EP3630620B1

EP3630620B1 - A method for controlling a packing machine manufacturing packets of smoking articles, each containing two distinct groups of smoking articles

Info

Publication number: EP3630620B1
Application number: EP18732897.6A
Authority: EP
Inventors: Massimo Fortini; Alessandro RONCONI; Luca Federici
Original assignee: GD SpA
Current assignee: GD SpA
Priority date: 2017-05-23
Filing date: 2018-05-23
Publication date: 2021-12-15
Anticipated expiration: 2038-05-23
Also published as: PL3630620T3; IT201700055610A1; EP3630620A1; WO2018215950A1

Description

PRIORITY CLAIM

This application claims priority from Italian Patent Application No. 102017000055610 .filed on May 23, 2017 .

TECHNICAL FIELD

The present invention relates to a method for controlling a packing machine manufacturing packets of smoking articles, each containing two distinct groups of smoking articles.
The present invention finds advantageous application to a cigarette packing machine which manufactures so-called "twin" packets of cigarettes each containing two distinct groups of cigarettes, wrapped in separate wrappers, to which the following discussion will make explicit reference without thereby incurring any loss of generality.

PRIOR ART

For several years, a packet of cigarettes commercially called a "twin" packet has been known, the packet comprising a rigid outer container which houses within it two identical groups of cigarettes (i.e. "twins" from which the commercial name of the packet of cigarettes derives), which are arranged side by side and wrapped in corresponding wrappers. The patent US4258528A1 describes part of a packing machine for producing a "twin" packet of cigarettes; this packing machine comprises two rectilinear wrapping lines, twin and side by side, to manufacture in parallel two inner wraps (each consisting of a group of cigarettes wrapped in a wrapper of metallised paper) which are then coupled to a common blank which is folded around the two inner wraps to form a corresponding rigid external container. Each rectilinear wrapping line originates at a hopper from whose mouths the groups of cigarettes are extracted and ends at a wrapping drum provided with pockets suitable for storing the blanks.
A packing machine for producing a "twin" packet of cigarettes is also described in the patent application WO2017064659A1 (corresponding to the Italian patent application 102015000062561 ).
The hopper has an upper inlet portion connected with a feeding channel for a mass of cigarettes and a lower portion with a plurality of output mouths. Each output mouth is associated with a predefined number of vertical channels (or veins) along each of which a row of cigarettes falls by gravity and is cyclically engaged by a respective extractor which extracts an ordered group of cigarettes from the bottom of the hopper and feeds the group of cigarettes to a pocket of a forming conveyor which is stationary in front of the output mouth. Each extractor is comb-shaped and has a number of teeth which go through the grooves of the output mouth transversely to push a group of cigarettes out of the channels and feed the group of cigarettes to the pocket of the forming conveyor.
In use, the hopper is completely filled with a mass of cigarettes, which are fed from the feeding channel, fall down through the hopper by gravity, and all have the same longitudinal orientation which is necessary to allow the cigarettes to enter the vertical channels which lead to the output mouths; as the groups of cigarettes are extracted from the output mouths, the cigarettes fall down through the hopper by gravity and new cigarettes are fed into the hopper through the feeding channel. It can happen that during the fall down through the hopper by gravity a cigarette gets "crossed up ", i.e. it is arranged transversely with respect to the other cigarettes; a possible "crossed up" cigarette cannot enter a vertical channel which leads to an output mouth and remains lodged over the entrance of some adjacent vertical channels, constituting a barrier which also prevents other correctly aligned cigarettes from entering these vertical channels. When a cigarette is crossed up it is often necessary to interrupt the operation of the packing machine and it is always necessary for an operator to intervene, who must manually eliminate the "crossed up" cigarette; as a result, "crossed up" cigarettes tend to decrease the long-term productivity of the packing machine, i.e. the number of packets of cigarettes correctly produced over a long period of time (for example an 8-hour conventional work shift, 1-day work shift, 1-week work shift, 1-month work shift, 1-year work shift, etc.).
It has been observed that the number of "crossed up" cigarettes tends to increase as the length of the cigarettes decreases and tends to increase when the cigarettes have a slightly conical (i.e. not perfectly cylindrical) shape.
The patent application EP1020357A1 describes a cigarette packing machine, wherein a group of cigarettes is formed by picking the cigarettes from one or more output mouths of a hopper; the shutting-off, in response to a control signal, of the flow of cigarettes fed from any output mouth of the hopper involves the simultaneous shutting-off of the flow from all the output mouths competing with the shut-off output mouth for forming the group, without causing a simultaneous stoppage of the entire packing machine.
The patent US4528801A describes a device for forming groups of cigarettes in a packing machine, wherein an exit hopper of a cigarette feeder has a plurality of output mouths positioned side by side, each suitable to deliver successive layers of cigarettes. Pushing elements arranged under each output mouth insert these layers, overlapping them with each other, in drawers evenly distributed along a conveyor which is stepwise mobile near the bottom of the hopper; each pusher can be operated independently of the others, and can be deactivated following the detection of certain abnormal situations within the drawers or during the starting or stopping phases of the packing machine.

DESCRIPTION OF THE INVENTION

The object of this invention is to provide a method of controlling a packing machine which manufactures packets of smoking articles each containing two distinct groups of smoking articles, said control method making it possible to increase the productivity of the packing machine without, at the same time, increasing the quantity of cigarettes and wrapping material which is discarded.
In accordance with the present invention, a method is provided for controlling a packing machine manufacturing packets of smoking articles, each containing two distinct groups of smoking articles, as claimed in the attached Claims.
The dependent claims describe preferred embodiments of the present invention and form an integral part of the present description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the accompanying drawings which illustrate a non-limiting embodiment example, wherein:

Figure 1 is a front perspective view of a "twin" packet of cigarettes in a closed configuration;
Figure 2 is a front perspective view of the "twin" packet of cigarettes of Figure 1 in an open configuration;
Figure 3 is a perspective view of an inner wrap of the "twin" packet of cigarettes of Figure 1;
Figure 4 is a perspective view of a group of cigarettes contained in the inner wrap of Figure 3;
Figure 5 is a schematic front view of part of a packing machine which produces the "twin " packet of cigarettes of Figure 1 and is controlled in accordance with the control method of the present invention;
Figure 6 is a schematic plan view of a forming unit for groups of cigarettes of the packing machine of Figure 5;
Figure 7 is a schematic front view of a hopper of the forming unit of Figure 6; and
Figure 8 is a schematic plan view of a variant of the forming unit of Figure 6.

PREFERRED EMBODIMENTS OF THE INVENTION

In Figures 1 and 2, the number 1 indicates, in its entirety, a rigid "twin" packet of cigarettes comprising a rigid outer container 2 provided with a hinged lid and a pair of inner wraps 3, which are arranged side by side and are housed in the outer container 2. Each inner wrap 3 (better shown in Figure 3) contains a parallelepipedshaped group 4 of cigarettes (shown in Figure 4) and has a removable tear-off portion at the top that is removed to allow access to the cigarettes.
Each inner wrap 3 is manufactured by folding a rectangular-shaped wrapper 5 (schematically illustrated in Figure 5) around the group 4 of cigarettes in a known manner. Each inner wrap 3 can be free of stabilisation (i.e. the corresponding wrapper 5 has no connections between the overlapping parts and therefore must always be firmly held to prevent the folds from unfolding by elastic return), can be stabilised by the use of glue, or can be stabilised by heat-sealing (in the latter case the inner wrap 3 is normally tightly sealed). According to an alternative embodiment, the inner wraps 3 are absent and each group 4 of cigarettes is directly housed in the outer container 2 without the interposition of the corresponding inner wrap 3.
Each rigid outer container 2 is provided with a hinged lid manufactured in a known way by folding an elongated rectangular-shaped blank 6 around a side by side pair of inner wraps 3.
According to a possible embodiment shown in Figure 2, the rigid outer container 2 comprises two collars 7, each of which is folded in a "U" to envelop a corresponding inner wrap 3 and connected (by gluing) to the outer container 2 to partially protrude outwards from an open top end of the outer container 2 and engage a corresponding inner surface of the lid when the lid is in the aforementioned closed position. According to an alternative non-illustrated embodiment, the rigid outer container 2 comprises a single collar 7, which is folded in a "U" to envelop both inner wraps 3.
In Figure 5, the number 8 indicates in its entirety a packing machine (only partially shown in Figure 5) which is suitable for manufacturing the above described packet 1 of cigarettes.
The packing machine 8 comprises a forming unit 9 (shown only schematically in Figure 5) wherein groups 4 of cigarettes are formed in succession, a wrapping unit 10 wherein the wrapper 5 is folded around each group 4 of cigarettes to form the corresponding inner wrap 3, a coupling unit 11 wherein the inner wraps 3 (i.e. groups 4 of cigarettes contained in the inner wraps 3) are coupled two by two to form the contents of the packets 1 of cigarettes, and a wrapping unit 12 wherein the collar 7 and the blank 6 are folded around each pair of inner wraps 3 (i.e. around each pair of groups 4 of cigarettes contained in the inner wraps 3) to form the corresponding outer container 2.
As shown in Figure 5, the wrapping unit 10 comprises a wrapping drum 13 which is mounted so it can rotate continuously (i.e. with a motion in which the various moving parts move at a constant speed without any resting phases) around a horizontal axis of rotation 14 perpendicular to the plane of Figure 5 and supports a plurality of (in particular twelve) wrapping heads 15 (only one of which, for simplicity, is shown in Figure 5). The rotation of the wrapping drum 13 around the axis of rotation 14 carries each wrapping head 15 through a feeding station S1 wherein the wrapping head 15 receives a wrapper 5, a transfer station S2 where the wrapping head 15 receives a group 4 of cigarettes from the forming unit 9, and a transfer station S3 where the wrapping head 15 dispenses an inner wrap 3 to the coupling unit 11. Between the feeding station S1 and the transfer station S3, each wrapper 5 is folded around a group 4 of cigarettes to form a corresponding inner wrap 3.
As shown in Figure 5, the coupling unit 11 comprises a coupling drum 16 which is mounted so that it can rotate continuously around an axis of rotation 17 parallel to the axis of rotation 14 and supports a plurality of (in particular six) support bodies 18 (only one of which, for simplicity, is shown in Figure 5). Each support body 18 is mounted so that it can rotate on the coupling drum 16 and supports a pair of housing heads 19, which in turn are mounted so that they can rotate on the support body 18 and are arranged side by side; each housing head 19 supports a corresponding coupling pocket which is suitable to accommodate (contain) an inner wrap 3 (i.e. a group 4 of cigarettes contained in an inner wrap 3). The rotation of the coupling drum 16 around the axis of rotation 17 carries each support body 18 through the transfer station S3 wherein the two corresponding housing heads 19 receive in succession two respective inner wraps 3 and through a transfer station S4 wherein both housing heads 19 simultaneously dispense the two inner wraps 3 side by side; in the transfer station S3, the two housing heads 19 of the same support body 18 are (relatively) far from each other to receive the two inner wraps 3 in succession, and then the two housing heads 19 come together to provide the two nearby (side by side) inner wraps 3 so that the two coupled inner wraps 3 are transferred together in the S4 transfer station (i.e. they leave the two housing heads 19 of the same support body 18 together).
As shown in Figure 5, the wrapping unit 12 comprises a wrapping drum 20 which is mounted so that it can rotate continuously around an axis of rotation 21 parallel to the axis of rotation 17 and supports a plurality of (in particular six) wrapping heads 22 (only one of which, for simplicity, is shown in Figure 5). The rotation of the wrapping drum 20 around the axis of rotation 21 carries each wrapping head 22 through a feeding station S5 where the wrapping head 22 receives the collar 7 (or alternatively a pair of collars 7), through the transfer station S4 where the wrapping head 22 receives two coupled inner wraps 3, and through a transfer station S6 where the wrapping head 22 dispenses the pair of inner wraps 3 together with the collar 7.
The wrapping unit 12 comprises a feeding drum 23 which is mounted so that it can rotate continuously around an axis of rotation 24 axis of rotation parallel to the axis of rotation 21 and supports a plurality of (in particular three) feeding heads 25 (only one of which, for simplicity, is shown in Figure 5). The rotation of the feeding drum 23 around the axis of rotation 24 carries each feeding head 25 through the feeding station S5 where the feeding head 25 dispenses the collar 7 and a wrapping head 22 to the wrapping drum 20.
As shown in Figure 5, the wrapping unit 12 comprises a wrapping drum 26 which is mounted so that it can rotate continuously around an axis of rotation 27 parallel to the axis of rotation 21 and supports a plurality of (in particular six) wrapping heads 28 (only one of which, for simplicity, is shown in Figure 5). The rotation of the wrapping drum 26 around the axis of rotation 27 carries each wrapping head 28 through a feeding station S7 wherein the wrapping head 28 receives a blank 6, through the transfer station S6 wherein the wrapping head 28 receives the inner wraps 3 together with the collar 7, and through the transfer station S8 wherein the wrapping head 28 dispenses the packet 1 of cigarettes to a drying conveyor 29 which carries the packets 1 of cigarettes towards the output of the packing machine 8. Between the feeding station S7 and the transfer station S8, each blank 6 is folded around two inner wraps 3 coupled together with a collar 7 to form a corresponding outer container 2.
According to a preferred embodiment, the "even" wrapping heads 15 of the wrapping drum 13 follow a different course of motion to that of the "odd" wrapping heads 15 of the wrapping drum 13: in other words, in order to dispense two internal wrappings 3 (which will then be coupled to be put into the same packet 1 of cigarettes) to the two housing heads 19 of the same support body 18, the "even" wrapping head 15 which dispenses the first inner wrap 3 into a housing head 19 follows a different course of motion with respect to the "odd" wrapping head 15 which dispenses the second inner wrap 3 into the other housing head 19; obviously, the course of motion of the "even" wrapping heads 15 of the wrapping drum 13 differs from the course of motion of the "odd" wrapping heads 15 of the wrapping drum 13 only at the transfer station S3 where the inner wraps 3 pass from the wrapping heads 15 of the wrapping drum 13 to the housing heads 19 of the wrapping drum 20. Similarly and necessarily, in each support body 18 of the coupling drum 16, the "left" housing head 19 follows a different course of motion to that of the "right" housing head 19 since they must interact with respective heads 15 of the wrapping drum 13 which follow different courses of motion from each other.
As shown in Figure 6, the forming unit 9 for groups 4 of cigarettes comprises a hopper 30 (better shown in Figure 7) provided with six output mouths 31 (identified by the letters A-F) from which groups 4 of cigarettes are extracted in succession. The forming unit 9 further comprises a forming conveyor belt 32 (only partially illustrated) which supports a series of drawers 33, each of which is suitable to receive and house a corresponding group 4 of cigarettes. The forming unit 9 further comprises six extraction devices 34, each of which is coupled to a corresponding output mouth 31 of the hopper 30 and is suitable to cyclically extract a group 4 of cigarettes from the output mouth 31 to insert the group 4 of cigarettes into a corresponding drawer 33 which is stationary in front of the output mouth 31. In the embodiment shown in Figure 6, each extraction device 34 comprises a comb pusher 35 which is suitable to fit inside a corresponding output mouth 31 and a linear electric motor 36 which moves the pusher 35 cyclically by imparting an alternating motion to it.
As will be better explained below, each output mouth 31 has an associated output mouth 31, so that two output mouths 31 are associated with each another when the two output mouths 31 are used to extract two corresponding groups 4 of cigarettes which will be coupled to one another so as to be part of the same packet 1 of cigarettes.
As shown in Figure 7, the hopper 30 comprises an upper part 37 and a lower part 38, both of which are delimited at the front and rear by respective vertical walls. The lower part 38 of the hopper 30 comprises the six equidistant lower output mouths 31, which are internally subdivided by a plurality of defining walls or baffles of the channels within which the cigarettes are arranged in essentially vertical stacks.
The upper part 37 of the hopper 30 is subdivided, starting from the upper inlet, into two separate channels 39 which are mirror images of each other, arranged respectively on the right and left and discharging into an empty chamber belonging to the lower part 38 of the hopper 30 and positioned immediately above the output mouths 31.
As shown in Figure 7, the hopper 30 is provided with sensors 40 (for example, optical sensors 40), each of which is coupled to a corresponding output mouth 31 and is suitable to detect the presence of cigarettes along the channels of the output mouth 31 (each output mouth 31 may comprise a single sensor 40 or several sensors 40 arranged in line). The function of the sensors 40 is to detect an occlusion (typically due to a "crossed-up" cigarette) in an output mouth 31 which prevents the correct flow of cigarettes along the output mouth 31; in other words, a "crossed-up" cigarette (i.e., positioned transversely with respect to the other cigarettes) may arrive over an output mouth 31 and rest on top of the corresponding channels constituting a "bridge" which thus prevents other properly aligned cigarettes from entering the channels and in this case the output mouth 31 becomes empty (at least partially, or at least in one of the channels) of cigarettes since it can no longer receive new cigarettes.
According to one embodiment, a (normally optical) sensor 41 is provided downstream of the output mouths 31, which checks each group 4 of cigarettes carried by a corresponding drawer 33 in order to verify both the completeness of the group 4 of cigarettes (i.e. that the group 4 of cigarettes has all the cigarettes provided), and the degree of filling of the tips of the cigarettes (i.e. that in each cigarette the corresponding tip is sufficiently "full" of tobacco); defective (incomplete or containing at least one cigarette with an "empty" tip) groups 4 of cigarettes are discarded by a discarding device (known and not shown) located downstream of sensor 41.
In use, each output mouth 31 can be identified as correctly functioning when complete groups 4 of cigarettes (i.e. those having all the foreseen cigarettes) are extracted from the output mouth 31 or it can be identified as malfunctioning when incomplete groups 4 of cigarettes (i.e. those lacking at least one of the foreseen cigarettes) are extracted from the output mouth 31.
Each output mouth 31 can be identified as malfunctioning when at least one of the corresponding channels is devoid of cigarettes (i.e. when the respective sensor 40 detects that at least one of the corresponding channels is devoid of cigarettes); this type of identification is "preventive", in that it can identify an output mouth 31 as malfunctioning before an incomplete group 4 of cigarettes is actually extracted from the exit port 31 (if at least one of the channels is empty or is emptying, it is clear that in the short term only incomplete groups 4 of cigarettes can be extracted from the output mouth 31).
Alternatively or in addition to the above, each output mouth 31 may be identified as malfunctioning when the sensor 41 detects that incomplete groups 4 of cigarettes (generally several consecutive incomplete groups 4 of cigarettes or a high percentage of incomplete groups 4 of cigarettes in a given time window) are being extracted from the output mouth 31; this type of identification is "final", since it can only identify an output mouth 31 as malfunctioning only after the exit mouth 31 has actually extracted incomplete groups 4 of cigarettes.
The following describes the operation of the packing machine 8 with reference to the management of an occlusion in an output mouth 31 detected by a corresponding sensor 40.
When all the output mouths 31 are working correctly (i.e. when all the sensors 40 detect the presence of cigarettes in all the output mouths 31), the packing machine 8 is operating in normal conditions, all the drawers 33 of the forming conveyor 32 are always filled (i.e. they always receive corresponding groups 4 of cigarettes from the corresponding output mouths 31), all the wrapping heads 15 always receive a corresponding wrapper 5 and a corresponding group 4 of cigarettes, all the support bodies 18 always receive a pair of inner wraps 3, all the wrapping heads 22 always receive a corresponding collar 7 and a corresponding pair of side by side inner wraps 3, and all the wrapping heads 28 always receive a corresponding blank 6 and a corresponding pair of side by side inner wraps 3 together with a collar 7. In other words, in normal conditions, the entire packing machine 8, without exception, is involved in the manufacture of packets 1 of cigarettes.
When a malfunctioning output mouth 31 is detected (i.e. one that is occluded and therefore prevented from receiving cigarettes with the necessary continuity), it is possible to stop the packing machine 8, completely stopping the production of packets 1 of cigarettes and waiting for a technical intervention (cleaning and resetting of the hopper). This option is certainly simple, but on the other hand it significantly reduces the long-term productivity of the packing machine,8 i.e. the number of packets 1 of cigarettes correctly produced in a long period of time (for example, a conventional 8-hour work shift, a working day, a working week, a working month, a working year...).
Whereas, according to the present invention, when a malfunctioning output mouth 31 is detected (i.e. one that is occluded and therefore prevented from receiving cigarettes with the necessary continuity) it is possible to keep the packing machine 8 running by using only the correctly functioning output mouths 31, and not those associated with the malfunctioning output mouth 31, for forming the groups 4 of cigarettes. In this regard, it is important to note that two groups 4 of cigarettes, necessarily coming from two associated output mouths 31, are inserted into each packet 1 of cigarettes therefore the groups 4 of cigarettes flowing out of two associated output mouths 31 are destined to be coupled together to be inserted into the same packet 1 of cigarettes: when an output mouth 31 is no longer in use due to an occlusion, it is convenient to no longer use the associated output mouth 31 (even if it is functioning correctly) in order to avoid forming an "orphan" group 4 of cigarettes which would necessarily have to be discarded (thus with an obvious waste of cigarettes).
In order not to use the malfunctioning output mouth 31 (i.e. the one that is occluded and therefore prevented from receiving cigarettes with the necessary continuity) and the associated output mouth 31, the corresponding extraction devices 34 are disabled (i.e. not operated); in this regard, it is important to note that the extraction devices 34 are independent from each other and therefore can be individually activated/deactivated.
For example, if an occlusion occurs in the output mouth 31 indicated with the letter "A", the extraction device 34 of the output mouth 31 indicated with the letter "A" is deactivated together with the extraction device 34 of the output mouth 31 indicated with the letter "B", which is associated with the output mouth 31 indicated with the letter "A"; therefore, only the extraction devices 34 of the output mouths 31 indicated with the letters "C-F" remain in operation.
Operating as described above, i.e. disabling the extraction devices 34 of the malfunctioning output mouth 31 and the associated output mouth 31, the empty drawers 33 are cyclically formed and thus cyclically some wrapping heads 15 in the transfer station S2 do not receive the corresponding groups 4 of cigarettes; to avoid wasting wrapping material, in the feeding station S1 the feeding of wrappers 5 to the wrapping heads 15 is suspended (avoided), which will not receive the corresponding groups 4 of cigarettes in the transfer station S2. In the same way, in the transfer station S4 some wrapping heads 22 do not receive the corresponding pairs of inner wraps 3; in order to avoid wasting wrapping material, in the feeding station S5 the feeding of the collars 7 to the wrapping heads 22 is suspended (avoided), which will not receive the corresponding pairs of inner wraps 3 in the transfer station S4. In the same way, cyclically in the transfer station S6 some wrapping heads 28 do not receive the corresponding pairs of inner wraps 3 together with the collar 7; in order to avoid wasting wrapping material, in the feeding station S7 the feeding of the blanks 6 to the wrapping heads 28 is suspended (avoided), which will not receive the corresponding pairs of inner wraps 3 together with the collar 7 in the transfer station S6.
This operating method makes it possible not to completely stop the packing machine 8 when a malfunctioning output mouth 31 is detected (i.e. one that is occluded and therefore prevented from receiving cigarettes with the necessary continuity); in fact, the packing machine 8 continues to operate normally with a penalty due to the temporary "loss " of two output mouths 31 (the malfunctioning output mouth 31 and the output mouth 31 associated with it) which, as a knock-on effect, causes a momentary "loss" of at least two wrapping heads 15 of the wrapping drum 13, at least one support body 18 of the coupling drum 16, at least one wrapping head 22 of the wrapping drum 20, and least one wrapping head 28 of the wrapping drum 26. It is thus possible to significantly increase the long-term productivity of the packing machine 8.
In the embodiment shown in Figure 6, six fully independent pushers 35 are provided, i.e. driven by six corresponding linear electric motors 36. In the embodiment shown in Figure 8, only three linear electric motors 36 are provided, each of which drives a pair of pushers 35 together, so that a single linear electric motor 36 drives the two pushers 35 of two output mouths 31 associated with each other.
The embodiments described herein can be combined with each other without departing from the protective scope of the present invention.
The control method described above has numerous benefits.
Firstly, the control method described above makes it possible to significantly increase the long-term productivity of the packing machine 8 because when the malfunction (occlusion) of an output mouth 31 occurs, the packing machine 8 is not completely stopped, instead the packing machine 8 is kept in operation with a penalty due to the temporary "loss " of two output mouths 31 (the malfunctioning output mouth 31 and the output mouth 31 associated with it). In this regard, it is important to note that an operator can easily intervene in the hopper 30 to eliminate an occlusion without having to stop the packing machine 8 and therefore the full functionality of the packing machine 8 can be resumed without ever stopping the packing machine 8; in fact, the area of the hopper 30 in which the occlusions (i.e. the "crossed-up" cigarettes) occur is free of moving parts that could constitute a danger for the operator.
The control method described above does not lead to an increase in the number of cigarettes which are discarded, since blocking the malfunctioning (occluded) output mouth 31 together with the associated output mouth 31 avoids forming groups 4 of cigarettes destined to be discarded as "orphans" (i.e. not associated with another group 4 of cigarettes to form the contents of a packet 1 of cigarettes). The control method described above does not lead to an increase in the quantity of discarded wrapping material, as the feeding of the wrapping material (wrappers 5, blanks 6, and collars 7) to the wrapping heads 15, 22 and 28 without groups 4 of cigarettes is interrupted.
Finally, the control method described above is simple and cost-efficient to implement since it does not require major changes to the physical structure of the packing machine 8.
The embodiment shown in the attached Figures refers to the manufacture of a packet of cigarettes, but the present invention is also applicable without substantial modification to the manufacture of any other type of packet of cylindrical smoking articles (for example, a packet of cigars, a packet of liquid vaporised electronic cigarettes, a packet of new generation cigarettes without tobacco combustion...).

LIST OF REFERENCE NUMBERS IN THE FIGURES

1: packet of cigarettes
2: outer container
3: inner wrap
4: group of cigarettes
5: wrapper
6: blank
7: collar
8: packing machine
9: forming unit
10: wrapping unit
11: coupling unit
12: wrapping unit
13: wrapping drum
14: axis of rotation
15: wrapping head
16: coupling drum
17: axis of rotation
18: support body
19: housing heads
20: wrapping drum
21: axis of rotation
22: wrapping head
23: feeding drum
24: axis of rotation
25: feeding head
26: wrapping drum
27: axis of rotation
28: wrapping head
29: drying conveyor
30: hopper
31: output mouth
32: forming conveyor
33: drawers
34: extraction devices
35: pusher
36: linear electric motor
37: upper part
38: lower part
39: channels
40: sensors
41: sensor
S1: feeding station
S2: transfer station
S3: transfer station
S4: transfer station
S5: feeding station
S6: transfer station
S7: feeding station

Claims

A method for controlling a packing machine (8) manufacturing packets (1) of smoking articles, each containing two distinct inner wraps (3) each realized by folding a wrapper (5) around a group (4) of smoking articles; the packing machine (8) comprises:
a forming unit (9), where the groups (4) of smoking articles are formed in succession and which comprises a hopper (30), which is provided with at least four output mouths (31), each used to extract a group (4) of smoking articles by means of a corresponding extraction device (34); and

a first wrapping unit (10), wherein each wrapper (5) is folded around each group (4) of smoking articles so as to form a corresponding inner wrap (3);

a coupling unit (11), wherein the inner wraps (3) are coupled so as to form the content of the packets (1) of smoking articles;

a second wrapping unit (12), wherein a blank (6) is folded around each pair of inner wraps (3) so as to form an outer container (2); and

a plurality of wrapping drums (13, 20, 26) which are part of the two wrapping units (10, 12) and each of which has a plurality of wrapping heads (15, 22, 28), which are suitable to receive the groups (4) of smoking articles together with corresponding wrapping materials (5, 6, 7);

wherein each output mouth (31) has an associated output mouth (31), so that two output mouths (31) are associated with each another when the two output mouths (31) are used to extract two corresponding groups (4) of smoking articles which will be coupled to one another so as to be part of the same packet (1) of smoking articles;

the control method comprises the steps of:
detecting the correct operation of each output mouth (31) of the hopper (30), so as to identify a possibly faulty output mouth (31);

using, for the formation of the groups (4) of smoking articles and in the absence of faulty output mouths (31), all the output mouths (31), always extracting from each output mouth (31) a corresponding group (4) of smoking articles; and

using, to manufacture the packets (1) of smoking articles and in the absence of faulty output mouths (31), all the wrapping heads (15, 22, 28), always supplying all the wrapping heads (15, 22, 28) with the corresponding wrapping materials (5, 6, 7);

the control method is characterised in that it comprises the further steps of:

avoiding using, for the formation of the groups (4) of smoking articles and in the presence of a faulty output mouth (31), the faulty output mouth (31) as well as the output mouth (31) associated with the faulty output mouth (31), thus avoiding extracting the corresponding groups (4) of smoking articles from the two output mouths (31);

avoiding using, to manufacture the packets (1) of smoking articles and in the presence of a faulty output mouth (31), the wrapping heads (15, 22, 28) that are supposed to receive the groups (4) of smoking articles from the faulty output mouth (31) and from the output mouth (31) associated therewith; and

avoiding supplying the corresponding wrapping materials (5, 6, 7) to the wrapping heads (15, 22, 28) that are supposed to receive the groups (4) of smoking articles from the faulty output mouth (31) and from the output mouth (31) associated therewith.
The control method according to Claim 1, wherein the faulty output mouth (31) and the output mouth (31) associated therewith are prevented from being used by disabling the corresponding extraction devices (34).
The control method according to Claim 1 or 2, wherein:
each output mouth (31) of the hopper (30) is associated with a plurality of walls defining small channels where the smoking articles are arranged in substantially vertical piles; and

each output mouth (31) of the hopper (30) is provided with at least one sensor (40),

which is suitable to detect the presence of smoking articles along the corresponding small channels.
The control method according to Claim 3 and comprising the further step of identifying an output mouth (31) as faulty when at least one of the corresponding small channels has no smoking articles.
The control method according to one of the Claims 1 to 4 and comprising the further steps of:
checking whether the groups (4) of smoking articles are complete downstream of the output mouths (31); and

identifying an output mouth (31) as faulty when one or more groups (4) of smoking articles extracted from the output mouth (31) are incomplete.