Transport device for containers

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.

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.

DETAILED DESCRIPTION

FIGS. 1 and 2show a transport device1that transports containers2between a container inlet1.1and a container outlet1.2. In the embodiment shown, the transport device1includes a transport star wheel3. The transport device1is suitable for many kinds of containers2, including bottles.

The transport device1is used as a component of a container handling system. Exemplary applications include, but are not limited to transferring the containers2from an outside transport element to handling positions of a container handling machine, such as a filling machine, and transferring containers2from one handling machine to a further handling machine or to a further transport element of the container handling system.

The transport star wheel3rotates in a rotation direction A about a vertical axis VA. As shown inFIG. 2, a hollow column4of a machine frame5supports the transport star wheel3. Container receptacles6are distributed around a circumference of the transport star wheel3at uniform angular intervals about the vertical axis VA, as shown inFIG. 1. Each container receptacle6comprises a pocket that opens radially outward.

Referring now toFIG. 2, containers2stand upright with their bases resting on a sliding strip7and with their container axes parallel to the vertical axis VA. A carrier element8projecting radially outward from the hollow column4supports the sliding strip7. The sliding strip7and accompanying outer guide rails7.1form an arc about the vertical axis VA between the container inlet1.1and the container outlet1.2, as shown inFIG. 1.

For each container receptacle6, the rotation direction A defines a leading flank6.1and a trailing flank6.2. The trailing flank6.2pushes the container along as the star wheel3rotates in the rotation direction A to bring the container2from the container inlet1.1to the container outlet1.2of the transport device1.

Each container receptacle6has an associated vertical middle plane M that includes the vertical axis VA. The middle plane M bisects the container receptacle6. Ideally, when a container is in a receptacle, its axis lies in the vertical middle plane M.

Referring toFIG. 2, the transport star wheel3includes first and second star plates9,10that are vertically offset relative to each other. The first and second star plates9,10have corresponding first and second pockets11,12that open radially outward. These first and second pockets11,12are best seen inFIG. 1, along their respective circumferences of the first and second star plates9,10. 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 plates9,10, the first pockets11will overlap the second pockets10by differing extents. The extent of the overlap defines the container receptacle6with its leading flank6.1and its trailing flank6.2. The leading flank6.1is a leading edge of a first pocket11whereas the trailing flank6.2is a trailing edge of a second pocket12.

Because the first and second star plates9,10can 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 receptacles6to conform to the diameter of the containers2in a sectional plane defined by the first and second star plates9,10. This adjustment also makes it possible to retain an angle setting of a middle plane M of each container receptacle6.

In the particular embodiment shown inFIG. 2, the first star plate9is above the second star plate10. An upper end of a first shaft13that is arranged coaxially with the vertical axis VA supports the first star plate9. A lower end of the first shaft13couples to a first motor14located inside the hollow column4. In the illustrated embodiment, the first motor14is a servomotor.

The first shaft13is mounted so that it can rotate on inner bearings15within a hollow second shaft16that concentrically encloses the first shaft13. The second shaft16, in turn, is mounted so that it can rotate on outer bearings17within the interior of the hollow column4.

A second motor18is placed between the second shaft16and either the hollow column4or the machine frame5. The second motor18is a drive motor, such as a torque motor. In one embodiment, the second motor18has a stator winding provided within the interior of the hollow column4and a permanent magnet arrangement arranged at the second shaft16.

A coupling19couples the first shaft13and the second shaft16. When coupled, the first shaft13rigidly connects with the second shaft16. The coupling19can be a mechanical, electrical, and/or pneumatic coupling.

Instead of the coupling19, other mechanical coupling and/or connections can be provided to fix the angular offset of the first and second star plates9,10relative 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 coupling19.

The first motor14and/or the second motor18make it possible to adjust the container receptacles6to conform to a diameter of containers2that are to be transported. This is achieved by turning the first and second star plates9,10relative to one another. Preferably, this includes maintaining the location of the middle plane M of the container receptacles6.

Once the container receptacles6have been adjusted to conform to the diameters of the containers2, the first and second motors14,18, of the transport star wheel3drive the first and second star plates9,10in the same direction and in synchrony, thus maintaining the angular offset. In this operating mode of the transport device1, the coupling19is no longer required.

In another embodiment, only one of the first and second motors14,18drives the transport star wheel3. Since only one of the star plates9,10is actually being driven, there must be a way to ensure that the other star plate also moves. In this operating mode, the coupling19maintains a rigid connection after the relative positions of the first and second star plates9,10have been set.

The hollow column4protects more than just the drive that transports the containers. In fact, the hollow column4also 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 column4. As a result, the hollow column4protects the adjustment mechanism from outside influences, in particular, against glass shards, and the disruptions caused thereby. In addition, a transport device1in which such components are sequestered within the hollow column can more easily meet hygiene and cleaning requirements.

Both the adjustment of the container receptacles6and the setting of the angular offset of the first and second star plates9,10are carried out by appropriate software for controlling the first and/or second motors14,18based on the container diameters.

The first motor14is arranged to be stationary in the hollow column4relative 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 motors14,18.

All function elements required for the bearing mounting of the first and second star plates9,10, in particular the inner bearing15and the outer bearing17, are also located entirely inside the hollow column4. As such, they are protected against outside influences and isolated from the hygiene region of the transport device1or from the hygiene region of a system comprising the transport device1.

In an alternative embodiment, shown inFIG. 3, the container receptacle6has an associated gripper arrangement20to secure the container2. The gripper arrangement20includes a gripper arm21that rotates about a pivot point22adjacent to a trailing flank6.2on the second star plate10. The gripper arm21thus rotates around an axis that is parallel to the vertical axis VA.

An actuation element23associated with the gripper arrangement20causes the gripper arm21to transition between an effective position and a non-effective position. A suitable actuation element23is a pneumatic cylinder.

In the non-effective position, a gripper arm section21.1of the gripper arm21projects over the circumference of the star plate10outside its associated receptacle. In the illustrated embodiment, the gripper arm section21.1is curved like a hoe. The gripper arm section21.1is outside its associated container receptacle6so that it trails the container receptacle6. In the effective position, the gripper arm section21.1contacts the circumferential region of the container2located outside the container receptacle6, and secures it into the container receptacle6.

Having described the invention, and a preferred embodiment thereof, what is claimed as new, and secured by letters patent is: