacuate the bottle  2 . 
         [0037]    When necessary, pressure between the inside of the bottle  2  and the gas space  8 . 1  of the annular tank  8  is equalized. Following this, with the first control valve  24  still open, the filling phase begins with the opening of the liquid valve  12 . 
         [0038]    Upon opening the liquid valve  12 , liquid filling material flows through the discharge opening  15  into the inner space of the bottle  2 . It does so as a result of a height difference between the bottle  2  and the filling material level in the annular tank  8 . The discharge opening  15  is preferably designed so that the filling material flows in an umbrella-like pattern from the discharge opening  15  onto the inner wall of the bottle. The gas forced out of the inner space of the bottle by the filling material exits through the probe  23  or its probe channel, through the open first control valve  24 , and on into the gas space  8 . 1  of the annular tank  8 . 
         [0039]    The filling phase ends when the actuation device  17  closes the liquid valve  16 . The actuation device  17  does so in response to lapse of a timer. However, other events can trigger closure. For example, measuring signals from a flow-meter that captures the quantity of filling material flowing into bottle  2  can be used to close the liquid valve  16 . In either case, the liquid valve  16  closes when the level of the liquid filling material in the bottle  2  is above the probe opening  23 . 1  at the bottom end of the probe  23 . 
         [0040]    In the fill level correction phase, which then follows by opening the second control valve  21 , the headspace of the bottle  2  is subjected to the pressure of the filtered pressure medium from the ring channel  22 . This causes the liquid filling material from the overfilled bottle  2  to be returned by the probe  23  and through the open first control valve  24  into the annular tank  8  until the desired target fill level is reached and the probe opening  23 . 1  is above the filling material level in the bottle  2 . 
         [0041]    After this, and after the closing of the second control valve  21 , the filled bottle  2  depressurizes through the probe  23  and the open first control valve  24  to the ambient pressure prevailing in the gas space  8 . 1 . After depressurization, the container carrier  10  lowers the filled bottle  2  from the filling element  9 . The bottle is then removed from the filling machine  1  by the container outlet  6 . When this filling method based on the Trinox method is used, the vacuum pump  26  is not necessary. 
         [0042]    The invention was described above using examples of embodiments. It is clear that modifications and variations are possible without thereby departing from the inventive idea underlying the invention. 
         [0043]    To facilitate understanding of the figures, the reference numerals referred to in the specification are as follows:
     1  Filling machine     2  Bottle     2 . 1  Edge of opening     3  Rotor     4  Filling position     5  Container inlet     6  Container outlet     7  Rotor element     8  Annular tank     8 . 1  Gas space     8 . 2  Liquid space     9  Filling element     10  Container carrier     11  Housing     12  Liquid channel     13  Product pipe     14  Centering element or centering bell     15  Discharge opening     16  Liquid valve     17  Actuation valve     18  Valve body     19  Gas return pipe     20  Gas space     21  Second Control valve     22  Ring channel     23  Probe     23 . 1  Probe opening     24  First Control valve     25  Flexible pipe     26  Vacuum pump     27  Gas or air filter   FA Filling element axis   MA Filling element axis