EP2334562A1

EP2334562A1 - Buffer device for labelling machines applying self-adhesive labels

Info

Publication number: EP2334562A1
Application number: EP08877375A
Authority: EP
Inventors: James Carmichael
Original assignee: Sidel SpA
Current assignee: Sidel SpA
Priority date: 2008-10-17
Filing date: 2008-10-17
Publication date: 2011-06-22
Also published as: CN102186728A; WO2010043267A1; CN102186728B

Abstract

The present invention relates to a buffer device (1) for a labelling machine having a driving rouer (5) continuously dispertsing a label film (3) and a feeding roil (6) which moves discontinuously the said label film (3) along a predefined path, wherein the said label film (3) forms a loop (4) comprising first an second substantially rectilinear portions (4a, 4b) joined by an arc-shaped portion (4c) and wherein the said buffer device (1) is positioned in such a way to contain the said loop (4) or part of it, characterised in that the said buffer device (1) comprises at ieast one side panel (7a) and blowing means (8a) that blow air tangentially to the said first rectilinear portion (4a) of the loop (4), towards its arc-shaped portion (4c) and along the said at least one side panel (7a).

Description

"BUFFER DEVICE FOR LABELLING MACHINES APPLYING SELF-ADHESIVE LABELS" DESCRIPTION

The present invention relates to a buffer device to be used in labelling machines that apply self-adhesive labels to objects, particularly containers.

Labelling machines that separate self adhesive labels from a backing film and transfer them onto the surface of containers are known and widespread used. In these machines the containers are carried by a carrousel and come into contact with a labelling unit. In such labelling unit, a reel film comprising a backing film that carries a plurality of self adhesive labels adhered thereon is delivered, by means of appropriate driving gears, to the containers rotating around the carrousel. Before the application to the container, the self adhesive label is separated by the backing film by means of a suitable blade or wedge device. The backing film portion separated from the labels is wound again to form a recovering reel.

Typically, the driving system comprises a driving roller that moves the film from the reel to the containers labelling station, a feeding roll that synchronises the label film to the containers and a rewinding motor that recovers the empty portion of the film onto a recovering reel.

While the main carrousel carrying the containers has a continuous motion, the feeding roll and the removing roll move discontinuously . This is due to the fact that the pitch between the containers on the carrousel is greater than the pitch between the labels on the backing film, as it is convenient to adhere the labels close together on the backing film to save costs, the said backing film being very expensive with respect to the labels. It is therefore necessary that the feeding roll stops dispensing the labels to the carrousel between an application and the subsequent one and that the removing roll follow the same motion law.

Also the dispensing reel and the recovering reel are motorized and move of a continuous motion. This means that both upstream the feeding roll and downstream the removing roll the label strip tends to form a loop that lengthen or shorten with an oscillating behaviour, as the rolls stop or move. In fact, when the feeding roll stops, the dispensing reel continues to dispense the film and the loop lengthens. When the feeding roll starts, the loop shortens. The contrary happens for the loop downstream the removing roll.

Normally, the film loop is routed through a box that is called buffer. The control of the loop is typically given by a blower that is positioned outside the buffer, at the other side with respect to the label film, and that blows air perpendicularly to the label film to push the loop into the box. However, this conventional solution is not very practical, as the system is bulky, particularly for the presence of the blower. As a consequence, the access to the machine is difficult, particularly in case of maintainance or cleaning operations. It is therefore an object of the present invention to provide a self-adhesive label feeding system that overcomes the above drawbacks, as defined in the appended claims whose definitions are integral part of the present description. Further features and advantages of the present invention will be better understood from the description of preferred embodiments, which are given below by way of a non-limiting illustration, with reference to the following figures: Fig. 1 is a schematic sectional plan view of the buffer device according to the invention;

Fig. 2 is a perspective view with phantom lines of the buffer of figure 1 ;

Fig. 3 is a schematic sectional plan view of a second embodiment of the buffer device according to the invention .

With reference to the figures, the buffer device of the invention is indicated with the numeral 1.

The buffer device 1 is positioned along the path of the self-adhesive label film 3, only part of which is shown in the figures, and particularly it is intermediate between the driving roller 5 of a label film, coming from a label reel 50, and a feeding roll 6 that moves the label film toward the point of the application of the label onto the objects.

Analogously, a second buffer device 1 is positioned between the removing roll - that moves the backing film free from labels from the point of application of the labels onto the objects toward the recovering reel and the recovering reel itself. This path is not shown in the figures as it is specular to the one of figure 1.

In figure 1, two pinching rollers 2, 2' are provided to press the label film against the driving roller 5 and the feeding roll 6, respectively. As it can be seen, between the driving roller 5 and the feeding roll 6, the self-adhesive label film 3 forms a loop 4. The said loop 4 is due to the fact that, while the label film 3 is dispensed continuously from the driving roller 5, it is pulled in a discontinuous way by the feeding roll 6 as explained in the background discussion above. For this reason, the loop 4 oscillates between two different loop lengths 4', 4'', wherein the shorter loop length 4' is reached at the end of the motion of the feeding roll 6, while the longer loop length 4" occurs just before the said feeding roll 6 starts again to work.

The label loop 4 comprises a first rectilinear portion 4a, a second rectilinear portion 4b and an arc- shaped portion 4c joining the two rectilinear portions 4a, 4b.

The buffer device 1 is designed to contain the said loop 4 of the label film 3 in the way that will be described herein below.

The buffer device 1 comprises a first side panel 7a and a second side panel 7b, that extend substantially parallel to each other and to the said first and second rectilinear portions 4a, 4b of the label loop 4, for a length that is at least equal to the longer loop length 4". In the region close to the ends of the loop 4 that are proximal to the driving roller 5 and to the feeding roll 6, the said side panels 7a, 7b comprise respective first and second blowing means 8a, 8b for blowing air tangentially to the loop 4, towards its arc-shaped portion 4c. The blowing means 8a, 8b comprise a body 9a, 9b that has a substantially V-shaped recess 10a, 10b (or other aerodynamic shaped slot or orifice) being vertically carved on the body 9a, 9b side facing the loop 4.

The body 9a, 9b also comprises a vertical blind channel 11a, lib, open at the top of the body 9a, 9b. From the channel 11a, lib a plurality of transversal ducts 12a, 12b depart, the ducts 12a, 12b opening at corresponding outlets 13a, 13b positioned on the side of the recess 10a, 10b facing towards the arc-shaped portion 4c of the loop 4.

A cannula 14a, 14b is slidably inserted in the said channel 11a, lib such as to be set at a desired height. The cannula 14a, 14b is in fluid communication with fan means or any other source of pressurised air (not shown) . Depending on the height which the cannula 14a, 14b is set to, only some or all of the ducts 12a, 12b are put into flow communication with the source of pressurised air. This different arrangement depends on the width of the label film 3 that on its turn depends on the dimension, shape and requirements of the object to be labelled.

The distal end of at least one of the first and second side panels 7a, 7b is bended inwardly of an angle of between 45° and 90°, in order to create a shield 15a, 15b that directs the air flow in a downward direction far from the operator of the machine.

The inventive buffer device 1 operates as it will be now described.

The air blown off the outlets 13a, 13b flows as a laminar layer along the side panels 7a, 7b. In such a way it creates a sort of "Venturi effect" or "ejector effect", wherein the loop 4 of the label film 3 is aspirated and maintained substantially parallel to the side panels 7a, 7b without contacting them. While the first rectilinear portion 4a of the loop 4 is driven inwardly into the buffer device 1 by the said air flow, the second rectilinear portion 4b is pulled by the feeding roll 6 against the force imparted by the air flow exiting the respective outlets 13b, that would recall the loop into the buffer device 1. As a result, also the second rectilinear portion 4b of the loop 4 is tensioned. In a second embodiment of the invention, as shown in figure 3 (wherein the same numbers indicate the respective parts of the first embodiment of fig. 1), the second side panel 7b and blowing means 8b, respectively, are replaced by vacuum means 20. The vacuum means 20 comprise a hollow body 21 in fluid communication with a vacuum source 23 such as a vacuum pump. The face of the hollow body 21 looking at the rectilinear portion 4b of the loop 4 has a plurality of through holes 22 from which vacuum is applied on the said rectilinear portion 4b of the loop 4 to keep it tensioned.

In this case, the operation of the buffer device 1 is substantially similar to the first embodiment, but the vacuum means 20 withdraw the rectilinear portion 4b of the loop 4 against them, so that it slides on the surface of the vacuum means 20.

Therefore, it is another object of the present invention a method for buffering and/or containing a loop 4 formed along the path of a label film 3, wherein the said loop 4 has a first and second substantially rectilinear portions 4a, 4b joined by an arc-shaped portion 4c, the method comprising a step of blowing a laminar flow of pressurised air tangentially along the external side of at least one of the said first and second substantially rectilinear portions 4a, 4b of the loop 4.

The inventive buffer device achieves the scope of the invention, as it is simple in operation, of low cost and moreover allows to avoid bulky fan means or any other part positioned outside the buffer box long the path of the label film 3. This latter is always easily accessible by the operator of the machine.

Additionally, the inventive buffer device does not need an adjustable cover plate to be provided on the top of the device and which must be regulated, according to the prior art machine, depending on the label height.

It will be appreciated that only particular embodiments of the present invention have been described herein, to which those skilled in the art will be able to make any and all modifications necessary for its adjustment to specific applications, without however departing from the scope of protection of the present invention as defined in the annexed claims.

Claims

1. Buffer device (1) for a labelling machine having a driving roller (5) continuously dispensing a label film (3) and a feeding roll (6) which moves discontinuously the said label film (3) along a predefined path, wherein the said label film (3) forms a loop (4) comprising first and second substantially rectilinear portions (4a, 4b) joined by an arc-shaped portion (4c) and wherein the said buffer device (1) is positioned in such a way to contain the said loop (4) or part of it, characterised in that the said buffer device (1) comprises at least one side panel (7a) and blowing means (8a) that blow air tangentially to the said first substantially rectilinear portion (4a) of the loop (4), towards its arc-shaped portion (4c) , and along the said at least one side panel (7a) .

2. Buffer device (1) according to claim 1, wherein there are provided first and second side panels

(7a, 7b) and first and second blowing means (8a, 8b) , wherein the said side panels (7a, 7b) and the said blowing means (8a, 8b) are positioned along the said first and second substantially rectilinear portions (4a, 4b) of the loop (4), respectively.

3. Buffer device (1) according to claim 1, wherein there is provided one side panel (7a) and one blowing means (8a) along the said first substantially rectilinear portion (4a) of the loop (4) and vacuum means (20) along the said second substantially rectilinear portion (4b) of the loop (4) .

4. Buffer device (1) according to any one of claims 1 to 3, wherein the said blowing means (8a, 8b) comprise a body (9a, 9b) that has a recess (10a, 10b) being vertically carved on the side of the body (9a, 9b) facing the loop (4), the body (9a, 9b) also comprising a vertical blind channel (Ha, lib) from which a plurality of transversal ducts (12a, 12b) depart, the ducts (12a, 12b) opening at corresponding outlets (13a, 13b) positioned on the side of the recess (10a, 10b) facing toward the arc-shaped portion (4c) of the loop (4) .

5. Buffer device (1) according to claim 4, wherein the said recess (10a, 10b) is substantially V- shaped.

6. Buffer device (1) according to claim 4 or 5, wherein a cannula (14a, 14b) is slidably inserted in the said channel (Ha, lib) such as to be set at a desired height, the cannula (14a, 14b) being in fluid communication with fan means or any other source of pressurised air.

7. Buffer device (1) according to claim 6, wherein, depending on the height which the cannula (14a, 14b) is set to, only some or all of the ducts (12a, 12b) are put into flow communication with the said source of pressurised air.

8. Buffer device (1) according to any of claims from 1 to 7, wherein the distal end of at least one of the first and second side panels (7a, 7b) is bended inwardly of an angle of between 45° and 90°, in order to create a shield (15a, 15b) that directs the air flow in a downward direction .

9. Buffer device (1) according to claim 3, wherein the said vacuum means (20) comprise a hollow body (21) in fluid communication with a vacuum source (23), the face of the hollow body (21) looking at the second rectilinear portion (4b) of the loop (4) having a plurality of through holes (22) from which vacuum is applied on the said second rectilinear portion (4b) of the loop (4) to keep it tensioned.

10. Method for buffering and/or containing a loop

(4) formed along the path of a label film (3), wherein the said loop (4) has a first and second substantially rectilinear portions (4a, 4b) joined by an arc-shaped portion (4c), the method comprising a step of blowing a laminar flow of pressurised air tangentially along the external side of at least one of the said first and second substantially rectilinear portions (4a, 4b) of the loop (4) .

11. The method of claim 10, wherein the said laminar flow of pressurised air is applied at both the first and second substantially rectilinear portions (4a, 4b) of the loop (4) .

12. The method according to claim 10, wherein vacuum is applied on the said second substantially rectilinear portion (4b) of the loop (4) .