Method to control a hopper for a packaging machine for smoking articles

Abstract

A method to control a hopper (1) floor a packaging machine for smoking articles is described comprising at least one output mouth (2), from which groups of smoking articles are cyclically extracted by means of extraction devices; and wherein the output mouth (2) comprises a plurality of dividing walls (7) defining veins (8), each configured to contain a vertical stack of smoking articles; a number of upper selection devices (13), which are designed to allow the smoking articles to move downward towards the output mouths (2) and comprise a plurality of partitions (14) defining downward channels (15) for the smoking articles; and a compensation chamber (17), which is interposed between the upper selection devices (13) and the veins (8), receives the smoking articles through the downward channels (15) and feeds them into the veins (8). The method comprises housing a plurality of sensors (18) in the area of the downward channels (15), which are designed to detect when there is an interruption in the downward movement of the smoking articles through the downward channels (15); and adjust the speed (V) with which the groups of smoking articles are extracted from the output mouth (2) depending on the signals received from said sensors (18).

Description

[0001] METHOD TO CONTROL A HOPPER FOR A PACKAGING MACHINE FOR

[0002] SMOKING ARTICLES

[0003] Cross-Reference to Related Applications

[0004] This Patent Application claims priority from Italian Patent Application No . 102022000026232 filed on December 21 , 2022 , the entire disclosure of which is incorporated herein by reference .

[0005] Technical Field

[0006] The present invention falls within the technical field of the production of packs for smoking articles . In detail , the present invention relates to a method to control a hopper for a packaging machine for smoking articles .

[0007] Prior Art

[0008] As is known, in the production of packs of smoking articles the hoppers are used to sort masses of smoking articles so as to be able to insert the same , in groups or rows , inside a packing material to be used for producing a pack .

[0009] A hopper of a known type has a vertical extension and comprises : an input portion for the entering of the smoking articles arranged in disorderly masses into the hopper, a plurality of output mouth, each comprising a plurality of vertical channels ( or veins ) for the exiting of the smoking articles from the hopper (with the aid of suitable extractor means ) , and a connection area, which connects the input portion to the output mouths and is delimited by side walls with which the smoking articles come into contact during their downward path .

[0010] To date , the need to increase the productivity of the packaging machines for smoking articles is increasingly felt . Therefore , it is necessary to increase the downward speed of the smoking articles within the hoppers towards the output mouths .

[0011] However, the increase in the downward speed of the smoking articles towards the output mouths often causes , in hoppers of a known type such as the one described above , blockages , namely unwanted obstructions of one or more output mouths . These obstructions are mostly caused by the incorrect positioning, namely orientation, of one or more smoking articles which during the downward movement at high speed causes the closure of the veins of the output mouths ( or in any case slows down the downward movement of the other smoking articles ) .

[0012] In the event of obstruction of one or more output mouths , it is normally necessary to stop the operation of the packaging machine and it is always necessary for an operator to intervene and manually eliminate the obstruction; consequently, obstructions in the output mouths tend to reduce the long-term production of the packaging machine , namely, the number of packs of smoking articles correctly produced in a long period of time . In this regard, it is important to note that the best packaging machine is not the one that has the highest nominal ( theoretical ) speed, but is the one that manages to maintain the highest average speed in the long term .

[0013] For this reason, hoppers have been proposed provided with a higher number of selection devices which are designed to allow compliant smoking articles to move downward towards the output mouths and, at the same time , to allow to block the downward movement of defective or non-compliant smoking articles before they reach the veins .

[0014] However, even i f an obstruction occurs at the upper selection devices , it is normally necessary to interrupt the operation of the packaging machine and an operator must intervene to manually eliminate the obstruction .

[0015] Description of the Invention

[0016] The obj ect of the present invention is therefore to provide a method to control a hopper for a packaging machine for smoking articles , which method is free from the drawbacks of the state of the art and is at the same time easy and inexpensive to implement . According to the present invention, a method is provided to control a hopper for a packaging machine for smoking articles as claimed in the attached claims .

[0017] The claims describe preferred embodiments of the present invention and form an integral part of the present description .

[0018] Brief Description of the Drawings

[0019] The present invention will now be described with reference to the attached drawings , which illustrate a non-limiting embodiment thereof , wherein :

[0020] • Figure 1 is a front view of a hopper for a packaging machine for smoking articles controlled by the method of the present invention;

[0021] • Figure 2 is a perspective and front view of the hopper of Figure 1 ;

[0022] • Figure 3 is a perspective and rear view of the hopper of Figure 1 ;

[0023] • Figure 4 is an enlarged view of a detail of Figure 3 ; and

[0024] • Figure 5 is an enlarged view of a detail of Figure 1 .

[0025] Preferred Embodiments of the Invention

[0026] With reference to Figure 1 , number 1 denotes as a whole a hopper for smoking articles , in particular for cigarettes , which defines the initial part of a packaging machine for smoking articles .

[0027] The hopper 1 has a vertical extension and comprises a number of output mouths 2 , in particular three output mouths 2 , ( identi fied by the letters A, B and C ) from which groups of smoking articles are extracted in succession by means of a number of corresponding extraction devices (not illustrated) . Each extraction device is coupled to a corresponding output mouth 2 of the hopper 1 and is designed for cyclically extracting a group of smoking articles from the output mouth 2 to insert the group of smoking articles into a corresponding sliding container (not illustrated) of a forming conveyor standing still in front of the output mouth 2 .

[0028] The hopper 1 comprises an upper part 3 and a lower part 4 , both of which are delimited at the back by a vertical wall 5 . Furthermore , the upper part 3 and the lower part 4 are both delimited at the front by a front cover panel 6 (partially illustrated in Figure 2 ) ; the front cover panel 6 is preferably transparent and provided with a door to make the inside of the hopper 1 accessible to an operator of the hopper 1 so as to remove any obstructing smoking articles .

[0029] The lower part 4 of the hopper 1 comprises the equally spaced lower output mouths 2 , which are internally divided by a plurality of dividing walls 7 or partitions defining the veins 8 within which the smoking articles are arranged in substantially vertical stacks . For example , the two end output mouth 2 identi fied as A, C are divided into seven veins 8 by means of six dividing walls 7 while the central output mouth 2 identi fied as B is divided into six veins 8 by means of five dividing walls 7 . The groups of dividing walls 7 that define the output mouths 2 are separated from one another by means of fixed wedge-shaped separator elements 9 , on whose lateral surfaces the smoking articles slide on their downward movement towards the veins 8 .

[0030] According to a preferred embodiment , a plurality of lower agitator elements 10 are provided which are controlled by actuation means M and are suitable , by means of the vibrations thereof , to facilitate the downward movement of the smoking articles into the veins 8 . Each lower agitator element 10 is connected to the vertical wall 5 and is substantially arranged in the area of a dividing wall 7 ; in particular, each lower agitator element 10 is arranged immediately above a corresponding dividing wall 7 .

[0031] The upper part 3 of the hopper 1 is divided, starting from an upper input opening, into two distinct and mirror-like channels 11 which are arranged respectively to the right and to the left of a wedge-shaped separator element 12 , respectively .

[0032] Inside the hopper 1 a number of upper selection devices 13 are also housed, which are designed to allow the downward movement towards the output mouths 2 of the compliant smoking articles and, at the same time , to allow to block the downward movement of the defective or non-compliant smoking articles before reaching the veins 8 . The upper selection devices 13 comprise a plurality of partitions 14 arranged at the same height and equally spaced in the transverse direction which identi fy a plurality of downward channel s 15 between two partitions 14 arranged in succession one after the other . The partitions 14 are connected to the vertical wall 5 and protrude inside the hopper 1 . According to a first embodiment , each partition 14 has two flat lateral surfaces which identi fy linear downward channels 15 in which the smoking articles slide in the downward movement towards the veins 8 .

[0033] According to a further and not illustrated embodiment , each partition 14 has two lateral surfaces having a non- flat shape ( for example , substantially V-shaped or S-shaped) so as to identi fy downward channels 15 ( substantially V-shaped or S- shaped) in which the smoking articles slide in the downward movement towards the veins 8 .

[0034] The upper selection devices 13 further comprise a plurality of upper agitator elements 16 which are controlled by actuation means K and are suitable , by means of the vibrations thereof , to facilitate the downward movement of the smoking articles into the downward channels 15 . Each upper agitator element 16 is connected to the vertical wall 5 and protrudes inside the hopper 1 . Each upper agitator element 16 is substantially arranged in the area of a partition 14 ; in particular, each upper agitator element 16 is arranged immediately above a corresponding partition 14 . A compensation chamber 17 is defined between the lower agitator elements 10 and the upper selection devices 13 which receives the smoking articles through the downward channels 15 and subsequently feeds them into the veins 8 . In the event of an interruption in the downward movement of smoking articles through the upper selection devices 13 ( for example due to an obstructing smoking article ) , the compensation chamber 17 is in any case able to guarantee that the flow of smoking articles inside the veins 8 is not interrupted . In particular, the operator of the hopper 1 can reach the mass of smoking articles contained inside the hopper 1 through the door obtained in the front cover panel 6 to remove the obstructed smoking article without stopping the operation of the hopper 1 .

[0035] According to a preferred embodiment , the upper selection devices 13 comprise a number of upper sensors 18 connected to a control unit CU and designed to detect when there is an interruption in the downward movement of the smoking articles through the downward channel s 15 caused, for example , by an obstructed smoking article .

[0036] According to a preferred embodiment , an upper sensor 18 is provided for each downward channel 15 . In particular, an optical fibre sensor 18 i s provided, placed in the area of each downward channel 15 ; preferably, each optical fibre sensor 18 is inserted inside the respective downward channel 15 through a hole obtained in the vertical wall 5 . Said optical fibre sensors 18 are designed to detect the passage of smoking articles in the corresponding downward channel 15 and to send a signal to the control unit CU in case the passage of smoking articles in the corresponding downward channel 15 is not detected to signal an interruption in the downward movement of smoking articles .

[0037] As an alternative or in combination with the optical fibre sensors 18 , a number of optical devices are provided, in particular a number of video cameras , placed in the area of the downward channels 15 ; more in detail , the optical devices are connected to the front cover panel 6 and face the downward channels 15 so as to detect the passage of smoking articles in a number of downward channel s 15 . According to a preferred alternative , at least two optical devices are provided, each intended to detect the passage of smoking articles in one hal f of the downward channels 15 .

[0038] According to a preferred embodiment , a further number of lower sensors 19 are provided, connected to the control unit CU and intended to detect when there is an interruption in the downward movement of the smoking articles through the veins 8 .

[0039] In particular, a number of optical devices 19 , preferably a number of video cameras , are provided, placed in the area of the veins 8 ; more in detail , the optical devices 19 are connected to the front cover panel 6 and face the veins 8 so as to detect the passage of the smoking articles in the veins 8 . Preferably, at least one optical device 19 is provided in the area of the group of veins 8 of each output mouth 2 .

[0040] Alternatively, the sensors 19 comprise optical fibre sensors 19 placed in the area of the veins 8 ; preferably, each optical fibre sensor 19 is inserted inside the respective vein 8 through a hole obtained in the vertical wall 5 . Said optical fibre sensors 19 are designed to detect the passage of smoking articles in the corresponding vein 8 and to send a signal to the control unit CU in case the passage of smoking articles in the corresponding vein 8 is not detected to signal an interruption in the downward movement of the smoking articles .

[0041] The control unit CU supervises the operation of the hopper 1 and is connected to both the upper sensors 18 and the lower sensors 19 and to the extraction devices . In particular, the control unit CU is designed to regulate the speed of the extraction devices , that is , to regulate the speed with which the groups of smoking articles are extracted from the output mouths 2 , preferably depending on the signals received from the upper sensors 18 .

[0042] The smoking articles pass through the hopper 1 descending by gravity from top to bottom along a vertical output direction D; consequently, the smoking articles that enter the hopper 1 from above are divided into two flows which, passing through the two channels 11 , reach the upper selection devices 13 where , due to the action of the upper agitator elements 16 , pass through the downward channels 15 to reach the compensation chamber 17 from which the smoking articles enter the veins 8 ending in the output mouths 2 .

[0043] The control mode implemented by the control unit CU to regulate the speed with which the groups of smoking articles are extracted from the output mouths 2 by means of the extraction devices ( speed typically expressed in strokes per minute ) is described in the following .

[0044] The control unit CU is designed to regulate the speed V of the extraction devices depending on the signals received from the upper sensors 18 . Preferably, the control method comprises regulating ( in particular, reducing) the extraction speed V in a manner proportional to the number of obstructed downward channels 15 in which the passage of the smoking articles is not detected .

[0045] In particular, in a preliminary setting step, a nominal value of the extraction speed V of the extraction devices is determined . The nominal value of the extraction speed V is determined in an initial learning step and is variable depending on some parameters which comprise , among other things , the dimensions of the smoking articles .

[0046] During normal operation of the hopper 1 , in case the number of obstructed downward channels 15 is less than a value ni ( for example , equal to four ) , the control unit CU is set up to drive the extraction devices with an extraction speed V equal to the nominal value .

[0047] In the event that the number of obstructed downward channels 15 is greater than the value ni and smaller than or equal to a value n2 ( greater than the value ni, for example equal to six ) , the control unit CU is set up to reduce the extraction speed V relative to the nominal value , for example by 25% .

[0048] In the event that the number of obstructed downward channels 15 is greater than the value n2 and smaller than or equal to a value ns ( greater than the value ni, for example equal to 10 ) , the control unit CU is set up to halve the extraction speed V relative to the nominal value .

[0049] In the event that the number of obstructed downward channels 15 is greater than the value ns, the control unit CU is instead set up to stop the hopper 1 ( that is , reset the extraction speed V) .

[0050] Said values ni, n2 and ns are determined in an initial learning step and are stored inside the control unit CU .

[0051] The number of said threshold values ( for example , two or three threshold values ni, n2 and ns ) is variable and is determined in an initial learning step and stored inside the control unit CU .

[0052] Advantageously, said values nl , n2 and n3 are variable depending on some parameters which comprise , for example , the dimensions of the smoking articles and the nominal value of the extraction speed V .

[0053] The applicant has veri fied that regulating the extraction speed V according to the number of obstructed downward channels 15 brings signi ficant advantages for the operation of the hopper 1 .

[0054] In particular, identi fying said values ni, n2 and ns allows to adj ust the extent of the intervention on the hopper 1 ( in particular on the extraction speed V) depending on the number of downward channels 15 actually obstructed .

[0055] In the event that the hopper 1 is provided with optical devices , in particular video cameras , placed in the area of the downward channels 15 , the control unit CU i s designed to detect , by means of optical devices , the width of the opening generated in the compensation chamber 17 ( that is , of the "hole" that is generated in the mass of smoking articles ) due to the obstruction of a number of downward channel s 15 . The control unit CU is designed to regulate the extraction speed V depending on the dimensions of the opening generated in the compensation chamber 17 . In other words , the extraction speed V can be further reduced in the case in which the opening generated in the compensation chamber 17 is very large ( that is , greater than a reference si ze of the opening generated in the compensation chamber 17 ) ; and vice versa .

[0056] In the preceding disclosure , explicit reference was made to the case in which three reference values are provided for the number of obstructed downward channel s 15 , that is , the values ni, n2 and ns, by which to regulate the extraction speed V but it appears clear that any number of reference values for the number of obstructed downward channels 15 can be provided on the basis of which the extraction speed V can be adj usted .

[0057] List of Reference Numbers

[0058] 1 hopper

[0059] 2 output mouth

[0060] 3 upper part

[0061] 4 lower part

[0062] 5 vertical wall

[0063] 6 front cover panel

[0064] 7 dividing wall

[0065] 8 vein

[0066] 9 fixed wedge-shaped separator elements 10 lower agitator element

[0067] 11 channel

[0068] 12 wedge-shaped separator element

[0069] 13 upper selection device 14 partitions

[0070] 15 downward channels

[0071] 16 upper agitator element

[0072] 17 compensation chamber

[0073] 18 upper sensor 19 lower sensor

[0074] M actuation means

[0075] K actuation means

[0076] CU control unit

[0077] D output direction

[0078] A, B, C output mouths

[0079] V extraction speed

Claims

CLAIMS1. A method to control a hopper (1) for a packaging machine for smoking articles comprising: at least one output mouth (2) , from which groups of smoking articles are cyclically extracted by means of extraction devices; and wherein the output mouth (2) comprises a plurality of dividing walls (7) defining veins (8) , each configured to contain a vertical stack of smoking articles; a number of upper selection devices (13) , which are designed to allow the smoking articles to move downward towards the output mouths (2) and comprise a plurality of partitions (14) defining downward channels (15) for the smoking articles; and a compensation chamber (17) , which is interposed between the upper selection devices (13) and the veins (8) , receives the smoking articles through the downward channels (15) and feeds them into the veins ( 8 ) ; the method is characterized in that it comprises the following steps :- placing a number of sensors (18) in the area of the downward channels (15) , which are configured to detect when there is an interruption in the downward movement of the smoking articles through the downward channels (15) ;- determining a nominal value of the extraction speed (V) of the smoking articles;- in case the number of obstructed downward channels (15) is smaller than a first value (ni) , preferably equal to four, maintaining an extraction speed (V) equal to said nominal value;- reducing the extraction speed (V) relative to the nominal value, in case the number of obstructed downward channels (15) is greater than the first value (ni) and smaller than or equal to a second value (n2, ns) , which is greater than the first value (ni) ; and- stopping the hopper (1) , in case the number of obstructed downward channels (15) is greater than the second value (n2, n3) .

2. The method according to claim 1 and comprising an initiallearning step to learn said first and second values (ni, n2, ns) , wherein said first and second values (ni, n2, ns) are variable depending on parameters such as the dimensions of the smoking articles and the nominal value of the extraction speed (V) .

3. The method according to claim 1 or 2, wherein said sensors (18) comprise optical fibre sensors and wherein the placing step comprises a sub-step in which to place an optical fibre sensor (18) in the area of each downward channel (15) , preferably through a hole obtained in a rear wall (5) of the hopper (1) .

4. The method according to any one of the preceding claims, wherein said sensors (18) comprise optical devices, in particular video cameras, and wherein the placing step comprises a sub-step in which to place the optical devices in the area of and frontally facing the downward channels (15) .

5. The method according to claim 4 and comprising the further steps of:- detecting, by means of the optical devices, the width of the opening generated in the compensation chamber (17) due to the obstruction of a number of downward channels (15) ;- adjusting the speed (V) with which the groups of smoking articles are extracted from the output mouth (2) depending on the dimensions of the opening generated in the compensation chamber ( 17 ) .

6. The method according to any of the preceding claims wherein the step of reducing the extraction speed (V) comprises the substeps of:- reducing, preferably by 30%, the extraction speed (V) relative to the nominal value, in case the number of obstructed downward channels (15) is greater than the first value (ni) and smaller than or equal to the second value (n2) , preferably equal to six; -reducing by half the extraction speed (V) relative to the nominal value, in case the number of obstructed downward channels (15) is greater than the second value (n2) and smallerthan or equal to a third value (ns) , preferably equal to ten; and- stopping the hopper (1) , in case the number of obstructed downward channels (15) is greater than the third value (n3) .

Images