EP2673201B1

EP2673201B1 - A vacuum drum and a method for transferring labels

Info

Publication number: EP2673201B1
Application number: EP11788851.1A
Authority: EP
Inventors: Mirko Rossi; Mattia Giuliani; Andrea Bocchi; Antonio Secchi
Original assignee: Sidel SpA
Current assignee: Sidel SpA
Priority date: 2011-02-11
Filing date: 2011-11-30
Publication date: 2017-01-04
Anticipated expiration: 2031-11-30
Also published as: WO2012107123A1; EP2673201A1

Description

TECHNICAL FIELD

The present invention relates to a vacuum drum for transferring labels.
The present invention also relates to a method for transferring labels.

BACKGROUND ART

As it is generally known, labelling machines are used to transport, prepare and apply labels to containers, such as bottles, or articles of all sort.
Typically used with beverage bottles or vessels are tubular labels (commonly called "sleeve labels"), which are obtained by:

cutting the web unwound from a supply roll into a plurality of rectangular or square labels;
bending each label in a cylindrical configuration such that the opposite vertical edges overlap one another; and
welding the overlapped edges of each cylindrical label.

Also widespread used are gluing labels, which, after being cut from a web at appropriate lengths, are glued by gluing means, such as a gluing roller, spray and injector systems or the like, and are finally transferred to respective containers or articles.
In both cases, the labels are retained on a vacuum drum by means of vacuum applied on the labels. In particular, a conventional vacuum drum has an approximately cylindrical lobed configuration and normally receives a succession of labels at an input station and, after a given rotation about its axis, transfers the labels at an output station so that they can be applied to respective articles or containers.
The vacuum drum is typically mounted, in a rotatable manner about its axis, on a stationary distributor member having first air passages connected to a vacuum source; the vacuum drum is in turn provided with second air passages, which communicate with the first air passages at certain angular positions of the drum around its axis and end into a plurality of vacuum ports formed through a drum outer lateral surface for receiving the labels.
Conventional vacuum drums are normally fabricated from monolithic aluminum castings and basically comprise a main body and a number of damping pads mounted into respective cavities formed in the peripheral portion of the main body.
The pads and the sections of the drum outer lateral surface interposed between each pair of pads are provided with the vacuum ports for retaining the labels by suction.
During transfer, each label has the leading end in the direction of rotation of the vacuum drum held on one pad, the trailing end held on another pad and the remaining part held on a section of the drum outer lateral surface comprised between the two mentioned pads.
In this way, the distance between these pads is equal to the length of the label to be processed measured along the circumference of the drum.
Furthermore, the height of the drum is equal to the height of the label to be processed measured parallel to the axis of the drum.
As a result, each format of the label calls for a vacuum drum having a given height and a given distance between the pads.
In other words, each format of the label to be transferred calls for a given format of the vacuum drum.
It is therefore needed the storing of a high number of drums and the mounting/dismounting of vacuum drum every time that the label format must be changed.
EP-A-2103530 discloses a vacuum drum according to the preamble of claim 1, and a method according to the preamble of claim 10.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a vacuum drum for use in labelling machines, which allows to overcome the above drawback in a straightforward and low-cost manner.
This object is achieved by a vacuum drum as claimed in claim 1.
The present invention also relates to a method for transferring a label along a path as claimed in claim 10.

BRIEF DESCRIPTION OF THE DRAWINGS

A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a perspective exploded view, with parts removed for clarity, of a vacuum drum in accordance with the teachings of the present invention;
Figure 2 shows the vacuum drum of Figure 1 during the processing of labels having a first format;
Figure 3 is an enlarged view of some components of the vacuum drum of Figures 1 and 2;
Figure 4 shows the vacuum drum of Figure 1 during the processing of labels having a second format;
Figure 5 is an enlarged view of some components of the vacuum drum of Figure 4;
Figure 6 is top a view of some components of a vacuum drum system comprising the vacuum drum of Figure 5; and
Figure 7 shows a schematic view of the vacuum drum system comprising the vacuum drum of Figures 1 to 6.

BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in Figure 7 indicates as a whole a vacuum drum system adapted to be used for handling and transferring labels 2a, 2b along an arc-shaped path P around an axis A to a labelling machine (known per se and not shown) for applying labels 2a, 2b to respective articles or more specifically containers, such as bottles (known per se and not shown).
Path P is shaped as a circular arc having the centre on the axis A and extends from station 3 to station 4.
Very briefly, the so-called "sleeve labeling machine" comprises:

cutting means for cutting a web of heat-shrinkable material unwound from a supply roll into a plurality of labels 2a, 2b;
vacuum drum system 1 for advancing each label 2a, 2b which has been previously cut;
bending means for bending each label 2a, 2b into a tubular configuration such that the opposite edges overlap one another;
welding means for welding the overlapped edges of each cylindrical label, so as to from a sleeve element;
movable mandrels for moving bottles towards corresponding sleeve elements, until these bottles engage relative sleeve elements; and
heating means for heat-shrinking the sleeve elements onto relative bottles and, accordingly, thus fixing the sleeve elements on to relative bottles.

Alternatively, the so-called "roll fed labeling machine" comprise:

a shaft for rotatably supporting a reel off which a strip of labels 2a, 2b is unwound and fed along a feed path;
a plurality of unwinding rollers for unwinding the backing web along a rectilinear feed path;
a cutter for cutting a sequence of single labels 2a, 2b from the strip;
vacuum drum system 1 for advancing each label 2a, 2b which has been previously cut; and
a gluing drum for applying glue onto the each previously cut label 2a, 2b.

Finally, labels 2a, 2b which have been cut and covered with glue are transferred to and applied onto the relative containers.
With reference to Figures 2, 4 and 7, vacuum drum system 1 is adapted to receive a succession of labels 2a, 2b at an input station 3 and to transfer labels 2a, 2b at an output station 4 (shown in Figure 2 and 4) located at a given angular distance from the input station 3 about axis A; the labels 2a, 2b are then applied to respective articles or containers on the labelling machine.
Labels 2a, 2b have a rectangular or square shape and are cut, in a known and not shown manner, from a web unwound from a supply roll.
More precisely, each label 2a, 2b has first sides 40a, 40b parallel to each other and second sides 41 parallel to each other and orthogonal to sides 40a, 40b.
The extension of sides 40a, 40b defines height H of label 2a, 2b while the extension of sides 41 defines length L of label 2a, 2b.
Length L and height H define the format of each label 2a, 2b.
In the embodiment shown, label 2a has a first format (Figures 2 and 3) whilst label 2b has a second format (Figures 4 and 5).
As each label 2a, 2b is transferred by vacuum drum 7, sides 40a, 40b are arranged parallel to axis A and sides 41 extend along a circular arc having the centre on the axis A.
Vacuum drum system 1 extends about axis A and basically comprises:

a stationary distributor member 5 (Figure 6) provided with a plurality of vacuum sources 22; and
a vacuum drum 7 (Figures 1 to 5) in accordance with the present invention, which is supported on distributor member 5 in a rotatable manner about axis A.

More precisely, distributor member 5 substantially comprises (Figure 6):

a plurality, four in the embodiment shown, of vacuum sources 22; and
an annular plate 23 defining a plurality, four in the embodiment shown, of through grooves 24 fluidly connected to respective vacuum sources 22 in a not shown way.

Drum 7 comprises (Figures 1 to 5):

a cylindrical main body 9 comprising a lateral outer surface 11 extending cylindrically with respect to axis A;
an annular base 14 arranged below body 9 and lying on a plane orthogonal to axis A;
an annular top plate 17 which covers the top of body 9; and
a bottom plate 13 arranged on the opposite side of plate 17 relative to body 9 and resting on plate 23 of distributor 5.

Surface 11 receives labels 2a, 2b and comprises a plurality of vacuum ports 10a, 10b.
Ports 10a, 10b are arranged (Figures 3 and 5) along:

a plurality of circumferential rows 15a, 15b, .. 15n parallel to each other, proceeding along the advancing sense of drum 7; and
a plurality of columns 16a, 16b, .., 16n parallel to each other and orthogonal to rows 15a, 15b, .., 15n, proceeding from the top towards the bottom of drum 7.

In the embodiment shown, rows 15a, 15b, .. 15n extend about axis A and columns 16a, 16b, .. 16n are vertical and parallel to axis A.
Base 14 defines a plurality of axially through grooves 26 which are distributed about axis A.
Plate 13 defines a plurality of axially through holes 25, arranged below grooves 26 and resting on grooves 24 of plate 23.
The position of holes 25 and grooves 24 is such that, as drum 7 rotates relative to distributor 5, each hole 25 is fluidly connected with one groove 24.
As a result, as drum 7 rotates relative to distributor 5, each hole 25 and groove 26 is fluidly connected to one of vacuum sources 22.
Body 9 of drum 7 is provided with:

a plurality of air passages 8 (only schematically shown in Figure 7) fluidly connected, on a first side, with relative ports 10a, 10b; and
a plurality of fluidic lines 12 (shown only in Figure 7).

Each fluidic line 12 fluidly connects a relative groove 26 with second sides of air passages 8 serving ports 10a, 10b of a relative column 16a, 16b, .., 16n, for each and every angular position of drum 7 about axis A.
In this way, air passages 8 are fluidly connected, on one side, with vacuum source 22 and, on the opposite side, with vacuum ports 10a, 10b of relative column 16a, 16b, .., 16n, for each and every angular position of drum 7 about axis A.
In other words, grooves 24, holes 25, grooves 26 and fluidic lines 12 form a pneumatic slip-ring 35 (only schematically shown in Figure 7) adapted to fluidly connect stationary vacuum sources 22 with rotary air passages 8, for each and every angular position of drum 7 about axis A.
When a fluid connection is established between ports 10a, 10b and vacuum sources 22, air is suctioned from the ports 10a so as to produce an attractive force on a relative label 2a, 2b towards the portion of outer lateral surface 11 of drum 7 where such ports 10a, 10b are formed.
As labels 2a, 2b are transferred by drum 7, their sides 40a, 40b define respectively a trailing and a leading edge of respective labels 2a, 2b with reference to the rotation sense of drum 7 about axis A.
Drum 7 is independently driven by a motor (not shown), such as a brushless motor or the like, placed below the drum or is driven by the motor of the labelling machine through suitable gears or transmissions.
The outer lateral surface 11 of drum 7 has an approximately cylindrical configuration. In particular, surface 11 does not comprise, in the embodiment shown, any pad projecting thereof.
Advantageously, vacuum drum 7 comprises control means 30 (Figure 7) configured for selectively connecting a given number of ports 10b to vacuum source 22, on the basis of the format of labels 2a, 2b to be transferred along path P, when air ports 10b of this given number are arranged between stations 3, 4 of path P, so as to transfer labels 2a, 2b along this path P.
For example, when labels 2a having the first format must be processed, vacuum is generated, for example, only through ports 10b of rows 15b, 15c, 15d and columns 16b, 16c, 16d, 16e, 16f, 16g; the other ports 10a failing to exert any suction action on labels 2a.
In this way, the vacuum is generated only through those ports 10b that form a pattern having a shape associated to the format of labels 2a to be transferred.
In particular, the vacuum is generated only through that ports 10b that are covered by label 2a, once that the latter has been fully received by surface 11.
More precisely, the distance measured parallel to axis A between rows 15b and 15d is less or equals the height H of labels 2a to be transferred.
The angular distance measured on surface 11 and around axis A between columns 16b and 16g is less or equals the length L of labels 2a to be transferred.
In the very same way, when labels 2b having the second format must be processed, the vacuum is generated only through ports 10b of rows 15b, 15c, 15d and columns 16c, 16d, 16e, the other ports 10a failing to exert any suction action on labels 2b.
In this way, the vacuum is generated only through those ports 10b that form a pattern having a shape associated to the format of labels 2b to be transferred.
In particular, the vacuum is generated only through those ports 10b that are covered by label 2b, once that the latter has been fully received by surface 11.
More precisely, the distance measured parallel to axis A between rows 15b and 15d is less or equals the height H of labels 2b to be transferred.
The distance measured onto surface 10 and around axis A between columns 16c and 16e is less or equals the length L of labels 2b to be transferred.
With reference to Figure 7, control means 30 comprise:

a control unit 31 for acquiring the format of labels 2a, 2b to be transferred along path P; and
a plurality of valves 32 controlled by control unit 31 and adapted to control the vacuum suction along passages 8 from vacuum sources 22 to ports 10a, 10b.

Each valve 32 is interposed along a relative passage 8.
Furthermore, each valve 32 may be arranged by control unit 31 and on the basis of the format of labels 2a, 2b to be transferred either:

in an open position in which it fluidly connects vacuum source 22 with relative port 10b, so that the vacuum is generated at relative port 10b; or
in a closed position in which it prevents the fluidic connection between vacuum source 22 and relative port 10a, so that the vacuum is not generated at relative port 10a.

More precisely, each valve 32 leaves open relative passage 8, when arranged in the first position and closes relative passage 8 when arranged in the closed position.
Each valve 32 is, in the embodiment shown, a silicon micro-valve.
Vacuum drum system 1 also comprises (Figure 7):

a stationary human machine interface 36 which allows the operator to select the format of labels 2a, 2b to be transferred;
a stationary programmable logic controller 37 which outputs command signals for control unit 31, on the basis of the format of labels 2a, 2b selected through human machine interface 36; and
an electric slip-ring 38 which electrically connects rotary control unit 31 with stationary programmable logic controller 37.

The operation of vacuum drum system 1 is briefly described hereafter with reference to labels 2a all having a given first format (Figures 2 and 3). In other words, all labels 2a have a given value of height H and length L.
Vacuum sources 22 are fluidly connected to lines 12 through the fluidic path formed by grooves 24, holes 25 and grooves 26, for each and every angular position of drum 7 relative to distributor 5.
Human machine interface 36 acquires the first format of labels 2a, and programmable logic controller 37 outputs, on the basis of this first format, command signals for control unit 31.
Control unit 31 controls, on the basis of this first format, valves 32 in such a way that:

first valves 32 are arranged in relative first position, thus allowing the air flow along relative first air passages 8 and establishing vacuum through ports 10b of rows 15b, 15c, 15d and columns 16b, 16c, 16d, 16e, 16f, 16g; and
second valves 32 are arranged in relative second positions, thus preventing the air from flowing along relative air passages 8 and preventing the vacuum from being established through other ports 10a.

In particular, ports 10b of rows 15b, 15c, 15d and columns 16b, 16c, 16d, 16e, 16f, 16g form a pattern which has a shape associated to shape of the first format of labels 2a (Figure 3).
Furthermore, columns 16b and 16g are the rearmost and the forwardmost respectively, proceeding according to the advancing sense of drum 7 around axis A.
More precisely, the distance measured along axis A between the uppermost row 15b and the lowermost row 15c is less than or equals height H of labels 2a.
The angular distance measured onto surface 11 and about axis A between the rearmost column 16b and the forwardmost column 16g is less than or equals length L of labels 2a.
When ports 10b of forwardmost column 16g reach input station 3, a label 2a can be transferred to the drum 7; in this condition, the label 2a positioned at input station 3 begins to be attracted towards the drum 7.
In this condition, side 40b is suctioned by ports 10a forming column 16e.
As drum 7 continues to rotate, the other ports 10b of columns 16f, 16e, 16d, 16c, 16b reach, one after the other, input station 3, so that whole label 2a contacts surface 11.
At this stage, also side 40a contacts surface 11 and label 2a can be transferred along path P.
As ports 10b of rearmost column 16b reach output station 4, relative valves 32 prevents the air from flowing along relative air passages 8. Accordingly, label 2a gradually detaches from vacuum drum 7 at output station 4 and can be applied onto a relative container.
When the format of labels 2a, 2b to be processed needs to be changed, for example by switching from the first to the second format, control unit 31 controls valves 32 in such a way that vacuum is generated through only ports 10b of rows 15b, 15c, 15d and column 16c, 16d, 16e.
In particular, control unit 31 controls, on the basis of this second format (Figures 4 and 5), valves 32 in such a way that:

first valves 32 are arranged in relative first position, thus allowing the air flow along relative first air passages 8 and establishing vacuum through ports 10b of rows 15b, 15c, 15d and column 16c, 16d, 16e; and
second valves 32 are arranged in relative second positions, thus preventing the air from flowing along relative air passages 8 and preventing the vacuum from being established through other ports 10a.

Accordingly, the vacuum is generated only at ports 10b which form a pattern having a shaped associated to the shape of second format of labels 2b.
In detail, the distance measured along axis A between the uppermost row 15b and the lowermost row 15d is less than or equals height H of labels 2b.
The angular distance measured onto surface 11 between the rearmost column 16c and the forwardmost column 16e is less than or equals length L of labels 2b.
The transfer of labels 2b is identical to the transfer of label 2a and is, therefore, not described in detail.
The advantages of vacuum drum 7 and of the method according to the present invention will be clear from the above description.
In particular, only one drum 7 is necessary for a wide range of formats of labels 2a, 2b to be transferred.
As a matter of facts, in case that the format of labels 2a, 2b needs to be changed, for example switching from the first format of labels 2a to the second format of labels 2b, the vacuum will be established only at those ports 10b which form a pattern shaped as such second format.
Accordingly, in order to change the format of the labels 2a, 2b to be transferred, it is necessary only that human machine interface 36 acquires the new value of this format and control unit 31 controls valves 32 on the basis of the acquired format.
As a consequence, a wide range of format of labels 2a, 2b can be processed without changing the vacuum drum 7, so dramatically reducing the storing and setting-up costs.
Clearly, changes may be made to vacuum drum 7 and to the method as described and illustrated herein without, however, departing from the scope of protection as defined in the accompanying claims.

Claims

A vacuum drum (7) adapted to transfer at least one label (2a, 2b) along a given path (P) around a rotation axis (A), comprising:
- a main body (9) delimited by an outer lateral surface (11) which is adapted to receive said label (2a, 2b) to be transferred;

- a plurality of air ports (10a, 10b) defined by said surface (11) and connectable to a vacuum source (22);

- control means (30) configured for selectively connecting, on the basis of a selected format of the label (2a, 2b) to be transferred along said path (P), a given number of said air ports (10b) to said vacuum source (22), when said air ports (10b) of said given number are arranged between an inlet and an outlet station (3, 4) of said path (P), so as to transfer said label (2a, 2b) along said path (P);
characterized in that said control means (30) comprise a plurality of valves (32) controllable by a control unit (31) of said control means (30) on the basis of said selected format to allow an air flow between said vacuum source (22) and only said given number of air ports (10b).
The vacuum drum of claim 1, characterized in that at least one of said valves (32) is a silicon micro-valve.
The vacuum drum of claims 1 or 2, characterized by comprising a plurality of air passages (8) having each a first end connected to a relative said air port (10a, 10b and a second end, opposite to said first end, connectable to said vacuum source (22);
each said valve (32) being interposed along a relative air passage (8).
The vacuum drum of any one of foregoing claims, characterized in that said surface (11) is cylindrical.
The vacuum drum of any one of the foregoing claims, characterized in that said given number of air ports (10b) forms, in use, a pattern associated to said selected format of said label (2a, 2b).
The vacuum drum of any one of the foregoing claims, characterized by comprising a plurality of fluidic lines (12) connected each to a respective number of said air passages (8) and connectable to said vacuum source (22) for each and every angular position of said vacuum drum (7) about said axis (A).
A vacuum transfer system (1) comprising:
- a stationary distributor member (5) housing said vacuum source (22); and

- a vacuum drum (7) according to any one of the foregoing claims, and movable relative to said distributor member (5).
The vacuum transfer system of claim 7, when depending on claim 6, characterized by comprising a pneumatic slip-ring (35) for fluidly connecting said vacuum source (22) and said fluidic lines (12) for each and every angular position of said drum (7) about said axis (A) .
The vacuum transfer assembly of claim 7 or 8, characterized by comprising a stationary human machine interface (36) for receiving an indication associated to said format of said label (2a, 2b) to be transferred, and electrically connected to said control means (30).
A method for transferring at least one label (2a, 2b) along a given path (P) around a rotation axis (A), by using a vacuum drum (7) comprising:
- a main body (9) delimited by an outer lateral surface (11); and

- a plurality of air ports (10a, 10b) defined by said surface (11);
said method comprising the steps of:
- driving in rotation said vacuum drum (7) about said axis (A); and

- receiving said label (2a, 2b) at said outer lateral surface (11);

- selecting a given number of said air ports (10b), on the basis of a selected format of the label (2a, 2b) to be transferred; and

- establishing vacuum through said given number of air ports (10b) only, when air ports (10b) of said given number are between an inlet station (4) and an outlet station (5) of said path (P);
characterized by comprising the step of:
- controlling a plurality of valves (32) by means of a control unit (31) of control means (30) on the basis of said selected format to allow an air flow between said vacuum source (22) and only said given number of air ports (10b).
The method of claim 10, characterized in that said step of establishing comprises the step of fluidly connecting only said air ports (10b) of said given number to a vacuum source (22), when said air ports (10b) of said given number are between an inlet station (4) and an outlet station (5) of said path (P).
The method of claim 10 or 11, characterized in that said step of selecting comprises the step of selecting those air ports (10b) that form a pattern associated to the format of said label (2a, 2b) to be conveyed.
The method of any one of claims 10 to 12, characterized in that said step of establishing vacuum comprises steps of:
- fluidly connecting a plurality of fluidic lines (12) to said vacuum source (22), for each and every angular position of said vacuum drum (7) about said axis (A); and

- fluidly connecting only said given number of air ports (10b) to said fluidic lines (12).