Abstract:
A container transport device includes a drive driving a star wheel mounted on bearings within a hollow column that is part of the machine frame. The star wheel comprises two star wheel elements, one forming the leading flanks and the other forming trailing flanks. The two elements adjust to define an angular offset between them. During transport, the elements rotate synchronously while maintaining the angular offset. The hollow column encloses all function elements for setting or maintaining an angular offset, thus protecting them from exterior influence.

Description:
RELATED APPLICATIONS 
     Under 35 USC 371, this application is the national stage of international application PCT/EP2014/000960, filed on Apr. 10, 2014, which claims the benefit of the Apr. 23, 2013 priority date of German application DE 102013104082.9, the contents of which are herein incorporated by reference. 
     FIELD OF INVENTION 
     The invention relates to container processing, and in particular, to a transport device for transporting containers. 
     BACKGROUND 
     Known devices for transporting containers include transport stars with receptacles for engaging containers. Since containers come in different sizes, it is useful to be able to adjust the sizes of these receptacles to accommodate containers of different sizes. 
     Known adjustment mechanisms have the disadvantage of having parts that are exposed to outside influence during operation of the transport star. This tends to make it difficult to maintain proper adjustment. In particular, known adjustment, fixing, and/or clamping mechanisms are prone to disruption, for example by being jammed with glass shards. 
     These components are also located in a hygienic region of a system for filling containers. Unfortunately, they are difficult to clean. As a result, this arrangement is particularly disadvantageous if it is intended that the containers should be filled with microbiologically sensitive and easily contaminated beverages or other foodstuffs. 
     SUMMARY 
     Among the objects of the invention is that of providing a container-transport device that avoids the above disadvantages, and that also permits simplified cleaning with a high degree of operational reliability. 
     With the transport device according to the invention, the function elements that are required for adjustment of the container receptacles to different container diameters, i.e. for the adjustment setting and/or maintaining of the corresponding angular offset between the at least two transport star elements, and also the bearing arrangement of the transport star elements and the drive units are safely ensconced within a machine frame or a column thereof, fully protected against the outside. 
     In one aspect, the invention features a transport device for transporting a container. Such a transport device includes a star wheel mounted on bearings within a column that is part of a machine frame, a drive that drives the star wheel about an axis perpendicular to a plane defined by the star wheel, and a plurality of receptacles, each of which receives a container to be transported. These receptacles are disposed circumferentially about the star wheel. A first flank and a second flank together define a corresponding receptacle. The first flank is a leading flank that leads in relation to a rotation direction of the star wheel. The second flank is a trailing flank that trails the leading flank in relation to the rotation direction of the star wheel. The star wheel has first and second star wheel elements, of which the first star wheel element forms the leading flanks and the second star wheel element forms the trailing flanks. These star wheel elements are adjustable about the axis to define an angular offset between the first and second star wheel elements. This angular offset governs the size of each receptacle. During container transport, the drive rotates the first and second star wheel elements synchronously in a common direction while maintaining the angular offset. The column has a hollow portion that defines a first space, which is inside the column, and a second space, which is outside the column. Within the first space is a function element set that includes one or more function elements necessary for either setting the angular offset, maintaining the angular offset, or both. As a result, the column protects the function element set from the second space and vice versa. 
     In some embodiments, the star wheel elements comprise plates. 
     In other embodiments, the bearings comprise first bearings and second bearings mounted independently of each other. Both the first and second bearings are disposed within the first space. 
     In some embodiments, the drive includes a first and second electric motors for driving the first and second star wheel elements respectively. Both motors are in the first space so that they are isolated from the second space. Among these embodiments are those in which the star wheel elements connect to and rotate with corresponding coaxial first and second shafts. The second shaft has a hollow shaft section that surrounds the first shaft. The second electric motor has a stator winding that is disposed in an interior of the column to interact with a permanent magnet arrangement arranged in the second shaft. Also among these embodiments are those in which either the first or second electric motor functions is an angular-offset adjustment motor for adjusting an angular offset between the first and second star wheel elements, those in which the two motors are driven synchronously in a common direction so as to maintain a constant angular offset between the two star wheel elements, and those in which the motors move their respective star wheel elements relative to the column. 
     Some embodiments include a rigid coupling between the first star wheel element and the second star wheel element for maintaining a constant angular offset between the first star wheel element and the second star wheel element. Among these are those in which the rigid coupling is accommodated within the first space so as to be protected from activity in the second space. 
     Other embodiments that include such a rigid coupling include those in which the rigid coupling switches between a first state, in which the star wheel elements are coupled, and a second state, in which they are not. In the second state, the star wheel elements move independently of each other. 
     In some embodiments, a rigid coupling couples the star wheel elements by coupling the first and second shafts. Among these are embodiments in which the rigid coupling transitions between a first state, in which the shafts are coupled, and a second state, in which the shafts are decoupled. 
     In all cases that include a rigid coupling, that coupling can be mechanical, pneumatic, or electrical. 
     Also among the embodiments are those that include an actuation device and a gripper arrangement that includes a gripper arm. The gripper arrangement secures the container in one of the receptacles. The actuating device moves the gripper arm between a first state and a second state. In the second state, the gripper arm secures the container in the receptacle, and in the first state, the gripper arm leaves the container unsecured. Among these embodiments are those in which the gripper arrangement is disposed on a star wheel element that forms one of the second flanks, and those in which the gripper arm is pivotable between a first state in which the gripper arm trails an associated receptacle and a second state in the gripper arm engages behind the container and secures the container to the receptacle. The gripper arm rotates in the direction of rotation of the star wheel when pivoting from the first position to the second position. 
     As used herein, a “transport star wheel” or a “star wheel” refers to a rotating transporter that has container receptacles on its circumference, each of which lies between a leading flank and a trailing flank. Each receptacle is open in the radial direction so that a container can be at least partially accommodated within the container receptacle. Once accommodated, the trailing flank pushes against the container, thus causing the container to move with the transport star wheel. 
     As used herein, the term “container” includes cans, and bottles, tubes, pouches, whether made of metal, glass, and/or plastic, as well as other packing media suitable for the filling of products that are powdered, granulated, or fluid form, and in the latter case, regardless of viscosity thereof. 
     As used herein, terms such as “essentially” or “approximately” are intended to include deviations from an exact value by ±10%, preferably by ±5%, and/or deviations in the form of changes that are not of significance for the function. 
     Further embodiments, advantages, and possible applications of the invention can also be derived from the following description of embodiments and from the figures. In this context, all the features described and/or represented as images are basically the object of the invention, taken alone or in any desired combination, irrespective of their integration in the claims or references made to them. The contents of the claims are also deemed to be constituent parts of the description. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       These and other features of the invention will be apparent from the following detailed description and the accompanying figures, in which: 
         FIG. 1  shows a transport star wheel for the transporting of containers, in particular bottles; 
         FIG. 2  is a vertical section of the transport device from  FIG. 1 ; and 
         FIG. 3  shows details of a receptacle in another embodiment of a transport device. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  show a transport device  1  that transports containers  2  between a container inlet  1 . 1  and a container outlet  1 . 2 . In the embodiment shown, the transport device  1  includes a transport star wheel  3 . The transport device  1  is suitable for many kinds of containers  2 , including bottles. 
     The transport device  1  is used as a component of a container handling system. Exemplary applications include, but are not limited to transferring the containers  2  from an outside transport element to handling positions of a container handling machine, such as a filling machine, and transferring containers  2  from one handling machine to a further handling machine or to a further transport element of the container handling system. 
     The transport star wheel  3  rotates in a rotation direction A about a vertical axis VA. As shown in  FIG. 2 , a hollow column  4  of a machine frame  5  supports the transport star wheel  3 . Container receptacles  6  are distributed around a circumference of the transport star wheel  3  at uniform angular intervals about the vertical axis VA, as shown in  FIG. 1 . Each container receptacle  6  comprises a pocket that opens radially outward. 
     Referring now to  FIG. 2 , containers  2  stand upright with their bases resting on a sliding strip  7  and with their container axes parallel to the vertical axis VA. A carrier element  8  projecting radially outward from the hollow column  4  supports the sliding strip  7 . The sliding strip  7  and accompanying outer guide rails  7 . 1  form an arc about the vertical axis VA between the container inlet  1 . 1  and the container outlet  1 . 2 , as shown in  FIG. 1 . 
     For each container receptacle  6 , the rotation direction A defines a leading flank  6 . 1  and a trailing flank  6 . 2 . The trailing flank  6 . 2  pushes the container along as the star wheel  3  rotates in the rotation direction A to bring the container  2  from the container inlet  1 . 1  to the container outlet  1 . 2  of the transport device  1 . 
     Each container receptacle  6  has an associated vertical middle plane M that includes the vertical axis VA. The middle plane M bisects the container receptacle  6 . Ideally, when a container is in a receptacle, its axis lies in the vertical middle plane M. 
     Referring to  FIG. 2 , the transport star wheel  3  includes first and second star plates  9 ,  10  that are vertically offset relative to each other. The first and second star plates  9 ,  10  have corresponding first and second pockets  11 ,  12  that open radially outward. These first and second pockets  11 ,  12  are best seen in  FIG. 1 , along their respective circumferences of the first and second star plates  9 ,  10 . Hidden portions of a pocket are shown in dashed lines. Although only two star plates are described, more than two star plates can be used. 
     Depending on the angular offset between the first and second star plates  9 ,  10 , the first pockets  11  will overlap the second pockets  10  by differing extents. The extent of the overlap defines the container receptacle  6  with its leading flank  6 . 1  and its trailing flank  6 . 2 . The leading flank  6 . 1  is a leading edge of a first pocket  11  whereas the trailing flank  6 . 2  is a trailing edge of a second pocket  12 . 
     Because the first and second star plates  9 ,  10  can move independently of each other about the vertical axis VA, it is possible to adjust the angular offset between them. Adjusting the angular offset amounts to adjusting the size of the container receptacles  6  to conform to the diameter of the containers  2  in a sectional plane defined by the first and second star plates  9 ,  10 . This adjustment also makes it possible to retain an angle setting of a middle plane M of each container receptacle  6 . 
     In the particular embodiment shown in  FIG. 2 , the first star plate  9  is above the second star plate  10 . An upper end of a first shaft  13  that is arranged coaxially with the vertical axis VA supports the first star plate  9 . A lower end of the first shaft  13  couples to a first motor  14  located inside the hollow column  4 . In the illustrated embodiment, the first motor  14  is a servomotor. 
     The first shaft  13  is mounted so that it can rotate on inner bearings  15  within a hollow second shaft  16  that concentrically encloses the first shaft  13 . The second shaft  16 , in turn, is mounted so that it can rotate on outer bearings  17  within the interior of the hollow column  4 . 
     A second motor  18  is placed between the second shaft  16  and either the hollow column  4  or the machine frame  5 . The second motor  18  is a drive motor, such as a torque motor. In one embodiment, the second motor  18  has a stator winding provided within the interior of the hollow column  4  and a permanent magnet arrangement arranged at the second shaft  16 . 
     A coupling  19  couples the first shaft  13  and the second shaft  16 . When coupled, the first shaft  13  rigidly connects with the second shaft  16 . The coupling  19  can be a mechanical, electrical, and/or pneumatic coupling. 
     Instead of the coupling  19 , other mechanical coupling and/or connections can be provided to fix the angular offset of the first and second star plates  9 ,  10  relative to each other. In particular, some embodiments include a mechanical means with an angular offset that is adjusted to some value and that can be secured so that the value does not change. Such a mechanical means can be used instead of or in addition to the coupling  19 . 
     The first motor  14  and/or the second motor  18  make it possible to adjust the container receptacles  6  to conform to a diameter of containers  2  that are to be transported. This is achieved by turning the first and second star plates  9 ,  10  relative to one another. Preferably, this includes maintaining the location of the middle plane M of the container receptacles  6 . 
     Once the container receptacles  6  have been adjusted to conform to the diameters of the containers  2 , the first and second motors  14 ,  18 , of the transport star wheel  3  drive the first and second star plates  9 ,  10  in the same direction and in synchrony, thus maintaining the angular offset. In this operating mode of the transport device  1 , the coupling  19  is no longer required. 
     In another embodiment, only one of the first and second motors  14 ,  18  drives the transport star wheel  3 . Since only one of the star plates  9 ,  10  is actually being driven, there must be a way to ensure that the other star plate also moves. In this operating mode, the coupling  19  maintains a rigid connection after the relative positions of the first and second star plates  9 ,  10  have been set. 
     The hollow column  4  protects more than just the drive that transports the containers. In fact, the hollow column  4  also protects the entire adjustment mechanism that is used for adjusting the container receptacles so that they can accommodate different sized containers. Both the drive and the adjustment mechanism are thus contained within the hollow column  4 . As a result, the hollow column  4  protects the adjustment mechanism from outside influences, in particular, against glass shards, and the disruptions caused thereby. In addition, a transport device  1  in which such components are sequestered within the hollow column can more easily meet hygiene and cleaning requirements. 
     Both the adjustment of the container receptacles  6  and the setting of the angular offset of the first and second star plates  9 ,  10  are carried out by appropriate software for controlling the first and/or second motors  14 ,  18  based on the container diameters. 
     The first motor  14  is arranged to be stationary in the hollow column  4  relative to its power supply. The second motor is arranged to be stationary in the hollow column relative to its stator winding. Accordingly, no electrical rotating mmf or slip ring distributor is required for the power supply for the first and second motors  14 ,  18 . 
     All function elements required for the bearing mounting of the first and second star plates  9 ,  10 , in particular the inner bearing  15  and the outer bearing  17 , are also located entirely inside the hollow column  4 . As such, they are protected against outside influences and isolated from the hygiene region of the transport device  1  or from the hygiene region of a system comprising the transport device  1 . 
     In an alternative embodiment, shown in  FIG. 3 , the container receptacle  6  has an associated gripper arrangement  20  to secure the container  2 . The gripper arrangement  20  includes a gripper arm  21  that rotates about a pivot point  22  adjacent to a trailing flank  6 . 2  on the second star plate  10 . The gripper arm  21  thus rotates around an axis that is parallel to the vertical axis VA. 
     An actuation element  23  associated with the gripper arrangement  20  causes the gripper arm  21  to transition between an effective position and a non-effective position. A suitable actuation element  23  is a pneumatic cylinder. 
     In the non-effective position, a gripper arm section  21 . 1  of the gripper arm  21  projects over the circumference of the star plate  10  outside its associated receptacle. In the illustrated embodiment, the gripper arm section  21 . 1  is curved like a hoe. The gripper arm section  21 . 1  is outside its associated container receptacle  6  so that it trails the container receptacle  6 . In the effective position, the gripper arm section  21 . 1  contacts the circumferential region of the container  2  located outside the container receptacle  6 , and secures it into the container receptacle  6 . 
     Having described the invention, and a preferred embodiment thereof, what is claimed as new, and secured by letters patent is: