The present invention relates to a method and unit for applying a label to an article.
The present invention is particularly advantageous for use on a cigarette packing machine, for applying revenue labels to packets of cigarettes, to which the following description refers purely by way of example.
In many countries, a non-removable revenue label must be applied to the outer surface of a packet of cigarettes in such a position as to be torn when the packet is unsealed, and serves to demonstrate payment of tobacco retail taxes.
Various types of units for applying revenue labels to packets of cigarettes on a cigarette packing machine are known, some of which are described in patents U.S. Pat. No. 5,203,953 A1, EP1125843A1, DE19730307A1, U.S. Pat. No. 5,607,526 A1, U.S. Pat. No. 5,111,633 A1, and GB2103584A.
U.S. Pat. No. 4,655,871 A1 describes a unit for supplying revenue labels on a cigarette packing machine, in which each packet coming off a packing assembly is fed along an unloading path extending through a fork-type gripper; between two arms of the gripper is stretched a revenue label removed beforehand by the gripper from a respective pocket integral with the periphery of a roller tangent to a conveyor roller, which has projections for retaining and feeding a revenue label to the relative pocket along a path tangent to a gumming roller.
EP662423A1 describes a unit for applying revenue labels to packets of cigarettes bounded by two parallel faces connected by a further face; and the unit comprises a conveyor for feeding the packets to a labelling station, and a label feeder having at least one device for retaining two opposite end portions of a label. The conveyor feeds the packets successively, with the further face downstream with respect to the travelling direction of the conveyor; and an actuator is provided to move the label-retaining device between a position interfering with the path of each packet at the labelling station, and a position of non-interference with the path.
U.S. Pat. No. 6,763,870 B1 describes a unit for applying revenue labels to packets of cigarettes travelling in a feed direction along a first path; a gripping head is fed along a second path; and each label is applied to a first face of a respective packet by inserting the gripping head between a packet and the adjacent downstream packet, and rolling the gripping head to apply the label along the first face, which is perpendicular to the feed direction.
U.S. Pat. No. 5,309,695 A1 describes a unit for applying adhesive revenue labels to packets of cigarettes. The unit comprises an endless conveyor for feeding labels along a path having a first portion extending along a portion of a packet feed path, a second portion extending from the output of the first portion to a loading station for loading the labels onto the conveyor, and a third portion extending from the loading station to the input of the first portion and through a gumming device. The conveyor is a suction conveyor, and comprises a first suction chamber, in which a vacuum is maintained selectively and which extends along the first and second portion of the label path; and a second suction chamber, in which a vacuum is maintained constantly and which extends along the third portion of the path.
Patent Application ITBO200300047A describes a device for applying a revenue label to a packet of cigarettes travelling along a conveying path. To apply the label to the packet, a gripping head is fed along a feed path by rotating the gripping head about two parallel axes, and by moving the gripping head radially with respect to one of the two axes.
U.S. Pat. No. 5,111,633 A1 describes a unit for applying revenue labels to packets of cigarettes, and which comprises a device for feeding the packets to a labelling station; and a label feeder, in turn comprising a rotary conveyor substantially tangent to the labelling station and having suction retaining means for retaining individual labels on the cylindrical surface of the rotary conveyor. Each retaining means has a folding member movable substantially radially with respect to the rotary conveyor; and actuating means for activating the folding member, and which operate between a withdrawn position with respect to the rotary conveyor, and an extracted work position at the labelling station.
Known units for applying revenue labels to packets of cigarettes are relatively cheap and easy to produce, but only perform satisfactorily at low operating speeds (roughly 400-500 applications a minute), i.e. fail to provide for precise application of revenue labels to packets of cigarettes at high operating speeds. To overcome this drawback, new types of units for applying revenue labels have been proposed, but have proved complex and expensive, while still failing to ensure good performance at very high operating speeds (roughly 700-800 applications a minute).
It is an object of the present invention to provide a method and unit for applying a label to an article, designed to eliminate the aforementioned drawbacks, and which, in particular, are cheap and easy to implement.
According to the present invention, there are provided a method and unit for applying a label to an article, as recited in the attached Claims.
A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:
FIGS. 3 to 5 show larger-scale views in perspective, with parts removed for clarity, of a detail of the
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Each supporting head 10 also comprises a U-shaped folding member 25 fitted to supporting head 10 to move linearly in a direction parallel to the rotation axis 9 of wheel 8 and therefore perpendicular to labelling path P1. To allow passage of U-shaped folding member 25, each seat 11 has two through holes 26, which come out at suction surface 13. Each seat 11 preferably comprises a control member (not shown in detail) for cutting off suction through suction surface 13 of seat 11, and which is activated by passage of U-shaped folding member 25 through the through holes 26 in seat 11.
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Along labelling path P1 and upstream from feed station S1, labelling unit 1 comprises a gumming station S4 for gumming an inner surface of each revenue label 2 as revenue label 2 is advanced by seat 11 of a respective supporting head 10.
Finally, labelling unit 1 comprises a feed station S5 located upstream from feed station S1 along labelling path P1; and a release station S6 located upstream from feed station S5 along labelling path P1.
At feed station S5, packets 3 of cigarettes are fed to respective seats 12 of supporting heads 10 by a number of seats 35 fed by a packing conveyor (not shown in detail) along a packing path P3 tangent to labelling path P1 at feed station S5.
At release station S6, packets 3 of cigarettes, complete with respective revenue labels 2, are released from seats 12 of supporting heads 10 to seats 36 fed by a transfer conveyor 37 along a transfer path P4 partly coincident with labelling path P1 at release station S6. Transfer conveyor 37 comprises an endless flexible support (typically a chain) looped about at least two end pulleys 39 (only one shown in
Each deformable body 40 comprises a rigid jaw 41 having one end 42 for retaining packet 3 of cigarettes, and an end 43 opposite end 42. End 42 of each jaw 41 is connected to flexible support 38 by a connecting member 44 hinged to both jaw 41 and flexible support 38, while end 43 of each jaw 41 is connected to flexible support 38 by a connecting member 45 hinged to jaw 41 and fixed rigidly to flexible support 38. Jaws 41 are preferably arranged so that ends 43 of each two adjacent jaws 41 are superimposed, and the superimposed ends 43 of each two adjacent jaws 41 are both hinged to the same connecting member 45.
It is important to note that jaws 41 of transfer conveyor 37 are entirely passive, i.e. no actuating devices are provided to produce any movement between jaws 41 and flexible support 38. Given the way in which jaws 41 are connected to flexible support 38, each jaw 41 tends to oscillate with respect to end 43 when flexible support 38 assumes a curved configuration, thus opening seats 36, i.e. spreading jaws 41 defining each seat 36, when flexible support 38 assumes a curved configuration, and subsequently closing seats 36, i.e. bringing closer together jaws 41 defining each seat 36, when flexible support 38 assumes a straight configuration.
Operation of labelling unit 1 will now be described with reference to one packet 3 of cigarettes and a corresponding revenue label 2.
Label 2 is picked up by a gripping head 30 from the bottom of stack 32 in store 31 or from strip 34 at cutting unit 33, and is then transferred in known manner by gripping head 30 to seat 11 of a supporting head 10 at feed station S1. On receiving label 2, supporting head 10 continues along feed path P1 through gumming station S4, where an inner surface of label 2 is gummed in known manner.
At feed station S5, packet 3 of cigarettes is fed from a seat 35 to seat 12 of supporting head 10, by moving packet 3 with respect to both seat 35 and seat 12, and in a direction perpendicular to both packing path P3 and labelling path P1.
Up to feed station S5, seat 11 of supporting head 10 is maintained stationary with respect to supporting head 10 and seat 12. More specifically, seat 11 is maintained in such a position as to receive label 2 with suction surface 13 perpendicular to and alongside end walls 4 and 5 of packet 3. Once through feed station S5, seat 12 remains stationary with respect to supporting head 10, and seat 11 is moved with respect to seat 12 and supporting head 10 to apply label 2 to packet 3 of cigarettes under the control of actuating device 14. As stated, seat 11 is moved with respect to seat 12 and supporting head 10 by rotating about axis 15, which slants with respect to suction surface 13 of seat 11. More specifically, rotation of seat 11 about axis 15 positions suction surface 13 of seat 11 facing top end wall 4 of packet 3 of cigarettes, to apply label 2 to top end wall 4. Label 2 is then folded into a “U” onto major lateral walls 7 of packet 3 of cigarettes by U-shaped folding member 25 moving through holes 26 in seat 11. As stated, when inserted through holes 26 in seat 11, U-shaped folding member 25 activates a control member (not shown) to cut off suction through suction surface 13 of seat 11.
Finally, at release station S6, packet 3 of cigarettes, complete with label 2, is released from seat 12 of supporting head 10 to a seat 36 on transfer conveyor 37. More specifically, when fed from seat 12 to seat 36, packet 3 is maintained stationary with respect to both seat 12 and seat 36, and transfer is possible by transfer path P4 being partly coincident with labelling path P1, so that seat 36 can engage packet 3 of cigarettes while packet 3 of cigarettes is still engaged by seat 12.
Labelling unit 1 as described above has numerous advantages: it is compact, is cheap and easy to produce, and operates accurately at high operating speed. Precision labelling is particularly ensured by seat 11, for receiving a revenue label 2, and seat 12, for receiving a corresponding packet 3 of cigarettes, being conveyed together by the same supporting head 10, so that an extremely precise position of seat 11 with respect to seat 12 is guaranteed at all times, regardless of the travelling speed of supporting head 10.
In view of its numerous advantages, labelling unit 1 as described above may also be used to advantage on other automatic machines for packing products other than cigarettes, or on other than automatic packing machines, for applying a label of any type to the outer surface of an article. For example, labelling unit 1 as described above may be used to apply labels to bottles or packages of food products.
Number | Date | Country | Kind |
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BO2004A000589 | Sep 2004 | IT | national |