Labelling machine

Technical Field

This invention relates to a labelling machine of the type with a rotary carrousel, and in particular to a labelling machine with variable set-up, that is to say, a machine of the type equipped with a plurality of labelling devices which can be placed in various positions along the edge of the carrousel.

Background Art

Examples of a such a type of machine are described in patents WO 2005/011363, US 4 362 594 and GB 2 138 388 and in recent patent application PCT/IT2009/000398 by the same Applicant.

In general, the labelling machines for which this invention is intended comprise a supporting frame on which a carrousel is mounted in such a way that it can rotate about a vertical axis of rotation. The edge of the carrousel is equipped with a plurality of supporting means, such as plates, for items to be labelled.

The machine also comprises means for moving the carrousel relative to the frame and, if necessary, the supporting means relative to the carrousel.

Feeding of products to be labelled to the supporting means and subsequent removal of labelled products are guaranteed respectively by feed means and by pick up means (both usually consisting of a transfer star-wheel coupled with a product feed track).

Positioned around the carrousel there is at least one labelling device which is designed in practice to apply labels to objects placed on the supporting means which pass it during carrousel rotation. In the labelling machines for which this invention is intended, the labelling device is removably connected to the frame so that it can be freely positioned in different angular positions relative to the carrousel axis of rotation. In general, this is done by fastening the labelling device to a circular track which is integral with the frame and substantially extends along the edge of the carrousel. Suitable actuator means guarantee operation of the labelling device.

Moreover, in the case of more complex machines, there are two or more labelling devices distributed along the edge of the carrousel for applying two or more labels to the same products. Finally, the entire machine operation is controlled by at least one control unit which is operatively connected at least to the movement means and to the actuator means for controlling their operation in a synchronised way.

With this type of prior art labelling machines, when the size or type of container to be labelled has to be changed, the labelling devices must be moved to a different position. However, each time that is done, the control unit must be reprogrammed, in particular in the case of the machine described in patent application No. PCT/IT2009/000398 where each labelling device may be placed in any position around the carrousel.

Obviously, in order to reprogram the machine the position of each of the labelling devices must be known.

However, reprogramming is a lengthy operation which is exposed to the risk of operator error. Before continuing production some operating tests are always necessary to check that everything is in order.

Consequently, prior art machines with variable set-up are greatly disadvantaged in terms of productivity if size change-operations are often needed.

Disclosure of the Invention

In this situation the technical purpose which forms the basis of this invention is to provide a labelling machine which overcomes the above-mentioned disadvantages.

In particular, the technical purpose of this invention is to provide a labelling machine with variable set-up which allows size change-overs to be performed must faster than for prior art machines.

This invention also has for a technical purpose to provide a labelling machine in which after moving the labelling devices a minimum number of operations is required before being able to continue production.

The technical purpose specified and the aims indicated are substantially achieved by a labelling machine as described in the appended claims.

Brief Description of the Drawings

Further features and the advantages of this invention are more apparent in the detailed description, with reference to the accompanying drawings which illustrate several preferred, non-limiting embodiments of a labelling machine, in which:

- Figure 1 is an axonometric view partly from above of a labelling machine of the type to which this invention can be applied; - Figure 2 shows the labelling machine of Figure 1 with some parts cut away and others moved; and

- Figure 3 is a schematic top view of the invention applied to a labelling machine of the type illustrated in Figure 1.

Detailed Description of the Preferred Embodiments of the Invention

With reference to the accompanying drawings the numeral 1 denotes as a whole a labelling machine made in accordance with this invention.

Similarly to the prior art machines, this machine according to this invention comprises first a supporting frame 2 on which a carrousel 3 (visible in Figure 1) is mounted in such a way that it can rotate about a vertical axis of rotation X. The edge of the carrousel 3 is equipped with a plurality of supporting means 4 for the objects to be labelled. In the embodiment illustrated, the supporting means 4 are plates which can rotate about their own vertical central axes. The movement of the carrousel 3 relative to the frame 2 and the movement of the supporting means 4 relative to the carrousel 3 are guaranteed by suitable movement means 5 (the accompanying drawings show only the carrousel movement motor). Moreover, the two movements are advantageously synchronised. In particular, in the preferred embodiment of this invention that is done using different electronically- controlled motors for the movement of the carrousel 3 and for the movement of the individual plates, and using an "electronic cam", that is to say, a synchronised electronic control for the individual motors.

Figure 1 also shows how the carrousel 3, in the known way, comprises a lower part 6 which supports the plates and an upper part 7 to which there is connected a part of the supporting means 4 (not visible) which is designed to retain the upper part of the products to be labelled (not illustrated). Said upper part 7 of the carrousel 3 is supported by an upper part 8 of the frame 2.

The machine also comprises means 9 for feeding the objects to be labelled to the supporting means 4 and means 10 for picking up the labelled objects from the supporting means 4, both of the known type. The feed means 9 and the pickup means 10 are schematically illustrated in Figure 3. As can be seen, both comprise a transfer star- wheel 11 interposed between the carrousel 3 and a feed track 12 for the products to be labelled. In addition, the feed means 9 comprise a screw feeder 13 designed to space out the products by the correct step, allowing them to be picked up by the transfer star- wheel 11.

At least one labelling device 14 (two in the accompanying Figures 1 and 2) is positioned radially along the edge of the carrousel 3 and in practice applies labels to the objects placed on the supporting means 4 which pass it during carrousel 3 rotation. In particular, the labelling device 14 is removably connected to the frame 2 so that it can be freely positioned in different angular positions relative to the carrousel 3 axis of rotation X. In the embodiment illustrated in Figure 1, this is achieved thanks to the fact that the supporting frame 2 comprises a sliding track 15 extending along an arc of a circle centred on the axis of rotation X and also thanks to the fact that each labelling device 14 can be connected to the track 15 in any angular position. In particular, as Figure 2 shows more clearly, each labelling device 14 is connected to the frame 2 by an interface element 16 which can be slidably fastened to the frame 2 track 15. The labelling device 14 is coupled with the interface element 16 only at the moment when the latter has been brought into the correct position and locked relative to the frame 2 (the structure is described in detail in patent application No. PCT/IT2009/000398). In any case the specific method for positioning the labelling devices 14 and coupling them to the frame 2 is not limiting for the purposes of this invention.

Actuator means 17 are connected to the labelling device 14 for making it operate and so apply the labels.

The entire machine operation is controlled by at least one control unit (not visible in the accompanying drawings) which is operatively connected at least to the movement means 5 and to the actuator means 17 for controlling their operation in a synchronised way. In general, the control unit comprises at least one CPU and is programmed (in the known way) to create a set of synchronised movements by the carrousel 3, supporting means 4 and labelling devices 14 which allows correct application of the label on the products. Advantageously, the control unit is also operatively connected to the feed means 9 and to the pickup means 10 for controlling their operation in a way synchronised with the movement means 5.

According to this invention, control unit programming has been made dependent on a variable parameter, the position of the labelling device 14 relative to the carrousel 3.

For that purpose, according to this invention, the labelling machine 1 comprises means (not illustrated) for detecting the angular position of the labelling device 14 relative to the axis of rotation X, the detection means being operatively connected to the control unit. In general, said detection means identify the angular position of the labelling device 14 relative to a reference point integral with the frame 2 and they transmit the information to the control unit.

The latter is programmed first to save said labelling device 14 angular position detected- by the detection means, as the "position detected" (it should be noticed that saving may also be of the implicit type). Second, the control unit is programmed to control the movement means 5 and the actuator means 17 depending on the position detected which is saved.

Moreover, in the preferred embodiment the machine comprises means 18 for identifying the labelling device 14 which in turn comprise at least a first element 19 (shown in three different positions in Figure 3) and at least a second element 20.

The first element 19 can rotate about the axis of rotation X, whilst the second element 20 is integral with the labelling device 14 (directly or by means of the interface element 16). The first element 19 and the second element 20 are also positioned in such a way that they are operatively coupled with each other when the labelling device 14 is connected to the frame 2 and the first element 19 is in an angular position, relative to the axis of rotation X, corresponding to that of the second element 20. In other words, the two elements 19, 20 are advantageously operatively coupled when they are coplanar in a plane passing through the axis of rotation X and they are located on the same side of the axis. Moreover, advantageously the first element 19 is integral with the carrousel 3.

At least one out of the first element 19 and the second element 20 is operatively connected to the control unit for indicating to it when the two elements 19, 20 are operatively coupled (at that moment the first element 19 is in the same angular position as the labelling device 14). For that purpose, the first element 19 and the second element 20 consist one of a sensor connected to the control unit, and the other of an element which can be detected by the sensor.

To provide the reference point for identifying the position detected, the identification means 18 also comprise at least a third element 21 which is fixed relative to the supporting frame 2 and is operatively coupled with the first element 19, in the sense indicated above, at a predetermined angular position of the first element 19 relative to the axis of rotation X. In the embodiment illustrated, the third element 21 is positioned at the tangent point between the feed means 9 transfer star-wheel 11 and the carrousel 3 (said location is advantageous since it coincides with the start of the path of the products to be labelled on the carrousel 3)·

The detection means in turn detect the angular position of the labelling device 14, detecting the angular position of the first element 19 relative to the axis of rotation X. Advantageously, the detection means comprise an encoder (not illustrated) connected to the control unit and operatively connected to the first element 19 (and/or with the carrousel 3 if the first element 19 is integral with it) for calculating its angular movement relative to the reference point.

In the preferred embodiment, the control unit is programmed to save as the position detected the angular position of the first element 19, detected by the detection means when the identification means 18 indicate that the first element and the second element 20 are operatively coupled, and to control the movement means 5 and the actuator means 17 depending on the positioned detected which is saved in this way.

Figure 3 shows the case in which a labelling device 14 is moved from a first position (on the right in the drawing) to a second position (on the left). Before being moved, the device is in a first angular position rotated by a first angle a relative to the reference angle (angle 0) identified by the fixed third element 21. The movement consists of a rotation about the axis of rotation X according to the arrow F, by a second angle β relative to the starting position. Once the labelling device 14 has been positioned, the carrousel 3, on which the first element 19 is mounted, is made to rotate. At the moment when the first element 19 is operatively coupled with the third element 21, the relative angular position is recognised as the reference point and the encoder begins counting the pulses until the first element 19 encounters the second element 20. At that moment the angular position calculated by the encoder (equal to the sum of the first angle a and the second angle β) is taken as the position detected and is processed by the control unit which applies new parameters to its programming based on the positioned detected.

Moreover, depending on the embodiments, the control unit may be programmed to save the position detected for each labelling device 14 with each rotation of the carrousel 3 (thus guaranteeing continuous updating of the machine status) or only after a specific command which can be given by the operator after moving the labelling device 14.

Since each type of labelling device 14 requires specific programming for coordination of the various moving parts, in some more complex embodiments the second element 20 of the identification means 18 may also represent the type of labelling device 14 to which it is connected. If it is an active element (sensor), the information about the type of device may be saved in it so that it can transmitted to the control unit as required. If it is an element which can be detected by a sensor it may be made with distinctive features (e.g.: a particular colour in the case of an optical sensor, or a predetermined electromagnetic behaviour for a magnetic sensor). In these more complete embodiments, at the moment when the position detected is detected the detection means also detect the type of labelling device 14 and communicate this to the control unit. The latter is therefore programmed to control operation of the movement means 5 and the actuator means 17 partly depending on the type of labelling device 14 detected by the detection means.

For simplicity, up to this moment reference was made to a labelling machine 1 comprising only one labelling device 14.

However, in practice, in the more complete embodiments the machine is equipped with a series of labelling devices 14, and at least a plurality of them can be placed in two or more positions relative to the carrousel 3. In this case, the detection means comprise at least one second element 20 connected to each movable labelling device 14, and the control unit is programmed as indicated above for each movable labelling device 14.

By way of example, Figures 1 and 2 show a machine equipped with two labelling devices 14, one device 141 for applying adhesive labels and a cold glue application device 142.

This invention also relates to the method for managing a labelling machine 1 of the type with variable set-up described above.

The method according to this invention relates to setting up the machine after each movement of a labelling device 14 relative to the carrousel 3.

The method involves various operating steps.

The first step is to programme the control unit with a program which is expressed according to a variable representing the angular position of the labelling device 14 relative to the axis of rotation X and a fixed reference point. Thus the program must be such that it controls the "electronic cam" based on said variable. The start and end of each machine movement will therefore be expressed not with reference to the absolute position of the carrousel 3, but with reference to a differential position of the carrousel 3 relative to the angular position of each labelling device 14 (in other words, each position of the carrousel 3 will be expressed in terms of before or after the angular position of each labelling device 14).

Once the control unit has been programmed in this way, the management method involves, after each movement of one of the labelling devices 14 present, the angular position of the labelling device 14 moved (or, advantageously of all of them) relative to the fixed reference point being detected and saved as the position detected.

At that point the method involves entering the position detected in the program as the value to be assigned to the relative variable and using the machine with the program obtained in this way.

Obviously, the management method described herein is advantageously applied in the labelling machine 1 previously described in detail, but not only in that case.

Operation of the machine is similar to that of prior art machines and is not described in detail herein.

This invention brings important advantages.

Thanks to this invention, the machine set-up process after a size change- over involving movement of the labelling devices 14, can be carried out in just a few seconds with significant benefits in terms of productivity.

Secondly, any set-up errors can be avoided. Finally, thanks to the use of the control at a programming level, it is also possible to identify any labelling device 14 positioning errors (each type of device requires a predetermined amount of free space before and after it - along the path of the products to be labelled - to guarantee correct label application).

It should also be noticed that this invention is relatively easy to produce and that even the cost linked to implementing the invention is not very high.

The invention described above may be modified and adapted in several ways without thereby departing from the scope of the inventive concept.

Moreover, all details of the invention may be substituted with other technically equivalent elements and in practice all of the materials used, as well as the shapes and dimensions of the various components, may vary according to requirements.