Abstract:
A closing means for containers including a transport means for the containers having a drive and at least one closing unit for applying a closure by a linear motion along a central line and a rotary motion about the central line, wherein the rotary motion is applied by rolling off two gear members. To achieve a structurally simple and flexible embodiment the first one of the gear members is connected with a separate drive independent of the drive of the transport means.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims the benefit of priority of German Application No. 102011003118.9, filed Jan. 25, 2011. The entire text of the priority application is incorporated herein by reference in its entirety. 
       FIELD OF THE DISCLOSURE 
       [0002]    The disclosure relates to a closing means for containers, such as used in beverage bottling operations. 
       BACKGROUND 
       [0003]    Such a closing means is known, for example, from EP-A-1 103 513.The known closing means is part of a bottling plant for beverage containers, in particular bottles, and contains a bearing central column which is driven by a drive to rotate about a vertical axis. Mountings for the containers and one closing unit each allocated to each mounting and rotating about the vertical axis together with the central column are arranged at the central column. In the region of the closing units, a stationary frame is furthermore provided at which a cam curve is fixed on which the closing unit rolls off with a roller array such that a predetermined lifting motion of the closing unit along the extended central line of the container can take place, so that a closure can be placed onto the container from above. At the frame, a rotary drive for the closing unit is furthermore provided by means of which, for example, screw caps can be screwed onto the containers. The rotary drive contains a first gear member in the form of a gearwheel which is rotatably mounted at the stationary frame. A second gear member in the form of a gearwheel is located at the periphery of the closing unit and moves with the latter about the vertical axis of the support. Both gear members are engaged, so that the gear members mutually roll off and the closing unit is thereby rotated. The drive of the closing unit is thus derived from the drive of the transport means. By this, however, the sense of rotation and the rotational speed are fixed. Moreover, this type of drive requires extensive retrofitting measures if special customer requests must be considered. 
         [0004]    It is furthermore known from WO 2008/145363 to equip each closing unit of a closing means with a separate motor. This, however, is extremely cost-intensive. 
       SUMMARY OF THE DISCLOSURE 
       [0005]    One aspect of the disclosure thus is to provide a closing means which, in a structurally simple manner, offers higher flexibility when it comes to fulfill the customers&#39; requests for the closing means. 
         [0006]    By the embodiment according to the disclosure, the advantages of the gear members in view of a simple construction and a fail-safe, robust embodiment are maintained, while flexibility is increased by a separate drive of the first one of the gear members. By the drive, the speed can be adapted to the particularly employed screw cap, and the torque to the material of the screw cap and the container, moreover, rotary motions into both directions are easily possible. 
         [0007]    Particularly suited as a drive is a torque motor due to its simple and robust embodiment and its good controllability; it is preferably employed with a hollow shaft design and an outer rotor. Torque motors are relatively compact, so that their rotor can have a smaller outer diameter than the partial circle of the mountings of the containers in the closing means, and thus they permit a compact design. 
         [0008]    The drive can be easily seated on the rotating support which acts as a drive for the transport means, in particular when a hollow shaft motor is used. The torque motor thus moves together with the support and independent of it, so that changes in the transport speed can be easily included in the drive speed of the closing means. 
         [0009]    As gear members, the well-tried gearwheels can be employed, though frictional guide rollers or the like are also possible. 
         [0010]    Despite a separate drive, it is also possible to drive all closing units of a closing means by one single separate drive by maintaining the gear members. 
         [0011]    To compensate the linear motions along the container&#39;s central line, one of the gear members is extended, so that the engagement is maintained across the total length of the linear motion. 
         [0012]    Another possibility of increasing flexibility when considering customer requests, which can be provided together with or independent of the separate independent drive is the embodiment of the closing unit in a modular way, wherein the various functions are each combined in one assembly, so that, for example, various rotating assemblies match the same lifting assembly, or various lifting assemblies match the same rotating assembly, and can be exchanged depending on the type of container to be handled by the user. 
         [0013]    In addition or as an alternative, the closing unit can also comprise an exchangeable closing head which is adapted to different closure constructions. 
         [0014]    The closing units can be held ready for any type of container or closure and optionally also be held ready for retrofitting closing means already in operation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    One embodiment of the disclosure will be illustrated more in detail below with reference to the drawings. In the drawings: 
           [0016]      FIG. 1  shows a perspective partial representation of a closing means according to the disclosure, 
           [0017]      FIG. 2  shows an axial section of the closing means according to  FIG. 1 , 
           [0018]      FIGS. 3 to 5  show different embodiments of closing units. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]      FIG. 1  shows, in a perspective schematic partial representation, a closing means  1  of an essentially conventional design. The closing means  1  contains a vertical central column  2  which comprises an inner, not generally, but vertically stationary support  3 , and an outer rotary sleeve  4  driven about its vertical central line  4 ′. The mountings for the containers and a mounting  5  for at least one closing unit  6  are fixed on the rotary sleeve  4  in a common, not shown way. The mounting  5  in the represented embodiment contains two partial circles  5   a  and  5   b  lying one upon the other and keeping the closing units  6  at a peripheral distance with respect to each other. 
         [0020]    Above the central column  2 , a stationary head plate  7  is provided at which a cam curve  9  is arranged at a flange  8  projecting downwards, into which cam curve a guide roller  10  engages in a known manner, the guide roller being rotatably mounted at the closing unit  6 . A lifting cylinder  11  is connected with the guide roller  10  and arranged in a guide bush  12  to be shiftable in the vertical direction, i.e. in the direction of the oriented central lines  11 ′ of the lifting cylinder  11  and the central line  13 ′ of a container  13  ( FIG. 3 ). The guide bush  12  is connected to the mounting  5 . The guide roller  10  and the lifting cylinder  11  form a lifting assembly  14 . 
         [0021]    Instead of by the cam curve  9 , lifting can also be accomplished electromotively or pneumatically. 
         [0022]    At the lower level of the lifting cylinder  11  facing away from the guide roller  10 , a rotating assembly  15  is fixed to be rotatable about the central axis  11 ′ of the lifting cylinder  11 . Mounting is effected such that the two assemblies  14  and  15  are fixed to each other to be exchangeable. 
         [0023]    The rotating assembly  15  contains a bush-like support  16  which comprises, at the lower end facing away from the lifting cylinder  11 , either a stationarily arranged closing head or a coupling which is able to exchangeably receive various types of closing heads. 
         [0024]    The drive of the rotating assemblies  15  of all closing units  6  is effected via a separate drive  17  which is independent of the (not shown) drive of the central column. Preferably, the drive is effected via a hollow shaft motor, in particular a so-called torque motor in a hollow shaft design, which is seated with its hollow stator  17   a  on the rotary sleeve  4  of the central column  2  without connection to the cam curve  9  and rotates with it about the central line  4 ′, and an outer rotor  17   b  which is, at its outer side, provided with a first gear member  18  in the form of a gearwheel, a pinion or a toothed ring which extends coaxially about the central line  4 ′ of the rotary sleeve  4 . The motor and the bearing here form a unit. 
         [0025]    This first gear member  18  of the drive  17  drives, via a second gear member  19 , the rotating assembly  15  in the desired sense of rotation separately and independent of the drive of the rotary sleeve  4  of the central column  2 . The second gear member  19  is also a gearwheel, but has an axial length in the direction of the central line  11 ′ which is longer than the axial length of the first gear member  18  and at least as large as the stroke distance of the lifting cylinder  11  effected by the cam curve  4 , so that in each phase of the lifting motion, the drive  17  acts on the rotating assembly  15 . The second gear member  19  is, in the represented embodiment, fixed at the outer surface of the sleeve  16 . 
         [0026]    The control of the drive  17  and its power supply are effected via cables which preferably extend inside the central column  2 , and e.g. a slip ring transmitter, or in a contactless manner. 
         [0027]    With the embodiment according to the disclosure, thus the screwing on of screw caps of any type can be done in both directions and exactly controlled with a given torque, so that the containers are well closed, without there being any risk of damages. 
         [0028]    By the modular design, the closing means according to the disclosure can be structurally simply adapted to certain user requirements, either already during manufacture, or for retrofitting. 
         [0029]    Furthermore, a position-measuring system can be provided which traces the degree of screwing on the closures onto the containers and correspondingly controls the drive  17 . The position-measuring system can detect the speed of the closing head and optionally control it, for which e.g. a rotary encoder is arranged between the rotor and the stator. However, it is also possible to detect the speed of the closing head in the region of the gear member  19 . 
         [0030]      FIGS. 3 to 5  show different possibilities of using the closing means according to the disclosure.  FIG. 3  shows the use of the closing means according to the disclosure for applying screw caps. To this end, the container  13  is oriented with its central line  13 ′ aligned with the central line  11 ′ of the lifting cylinder, and a closing head  20  for applying screw caps or a gripper closing head or the like are inserted into the rotating assembly  15 . The central column  2  is driven and the drive  17  started to actuate the assemblies of the closing unit  6  by a combined linear motion in the vertical direction (lift) and rotary motion about the vertical axis  11 ′ for screwing the screw cap onto the container  13 . 
         [0031]      FIG. 4  shows a closing means according to the disclosure for applying aluminum roll-on closures onto containers  13 . As  FIG. 4  shows, the closing means according to  FIG. 4  corresponds to the closing means according to  FIG. 3  with respect to the lifting assembly  14  and the rotating assembly  15 . Only the closing head was changed, i.e. replaced by an aluminum roll-on head  21  which can apply these aluminum roll-on closures. 
         [0032]      FIG. 5  shows a closing means according to the disclosure, equipped for applying crown caps. The closing unit here contains the lifting assembly  14 , while the rotating assembly was removed and a crown cap closing head  22  or an aluminum sealing head or the like was fixed directly to the lifting assembly  14 . The drive  17  is thus put out of service, but it can remain at its place if one expects another retrofitting to screw caps. 
         [0033]    In variation to the described and drawn embodiment, the closing unit can also be embodied with a head drive, preferably if the modular or assembly design is not necessary. The rotary or screw drive is also located above the mounting for the containers. The torque motor can be easily encapsulated, i.e. accommodated in a protective housing which only exposes the toothed ring, so that cleaning is highly facilitated. Instead of the torque motor, other motors can be employed, preferably with a hollow shaft. Finally, the two gear members do not necessarily have to be engaged directly, intermediate members can also be provided. The described drive can also be provided in closing units without assembly division, and the assembly components can also be provided without separate drive.