Labelling machine having detection means for detecting the presence or absence of a label on a working drum

Abstract

A labelling machine comprising a conveying means (2) for the containers (3) to be labelled along a forward path and at least one labelling assembly (6) arranged along the forward path of the containers (3). The labelling assembly (6) comprises a working drum (8) which can move in rotation about its own axis and has a suction port on a side surface which can be connected by a connecting means (10) to a suction means (11) in order to enable the working drum (8) to receive a label (7) to be transferred to the containers (3) passing on the conveying means (2) so as to be adhered to the side surface. Means for detecting the presence or absence of a label (7) on the working drum (8) are provided. According to the invention, the aforementioned detecting means comprises at least one sensor for detecting the pressure in the connecting means (10).

Description

[Technical field]

[0001] The present invention relates to a labelling machine. [Background technology]

[0002] 2. Description of the Related Art Labelling machines are known which enable automatic labelling of containers with labels obtained by cutting a label ribbon on which a plurality of labels are printed in succession.

[0003] Generally, such a labelling machine includes a conveyor for the containers to be labelled along an advancing path, and at least one labelling assembly arranged along the advancing path of the containers defined by the conveyor and capable of applying at least one label onto the containers passing on the conveyor.

[0004] Typically, the labelling assembly has a working drum, commonly called a transfer drum, which rotates stepwise in tandem with the carousel, making it possible to apply respective labels onto the containers moving on the carousel, the labels typically being obtained by precutting a label ribbon which is taken off a spool by an unwinding assembly.

[0005] The label ribbon may be of the pre-glued type, i.e. it may already have a layer of adhesive pre-applied on the side of the label intended to come into contact with the container while still wound on the spool, or it may not have pre-glued, in which case there is an assembly in the labelling machine for applying adhesive to the label before it is transferred to the container.

[0006] In particular, labelling machines are known in which a cutting drum is inserted between the unwinding assembly and the transfer drum and is designed to receive, on its side, the label ribbon taken from the unwinding assembly and to cut off the individual labels which are transferred to the transfer drum, the individual labels remaining attached to the side of the cutting drum by means of suction ports until they are glued to the containers.

[0007] Typically, the transfer drum is circumferentially divided into sectors or sections, each of which is designed to receive a respective label from the cutting drum.

[0008] The cutting drum may integrally include one or more blades which cooperate with a fixed blade integrally fixed to the support structure of the machine to sever the label ribbon between one label and the next.

[0009] Labelling machines are also known in which both the label cutting and label transferring functions are performed by the same working drum, which is called the cutting and transferring drum.

[0010] In this case, the cutting and transferring drum receives the label ribbon supplied by the unwinding assembly by suction ports attached to the side of the cutting and transferring drum, using a blade associated therewith, to cut the label ribbon and transfer the separated individual labels to containers transported by the carousel.

[0011] For example, as disclosed in WO 2018 / 114618 in the name of the same applicant, a working drum is known which is designed to receive a label ribbon on its side and which is provided with a number of cutting devices around its side, each of the cutting devices comprising a blade integrally fixed to the cutting drum and housed in a corresponding suction chamber, which opens at the side of the working drum and communicates with air suction means which are able to draw the label ribbon inwardly into the suction chamber so as to press it against the blade, so that cutting takes place.

[0012] During operation of the labeling assembly, it is necessary to continuously check for the presence of cut labels on the label ribbon or working drum.

[0013] Typically, this check is performed using photocells positioned around the periphery of the working drum.

[0014] For example, a first photocell is arranged in front of a first part of the working drum, which is located upstream of the area for transfer of labels from the working drum to individual containers, with respect to the direction of rotation of the working drum, and its function is to detect the presence on the working drum of cut labels which are about to be applied to the respective containers.

[0015] A second photocell is positioned before a second portion of the working drum, located immediately downstream of the area for transfer of labels from the working drum to the containers, relative to the direction of rotation of the working drum, the function of which is to verify that there are no labels on that portion of the drum, i.e. that those labels have been effectively transferred to the containers.

[0016] Again with respect to the direction of rotation of the working drum, downstream of the second photocell and in front of the part of the working drum located downstream of the device for discharging untransferred labels from the working drum, there can optionally be a third photocell, the function of which is to confirm that the label has been removed from the working drum as a result of operation of the discharging device, in particular if the second photocell detects that a label is still present on the working drum.

[0017] The use of photocells as described above entails several drawbacks.

[0018] Firstly, the presence of photocells around the sides of the working drum makes it rather difficult to change to another working drum of a different diameter from the one in use, in which case it becomes necessary to relocate the photocells which, for the sake of space occupied and ease of reading, must be located very close to the outer surface of the working drum.

[0019] Furthermore, the photocells used cannot easily detect transparent labels. [Prior art documents] [Patent documents]

[0020] [Patent Document 1] International Publication No. 2018 / 114618 Summary of the Invention [Problem to be solved by the invention]

[0021] It is an object of the present invention to provide a labelling machine which is able to avoid the drawbacks of the known art in one or more of the above mentioned aspects.

[0022] Within this objective, it is an object of the invention to provide a labelling machine which makes it possible to detect the presence or absence of a label on the working drum of the labelling assembly without the use of photocells.

[0023] Another object of the present invention is to provide a labelling machine capable of detecting the presence or absence of a label on the working drum of a labelling assembly without occupying external space around the working drum.

[0024] Another object of the invention is to provide a labelling machine which makes it possible to detect the presence or absence of a label on a working drum without affecting the operation for changing the format of the working drum.

[0025] Another object of the invention is to provide a labelling machine which makes it possible to detect the presence or absence of a label on the working drum of the labelling assembly independently of the colour of the label.

[0026] A further object of the present invention is to overcome the drawbacks of the background art in an alternative manner to any existing solutions.

[0027] Another object of the present invention is to provide a labelling machine which is reliable, relatively easy to implement and can be manufactured at low cost. [Means for solving the problem]

[0028] This object, as well as these and other objects which will become more apparent hereinafter, are achieved by a labelling machine according to claim 1, optionally comprising one or more of the features of the dependent claims.

[0029] Further features and advantages of the invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a labelling machine according to the invention, illustrated by way of non-limiting example in the accompanying drawings, in which: [Brief description of the drawings]

[0030] [Figure 1] 1 is a schematic perspective view of a labelling machine according to the invention; [Diagram 2] FIG. 2 is a perspective view of the working drum of the machine according to the invention; [Diagram 3] FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 2 is a schematic plan view from above of a vacuum distribution unit associated with a working drum of the labeling assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] With reference to the figures, a labelling machine according to the invention is generally designated by the numeral 1 and comprises conveying means 2 for containers 3 to be labelled along an advancing path.

[0032] Conveniently, the transport means 2 comprises a rotating carousel 4 having mounted therearound a rotating pan 5 for supporting the individual containers 3 to be labelled.

[0033] Along the forward path of the containers 3 is positioned at least one labelling assembly 6 which applies a respective label 7 to each container 3 .

[0034] In particular, the labelling assembly 6 comprises a working drum 8 which can move in rotation about its own axis and has a suction port 9 on a side which can be connected by a connection means 10 to a suction means 11 in order to enable the working drum 8 to receive a label 7 which is to be transferred to a container 3 passing on the conveying means 2 and adhered to the side.

[0035] It should be noted that the suction ports 9 may, as is conventional, be defined in at least a portion of the runners 12 arranged slightly raised relative to the remainder of the side of the working drum 8, and may further be defined in a circumferential portion or sector of the side of the working drum 8 arranged between the runners 12.

[0036] Conveniently, the working drum 8 is fed via an unwinding assembly 13 which unwinds label ribbon 15 taken from a respective spool 15a via a tensioning device 14 as known in the art.

[0037] In the unwinding direction of the label ribbon 15, upstream of the working drum 8 there may be means for cutting the label ribbon 15, which are constituted, for example, by a cutting drum not shown, in which case the working drum 8 simply performs the function of a transfer drum for transferring the label 7 to the container 3.

[0038] Alternatively, as shown, the working drum 8 can include at least one cutting device 16, which enables the working drum 8 to cut the label ribbon 15 which it receives, in this case directly, from the unwinding assembly 13, thus performing the functions of a cutting and transfer drum.

[0039] For example, as shown, the (or each) cutting device 16 can be constituted by a blade 16a housed in a suction chamber 16b opening on a side of the working drum 8 and which can be connected to an air suction means, which can optionally be constituted by said suction means 11, drawing the label ribbon 15 into the suction chamber 16b and pressing it against the blade 16a, as a result of which the label ribbon 15 can be cut.

[0040] The label ribbon 15 may be of the type pre-glued with adhesive or may not be pre-glued, in which case, as shown, means for applying adhesive to the labels 7 may be arranged around the working drum 8, said means being constituted, for example, by an adhesive roller 17 making it possible to apply a respective adhesive strip to the end area of ​​each label 7 arranged on the runner 12.

[0041] Likewise, there are detection means on the machine which make it possible to detect the presence or absence of the label 7 on the working drum 8 .

[0042] The detection means comprises at least one sensor 18 for detecting the pressure present in the connection means 10 enabling the connection between the suction port 9 and the suction means 11 .

[0043] Advantageously, there is at least one control unit 19 functionally connected to the sensor 18 (or each sensor) and configured to compare the pressure value detected by the sensor 18 with at least one preset reference pressure value, for example a pressure value close to or substantially equal to the atmospheric pressure value, the control unit 19 being preferably constituted by an electronic controller.

[0044] In particular, when the label 7 is present on the working drum 8, due to the fact that the suction port 9 is closed by the label 7, the pressure value detected by the sensor 18 in the connection means 10 will be lower than the reference pressure value, whereas when the label 7 is not present, the pressure value detected by the sensor 18 will be closer to the reference pressure value.

[0045] Advantageously, the control unit 19 is functionally connected to at least one detector 20 of the angular position of the working drum 8 relative to a fixed reference position, which makes it possible to correlate the pressure values ​​detected by the sensor 18 during the rotation of the working drum 8 with the angular position assumed by the working drum 8.

[0046] For example, such a detector 20 is constituted by an encoder attached to the rotation shaft 21 of the working drum 8 .

[0047] Advantageously, signaling means 22 can be provided which are able to emit a warning signal, for example an acoustic or luminous signal, which is functionally connected to the control unit 19 and operates on command by the control unit 19 to emit a warning signal based on a comparison performed by the control unit 19 between the pressure value detected by the sensor 18 and a reference pressure value.

[0048] It should be noted that the sensor 18 is arranged within the lateral occupied space of the working drum 8 in order to facilitate the possibility of replacing the working drum 8 with another one of different dimensions.

[0049] More specifically, the connection means 10 comprises a fixed vacuum distribution unit 25 on which the working drum 8 is rotatably mounted.

[0050] At least one suction cavity 26 is defined in the distribution unit 25 and is connected to a vacuum generator 27 providing suction means, the vacuum generator 27 being constituted for example by a vacuum pump.

[0051] The (or each) suction cavity 26 has or is connected to at least one communication opening 28 arranged on the face of the distribution unit 25 facing the working drum 8 .

[0052] For example, as shown in FIG. 4, the suction port 9 arranged on the side of the working drum 8 is connected, for example via at least one duct 29, to at least one connection opening 30 defined in the face of the working drum 8 directed towards the distribution unit 25, so that the connection opening 30 can establish communication with each communication opening 28 defined in the distribution unit 25 during rotation of the working drum 8.

[0053] As shown in FIG. 4, the sensor 18 can be mounted on the distribution unit 25 or alternatively can be integral with the working drum 8 .

[0054] Preferably, several sensors 18 are provided in order to be able to detect the presence or absence of a label 7 on different parts of the working drum.

[0055] In particular, there may be at least one first sensor, indicated as 18a in FIG. 5, which is capable of detecting the presence of a label 7 which is about to be attached to a corresponding container 3, i.e. which is positioned on the first part 8a of the working drum 8, and which is positioned upstream of the area 31 in which the working drum 8 performs the transfer of the label 7 to the arrived container 3 on the conveying means 2, with respect to the direction of rotation of the working drum 8.

[0056] Advantageously, there is again a second sensor, indicated as 18b in FIG. 5, the function of which is to detect the absence of label 7 on a second part 8b of the working drum 8 located downstream of the area 31 for transferring the label 7 to the container 3, relative to the direction of rotation of the working drum 8, in order to make it possible to verify that the label 7 has been effectively transferred to the container 3 by the working drum 8.

[0057] Advantageously, downstream of the area 31 for transferring the label to the container, with respect to the direction of rotation of the working drum 8, there is also at least one removal device 32, the function of which is to remove from the working drum 8 any labels 7 that have not been transferred to the container 3 in the area 31 for transferring the label 7 to the container 3.

[0058] For example, as is known per se, such a removal device 32 can be provided by using a set of suction ports 9 arranged in a part of the working drum 8 that is located downstream of the area 31 for transferring the label 7 to the container 3, relative to the direction of rotation of the working drum 8, to eject an outwardly directed jet of air so as to remove from the working drum 8 the label 7 that has not been transferred to the container 3 and remains on said working drum.

[0059] More specifically, the removal device 32 is provided, for example, by having at least one opening 32a on the upper surface of the distribution unit 25, connected to a compressor 32b and arranged to communicate with a suction port 9 of the working drum 8 arranged in a part of the working drum 8 located in each case downstream of the area 31 for transferring the label 7 to the container 3.

[0060] Advantageously, there is also at least one third sensor, indicated with 18c, which is able to detect the absence of a label on a third part 8c of the working drum 8 located downstream of the removal device 32, with respect to the direction of rotation of the working drum 8, thereby making it possible to ensure that the labels 7 which have not been transferred in the transfer area 31 have been effectively removed from the working drum 8 by the removal device 32.

[0061] As shown in particular in FIG. 5 , in the distribution unit 25, at least one first communication opening, indicated with 28a, is defined, which allows connection of the suction port 9 located in the first part 8a of the working drum 8 to a vacuum generator 27.

[0062] Advantageously, the first communication opening 28a has an elongated slot shape and extends substantially parallel to the segment of the path of the label 7 on the working drum 8 along which the label 7 must be held against the side of the working drum 8 so that the label 7 can be transported towards the area 31 for transfer to the container 3.

[0063] Advantageously, as shown in FIG. 5, the first sensor 18a is associated with a first communication opening 28a of the distribution unit 25.

[0064] Again, as can be seen in FIG. 5, in the distribution unit 25 there is a second communication opening 28b arranged angularly spaced relative to the first communication opening 28a around the axis of the distribution unit 25 to enable connection of the suction port 9 located in the second part 8b of the working drum 8 to a vacuum generator 27.

[0065] As shown, the second sensor 18b is conveniently associated with a second communication opening 28b.

[0066] Furthermore, the distribution unit 25 advantageously has at least one third communication opening 28c, the function of which is to enable connection of the suction port 9 located in the third part 8c of the working drum 8 to a vacuum generator 27.

[0067] In this case, the third sensor 18c is associated with the third communication opening 28c.

[0068] The operation of the machine according to the invention is as follows.

[0069] The working drum 8 receives the label ribbon 15 supplied by the unwinding assembly 13 substantially at a first portion 8a and holds the label ribbon by means of suction ports 9 present in the first portion 8a.

[0070] The labels 7 arranged on the first part 8a of the working drum 8 receive adhesive from an adhesive roller 17 and are cut off from the label ribbon 15 by a cutting device 16 before reaching a transfer area 31 where they are transferred from the working drum 8 to the respective containers 3 being transported on the transport means 2.

[0071] The control unit 19 receives the pressure value actually present at the first communication opening 28a from the first sensor 18a and compares it with a reference pressure value, which is set, for example, to the atmospheric pressure value.

[0072] If a label 7 is present on the first part 8a of the working drum 8, the pressure value detected by the first sensor 18a will be lower than a preset threshold, a reference pressure value, and the control unit 19 will infer the presence of the label 7 on the first part 8a of the working drum 8 from a comparison of the pressure value detected by the first sensor 18a with the reference pressure value.

[0073] On the other hand, if the pressure value detected by the first sensor 18a is substantially equal to the reference pressure value or in any case close to it, the control unit 19 deduces that no label 7 is present in the first part 8a of the working drum 8.

[0074] The labels 7 that have reached the transfer area 31 are transferred onto the respective containers 3 in such a way that no labels 7 are present in the second part 8b of the working drum 8.

[0075] As a result, the second sensor 18b detects a pressure value that is substantially equal to or close to the reference pressure value and, from a comparison of the pressure value received from the second sensor 18b with the reference pressure value, the control unit 19 deduces that no label 7 is present in the second part 8b of the working drum 8.

[0076] On the other hand, if the label 7 is not transferred in the transfer area 31, for example due to a shortage of containers 3 on the conveying means 2 or other anomalies, the label 7 will be present on the second part 8b of the working drum 8, which will be detected by the control unit 19 due to the fact that the pressure value received from the second sensor 18b is lower than a preset threshold value, the reference pressure value.

[0077] The labels 7 which have not been transferred to the containers 3 in the transfer area 31 and remain on the working drum 8 are then removed from the working drum 8 by a removal device 32 .

[0078] After removal by the removal device 32 of the label 7 that has not been transferred from the working drum 8 in the transfer area 31, the control unit 19 confirms that no label 7 is substantially present in the third portion 8c of the working drum 8 by comparing the pressure value detected by the third sensor 18c with a reference pressure value.

[0079] If the label 7 should not be removed by the removal device 32 from the working drum 8 due to an operational abnormality of the removal device 32, the control unit 19 infers the presence of a label on the third part 8c of the working drum 8 by the pressure value detected by the third sensor 18c being lower than a preset threshold, reference value.

[0080] In this case, the control unit 19 can activate the signaling means 22 to warn an operator of an anomaly in the operation of the removal device 32 .

[0081] It should be noted that the control unit 19 can also identify the possible presence of an obstruction in the suction port 9 or the connection means 10 if it finds a deviation between the pressure value detected by the sensor 18 and the value expected under normal operating conditions, both in the presence of the label 7 and in the absence of the label 7.

[0082] In fact, it has been found that the present invention fully achieves its intended aims and objectives by providing a labelling machine with pressure measurements by sensors for detecting pressure for monitoring the presence or absence of labels on the working drum, completely independent of the colour of the label and which are inside the working drum and do not require outside the occupied space of the drum, in that their position is independent of the dimensions of said working drum.

[0083] Another advantage of the machine according to the invention is that, again by using a sensor for detecting pressure, it makes it possible to detect possible blockages in the suction port of the working drum and to carry out preventive cleaning of the duct or to replace the blocked parts.

[0084] The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other technically equivalent elements.

[0085] In practice, the materials used, as well as the conditional shapes and dimensions, can be any, depending on the requirements and the state of the art.

[0086] The disclosures of Italian Patent Application No. 102022000003122, from which this application claims priority, are incorporated herein by reference.

[0087] Where technical features described in any claim are followed by reference signs, those reference signs are included solely for the purpose of enhancing the comprehension of the claim, and therefore such reference signs do not have any limiting effect on the interpretation of the respective elements identified by such reference signs as examples.

Claims

1. A labelling machine comprising a conveying means (2) for containers (3) to be labelled along a forward path and at least one labelling assembly (6) arranged along said forward path of said containers (3), The labelling assembly (6) comprises a working drum (8), said working drum (8) is capable of rotating about its own axis and has a suction port on its side which can be connected to a suction means (11) by a connection means (10); the suction port enables the working drum (8) to receive the label (7) to be transferred onto the container (3) passing on the conveying means (2) so as to be adhered to the side surface; 13. A labelling machine, characterized in that means are provided for detecting the presence or absence of said label (7) on said working drum (8), said detection means including at least one sensor (18) for detecting the pressure in said connecting means (10).

2. 2. A labelling machine according to claim 1, characterised in that it comprises at least one control unit (19) functionally connected to said at least one sensor (18) and configured to compare pressure values ​​detected by said at least one sensor (18) with at least one reference pressure value.

3. at least one detector (20) of the angular position of said working drum (8) relative to a fixed reference position, 3. A labelling machine according to claim 2, characterized in that the detector (20) is functionally connected to the control unit (19) enabling the control unit (19) to correlate the pressure values ​​detected by the at least one sensor (18) with the angular position assumed by the working drum (8).

4. 3. A labelling machine according to claim 2, characterized in that it comprises signalling means (22) functionally connected to said control unit (19) and operable on command by said control unit (19) to emit a warning signal based on a comparison, performed by said control unit (19), of said pressure values ​​detected by said at least one sensor (18) with said reference pressure values.

5. 2. A labelling machine according to claim 1, characterised in that the at least one sensor (18) is arranged in the lateral occupied space of the working drum (8).

6. said connecting means (10) comprising a vacuum distribution unit (25) on which said working drum (8) is rotatably mounted, in said vacuum distribution unit (25) at least one suction cavity (26) is defined which is connected to a vacuum generator (27) and which is provided with at least one communication opening (28) located on a face of said vacuum distribution unit (25) directed towards said working drum (8); 6. A labelling machine according to claim 1, characterized in that the suction port (9) communicates with at least one connecting opening (30) defined on a face of the working drum (8) directed towards the vacuum distribution unit (25) and establishes communication with the at least one communication opening (28) during rotation of the working drum (8).

7. 7. A labelling machine according to claim 6, characterised in that said at least one sensor (18) is mounted on said vacuum distribution unit (25).

8. 2. A labelling machine according to claim 1, characterised in that said at least one sensor (18) is mounted on said working drum (8).

9. 2. A labelling machine according to claim 1, characterized in that the at least one sensor comprises at least one first sensor (18a) for enabling detection of the presence of the label (7) on a first part (8a) of the working drum (8) located upstream of an area (31) for transferring the label (7) to the container (3) with respect to the direction of rotation of the working drum (8).

10. 10. A labelling machine according to claim 1, characterized in that the at least one sensor comprises at least one second sensor (18b) for making it possible to detect the absence of the label (7) on a second part (8b) of the working drum (8) located downstream of an area (31) for transferring the label (7) to the container (3) with respect to the direction of rotation of the working drum (8).

11. 11. A labelling machine according to claim 1, characterised in that it comprises, downstream of the area (31) for transferring the labels (7) to the containers (3), with respect to the direction of rotation of the working drum (8), at least one removal device (32) for labels which have not been transferred to the containers (3) in the area (31) for transferring the labels (7) to the containers (3).

12. 12. A labelling machine according to claim 1, characterized in that the at least one sensor comprises at least one third sensor (18c) for detecting the absence of the label (7) in a third part (8c) of the working drum (8) which is located downstream of the removal device (32) with respect to the direction of rotation of the working drum (8).

13. 13. A labelling machine according to any one of claims 1 to 12, characterized in that at least one first communication opening (28a) is defined in the distribution unit (25) for connecting a suction port (9) located in the first part (8a) of the working drum (8) to the vacuum generator (27), and that the first sensor (18a) is associated with the first communication opening (28a).

14. 14. A labelling machine according to claim 1, characterized in that at least one second communication opening (28b) is defined in the distribution unit (25) for connecting a suction port (9) located in the second part (8b) of the working drum (8) to the vacuum generator (27), and that the second sensor (18b) is associated with the second communication opening (28b).

15. 15. A labelling machine according to claim 1, characterized in that at least one third communication opening (28c) is defined in the distribution unit (25) for connecting a suction port (9) located in the third part (8c) of the working drum (8) to the vacuum generator (27), and that the third sensor (18c) is associated with the third communication opening (28c).

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