EP1122175A1

EP1122175A1 - A unit for feeding self-adhesive labels in a container labelling machine

Info

Publication number: EP1122175A1
Application number: EP01830072A
Authority: EP
Inventors: Sante Lorenzi; Guerrino Bonizzi; Carlo Corniani
Original assignee: Azionaria Costruzioni Macchine Automatiche ACMA SpA
Current assignee: Azionaria Costruzioni Macchine Automatiche ACMA SpA
Priority date: 2000-02-07
Filing date: 2001-02-06
Publication date: 2001-08-08
Also published as: ITBO20000054A1; IT1321008B1

Abstract

A unit for feeding self-adhesive labels (4) in a container labelling machine where the labels (4) are fed from a label web (3) which comprises a web (8) of backing material to which the labels (4) are attached. The unit (1) comprises a labelling station (5) where the labels (4) are applied to the containers (6), a feed device (29) to feed the label web (3) and the backing web (8) along a defined path. The feed device (29) is located downstream of the labelling station (5), relative to the feed direction of the backing web (8), and comprises a first roller (10) and a second roller (11) that act in conjunction with each other and are located on opposite sides of the backing web (8), both the rollers being driven by a drive device (35).

Description

The present invention relates to a unit for feeding self-adhesive labels in a container labelling machine.
The invention relates in particular to a unit for self-adhesive labels in a container labelling machine where the labels are unwound from rolls of web consisting of a web of backing material to which the labels are attached with their adhesive side in contact with one of the surfaces of the backing web .
On the surface of the backing web to which the labels are attached side by side and equally spaced, there is usually a silicone based release coating which allows the labels to be pulled away from the backing without altering their adhesive properties. The containers to which the labels are applied may be bottles of any shape for liquid products such as oil, water or liquid detergent, to which the present description refers by way of example but without thereby departing from the scope of the inventive concept.
In the above mentioned labelling machines, the full containers to be labelled are supported by a starwheel equipped with a plurality of peripheral recesses. The starwheel feeds each container to a labelling station where a self-adhesive label is removed from the backing web and applied to the container.
These labelling machines comprise at least one label feed unit equipped with a plurality of feed rollers which unwind the backing web with the labels attached to it from a roll and feed it to the labelling station. The labelling station comprises a detaching unit which separates the label from the backing web. The backing web is then fed back along a rewinding path and wound onto another roll. The unwinding of the label web to the labelling station and, from there, of the backing web only is performed by a feed device which comprises a pair of rollers positioned with their axes on opposite sides of the rewinding path. One of the rollers is power driven and presses the web against the other roller to create just enough friction to feed the web along the rewinding path according to a defined law of motion.
The detaching unit which separates the label from the backing web of normally comprises an angle feed element comprising a blade having a free end around which the backing web slides in such a way as to suddenly change direction, thus detaching the label from the backing. To enable the label to be correctly applied to the container, the angle feed blade is positioned extremely close to the path along which the containers are fed so that, during use, each container passing through the labelling station is tangent to the free end of the angle feed blade and therefore comes into contact with the label so that the latter is gradually detached from the backing material and transferred to the container in the correct position.
One of the problems of using a feed unit of this type is that while the label is being applied to the container, the backing web is very close to the containers and collects impurities and liquid residue present on the outside of the containers and transfers them to the feed rollers located on the rewinding path. The feed rollers thus become dirty and unable to create the right amount of friction to properly pull the backing web and hence the web to which the labels are attached.
At present, this problem is solved by manual cleaning. This means frequent maintenance of the rewinding path which in turn means stopping not only the labelling machine but also the entire packaging line, considerably reducing the productivity of the line.
The aim of the present invention is to overcome the above mentioned problem by providing a feed device that continues to operate correctly even when it is dirty, thus appreciably reducing the number of stops required to clean the machine during normal operating hours.
Accordingly, the invention provides a unit for feeding self-adhesive labels in a container labelling machine, the labels being fed from a label web which comprises a backing web to which a plurality of self-adhesive labels are attached; the unit comprising a labelling station in which the self-adhesive labels are applied to the containers, drive means for feeding the label web and the backing web along a defined path; the drive means being located downstream of the labelling station relative to the feed direction of the web and comprising a first feed roller and a second feed roller which act in conjunction with each other and which are located on opposite sides of the backing web; the unit being characterised in that it comprises drive means for powering both the feed rollers.
The invention will now be described with reference to the accompanying drawings which illustrate a preferred embodiment of it by way of example without restricting the scope of the inventive concept, and in which:

Figure 1 is a schematic plan view, with some parts represented as blocks, of a label feed unit;
Figure 2 is a schematic perspective view of a label web wound in a roll, with labels attached to it;
Figure 3 is a perspective view of a detail from Figure 1;
Figure 4 is a schematic side view, with some parts cut away, of a detail from Figure 1.

With reference to Figure 1, the numeral 1 denotes a container labelling machine comprising a unit 2 for feeding the self-adhesive labels 4 to a labelling station 5 where the labels 4 are transferred to containers 6 moving on a starwheel 7.
The labels 4 are fed to the labelling machine 1 in rolls 9 of label web 3 comprising a backing web 8 to which the labels 4 are attached with their adhesive side in contact with a surface 8a of the backing web 8. The labels 4 are attached one after the other and are equally spaced on the surface of the backing web.
As shown in Figures 1 and 2, the web 3 is unwound from a feed roll 9 that is rotatably supported by a shaft 9a connected to a bed 100 of the machine 1. The label web 3 is unwound along a feed path P1 through a plurality of idle feed rollers 101, 102, 103, 104 to the labelling station 5, where the labels 4 are removed from the backing web 8 and applied to the containers 6. The backing web 8, without the labels 4 on it, continues to be fed along a rewinding path P2 extending through a plurality of idle feed rollers 105, 106, 107, 108, 109 and wound onto a rewinding roll 12 on which the used backing web 8 can be collected. The feeding of the label web 3 to the labelling station 5 and the subsequent rewinding of the backing web 8, downstream of the labelling station 5, in the feed direction of the web 3, are performed by drive means consisting of a feed device 29 located downstream of the labelling station 5, between the roller 106 and the roller 107, with reference to Figure 1.
The feed device 29 comprises a first feed roller 10 and a second feed roller 11, tangent to each other, acting in conjunction and rotating in opposite directions. The rollers 10 and 11 are located on opposite sides of the backing web 8 without the labels 4 on it. The rollers 10 and 11 feed the web 8 and rewind it onto the rewinding roll 12, that is rotatably mounted on a corresponding shaft 12a whose axis is parallel to the shaft 9a and which is also connected to the bed 100 of the machine 1. The axes of the rollers 101, 102, 103, 104, 105, 106, 107, 108, 109 are also parallel to the axis of shaft 9a of the roll 9 and are supported by the bed 100 of the machine 1 in a known manner which is not illustrated.
In the section of the path P1 between the rollers 103 and 104, there is a station 13 for detecting the presence and the position of the labels 4 on the web 3. At the detecting station 13, there is a sensor 14 supported by an arm 15 connected to a blade 16 of the bed 100 by means of a pin 17. The sensor 14 acts in conjunction with a fixed stop 19 located on the opposite side of the web. The sensor 14 detects the presence/absence of the labels 4 on the web 3 and is connected to the central control unit 18 of the labelling machine 1.
With reference to Figures 1 and 3, the labelling station 5 comprises a backing web 8 feed blade 20, the blade 20 having a first end 21 and a second free end 22. The end 21 is solidly connected to two arms 23a and 23b, located on opposite sides of the blade 20 and parallel to it.
The two arms 23a and 23b are connected to corresponding circular supports 24a and 24b which are coaxial with an axis 25 and joined to the bed 100 by an upper bracket 40 and a lower bracket 41, located on opposite sides of the blade 20. The two supports 24a and 24b also support the idle feed rollers 104, 105.
The end 22, on the other hand, is unsupported and is substantially tangent to the outer path followed by the containers 6 as they move on the starwheel 7 at the labelling station 5.
At an end section T1 of the path P1, the web 3 moves towards the end 22 in a direction D1 substantially parallel to the blade 20, while at a starting section T2 of the path P2, the backing web 8 moves towards the end 21 of the blade 20 in a direction D2. The direction D2 is therefore substantially parallel and opposite to the direction D1.
During use, the web 8 is fed around the blade 20 and the sudden change of direction which the backing web 8 makes as it passes the end 22 of the blade 20 has the effect of detaching the self-adhesive labels 4 from the web 8. The labels 4 do not follow the path of the web 8 around the end 22 of the blade 20 but continue along a path extending straight on past the end 22. The labels 4 are thus transferred to the containers 6, being gradually separated from the backing web 8 starting from an edge 4a at the end 22, the latter being substantially tangent to the path of the containers 6 on the starwheel 7.
Looking in more detail, each container 6 is placed in a recess 27, located at an edge 28 of the starwheel 7 in such a way that, at the labelling station 5, a surface 26 of the container 6 faces outwards from the starwheel and barely touches the end 22 of the angle feed plate 20.
An angular encoder EM mounted on the starwheel 7 and connected to the central control unit 18 checks the angular position and alignment of the container 6 at the labelling station 5.
With reference to Figures 1, 3 and 4, downstream of the labelling station 5 along the path P2, the backing web 8 is fed along the section T2 of the path P2 as far as the feed device 29, which comprises the feed rollers 10 and 11, the latter being located on opposite sides of the web 8, tangent to each other and whose axes 10a and lla are parallel to the axis of the shaft 9a of the roll 9. The feed rollers 10 and 11 are rotatably mounted on shafts 30 and 31, respectively.
The roller 10, which has a protective guard 110 covering the part of it facing the operator, is keyed to its shaft 30 which, close to a first end 30b of it, is rotatably mounted on the bed 100. At its first end 30b, the shaft 30 is coupled to a pulley 33 which is kinematically connected through a toothed belt 34 to drive means 35 comprising a motor M connected to the central control unit 18.
The shaft 30 also has a second end 30a, located opposite the first end 30b, engaged with a gear 38 which is kinematically connected to another gear 39 which is in turn keyed at an end 31a to a portion 36 of a shaft 31 which coaxially supports the roller 11.
The shaft 31 is in turn supported by a bracket 120 through a plurality of bearings 121 which allow it to turn freely. The bracket 120 is mounted in known manner on another service and support roller 111 whose axis llla is parallel to the axis of the shaft 9a and which is rotatably and coaxially mounted to a corresponding shaft 112, which is in turn connected to the bed 100 at one end 112b.
An external portion 113 of the shaft 112 protrudes from the roller 111 at an end 112a opposite the end 112b. A handle 114 is fitted to the portion 113 to enable the operator to turn the roller 111 about the axis llla to move the rollers 10 and 11 towards or away from each other when cleaning the machine 1 or inserting the backing web 8 between them.
The rollers 10 and 11 are driven by the motor M which is connected to them by kinematic connecting means 37 comprising the pair of gears 38 and 39, meshed with each other and constituting a kinematic chain capable of transmitting the motion from the motor M to both the rollers 10 and 11.
During use, the motor M drives the roller 10 and, through the gears 38 and 39, drive is transmitted to the roller 11 which acts in conjunction with the roller 10 to feed the web 8 placed between them.
The web 3 with the labels 4 on it is unwound from the roll 9 and fed to the angle feed blade 20. When it reaches the end 22 of the blade 20, the free edge 4a of the label 4 is detached from the backing web 8 and, as it moves forward, comes into contact with the lateral surface 26 of the container 6 to be labelled and adheres to the lateral surface 26 itself.
The backing web 8, without labels on it is rewound onto the rewinding roll 12 by the rollers 10 and 11, which are both power driven.
The central control unit 18 adjusts the rotation speed of the motor M to synchronise label 4 feed with the presence of the container 6 at the labelling station 5. To do this, it varies the unwinding speed of the web 3 according to the presence or absence and relative position of the label 4, and taking into account the position reached by the container 6 during its rotation on starwheel 7, in response to the signals generated by the sensor 14 and the encoder EM on the starwheel 7 and processed by the central control unit 18.
The drive means 35, which comprise the two gears 38 and 39, may be substituted by other conventional drive means. For example, two independent motors may be used, each connected directly to one of the rollers 10 and 11 in a known manner which is not illustrated.
Applying the drive power exerted by the two power driven rollers to the web 8 instead of dragging the web by friction considerably reduces down time and increases productivity accordingly.
It is clear therefore that powering both the rollers 10 and 11 prevents the web 8 from slipping on the rollers 10 and 11 on account of product residue that may be deposited on the surface of the web 8 itself.

Claims

A unit for feeding self-adhesive labels in a container labelling machine, the labels (4) being fed from a label web (3) which comprises a backing web (8) to which a plurality of self-adhesive labels (4) are attached; the unit (2) comprising a labelling station (5) in which the self-adhesive labels (4) are applied to the containers (6), and drive means (29) for feeding the label web (3) and the backing web (8) along a defined path (P1; P2); the drive means (29) being located downstream of the labelling station (5) relative to the feed direction of the web (8) and comprising a first feed roller (10) and a second feed roller (11) which act in conjunction with each other and which are located on opposite sides of the backing web (8); the unit being characterised in that it comprises drive means (35) for powering both the feed rollers (10, 11).
The unit according to claim 1, characterised in that the drive means (35) comprise a motor M to drive at least one of the two rollers (10, 11) and means (37) for kinematically connecting the two rollers (10, 11) to each other.
The unit according to claim 2, characterised in that the kinematic connecting means (37) comprise at least two toothed gears (38, 39), each being connected to one of the rollers (10, 11).