Abstract:
An apparatus for filling beverage containers under an inert-gas atmosphere. The apparatus includes a stationary filling tool ( 20 ) to which the containers ( 1 ) are moved and a device for filling the containers with inert gas prior to a beverage-filling procedure. A container engaging element ( 19 ) of the filling tool is mounted in a processing chamber ( 12 ) that is charged with inert gas and encloses the container ( 1 ) in a fill-ready position. The containers are moved through an entry sluice space ( 11 ), which can be shut off from the outside and from the processing chamber, by sluice doors ( 10.1, 10.2 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an apparatus for filling beverage containers ( 1 ) under an inert gas atmosphere, the apparatus having a stationary filling tool ( 20 ) to which are led the containers and implements to fill the containers with inert gas prior to the filling procedure. 
     2. Description of Related Art 
     Beverages such as beer, lemonades, cocoa etc. are filled into rigid containers such as glass bottles and furthermore into pliant containers such as thin-walled plastic bottles and, before closing, highly pliant metal cans or plastic pouches. 
     Many beverages are susceptible to oxygen and therefore must be filled into containers in an atmosphere of inert gas, typically CO 2 , in order to prevent taste alterations and other degradations in quality caused by oxygen entering the container during filling. 
     As regards highly dimensionally stable containers such as glass bottles or thick-walled plastic bottles, it is known to seal the containers at the site of the filling tool and to fill the containers with inert gas before filling same with the beverage. This procedure entails a complex sealing system and, furthermore, a device implementing the sealing action. Such sealing is very expensive as regards special containers and, in particular, pliant containers. Operational problems may arise. Pliant containers may be over-stretched when being filled with inert gas. In every case they are warped by such procedures and substantial operational difficulties may ensue. 
     SUMMARY OF THE INVENTION 
     An objective of the present invention is to create a beverage filling apparatus of the above kind which is of simple design and offers high operational reliability while allowing filling in the presence of only very low oxygen levels. 
     In the apparatus of the invention, the containers move through the entry sluice or buffer space into the processing chamber loaded with inert gas where they will be filled with inert gas. By pre-conditioning the containers at the sluice or buffer space, the contamination of the inert gas with air, that is the air exchange with the processing chamber, can be minimized. Illustratively the entry sluice space may be flushed with inert gas in order to lower the air contents in the containers before they are moved into the processing chamber. Because the containers within the processing chamber are in an inert-gas atmosphere, the filling tool need not be sealed. Accordingly, the filling tool&#39;s design can be substantially simplified. Therefore filling can take place in and “open” state in the processing chamber. Accordingly special bottles and, in particular, pliant containers can be filled in problem-free manner. 
     Advantages are secured especially with respect to highly pliant containers because these containers are subjected to the same pressure outside and inside within the processing chamber and, therefore, will not be stressed at their walls. The apparatus of the invention need only provide a slight excess pressure in the processing chamber to preclude air entering trough sealing leaks. Non-carbonated beverages may be filled while open within the processing chamber, the chamber also allowing filling beverages with CO 2  at higher pressures, in which case a container at the filling tool would have to be sealed during filling. However, the full CO 2  pressure may also be set in the processing chamber to fill carbonated beverages. In this case as well the seal between container and filling tool may be eliminated. 
     In further accordance with the present invention, it is possible in an especially efficacious manner to drag air into the inert gas atmosphere of the processing chamber. Moreover, the container, or at least its cover with fasteners to the container, is sealed inside the processing chamber under inert gas, and the air is prevented from penetrating the top container space after this container has been filled. 
     The container can be removed from the controlled atmosphere of the processing chamber in a manner which is the reverse of its introduction into the processing chamber. Advantageously, however, the containers are moved in a sluice-conditioned manner into and out of the processing chamber at increased processing speed. The exit buffer or sluice space prevents air-contamination of the processing chamber and pumping back inert gas saves material. Advantageously, moreover, inert gas also may be pumped back from the first sluice space into the processing chamber so that this processing chamber then be externally opened to receive the new container. 
     In further accordance with the present invention, container sterilization required for micro-organism sensitive beverages such as cocoa, iced tea and the like is integrated in simple manner into the beverage filling apparatus. The first sluice space is especially appropriate for this procedure because it is kept very clean by constantly being evacuated. 
     In accordance with another feature of the invention, the sterilizing system uses low-pressure plasma sterilization, which is advantageous, and the evacuation system used anyway may be used for attaining the low pressure. 
     In further accordance with the present invention, an evacuation-generated partial vacuum exists in the first sluice space, before its door to the processing chamber is opened, while for good sealing the inert gas is at slightly reduced pressure in the processing chamber. If the entry sluice-space door is opened abruptly, inert gas enters the entry sluice space as a pulse and might press inward a highly pliant container wall or it also might tip the container. If a vent of small cross-section is opened before the sluice-space door is, then the flooding of the first sluice space takes place gradually without affecting the container. 
     In further accordance with the present invention, the filling tool need enter the processing chamber only by its portion which engages the container, that is its lower end with the discharge element. The remaining elements remaining elements of the filling tool are advantageously configured outside the processing chamber and, for instance, are accessible for maintenance. As a result the processing chamber can be kept very compact and those elements of the filling tool requiring maintenance are externally accessible. In the same manner other components also present inside the processing chamber, in particular sealing components, may be configured so that their parts not touching the container shall be outside the processing chamber. 
     In further accordance with the present invention, a series beverage-filling apparatus are provided to fill containers in timed manner in parallel lines. In this manner the filling output is substantially increased. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     These and further features of the invention will be apparent with reference to the drawing FIGURE, which shows a beverage-filling apparatus of the invention in the form of a strongly schematic vertical section along the direction of container motion. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The shown beverage filling apparatus fills beverages into containers  1  illustratively made of a highly pliant plastic and fitted at their upper neck ends with a thread  2  to seat a cap. The containers also have a neck flange  3  that permits movement of the container on rail segments  4 . 1 - 4 . 5  through the apparatus. The apparatus is also fitted with advance mechanisms (not shown) which, for example, may be slides. The shown rail segments  4 . 1 - 4 . 5  also may be replaced by belts driven in conventional circulatory manner, each being configured left and right from the containers&#39; path of motion and carrying the neck flanges  3  on their inside running segments. 
     Containers are moved on the first rail segment  4 . 1  to the shown beverage filling apparatus, which substantially consists of a straight tunnel having an upper wall  5 , a lower wall  6  and sidewalls  7 . The tunnel can be sealed in the shown strongly schematized embodiment at its entrance aperture  8  and at its exit aperture  9  by sluice-space doors in the form of slides  10 . 1  and  10 . 4 . The slides  10 . 1 ,  10 . 4  are displaceable, in the direction of the arrow, by drive means (not shown). Two more slides  10 . 2  and  10 . 3  are present in corresponding slots of the tunnel between the end slides  10 . 1  and  10 . 4  to allow dividing of the tunnel into three compartments. As seen in the direction of container movement in the apparatus, which is indicated by the arrow, the containers move first into an entry sluice space  11 , then into a processing chamber  12 , and then finally into an exit sluice space  13 . As will be discussed more fully hereinafter, the entry and exit sluice spaces  11 ,  13  essentially serve as inlet and outlet buffers for the containers. The sluice-space doors shown in the form of the two center slides  10 . 2  and  10 . 3  are designed, as shown, to preclude communication with of outside air into the processing chamber  12  when the slides  10 . 1  and  10 . 4  are lifted to open such doors. 
     As shown, the containers  1  can be transported in timed manner on the rail segments  4 . 1 - 4 . 5  within the beverage filling apparatus. The rail segments are interrupted at the sluice-space doors to accommodate the slides  10 . 1 - 10 . 4 . 
     The entry sluice space  11  can be loaded with a container when the slide  10 . 2  is in the closed position and the slide  10 . 1  is in the open position. After receipt of the container in the entry sluice space  11 , the slide  10 . 1  is moved into the closed position. The presently closed entry sluice space  11  is evacuated by a vacuum pump  14 . Optionally, the container may be sterilized in the entry sluice space  11 , for instance by filling this space with H 2 O 2  or, in the manner shown, using a high-frequency plasma generator  15  generating, at the partial vacuum produced by the vacuum pump, a low-pressure plasma by an electrode  16  and the grounded wall parts of the entry sluice space  11 . 
     With the slide  10 . 1  closed, the slide  10 . 2  is opened to permit movement of the container into the processing chamber  12 . The processing chamber  12  is permanently loaded or charged with an inert gas, such as air-free CO 2 , through a conduit  17 . The processing chamber  12  is preferably charged with the inert gas at a slight excess pressure relative to the ambient atmosphere in order to preclude contaminations at leakage sites. However, to fill carbonated beverages, their filling pressure also may be adjusted inside the processing chamber  12 . 
     A communication conduit of small cross-section, which shall be opened before the slide  10 . 2  is opened, is present between the processing chamber  12  and the entry sluice space  11 . The communication conduit prevents a strong pressure pulse from occurring when the slide  10 . 2  is abruptly opened. The communication conduit can be configured as a vent  18  at a suitable site on the slide  10 . 2 . As such, the vent  18  is situated outside the entry sluice space and processing chamber when the slide is closed while setting up communication between them when the slide  10 . 2  is slightly raised while still separating the space and chamber. 
     The container-engaging element  19  of a filling tool  20  projects in sealed manner from above into the processing chamber  12 . The container-engaging element  19 , through a line  21 , receives the fill beverage and, through a line  22 , evacuates gas escaping during filling from the container. The evacuated gas may be fed back into the processing chamber  12 . A sealing-cap feed system  23 , which receives caps  24  through a chute  25 , is situated beyond the filling tool, as seen in the direction of advance T. A container engaging element  26  of the feed system  23  enters the processing chamber  12  in a sealed manner. As shown in the drawing FIGURE, the feed system  23  deposits a sealing cap  24  on each container. Thereupon, the containers arrive at a screwing-tight device  28  which, by its container engaging element  27 , projects in sealed manner into the processing chamber  12 . The screwing-tight device tightly screws, as shown, a cap  24  onto the thread  2  of the container  1 . Naturally, it is contemplated that other kinds of seals than the caps  24  screwed onto threads  2  may be also be used, for instance crown corks, sealed disks or the like. After the next slide  10 . 3  is opened, the containers arrive inside the exit sluice space  13  from where, after the slide  10 . 3  has closed and the slide  10 . 4  has opened, the containers move on the rail segment  4 . 5  into the ambient. 
     When a container is being sluice-conditioned in the exit sluice space  13 , this space first is opened at the side of the processing chamber  12  and is, therefore, filled with inert gas. Then the exit sluice space is opened outwardly toward the air. In order to minimize the loss of inert gas so incurred, the exit sluice space  13  communicates through a valve  29  and a pump  30  and pertinent conduits with the processing chamber  12 . Before the exit sluice space  13  is opened to the outside, any inert gas in it can be pumped back into the processing chamber  12 . If the exit sluice space  13  was outwardly open and next is to be opened relative to the processing chamber, the air in the exit sluice space  13  can be evacuated via the appropriately-switched valve  29  and a pump  31 . 
     Once a valve  32  has been switched and before the entry sluice space  11  has been opened to the outside, the inert gas again can be pumped back into the processing chamber  12  by a pump  33 . 
     The sectional FIGURE in each of the processing positions shows one container and one processing device, i.e. one filling tool  20 . The shown processing filling system may be configured as a linear array in which each of the processing sites is followed in a direction perpendicular to the plane of the drawing by several consecutive processing sites. For instance with respect to the position of the shown filling tool  20 , there are several consecutive filling tools along a line perpendicular to the plane of the drawing. Also, sealing-cap feed systems  23  and screwing-tight devices  28  are severally arrayed along a line perpendicular to the plane of the drawing. The spaces  11  and  13  and the chamber  12  as well as the slides  10 . 1 ,  10 . 2 ,  10 . 3  and  10 . 4  assume corresponding widths in the direction perpendicular to the plane of the drawing. The containers are moved in parallel lines perpendicular to the plane of the drawing in timed manner in the direction of the arrow T. The single-track apparatus shown in the FIGURE also may be expanded to several mutually parallel tracks to commensurately increase the output. 
     The illustrative embodiment shows containers in the form of pliant plastic bottles with flanged necks. When slightly modifying the conveying means, other containers as well may be processed with the shown beverage filling apparatus, for instance glass bottles, pliant metal cans or pouches on a conveyor means, and which, similar to the bottles  1 , are moved suspended by their neck apertures or standing in cardboard. 
     The required sluice doors are shown as mere slides  10 . 1 ,  10 . 2 ,  10 . 3  and  10 . 4  to close off on both sides the entry sluice space  11  and the exit sluice space  13 . However other door designs may be used, for instance rotary slides which with appropriate configuration of their insides may constitute the particular sluice space.