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(11) | EP 1 619 129 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A device for feeding labels to labelling machines |
| (57) A device for feeding labels to labelling machines comprises means (2) for feeding
a web (3) with labels attached to it, a station (4) for detaching the labels from
the web (3) and means (5) for recovery of the web (3) without labels attached to it.
There are also drive means (10) for the web (3), operating on the web (3) simultaneously
upstream and downstream of the detachment station (4) to supply to the detachment
station (4) and remove from the detachment station (4) practically the same quantity
of web (3) at any time. The device also comprises means (22) for detecting the quantity of web (3) supplied to and removed from the detachment station (4) at any time, and control means operatively connected to the feed means (2), the recovery means (5) and the detector means (22), for regulating the quantity of web (3) fed and recovered at any time, respectively by the feed means (2) and the recovery means (5), according to the instantaneous quantity of web (3) detected by the detector means (22). |
[0002] In particular, the present invention relates to a device for feeding labels in which the labels are applied on a web, from which they must be detached. Generally speaking, feed devices of this type comprise web feed means consisting of a support for a reel of web which is gradually unwound.
[0003] The web unwound, after a series of return parts, reaches a label detachment station where the labels are detached from the web by a sharp change in the direction in which the web runs, and picked up by the successive apparatuses of the labelling machine.
[0004] The web from which the labels were removed then, after another series of return parts, reaches a rewinding reel.
[0005] Along the path on which the web runs there may also be one or more web tensioning take up rollers.
[0006] Web motion is guaranteed by a drive roller on which the web is clamped by at least one counter-pressure roller.
[0007] The drive roller is positioned close to the detachment station and is controlled in such a way that it is synchronised with the parts of the labelling machine located downstream of the feed device.
[0008] Moreover, in some types of feed devices the drive roller acts directly and simultaneously on the web both upstream and downstream of the detachment station, to avoid excessive mechanical stresses on the web at the section of its path corresponding to the detachment station.
[0009] However, at the same time, the drive roller must impart to the web sufficient traction to unwind the reel, which is supported in such a way that it turns idly.
[0010] Also due to the fact that the idle support has a slight braking action applied to it to prevent the reel from oscillating, the feed devices known today have the significant disadvantage of requiring a relatively large drive roller both in terms of the dimensions and as regards the power it must be able to supply.
[0011] In addition, the feed devices known today have significant limits in terms of the maximum operating speeds, which are notably limited by problems with mechanical web management along the path on which it runs.
[0012] In this situation the technical need which forms the basis of the present invention is to provide a device for feeding labels to labelling machines which overcomes the above-mentioned disadvantages.
[0013] In particular, the technical need of the present invention is to provide a device for feeding labels to labelling machines in which a relatively small driving motor can be used.
[0014] Another technical need of the present invention is to provide a device for feeding labels to labelling machines which allows higher operating speeds than those of the devices known today to be achieved.
[0015] A further technical need of the present invention is to provide a device for feeding labels to labelling machines which minimises mechanical stresses on the web at the drive means and the detachment station.
[0016] The technical need specified and the aims indicated are substantially achieved by a device for feeding labels to labelling machines as described in the claims herein.
[0017] Further features and the advantages of the present invention are more clearly illustrated in the detailed description which follows, with reference to the accompanying drawings, which illustrate several preferred embodiments of a device for feeding labels to labelling machines, without limiting the scope of the inventive concept, in which:
- Figure 1 is a schematic top view of a device for feeding labels made in accordance with the present invention and in the operating condition;
- Figure 2 illustrates an enlarged part of the device shown in Figure 1;
- Figure 3 is a schematic axonometric view of the device illustrated in Figure 2 without the web;
- Figure 4 is a schematic cross-section of a detail of the device illustrated in Figure 3;
- Figures 5 and 6 are three-quarter axonometric views respectively from below and from above of a detail of the device illustrated in Figure 3;
- Figure 7 is a top view of the detail illustrated in Figures 5 and 6;
- Figure 8 is a partial cross-section according to line VIII-VIII of the detail illustrated in Figure 7; and
- Figure 9 is a partial cross-section according to line IX-IX of the lower part of the detail illustrated in Figure 7.
[0018] With reference to the accompanying drawings, the numeral 1 denotes as a whole a device for feeding labels to labelling machines in accordance with the present invention.
[0019] In general, the device comprises means 2 for feeding a web 3 on which the labels are attached, a station 4 for detaching the labels from the web 3, and means 5 for recovery of the web 3 without labels.
[0020] Figures 1 and 2 show how the web 3 runs along a path 6 (indicated by arrows in the drawings) extending from the feed means 2 to the recovery means 5, through the detachment station 4 and a plurality of idle return rollers 7.
[0021] According to known methods, the detachment station 4 consists of a so-called blade 8 which causes a sharp change in the web 3 direction of movement and consequent detachment of the labels which are collected by the apparatus 9 downstream of the feed device 1.
[0022] Web 3 feed at the detachment station 4 is guaranteed, synchronised with the other parts of the labelling machine, which are downstream of the feed device 1, by drive means 10 operating on the web 3 simultaneously both upstream and downstream of the detachment station 4.
[0023] The drive means 10 are designed to supply the detachment station 4 with and at the same time immediately remove from the detachment station 4 practically the same quantity of web 3.
[0024] In the embodiment illustrated, the drive means 10 comprise a central motor-powered drive roller 11 and at least two idle counter-pressure rollers 12 which in practice hold respectively the web 3 upstream of the detachment station 4 and the web 3 downstream of the detachment station 4 in contact with the drive roller 11 (Figure 2).
[0025] In the embodiment illustrated, the counter-pressure rollers 12 are each mounted on a central portion of a relative support 13 which has a first side part 14 pivoting relative to the device 1 supporting structure 15, and a second side part 16.
[0026] According to the preferred embodiment of the present invention, the counter-pressure rollers 12 are mobile, when the command is issued, between an operating position in which they are close to the drive roller 11 to clamp the web 3 on the drive roller 11, and a web 3 insertion position in which they are distanced from the drive roller 11 and allow insertion of the web 3 on the drive roller 11 according to an insertion direction perpendicular to the plane in which the path 6 lies (from above in Figure 2).
[0027] In the embodiment illustrated, the two counter-pressure rollers 12 are moved by rotation of the two supports 13 about the relative pivot point.
[0028] In particular, the counter-pressure rollers 12 are moved from the operating position to the web 3 insertion position by a cam element 17.
[0029] Figure 9 shows how the cam element 17 consists of a cam groove 18 rigidly connected to a movement knob 19, in which two pins 20 are inserted, the pins integral with the second side part 16 of the supports 13.
[0030] As a result, turning the movement knob 19 causes the second side parts 16 of the supports 13 to move away from one another and therefore, opens the counter-pressure rollers 12.
[0031] Advantageously, to improve the grip of the drive roller 11 on the web 3, for each counter-pressure roller 12 there is at least one elastic part 21 acting on the counter-pressure roller 12, pressing it against the drive roller 11.
[0032] In addition, whilst the counter-pressure roller 12 acting on the web 3 upstream of the detachment station 4 has a smooth surface to avoid ruining the labels attached to the web 3, the counter-pressure roller 12 acting on the web 3 downstream of the detachment station 4 has a knurled surface to improve its grip on the web 3.
[0033] Finally, to increase the surface for contact with the web 3 on the drive roller 11 there may be additional counter-pressure rollers 12 for each support 13, or each support 13 may be shaped in such a way that it forms part of the web 3 path 6 (Figure 2) forcing the web 3 to be wound on the support 13.
[0034] The device 1 disclosed also comprises means 22 for detecting the quantity of web 3 supplied to and removed from the detachment station 4 at any time, and control means (not illustrated) operatively attached to the feed means 2, the recovery means 5 and the detector means 22, to regulate the quantity of web 3 fed and recovered at any time, respectively by the feed means 2 and the recovery means 5, based on the instantaneous quantity of web 3 detected by the detector means 22.
[0035] In the embodiments illustrated, the means 22 for detecting the quantity of web 3 supplied to and removed from the detachment station 4 at any time are more specifically detector means 22 able to define the instantaneous variations in the quantity of web 3 supplied and removed.
[0036] Indeed, the detector means 22 preferably comprise at least a first part 23 which rotates about its own first axis of rotation, having at least a first external end 24 which in turn forms a return part for the web 3. In particular, this first external end 24 consists of an idle roller 25.
[0037] As illustrated in Figure 4, the first rotary part 23 is connected to at least a first device 26 for detecting the angular position of the first rotary part 23, as well as first yielding counter-pressure means 27 designed to impart a rotational torque to the first rotary part 23 in an attempt to make it rotate (in the absence of external stresses) in a direction of rotation corresponding to a movement of the first external end 24 to increase the extension of the path 6.
[0038] In Figure 2 the first external end 24 acts as a return part for the web 3 at a section of the web 3 path 6 between the drive means 10 downstream of the detachment station 4 and the recovery means 5.
[0039] Therefore, in Figure 2, the first yielding counter-pressure means 27 tend to make the first rotary part 23 rotate in a clockwise direction.
[0041] As can be seen, the first yielding counter-pressure means 27 consist of a spiral spring 28 attached between the fixed supporting body 29 of the first rotary part 23 and the first rotary part 23 itself. In contrast, the first detector 26 is attached to the fixed supporting body 29, on the axis of rotation of the first rotary part 23, in a recess 30 in the first rotary part 23.
[0042] In the embodiment illustrated, the first detector 26 is an electromagnetic sensor able to detect variations in the magnetic field caused during rotation of the first rotary part 23, by a ferromagnetic body (not illustrated) mounted asymmetrically on the first rotary part 23 in the recess 30.
[0043] The control means are connected to the first detector 26 and act (at least) on the web 3 recovery means 5 to change their web 3 recovery speed so as to keep the first rotary part 23 in a predetermined angular position, corresponding to a certain ferromagnetic body position relative to the electromagnetic sensor.
[0044] In the embodiment illustrated, the first rotary part 23 also has a second external end 31 rigidly connected to the first external end 24 and also forming a return part for the web 3, but at a section of the path 6 between the feed means 2 and the drive means 10 upstream of the detachment station 4.
[0046] In other embodiments (not illustrated) the detector means 22 may comprise at least a second part which rotates about a second axis of rotation.
[0047] In this case, the second external end 31 which forms the return part for the web 3 at the section of the path 6 between the feed means 2 and the drive means 10 upstream of the detachment station 4, will be on the second rotary part. However, at the same time, the second rotary part will be rigidly connected to the first rotary part 23 so that its turning motion is synchronised with it.
[0048] In both of the embodiments the first and second external ends 24, 31 act on the web 3 in a counterbalanced way, so that a rotation of the first rotary part 23 corresponds to an increase in the extension of the path 6 caused by one of the external ends 24, 31 and a reduction in the path 6 caused by the other external end 31, 24 (Figure 2). In the preferred embodiment for high operating speeds the detector means 22 also comprise at least one arm 32 whose first end 33 pivots at the device supporting structure 15, according to its axis of rotation.
[0049] The arm 32 has a second end 34 bearing at least one return element 35 (idle roller) which in practice acts on the web 3 at a section of the path 6 between the feed means 2 and the drive means 10 upstream of the detachment station 4. In the embodiment illustrated (Figures 2 and 3) there are two return elements 35.
[0050] The arm 32 is also connected to at least one second detector (not visible) for the angular position of the arm 32 relative to the axis of rotation. Although not illustrated in the accompanying drawings, this second detector may, for example, have a configuration corresponding to that of the first detector 26.
[0051] The arm 32 is also attached to second yielding counter-pressure means (also not visible) for making the arm 32 rotate in a direction of rotation corresponding to a movement of the return element 35 which increases the extension of the path 6 (anti-clockwise in Figure 2).
[0052] In this case, the control means act at least on the web 3 feed means 2 to change the web 3 recovery speed so as to keep the arm 32 in a predetermined angular position.
[0053] Although the preferred embodiment of the present invention is illustrated in Figure 2, in general the control means may act on both the recovery means 5 and the feed means 2 to change the respective web 3 recovery and feed speed, even based on a single reading, by the first detector 26 or the second detector.
[0054] In the embodiment illustrated, the feed means 2 comprise at least a first rotary support 36 designed to receive a first reel 37 of web 3 with labels attached to it, and a first motor (not visible in the accompanying drawings) connected to the first support 36 to make it rotate. The first motor is in turn controlled by the control means, which vary its speed to vary the web 3 feed speed.
[0055] In some embodiments the feed means 2 may also comprise a first sensor (not illustrated) for detecting the quantity of web 3 wound on the relative first reel 37, operatively connected to the control means, so that the web 3 unwinding speed is also varied according to the quantity of web 3 detected by the first sensor.
[0056] Given that the web 3 feed speed is equal to the peripheral speed of the first reel 37 at the point where the web 3 comes off the first reel 37, as the radius of the first reel 37 gets smaller the speed of the first motor must be increased.
[0057] Similarly, the recovery means 5 comprise at least one second rotary support 38 designed to receive a second reel 39 of web 3 without labels attached to it, and a second motor (also not visible) connected to the second support 38 in order to make it rotate. The second motor is also controlled by the control means, which vary its speed to vary the web 3 recovery speed.
[0058] In addition, the recovery means 5 may also comprise a second sensor (not illustrated) for detecting the quantity of web 3 recovered and wound on the second reel 39.
[0059] The second sensor will also be connected to the control means, so that the web 3 winding speed on the second reel 39 varies according to the quantity of web 3 detected by the second sensor.
[0060] As regards operation of the feed device 1 disclosed, it should firstly be emphasised how the motor of the drive roller 11 constitutes what is known in the sector as a master motor, that is to say, the motor which imposes the device operating rhythms, synchronised with the other apparatuses located downstream of the device.
[0061] When the instantaneous quantity of web 3 removed from (and supplied to) the detachment station 4 by the drive roller 11 exceeds the quantity recovered by the recovery means 5, the first yielding counter-pressure means 27 are no longer counterbalanced by the pull on the web 3 and so cause the first rotary part 23 to rotate (clockwise in Figure 2).
[0062] As a result, whilst the movement of the first external end 24 compensates for the greater quantity of web 3 removed, the movement of the second end compensates the greater quantity of web 3 supplied to the detachment station 4.
[0063] However, the movement of the first rotary part 23 is detected by the first detector 26, which reports it to the control means which increase the web 3 recovery speed of the recovery means 5.
[0064] Consequently, the increased pull exerted by the recovery means 5 causes another movement of the first rotary part 23, in the opposite direction (anti-clockwise in Figure 2), towards the predetermined angular position.
[0065] However, this new movement of the second external end 31 means that a greater quantity of web 3 is required from the feed means 2, which, in the case of an idle reel are further accelerated by traction until they reach a web 3 feed speed which equals the supply.
[0066] In contrast, in the most complex embodiments, in which the feed means 2 are also motor-powered, when the first movement of the first rotary part 23 occurs the control means, according to the reading by the first detector 26 or the second detector, act on the feed means 2 to increase the speed of web 3 feed.
[0068] Firstly, thanks to the presence of detector means and control means which act on the web recovery and/or feed speed it is possible, with a driving motor of the same dimensions, to obtain higher operating speeds than those of similar conventional devices.
[0069] This effect is accentuated when both the first and the second detectors are present and when the control means can directly vary both the feed speed and the recovery speed.
[0070] A particularly advantageous solution has mechanical compensation of the pull on the web between the portion of web upstream and the portion downstream of the drive means, which allows all variations in the pull on the web to be compensated for substantially without negative effects on the portion of web between the drive means and the detachment station.
[0071] It should also be noticed that the present invention is relatively easy to produce and even the cost linked to implementation of the invention is not very high.
1. A device for feeding labels to labelling machines, comprising:
means (2) for feeding a web (3) with labels attached to it;
a station (4) for detaching the labels from the web (3) ;
means (5) for recovering the web (3) without labels attached to it;
the web (3) moving along a path (6) extending from the feed means (2) to the recovery means (5) through the detachment station (4);
means (10) for driving the web (3), operating on the web (3) simultaneously upstream and downstream of the detachment station (4), supplying the detachment station (4) and removing from the detachment station (4) practically the same quantity of web (3) at any time;
the device being characterised in that it also comprises means (22) for detecting the quantity of web (3) supplied to and removed from the detachment station (4) at any time, and control means operatively connected to the feed means (2), the recovery means (5) and the detector means (22), for regulating the quantity of web (3) fed and recovered at any time, respectively by the feed means (2) and the recovery means (5), according to the instantaneous quantity of web (3) detected by the detector means (22).
2. The device for feeding labels according to claim 1, characterised in that the detector means (22) comprise at least a first part (23) rotating about a first
axis of rotation and having at least a first external end (24) forming a return part
for the web (3), and at least a first detector (26) for the angular position of the
first rotary part (23), there being first yielding counter-pressure means (27) for
making the first rotary part (23) rotate in a direction of rotation corresponding
to a movement of the first external end (24) which increases the extension of the
path (6), the control means acting on at least the web (3) recovery means (5) to vary
their web (3) recovery speed so as to keep the first rotary part (23) in a predetermined
angular position.
3. The device for feeding labels according to claim 2, characterised in that the first external end (24) acts as a return part on the web (3) at a section of
the path (6) between the drive means (10) downstream of the detachment station (4)
and the recovery means (5).
4. The device for feeding labels according to claim 3, characterised in that the first rotary part (23) also has a second external end (31) rigidly connected
to the first external end (24) and forming a return part for the web (3) at a section
of the path (6) between the feed means (2) and the drive means (10) located upstream
of the detachment station (4).
5. The device for feeding labels according to claim 3, characterised in that the detector means (22) also comprise at least a second part which rotates about
a second axis of rotation and has at least a second external end (31) forming a return
part for the web (3) at a section of the path (6) between the feed means (2) and the
drive means (10) upstream of the detachment station (4), the second rotary part being
rigidly connected to the first rotary part (23) so that its rotation is synchronised
with the latter.
6. The device for feeding labels according to claim 4 or 5, characterised in that the first and the second external ends (31) act in a counterbalanced way on the web
(3) in such a way that a rotation of the first rotary part (23) corresponds to an
increase in the extension of the path (6) caused by one of the external ends and a
reduction in the path (6) caused by the other external end.
7. The device for feeding labels according to any of the claims from 2 to 6, characterised in that the detector means (22) also comprise at least one arm (32) with a first end (33)
pivoting according to its axis of rotation and a second end (34) bearing at least
one return element (35), the latter in practice acting on the web (3) at a section
of the path (6) between the feed means (2) and the drive means (10) upstream of the
detachment station (4), and at least a second detector for the arm (32) angular position
relative to the axis of rotation, there being second yielding counter-pressure means
(36) for rotating the arm (32) in a direction of rotation corresponding to a movement
of the return element (35) to increase the extension of the path (6), the control
means acting on at least the web (3) feed means (2) to vary their web (3) recovery
speed in such a way as to keep the arm (32) in a predetermined angular position.
8. The device for feeding labels according to any of the claims from 2 to 6, characterised in that the control means also act on the feed means (2) to vary the speed at which they
feed the web (3) with the labels attached to it.
9. The device for feeding labels according to any of the foregoing claims, characterised in that the feed means (2) comprise at least a first rotary support (36) for receiving a
first reel (37) of web (3) with labels attached to it, and a first motor connected
to the first support (36) to make it rotate and controlled by the control means.
10. The device for feeding labels according to claim 9, characterised in that the control means vary the speed of the first motor to vary the web (3) feed speed.
11. The device for feeding labels according to claim 10, characterised in that the feed means (2) also comprise a first sensor for detecting the quantity of web
(3) wound on the first reel (37), the sensor being operatively connected to the control
means, the web (3) unwinding speed also varying according to the quantity of web (3)
detected by the first sensor.
12. The device for feeding labels according to any of the foregoing claims, characterised in that the recovery means (5) comprise at least a second rotary support (38) for receiving
a second reel (39) of web (3) without labels attached to it, and a second motor connected
to the second support (38) to make it rotate and controlled by the control means.
13. The device for feeding labels according to claim 12, characterised in that the control means vary the speed of the second motor to vary the web (3) recovery
speed.
14. The device for feeding labels according to claim 13, characterised in that the recovery means (5) also comprise a second sensor for detecting the quantity of
web (3) recovered and wound on the second reel (39), the sensor being operatively
connected to the control means, the speed of web (3) winding on the second reel (39)
also varying according to the quantity of web (3) detected by the second sensor.
15. The device for feeding labels according to any of the foregoing claims, characterised in that the drive means (10) comprise a motor-powered drive roller (11) and at least two
idle counter-pressure rollers (12) which in practice hold respectively the web (3)
upstream of the detachment station (4) and the web (3) downstream of the detachment
station (4) in contact with the drive roller (11).
16. The device for feeding labels according to claim 15, characterised in that the counter-pressure rollers (12) are mobile, when the command is given, between
an operating position in which they are close to the drive roller (11) to clamp the
web (3), and a web (3) insertion position in which they are distanced from the drive
roller (11).
17. The device for feeding labels according to claim 16, characterised in that it comprises a cam element (17) for moving the counter-pressure rollers (12) from
the operating position to the web (3) insertion position.
18. The device for feeding labels according to claim 15, 16 or 17, characterised in that it also comprises, for each counter-pressure roller (12), at least one elastic part
(21) acting on the counter-pressure roller (12) to press it against the drive roller
(11).
Amended claims in accordance with Rule 86(2) EPC.
1. A device for feeding labels to labelling machines, comprising:
means (2) for feeding a web (3) with labels attached to it;
a station (4) for detaching the labels from the web (3) ;
means (5) for recovering the web (3) without labels attached to it;
the web (3) moving along a path (6) extending from the feed means (2) to the recovery means (5) through the detachment station (4);
means (10) for driving the web (3), operating on the web (3) simultaneously upstream and downstream of the detachment station (4), supplying the detachment station (4) and removing from the detachment station (4) practically the same quantity of web (3) at any time;
the device being characterised in that it also comprises means (22) for detecting the quantity of web (3) supplied to and removed from the detachment station (4) at any time by the driving means, and
control means operatively connected to the feed means (2), the