WO2020058897A1 - Apparatus for the conveying and inspection of a semi-finished product of the tobacco industry - Google Patents

Apparatus for the conveying and inspection of a semi-finished product of the tobacco industry Download PDF

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Publication number
WO2020058897A1
WO2020058897A1 PCT/IB2019/057907 IB2019057907W WO2020058897A1 WO 2020058897 A1 WO2020058897 A1 WO 2020058897A1 IB 2019057907 W IB2019057907 W IB 2019057907W WO 2020058897 A1 WO2020058897 A1 WO 2020058897A1
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WO
WIPO (PCT)
Prior art keywords
suction belt
detecting
semi
electromagnetic
finished product
Prior art date
Application number
PCT/IB2019/057907
Other languages
French (fr)
Inventor
Eura Trivisonno
Ivan Eusepi
Marco FRASSON
Mauro Galli
Fausto Mengoli
Massimo Sartoni
Luca Federici
Original Assignee
G.D S.P.A.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by G.D S.P.A. filed Critical G.D S.P.A.
Priority to EP19786869.8A priority Critical patent/EP3852557B1/en
Publication of WO2020058897A1 publication Critical patent/WO2020058897A1/en

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Classifications

    • A—HUMAN NECESSITIES
    • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24C—MACHINES FOR MAKING CIGARS OR CIGARETTES
    • A24C5/00—Making cigarettes; Making tipping materials for, or attaching filters or mouthpieces to, cigars or cigarettes
    • A24C5/32—Separating, ordering, counting or examining cigarettes; Regulating the feeding of tobacco according to rod or cigarette condition
    • A24C5/34—Examining cigarettes or the rod, e.g. for regulating the feeding of tobacco; Removing defective cigarettes
    • A24C5/3412—Examining cigarettes or the rod, e.g. for regulating the feeding of tobacco; Removing defective cigarettes by means of light, radiation or electrostatic fields

Definitions

  • This invention relates to an apparatus for the conveying and inspection of a semi-finished product of the tobacco industry.
  • this invention is intended for making an apparatus for moving and at the same time inspecting a semi-finished product of the tobacco industry, capable of guaranteeing the correctness of the measurements performed, so as to allow an assessment of its conformity to one or more requirements of the end product to be made.
  • Prior art machines for the production of continuous rods of tobacco usually use a substantially vertical flue fed at the bottom by a continuous flow of tobacco particles, at the top end of which a suction belt is positioned, on which a continuous mass of tobacco forms.
  • That suction belt is suitable for feeding the continuous mass of tobacco along a predetermined path, at least partly defined by the suction belt itself, to a preforming device which creates a continuous ribbon and then to a forming channel for a continuous rod of tobacco in which a wrapping web, for example made of paper, is forced to wrap around the continuous ribbon of tobacco so as to form a continuous cylinder or rod of the tobacco industry, such as a cigarette rod, which will subsequently be divided into pieces by a suitable cutting device.
  • Such inspection stations comprise sensors capable of assessing the quantity of tobacco which is being conveyed along the channel in order to determine if the transfer from the ascending flue to the forming beam is happening in the desired way.
  • the suction belt also passes through the inspection station, thereby disturbing the measuring process.
  • the result obtained represents not just the properties of the semi-finished product to be measured, but also those of the suction belt.
  • suction belt undergoes substantial variations in its structure (for example length and thickness) in periods of time which may even be very short, for example compared with the length of a work shift.
  • the technical purpose which forms the basis of this invention is to propose an apparatus for the conveying and inspection of a semi-finished product of the tobacco industry which overcomes the above- mentioned disadvantages of the prior art.
  • this invention shows an apparatus for the conveying and inspection of a semi-finished product of the tobacco industry which comprises a conveyor with a suction belt and at least one electromagnetic detecting device.
  • the conveyor is configured to hold and convey the semi-finished product along a conveying path and comprises at least one guide channel for the semi-finished product, delimited at the sides by two side walls and at the top by a suction belt.
  • the at least one electromagnetic detecting device defines at least one detecting channel configured to slidably receive the suction belt and at least one portion of the semi-finished product held on that suction belt.
  • the apparatus is configured to operate in a first configuration, in which the at least one electromagnetic detecting device detects at least one property of the suction belt passing through the detecting channel and generates a reference signal, and in a second configuration, in which the at least one electromagnetic detecting device detects at least one property of the semi finished product and of the suction belt passing through the detecting channel and generates a measurement signal.
  • the conveying apparatus comprises, or is associated with, a control unit configured to receive and process the measurement signal, correcting or varying it as a function of the reference signal.
  • that apparatus allows a precise and exact assessment of the impact of the presence of the belt on the measuring process, so as to obtain an effective measurement data item relating only to the semi finished product, that is to say, representing only the properties of the semi-finished product.
  • This invention also relates to a method for the conveying and inspection of a semi-finished product of the tobacco industry, which comprises the following steps:
  • At least one electromagnetic detecting device which defines at least one detecting channel configured to slidably receive the suction belt and at least one portion of the semi-finished product held on the suction belt;
  • that method allows the generation of a reference signal as a function of which it is possible to correct the measurement signal in order to remove the contribution which is due to the presence of the suction belt.
  • the fact that the measurement signal is corrected or varied shall be understood to mean that said measurement signal is processed while taking into account the reference signal detected.
  • Figure 1 shows a first possible embodiment of the apparatus according to this invention
  • Figure 2 shows a further possible embodiment
  • Figure 3 shows a further possible embodiment
  • Figure 4 shows a further possible embodiment
  • Figure 5 is a perspective view of the embodiment of Figure 4.
  • the reference number 100 is used to indicate an apparatus for the conveying and inspection of a semi-finished product of the tobacco industry according to this invention.
  • the semi-finished product may be any material used in the tobacco industry for filling elements of a smoking article, such as: a mass of tobacco fibre, a ribbon of filter material, a ribbon of pieces of filter, even heterogeneous, or a crimped tobacco ribbon.
  • the apparatus 100 comprises a conveyor 10 with a suction belt and at least one electromagnetic detecting device 20.
  • the conveyor 10 is configured to hold and convey the semi-finished product along a conveying path and comprises at least one guide channel 11 , delimited at the sides by two side walls 12 and at the top by a suction belt 13.
  • the suction belt 13 is permeable to air so that an air flow generated inside the apparatus 100 can pass through the belt from the bottom upwards.
  • That air flow creates a vacuum on the lower surface of the suction belt 13 and this allows the bottom of the suction belt 13 to hold the semi-finished product, received from an ascending flue, conveying it along the guide channel 11.
  • the presence of the side walls allows the definition of a cross-section of the semi-finished product sliding through the guide channel 11 , at whose outfeed the semi-finished product reaches a forming station in which it will be wrapped in a wrapping material, which could even be at least partly metallic or metallized, so as to make a continuous rod of the tobacco industry.
  • the suction belt slides inside suitable guides which engage with a peripheral portion of it so as to aid its correct tensioning during use of the conveyor 10.
  • the guides are made in one piece with the side walls 12 and are therefore part of the conveyor 10.
  • the suction belt 13 is usually tensioned so that it can be pulled by a motor-driven pulley 14 of the conveyor 10.
  • the suction belt 13 is stretched, which over time reduces its effective tensioning, which therefore deviates from the desired and optimal degree of tensioning.
  • the conveyor comprises a tensioning pulley 15, which is movable in such a way as to allow suitable lengthening of the path which is followed by the suction belt 13, with the aim of guaranteeing constant application of the desired degree of tensioning.
  • the tensioning pulley 15 is associated with a suitable tensioning device 15a, for example a pneumatic cylinder or an equivalent thrust unit, movable according to a thrust motion suitable for applying to the suction belt 13 a force having an intensity and direction which are suitable for countering the stretching of the suction belt 13 over time, keeping it taut.
  • a suitable tensioning device 15a for example a pneumatic cylinder or an equivalent thrust unit, movable according to a thrust motion suitable for applying to the suction belt 13 a force having an intensity and direction which are suitable for countering the stretching of the suction belt 13 over time, keeping it taut.
  • the at least one electromagnetic detecting device 20 defines a detecting channel configured to slidably receive inside it at least one portion of the semi-finished product and of the suction belt 13.
  • the electromagnetic detecting device 20 comprises at least one electromagnetic sensor suitable for detecting at least one property of the semi-finished product and of the suction belt 13 when they pass through the detecting channel.
  • electromagnetic sensor means any sensor able to perform a non-destructive measurement through the thickness of the semi-finished product using electromagnetic waves.
  • the apparatus 100 is configured to operate in a first configuration and in a second configuration.
  • the at least one electromagnetic detecting device 20 detects at least one property of the suction belt 13 passing through the detecting channel and generates a reference signal representing that property.
  • the at least one electromagnetic detecting device 20 detects at least one property of the semi-finished product and of the suction belt 13 passing through the detecting channel and generates a measurement signal representing that property.
  • the apparatus 100 can operate in two configurations in which it is capable inspecting either only the suction belt 13, or both the suction belt 13 and the semi-finished product held by it, in both situations generating a suitable signal representing the measurement performed.
  • the apparatus 100 comprises, or is associated with, a control unit “C” configured to receive and process the measurement signal, correcting or varying it as a function of the reference signal.
  • control unit“C” is for collecting both of the signals, the measurement signal and the reference signal, and for processing them so as to obtain an effective measurement signal representing the properties of only the semi-finished product.
  • the apparatus 100 disclosed is capable of analysing and assessing the properties of the semi-finished product without being affected by any interference in the measuring process which is due to the presence and the possible imperfections of the suction belt 13.
  • the term property means one or more characteristics of interest which depend on the type of filling material and on the production step in which the detection is being performed.
  • such properties may include: weight, density, humidity, correct inclusion of additional elements.
  • the term property means one or more characteristics of the belt itself which are such that they create a disturbance in the measurement signal.
  • the suction belt 13 therefore allows an assessment of the interference that the suction belt 13 creates in the process for measurement of the at least one property of the semi-finished product. Therefore, it should be taken into account that the suction belt 13 might not be homogeneous even when just installed and might have, particularly at a joint portion of it, structural characteristics or properties which vary not just over time but also spatially along its entire length.
  • the suction belt 13 has at least one distinctive element defined by a portion of the suction belt 13 which has at least one distinctive property, that is to say, a property whose value is different from the value of that same property when assessed in a different portion of the suction belt 13.
  • the term distinctive element means any lack of homogeneity in the characteristics of the suction belt 13, which may be due to particular structural characteristics (thickening, thinning, structural defects, partial breaks or others) or to additional elements applied to it (graphical signs, notches, metal plates or others).
  • the apparatus 100 comprises an electromagnetic detecting device 20 and is operated alternatively in the first configuration, in which the semi-finished product is not fed and therefore only the suction belt 13 passes through the detecting channel, for generating the reference signal, or in the second configuration, in which the semi-finished product is fed and therefore passes through the detecting channel together with the suction belt 13, for generating the measurement signal.
  • the electromagnetic detecting device 20 generates, by means of the respective electromagnetic sensor, an electromagnetic field, in particular a microwave field, which strikes the portion of suction belt 13 which is sliding through the detecting channel.
  • the presence of the suction belt 13 causes a disturbance in the electromagnetic field present in the detecting channel which the electromagnetic sensor can read.
  • the disturbance in the electromagnetic field is expressed in terms of shifting of the peak frequency and of variation of the width of the resonance curve at half amplitude.
  • control unit“C” which can use it to correct the measurement signal in such a way as to suitably assess the component of it which is due to the presence of the belt when the apparatus 100 is operated in the second configuration, thereby obtaining information about the semi-finished product alone.
  • the electromagnetic detecting device 20 therefore operates alternatively in the first configuration, generating the reference signal, or in the second configuration, generating the measurement signal.
  • the apparatus 100 In order to accurately assess any structural variations in the suction belt 13, it is possible to operate the apparatus 100 in the first configuration in a predetermined way, that is to say, at predetermined time intervals, or each time that an event occurs which could modify the properties of the suction belt 13 which is located in the apparatus 100.
  • the apparatus 100 can be associated with a suitable machine encoder ⁇ ” forming part of the machine of the tobacco sector to which it belongs.
  • the suction belt 13 slides through the detecting channel and is inspected by the electromagnetic detecting device 20, simultaneously, by means of the encoder ⁇ ”, it is possible to know its angular position and therefore to generate a suitable identification signal representing the portion of the suction belt 13 which is being inspected.
  • the control unit“C” is therefore configured to use that information to associate with each individual portion of the suction belt 13 the reference signal generated by that portion. Indeed, the control unit“C” is capable of processing the identification signal and the reference signal in such a way as to generate a map of the lacks of homogeneity of the belt, associating them with corresponding values contained in the reference signal.
  • control unit“C” is configured to receive the identification signal, associating it with the reference signal in such a way as to define a spatial and/or temporal match between the reference signal and the various portions of the suction belt 13.
  • the apparatus 100 comprises an electromagnetic detecting device 20 and a position detector 30.
  • the position detector 30 is configured to detect the presence of a distinctive element in each portion of the suction belt 13, generating the identification signal which, as well as indicating which portion of the belt is being inspected, also represents the distinctive property of any distinctive elements identified in the various portions of the suction belt 13 and a time instant at which those distinctive elements pass through the detecting channel.
  • the position detector 30 comprises an encoder, labelled with the reference number 32, installed along the path followed by the suction belt 13 and configured to monitor the position of the various portions of the suction belt in particular relative to the electromagnetic detecting device 20 with which the position detector 30 it is part of is associated.
  • the encoder 32 is directly applied to the pulley 14 of the apparatus 100.
  • the position detector 30 further comprises a discontinuity sensor 31.
  • the discontinuity sensor 31 is configured to detect the at least one distinctive property by identifying when the distinctive element passes by the position detector 30.
  • the discontinuity sensor 31 may be an optical inspection device, such as a system of photocells, image capturing device or any other vision system.
  • an optical inspection device such as a system of photocells, image capturing device or any other vision system.
  • control unit“C” is configured to modify the reference signal as a function of the identification signal.
  • control unit“C” is capable of assessing the impact that any lacks of homogeneity of the suction belt 13, which may arise during its use, have on the measuring process.
  • the position detector 30 identifies the presence or development of a distinctive element, it could communicate this to the control unit, identifying both its type and position by means of the identification signal.
  • control unit“C” may, for example by referring to the check tables, modify the reference signal (therefore, in the final analysis the signal representing how the suction belt 13 influences the semi-finished product inspection process) to take into account the altered situation.
  • That aspect is particularly relevant for taking into account variations and/or any deterioration of the belt during its useful life.
  • the discontinuity sensor 31 may also have the function of zeroing the encoder 32.
  • the discontinuity sensor 31 may communicate to the encoder 32, preferably by means of the control unit “C”, that a predetermined distinctive element is again passing through the zone of the path of the suction belt 13 observed by the discontinuity sensor 31 and proximal to the encoder 32, therefore indicating that the suction belt 13 itself has performed a full turn relative to the encoder 32.
  • the apparatus 100 may be operated alternatively in the first configuration, in which only the belt is made to slide through the detecting channel, or in the second configuration, in which the semi finished product is fed to the apparatus 100 and then is inspected together with the portion of suction belt 13 which holds it.
  • the apparatus 100 comprises two electromagnetic detecting devices 40a, 40b and a position detector 30.
  • the apparatus 100 comprises a first electromagnetic detecting device 40a and a second electromagnetic detecting device 40b.
  • the first electromagnetic detecting device 40a defines a first detecting channel configured to slidably receive inside it at least one portion of the semi-finished product and of the suction belt 13.
  • the first electromagnetic detecting device 40a comprises at least one electromagnetic sensor suitable for detecting at least one property of the semi-finished product and of the suction belt 13 when they pass through the first detecting channel.
  • the second electromagnetic detecting device 40b defines a second detecting channel configured to slidably receive inside it at least one portion of the suction belt 13. Moreover, the second electromagnetic detecting device 40b comprises at least one electromagnetic sensor suitable for detecting at least one property of the suction belt 13 when it passes through the second detecting channel.
  • the first and second secondo electromagnetic detecting devices 40a, 40b are located on distinct stretches of the conveyor 10.
  • the first electromagnetic detecting device 40a for performing an overall measurement of the semi-finished product and of the belt 13, is located on an operating section of the conveyor 10, that is to say, on a stretch of the conveyor 10 where the semi-finished product is located inside the guide channel 11 and is constrained to the suction belt 13 by suction.
  • the second electromagnetic detecting device 40b for performing a measurement of only the suction belt 13, is located on a non operating section of the conveyor 10, or more generally upstream of an entry point of the semi-finished product in the guide channel 1 1 from the ascending flue or downstream of its release to the subsequent processing stations.
  • the second electromagnetic detecting device 40b will always operate in the first configuration, whilst the first electromagnetic detecting device 40a will always operate in the second configuration.
  • the apparatus 100 comprises two electromagnetic detecting devices 40a, 40b and two position detectors, in particular a first position detector 50a and a second position detector 50b.
  • the first position detector 50a is located at the first electromagnetic detecting device 40a and is configured to detect the at least one distinctive element of the suction belt 13, consequently generating a first identification signal representing a time instant at which that distinctive element passes through the first detecting channel.
  • the second position detector 50b is located at the second electromagnetic detecting device 40b and is configured to detect the at least one distinctive element of the suction belt 13, consequently generating a second identification signal representing a time instant at which that distinctive element passes through the second detecting channel.
  • the first position detector 50a is positioned downstream of the first electromagnetic detecting device 40a along the conveying direction and the second electromagnetic detecting device 50b is positioned upstream of the second electromagnetic detector 40b.
  • the apparatus comprises a pair of electromagnetic detecting devices 40a, 40b one of which is for inspecting only the suction belt 13 without measuring the semi-finished product, whilst the other is positioned relative to the conveyor 10 in such a way that it can perform an overall inspection of the suction belt 13 and of the semi-finished product. Therefore, the apparatus 100 comprises a pair of position detectors 50a, 50b each associated with a respective electromagnetic detecting device 40a, 40b in such a way that it can precisely assess the effective time instant at which a predetermined portion of the suction belt 13 passes through the first and/or the second detecting channel.
  • each position detector 30, 50a, 50b is made as described above, that is to say, comprises a respective discontinuity sensor 31 , 51 a, 51 b and/or a respective encoder 32, 52a, 52b.
  • each position detector 30, 50a, 50b comprises a discontinuity sensor 31 , 51 a, 51 b which can identify when the distinctive element passes and/or an encoder 32, 52a, 52b for measuring the movements of the suction belt 13, in such a way that it is always possible to calculate its sliding speed and to reconstruct, by means of the information contained in the identification signal, the position of that distinctive element relative, in particular, to the portions of the apparatus 100 which are the locations of the sensors for measuring the semi-finished product and/or the suction belt 13 and how much time it will take those distinctive elements to reach and pass through the detection zones of the electromagnetic detectors 40a, 40b.
  • the distinctive element is a graphical sign, an incision or a notch or a joint on the suction belt 13 and the discontinuity sensor 31 , 51 a, 51 b is an optical inspection device, preferably an image capturing device or a photocell suitable for detecting the passage of that type of distinctive element.
  • the distinctive element may be a metal insert and the discontinuity sensor 31 , 51 a, 51 b is an electromagnetic sensor suitable for detecting the passage of that type of distinctive element.
  • each electromagnetic detecting device 20, 40a, 40b is an electromagnetic microwave detecting device, in particular configured to operate at between 10 8 and 10 12 Hz.
  • the conveyor 10 comprises a plurality of guide channels 1 1 , preferably as shown in Figure 5, two guide channels 1 1 , each of which is couplable to respective electromagnetic detecting devices 20, 40a, 40b and position detectors 30, 50a, 50b according to the various embodiments indicated above.
  • the detecting devices 20, the first electromagnetic detecting devices 40a and the second electromagnetic detecting devices 40b are mounted on respective shared supports and are located in positions spaced from each other along the conveying direction of the semi-finished product.
  • the apparatus 100 will comprise two electromagnetic detecting devices 40a, and two second electromagnetic detecting devices 40b which are located on a shared support and in positions spaced from each other along the conveying direction of the semi-finished product.
  • this invention achieves the preset aims, overcoming the disadvantages of the prior art by providing the user with an apparatus 100 for the conveying and inspection of a semi-finished product of the tobacco industry which allows mapping of the influence of the suction belt 13 on the measuring process, so that it can be precisely removed in order to obtain final information which is associable solely with the properties of the semi-finished product to be inspected.
  • This invention also relates to a method for the conveying and inspection of a semi-finished product of the tobacco industry.
  • the method according to this invention comprises holding and conveying the semi-finished product along a guide channel 1 1 delimited at the sides by two side walls 12 and at the top by a suction belt 13.
  • guide channel 1 1 is part of a conveyor 10 made as described above.
  • the method then comprises providing at least one electromagnetic detecting device 20 which defines at least one detecting channel configured to slidably receive the suction belt 13 and at least one portion of the semi-finished product held on the suction belt.
  • the electromagnetic detecting device 20 is also preferably made with the specifications and characteristics described above.
  • the method then comprises using the electromagnetic detecting device 20 to detect at least one property of the suction belt 13 as it passes through the detecting channel and thereby generating a reference signal.
  • the electromagnetic detecting device 20 is configured to generate an electromagnetic field inside the detecting channel, the passage of the suction belt 13 through it causing a disturbance in that electromagnetic field, in particular in terms of peak frequency and variation of the width of the resonance curve at half amplitude, which is recorded by the electromagnetic detecting device 20 which generates the reference signal representing that disturbance, which depends on the properties of the suction belt 13.
  • the electromagnetic detecting device 20 is therefore configured to detect the disturbance in the electromagnetic field caused by the passage of the suction belt 13 and the semi-finished product, generating the measurement signal representing that disturbance, which depends on the properties of the semi-finished product and of the suction belt 13.
  • the method according to this invention comprises two measuring steps, which correspond to the first configuration and to the second configuration of the apparatus 100 described above.
  • the reference signal and the measurement signal are then processed in order to obtain unambiguous and precise information about the property of the semi-finished product to be measured.
  • the method comprises processing the measurement signal and correcting or varying it as a function of the reference signal so as to obtain an effective measurement signal by eliminating from the measurement signal a component which is due to the suction belt 13.
  • a first possible embodiment schematically illustrated in Figures 1 -2, wherein the method disclosed is performed using a single electromagnetic detecting device 20, the step corresponding to the first configuration is performed before or after the step corresponding to the second configuration.
  • the single electromagnetic detecting device 20 is configured to be operated alternatively in the first configuration or in the second configuration.
  • the step corresponding to the first configuration will be performed by causing the suction belt 13 to slide through the detecting channel of the electromagnetic detecting device 20 for one full turn of the suction belt 13.
  • the expression full turn means that the suction belt 13 is made to rotate until each of its portions has passed through the detecting channel and at least one of its properties has been suitably detected by the electromagnetic detecting device 20.
  • the at least one property measured is associated with the successive portions of the suction belt 13 and in this way the reference signal is generated which, since the suction belt 13 has performed a full turn, takes into account the influence of each portion of the suction belt 13 on the measuring process.
  • the method disclosed is carried out using a pair of electromagnetic detecting devices 40a, 40b, therefore making it possible for the apparatus 100 to simultaneously operate in both the first configuration and the second configuration, since each of them is associated respectively with a different electromagnetic detecting device 40a, 40b.
  • that embodiment comprises the step of providing at least one electromagnetic detecting device.
  • step comprises preparing a first electromagnetic detecting device 40a and a second electromagnetic detecting device 40b.
  • Each of the two sensors is therefore for performing a respective inspection, that is to say, either for detecting only the suction belt 13 or for measuring both the suction belt 13 and the semi-finished product which it holds on it.
  • the method comprises detecting, by means of the second electromagnetic detecting device 40b, at least one property of the suction belt 13 as it passes through the second detecting channel.
  • the method comprises measuring, by means of the first electromagnetic detecting device 40a, at least one property of the semi finished product and of the suction belt 13 as they pass through the first detecting channel.
  • that embodiment allows the step of detecting to be performed simultaneously with the step of measuring, since it involves the use of two different sensors, each for performing a single respective step.
  • the reference signal is continuously updated while the suction belt 13 slides through the second electromagnetic detecting device 40b and sent to the control unit“C”, so as to allow correction of the measurement signal using a reference signal which is effectively representative of the influence that the suction belt 13 has on the inspection process at a predetermined moment.

Abstract

An apparatus for the conveying and inspection of a semi-finished product of the tobacco industry comprises a conveyor (10) with a suction belt (13) and at least one electromagnetic detecting device (20). The conveyor (10) is configured to hold and convey the semi-finished product along a conveying path and comprises at least one guide channel (11) for the semi-finished product, delimited at the sides by two side walls (12) and at the top by a suction belt (13); the at least one electromagnetic detecting device (20, 40a, 40b) defines at least one detecting channel configured to slidably receive the suction belt (13) and at least one portion of the semi-finished product held on that suction belt (13). The apparatus is configured to operate in a first configuration, in which the electromagnetic detecting device (20, 40a, 40b) detects at least one property of the suction belt (13) passing through the detecting channel and generates a reference signal, and in a second configuration, in which the electromagnetic detecting device (20, 40a, 40b) detects at least one property of the semi-finished product and of the suction belt (13) passing through the detecting channel and generates a measurement signal. Moreover, the conveying apparatus comprises, or is associated with, a control unit (C) configured to receive and process the measurement signal, correcting or varying it as a function of the reference signal.

Description

DESCRIPTION
APPARATUS FOR THE CONVEYING AND INSPECTION OF A SEMIFINISHED PRODUCT OF THE TOBACCO INDUSTRY
This invention relates to an apparatus for the conveying and inspection of a semi-finished product of the tobacco industry.
In particular, this invention is intended for making an apparatus for moving and at the same time inspecting a semi-finished product of the tobacco industry, capable of guaranteeing the correctness of the measurements performed, so as to allow an assessment of its conformity to one or more requirements of the end product to be made.
In the tobacco industry there is a pressing need to be able to efficiently verify at least some properties, such as the degree of humidity and/or density, of products to be made during all of their production steps, in such a way as to ensure that the finished product is made correctly.
However, it is not always possible to precisely and exactly analyse such characteristics due to either the structure of the machinery used or the particular structural features of the product being made.
That problem will be more apparent with reference to the following example relating to machines for the production of continuous rods of tobacco.
Prior art machines for the production of continuous rods of tobacco usually use a substantially vertical flue fed at the bottom by a continuous flow of tobacco particles, at the top end of which a suction belt is positioned, on which a continuous mass of tobacco forms.
That suction belt is suitable for feeding the continuous mass of tobacco along a predetermined path, at least partly defined by the suction belt itself, to a preforming device which creates a continuous ribbon and then to a forming channel for a continuous rod of tobacco in which a wrapping web, for example made of paper, is forced to wrap around the continuous ribbon of tobacco so as to form a continuous cylinder or rod of the tobacco industry, such as a cigarette rod, which will subsequently be divided into pieces by a suitable cutting device.
In that context it is essential to measure the quantity of tobacco which is transferred at infeed to the forming channel, in such a way as to ensure that the articles resulting from that production process have a correct quantity of tobacco in them.
For performing that measurement there are prior art machines which have an inspection station located in the guide channel, defined by the suction belt, which allows the transfer of the semi-finished product in question from the ascending flue to the forming beam.
Such inspection stations comprise sensors capable of assessing the quantity of tobacco which is being conveyed along the channel in order to determine if the transfer from the ascending flue to the forming beam is happening in the desired way.
However, the Applicant has observed that even the latter solution is affected by disadvantages which render it not very efficient in the performance of its functions.
In particular, it is inevitable that, in addition to the semi-finished product, the suction belt also passes through the inspection station, thereby disturbing the measuring process.
In other words, when the inspection station performs a measurement, the result obtained represents not just the properties of the semi-finished product to be measured, but also those of the suction belt.
It is known in the sector that the suction belt undergoes substantial variations in its structure (for example length and thickness) in periods of time which may even be very short, for example compared with the length of a work shift.
Therefore, it is substantially impossible, using the prior art devices and apparatuses, to precisely assess the effective variation of the signal measured which is due to the presence of the suction belt.
Consequently, it is impossible to determine if a particular value measured, which is outside the tolerance limits set for a particular production process, is effectively due to an incorrect quantity of semi-finished product or to a defect of the suction belt.
In this context, the technical purpose which forms the basis of this invention is to propose an apparatus for the conveying and inspection of a semi-finished product of the tobacco industry which overcomes the above- mentioned disadvantages of the prior art.
In particular, it is the aim of this invention to provide an apparatus for the conveying and inspection of a semi-finished product of the tobacco industry which is capable of performing a correct measurement and assessment of the properties of the semi-finished product to be inspected, independently of the respective properties of the suction belt which allows the transfer of the semi-finished product, so as to be able to guarantee the correctness of the measurements performed.
The technical purpose indicated and the aims specified are substantially achieved by an apparatus for the conveying and inspection of a semi finished product of the tobacco industry, comprising the technical characteristics set out in one or more of the appended claims.
Accordingly, this invention shows an apparatus for the conveying and inspection of a semi-finished product of the tobacco industry which comprises a conveyor with a suction belt and at least one electromagnetic detecting device.
The conveyor is configured to hold and convey the semi-finished product along a conveying path and comprises at least one guide channel for the semi-finished product, delimited at the sides by two side walls and at the top by a suction belt.
The at least one electromagnetic detecting device defines at least one detecting channel configured to slidably receive the suction belt and at least one portion of the semi-finished product held on that suction belt.
The apparatus is configured to operate in a first configuration, in which the at least one electromagnetic detecting device detects at least one property of the suction belt passing through the detecting channel and generates a reference signal, and in a second configuration, in which the at least one electromagnetic detecting device detects at least one property of the semi finished product and of the suction belt passing through the detecting channel and generates a measurement signal.
Moreover, the conveying apparatus comprises, or is associated with, a control unit configured to receive and process the measurement signal, correcting or varying it as a function of the reference signal.
Advantageously, that apparatus allows a precise and exact assessment of the impact of the presence of the belt on the measuring process, so as to obtain an effective measurement data item relating only to the semi finished product, that is to say, representing only the properties of the semi-finished product.
Therefore, this makes it possible to carry out an analysis of the qualities of the semi-finished product which is independent of any influences on the measurement due to the presence of the suction belt.
This invention also relates to a method for the conveying and inspection of a semi-finished product of the tobacco industry, which comprises the following steps:
- holding and conveying the semi-finished product along a guide channel delimited at the sides by two side walls and at the top by a suction belt;
- providing at least one electromagnetic detecting device which defines at least one detecting channel configured to slidably receive the suction belt and at least one portion of the semi-finished product held on the suction belt;
- detecting at least one property of the suction belt as it passes through the detecting channel and generating a reference signal;
- measuring at least one property of the semi-finished product and of the suction belt as they pass through the detecting channel and generating a measurement signal;
- processing the measurement signal and correcting or varying it as a function of the reference signal. Advantageously, that method allows the generation of a reference signal as a function of which it is possible to correct the measurement signal in order to remove the contribution which is due to the presence of the suction belt.
In particular, the fact that the measurement signal is corrected or varied shall be understood to mean that said measurement signal is processed while taking into account the reference signal detected.
The dependent claims, included here for reference, correspond to different embodiments of the invention.
Further characteristics and advantages of this invention will be more apparent from the approximate, non-limiting description of a preferred, non-limiting embodiment of an apparatus for the conveying and inspection of a semi-finished product of the tobacco industry, as illustrated in the accompanying drawings in which:
Figure 1 shows a first possible embodiment of the apparatus according to this invention;
Figure 2 shows a further possible embodiment;
Figure 3 shows a further possible embodiment;
Figure 4 shows a further possible embodiment;
Figure 5 is a perspective view of the embodiment of Figure 4.
In the accompanying figures the reference number 100 is used to indicate an apparatus for the conveying and inspection of a semi-finished product of the tobacco industry according to this invention.
The semi-finished product may be any material used in the tobacco industry for filling elements of a smoking article, such as: a mass of tobacco fibre, a ribbon of filter material, a ribbon of pieces of filter, even heterogeneous, or a crimped tobacco ribbon.
The apparatus 100 comprises a conveyor 10 with a suction belt and at least one electromagnetic detecting device 20.
The conveyor 10 is configured to hold and convey the semi-finished product along a conveying path and comprises at least one guide channel 11 , delimited at the sides by two side walls 12 and at the top by a suction belt 13.
The suction belt 13 is permeable to air so that an air flow generated inside the apparatus 100 can pass through the belt from the bottom upwards.
That air flow creates a vacuum on the lower surface of the suction belt 13 and this allows the bottom of the suction belt 13 to hold the semi-finished product, received from an ascending flue, conveying it along the guide channel 11.
The presence of the side walls allows the definition of a cross-section of the semi-finished product sliding through the guide channel 11 , at whose outfeed the semi-finished product reaches a forming station in which it will be wrapped in a wrapping material, which could even be at least partly metallic or metallized, so as to make a continuous rod of the tobacco industry.
The suction belt slides inside suitable guides which engage with a peripheral portion of it so as to aid its correct tensioning during use of the conveyor 10.
According to a preferred embodiment, the guides are made in one piece with the side walls 12 and are therefore part of the conveyor 10.
The suction belt 13 is usually tensioned so that it can be pulled by a motor-driven pulley 14 of the conveyor 10.
During its useful life, chiefly due to wear, the suction belt 13 is stretched, which over time reduces its effective tensioning, which therefore deviates from the desired and optimal degree of tensioning.
In order to overcome that disadvantage, the conveyor comprises a tensioning pulley 15, which is movable in such a way as to allow suitable lengthening of the path which is followed by the suction belt 13, with the aim of guaranteeing constant application of the desired degree of tensioning.
In particular, in order to allow tensioning of the suction belt 13, the tensioning pulley 15 is associated with a suitable tensioning device 15a, for example a pneumatic cylinder or an equivalent thrust unit, movable according to a thrust motion suitable for applying to the suction belt 13 a force having an intensity and direction which are suitable for countering the stretching of the suction belt 13 over time, keeping it taut.
The at least one electromagnetic detecting device 20 defines a detecting channel configured to slidably receive inside it at least one portion of the semi-finished product and of the suction belt 13.
The electromagnetic detecting device 20 comprises at least one electromagnetic sensor suitable for detecting at least one property of the semi-finished product and of the suction belt 13 when they pass through the detecting channel.
The term electromagnetic sensor means any sensor able to perform a non-destructive measurement through the thickness of the semi-finished product using electromagnetic waves.
The apparatus 100 according to this invention is configured to operate in a first configuration and in a second configuration.
When the apparatus 100 operates in the first configuration, the at least one electromagnetic detecting device 20 detects at least one property of the suction belt 13 passing through the detecting channel and generates a reference signal representing that property.
In contrast, when the apparatus 100 operates in the second configuration, the at least one electromagnetic detecting device 20 detects at least one property of the semi-finished product and of the suction belt 13 passing through the detecting channel and generates a measurement signal representing that property.
In other words, the apparatus 100 can operate in two configurations in which it is capable inspecting either only the suction belt 13, or both the suction belt 13 and the semi-finished product held by it, in both situations generating a suitable signal representing the measurement performed. Moreover, the apparatus 100 comprises, or is associated with, a control unit “C” configured to receive and process the measurement signal, correcting or varying it as a function of the reference signal.
Therefore, the control unit“C” is for collecting both of the signals, the measurement signal and the reference signal, and for processing them so as to obtain an effective measurement signal representing the properties of only the semi-finished product.
In this way, the apparatus 100 disclosed is capable of analysing and assessing the properties of the semi-finished product without being affected by any interference in the measuring process which is due to the presence and the possible imperfections of the suction belt 13.
In general, relative to the semi-finished product, the term property means one or more characteristics of interest which depend on the type of filling material and on the production step in which the detection is being performed.
For example, according to a list which shall be understood as not exhaustive, such properties may include: weight, density, humidity, correct inclusion of additional elements.
In more detail, again by way of example, in the case in which the semi finished product is loose tobacco, it could be necessary to detect the weight of the tobacco which is effectively fed to the subsequent production steps, so as to ensure that each finished product which will be made contains the correct quantity of tobacco.
In contrast, relative to the suction belt 13, the term property means one or more characteristics of the belt itself which are such that they create a disturbance in the measurement signal.
Detecting a property of the suction belt 13 therefore allows an assessment of the interference that the suction belt 13 creates in the process for measurement of the at least one property of the semi-finished product. Therefore, it should be taken into account that the suction belt 13 might not be homogeneous even when just installed and might have, particularly at a joint portion of it, structural characteristics or properties which vary not just over time but also spatially along its entire length. In particular, the suction belt 13 has at least one distinctive element defined by a portion of the suction belt 13 which has at least one distinctive property, that is to say, a property whose value is different from the value of that same property when assessed in a different portion of the suction belt 13.
Therefore, the term distinctive element means any lack of homogeneity in the characteristics of the suction belt 13, which may be due to particular structural characteristics (thickening, thinning, structural defects, partial breaks or others) or to additional elements applied to it (graphical signs, notches, metal plates or others).
According to a first possible embodiment, schematically illustrated in Figure 1 , the apparatus 100 comprises an electromagnetic detecting device 20 and is operated alternatively in the first configuration, in which the semi-finished product is not fed and therefore only the suction belt 13 passes through the detecting channel, for generating the reference signal, or in the second configuration, in which the semi-finished product is fed and therefore passes through the detecting channel together with the suction belt 13, for generating the measurement signal.
In terms of operation, when the apparatus 100 is in the first configuration, only the suction belt 13 is made to turn, without feeding the semi-finished product.
At the same time, the electromagnetic detecting device 20 generates, by means of the respective electromagnetic sensor, an electromagnetic field, in particular a microwave field, which strikes the portion of suction belt 13 which is sliding through the detecting channel.
The presence of the suction belt 13 causes a disturbance in the electromagnetic field present in the detecting channel which the electromagnetic sensor can read.
For example, if the electromagnetic detecting device is a resonating device, the disturbance in the electromagnetic field is expressed in terms of shifting of the peak frequency and of variation of the width of the resonance curve at half amplitude.
Therefore, that information is communicated to the control unit“C” which can use it to correct the measurement signal in such a way as to suitably assess the component of it which is due to the presence of the belt when the apparatus 100 is operated in the second configuration, thereby obtaining information about the semi-finished product alone.
The electromagnetic detecting device 20 therefore operates alternatively in the first configuration, generating the reference signal, or in the second configuration, generating the measurement signal.
In order to accurately assess any structural variations in the suction belt 13, it is possible to operate the apparatus 100 in the first configuration in a predetermined way, that is to say, at predetermined time intervals, or each time that an event occurs which could modify the properties of the suction belt 13 which is located in the apparatus 100.
Moreover, in order to be able to take into account precisely the effective position of the various portions of the suction belt 13 relative to the detecting channel, the apparatus 100 can be associated with a suitable machine encoder Έ” forming part of the machine of the tobacco sector to which it belongs.
In this way, it is possible to perform and obtain mapping of the properties of the suction belt 13 along its entire length, with particular attention to the position of the distinctive elements.
Indeed, when the apparatus 100 is operated in the first configuration, the suction belt 13 slides through the detecting channel and is inspected by the electromagnetic detecting device 20, simultaneously, by means of the encoder Έ”, it is possible to know its angular position and therefore to generate a suitable identification signal representing the portion of the suction belt 13 which is being inspected.
The control unit“C” is therefore configured to use that information to associate with each individual portion of the suction belt 13 the reference signal generated by that portion. Indeed, the control unit“C” is capable of processing the identification signal and the reference signal in such a way as to generate a map of the lacks of homogeneity of the belt, associating them with corresponding values contained in the reference signal.
Therefore, the control unit“C” is configured to receive the identification signal, associating it with the reference signal in such a way as to define a spatial and/or temporal match between the reference signal and the various portions of the suction belt 13.
According to a further possible embodiment, schematically illustrated in Figure 2, the apparatus 100 comprises an electromagnetic detecting device 20 and a position detector 30.
The position detector 30 is configured to detect the presence of a distinctive element in each portion of the suction belt 13, generating the identification signal which, as well as indicating which portion of the belt is being inspected, also represents the distinctive property of any distinctive elements identified in the various portions of the suction belt 13 and a time instant at which those distinctive elements pass through the detecting channel.
In particular, the position detector 30 comprises an encoder, labelled with the reference number 32, installed along the path followed by the suction belt 13 and configured to monitor the position of the various portions of the suction belt in particular relative to the electromagnetic detecting device 20 with which the position detector 30 it is part of is associated.
In the particular schematic illustration in Figure 2, the encoder 32 is directly applied to the pulley 14 of the apparatus 100.
Also according to that embodiment, the position detector 30 further comprises a discontinuity sensor 31.
The discontinuity sensor 31 is configured to detect the at least one distinctive property by identifying when the distinctive element passes by the position detector 30.
The discontinuity sensor 31 may be an optical inspection device, such as a system of photocells, image capturing device or any other vision system. Advantageously, by calculating the sliding speed of the suction belt 13 using the information obtained by the encoder 32 and knowing the distance between the detecting channel and the position detector 30, it is also possible to calculate the time that each distinctive element identified by the discontinuity sensor 31 will take to enter the detecting channel.
In this way it is also possible over time to obtain check tables which associate with different possible distinctive elements of the suction belt 13 a respective impact on the reference signal and therefore on the semi finished product measuring process.
Moreover, the control unit“C” is configured to modify the reference signal as a function of the identification signal.
Therefore, the control unit“C” is capable of assessing the impact that any lacks of homogeneity of the suction belt 13, which may arise during its use, have on the measuring process.
In terms of operation, once the position detector 30 identifies the presence or development of a distinctive element, it could communicate this to the control unit, identifying both its type and position by means of the identification signal.
If the presence and influence of that distinctive element were not already among the information contained in the reference signal originally generated, the control unit“C” may, for example by referring to the check tables, modify the reference signal (therefore, in the final analysis the signal representing how the suction belt 13 influences the semi-finished product inspection process) to take into account the altered situation.
That aspect is particularly relevant for taking into account variations and/or any deterioration of the belt during its useful life.
In other words, it is possible to tabulate the effects that various possible distinctive elements have on the measuring process, in such a way that if the position detector 30 detects a particular lack of homogeneity not measured by the apparatus 100 when operated in the first configuration, a suitable identification signal is sent to the control unit “C”, which will consequently modify the reference signal to take into account that new lack of homogeneity.
Advantageously, the discontinuity sensor 31 may also have the function of zeroing the encoder 32.
In other words, the discontinuity sensor 31 may communicate to the encoder 32, preferably by means of the control unit “C”, that a predetermined distinctive element is again passing through the zone of the path of the suction belt 13 observed by the discontinuity sensor 31 and proximal to the encoder 32, therefore indicating that the suction belt 13 itself has performed a full turn relative to the encoder 32.
In this situation too, the apparatus 100 may be operated alternatively in the first configuration, in which only the belt is made to slide through the detecting channel, or in the second configuration, in which the semi finished product is fed to the apparatus 100 and then is inspected together with the portion of suction belt 13 which holds it.
According to a further possible embodiment, schematically illustrated in Figure 3, the apparatus 100 comprises two electromagnetic detecting devices 40a, 40b and a position detector 30.
Specifically, the apparatus 100 comprises a first electromagnetic detecting device 40a and a second electromagnetic detecting device 40b.
The first electromagnetic detecting device 40a defines a first detecting channel configured to slidably receive inside it at least one portion of the semi-finished product and of the suction belt 13.
Moreover, the first electromagnetic detecting device 40a comprises at least one electromagnetic sensor suitable for detecting at least one property of the semi-finished product and of the suction belt 13 when they pass through the first detecting channel.
In contrast, the second electromagnetic detecting device 40b defines a second detecting channel configured to slidably receive inside it at least one portion of the suction belt 13. Moreover, the second electromagnetic detecting device 40b comprises at least one electromagnetic sensor suitable for detecting at least one property of the suction belt 13 when it passes through the second detecting channel.
Preferably, the first and second secondo electromagnetic detecting devices 40a, 40b are located on distinct stretches of the conveyor 10.
In particular, the first electromagnetic detecting device 40a, for performing an overall measurement of the semi-finished product and of the belt 13, is located on an operating section of the conveyor 10, that is to say, on a stretch of the conveyor 10 where the semi-finished product is located inside the guide channel 11 and is constrained to the suction belt 13 by suction.
At the same time, the second electromagnetic detecting device 40b, for performing a measurement of only the suction belt 13, is located on a non operating section of the conveyor 10, or more generally upstream of an entry point of the semi-finished product in the guide channel 1 1 from the ascending flue or downstream of its release to the subsequent processing stations.
In this context, it is possible to operate the apparatus 100 simultaneously in the first and second configurations.
In particular, the second electromagnetic detecting device 40b will always operate in the first configuration, whilst the first electromagnetic detecting device 40a will always operate in the second configuration.
According to a further possible embodiment, schematically illustrated in Figure 4, the apparatus 100 comprises two electromagnetic detecting devices 40a, 40b and two position detectors, in particular a first position detector 50a and a second position detector 50b.
The first position detector 50a is located at the first electromagnetic detecting device 40a and is configured to detect the at least one distinctive element of the suction belt 13, consequently generating a first identification signal representing a time instant at which that distinctive element passes through the first detecting channel.
In contrast, the second position detector 50b is located at the second electromagnetic detecting device 40b and is configured to detect the at least one distinctive element of the suction belt 13, consequently generating a second identification signal representing a time instant at which that distinctive element passes through the second detecting channel.
Preferably, the first position detector 50a is positioned downstream of the first electromagnetic detecting device 40a along the conveying direction and the second electromagnetic detecting device 50b is positioned upstream of the second electromagnetic detector 40b.
In other words, the apparatus comprises a pair of electromagnetic detecting devices 40a, 40b one of which is for inspecting only the suction belt 13 without measuring the semi-finished product, whilst the other is positioned relative to the conveyor 10 in such a way that it can perform an overall inspection of the suction belt 13 and of the semi-finished product. Therefore, the apparatus 100 comprises a pair of position detectors 50a, 50b each associated with a respective electromagnetic detecting device 40a, 40b in such a way that it can precisely assess the effective time instant at which a predetermined portion of the suction belt 13 passes through the first and/or the second detecting channel.
Indeed, it is possible that in use the suction belt 13 experiences different degrees of tensioning and different speeds at distinct stretches of the conveyor 10.
The presence of two detecting devices 50a, 50b, and the combination of the information obtainable from them, therefore allows guaranteed correct assessment of the positioning of the distinctive element of the suction belt 13 relative to the first and second detecting channels and precise calculation of the time instant at which those distinctive elements will pass through them.
In general, in each of the possible embodiments considered, each position detector 30, 50a, 50b is made as described above, that is to say, comprises a respective discontinuity sensor 31 , 51 a, 51 b and/or a respective encoder 32, 52a, 52b.
In other words, each position detector 30, 50a, 50b comprises a discontinuity sensor 31 , 51 a, 51 b which can identify when the distinctive element passes and/or an encoder 32, 52a, 52b for measuring the movements of the suction belt 13, in such a way that it is always possible to calculate its sliding speed and to reconstruct, by means of the information contained in the identification signal, the position of that distinctive element relative, in particular, to the portions of the apparatus 100 which are the locations of the sensors for measuring the semi-finished product and/or the suction belt 13 and how much time it will take those distinctive elements to reach and pass through the detection zones of the electromagnetic detectors 40a, 40b.
In particular, according to one possible embodiment, the distinctive element is a graphical sign, an incision or a notch or a joint on the suction belt 13 and the discontinuity sensor 31 , 51 a, 51 b is an optical inspection device, preferably an image capturing device or a photocell suitable for detecting the passage of that type of distinctive element.
Alternatively, the distinctive element may be a metal insert and the discontinuity sensor 31 , 51 a, 51 b is an electromagnetic sensor suitable for detecting the passage of that type of distinctive element.
In general terms, relative to each of the embodiments described herein, each electromagnetic detecting device 20, 40a, 40b is an electromagnetic microwave detecting device, in particular configured to operate at between 108 and 1012 Hz.
According to one particular aspect of this invention, the conveyor 10 comprises a plurality of guide channels 1 1 , preferably as shown in Figure 5, two guide channels 1 1 , each of which is couplable to respective electromagnetic detecting devices 20, 40a, 40b and position detectors 30, 50a, 50b according to the various embodiments indicated above. Preferably the detecting devices 20, the first electromagnetic detecting devices 40a and the second electromagnetic detecting devices 40b are mounted on respective shared supports and are located in positions spaced from each other along the conveying direction of the semi-finished product.
That is to say, for example, if the conveyor 10 comprises two guide channels 1 1 , the apparatus 100 will comprise two electromagnetic detecting devices 40a, and two second electromagnetic detecting devices 40b which are located on a shared support and in positions spaced from each other along the conveying direction of the semi-finished product. Advantageously, this invention achieves the preset aims, overcoming the disadvantages of the prior art by providing the user with an apparatus 100 for the conveying and inspection of a semi-finished product of the tobacco industry which allows mapping of the influence of the suction belt 13 on the measuring process, so that it can be precisely removed in order to obtain final information which is associable solely with the properties of the semi-finished product to be inspected.
In this way, it is possible to unequivocally assess the effective quality level of the semi-finished product.
This invention also relates to a method for the conveying and inspection of a semi-finished product of the tobacco industry.
The method according to this invention comprises holding and conveying the semi-finished product along a guide channel 1 1 delimited at the sides by two side walls 12 and at the top by a suction belt 13.
Preferably that guide channel 1 1 is part of a conveyor 10 made as described above.
The method then comprises providing at least one electromagnetic detecting device 20 which defines at least one detecting channel configured to slidably receive the suction belt 13 and at least one portion of the semi-finished product held on the suction belt.
The electromagnetic detecting device 20 is also preferably made with the specifications and characteristics described above.
The method then comprises using the electromagnetic detecting device 20 to detect at least one property of the suction belt 13 as it passes through the detecting channel and thereby generating a reference signal.
In more detail, the electromagnetic detecting device 20 is configured to generate an electromagnetic field inside the detecting channel, the passage of the suction belt 13 through it causing a disturbance in that electromagnetic field, in particular in terms of peak frequency and variation of the width of the resonance curve at half amplitude, which is recorded by the electromagnetic detecting device 20 which generates the reference signal representing that disturbance, which depends on the properties of the suction belt 13.
Then comes measuring of at least one property of the semi-finished product and of the suction belt 13 holding it as they pass through the detecting channel and generating of a measurement signal.
In more detail, the electromagnetic detecting device 20 is therefore configured to detect the disturbance in the electromagnetic field caused by the passage of the suction belt 13 and the semi-finished product, generating the measurement signal representing that disturbance, which depends on the properties of the semi-finished product and of the suction belt 13.
In other words, the method according to this invention comprises two measuring steps, which correspond to the first configuration and to the second configuration of the apparatus 100 described above.
The reference signal and the measurement signal are then processed in order to obtain unambiguous and precise information about the property of the semi-finished product to be measured.
In particular, the method comprises processing the measurement signal and correcting or varying it as a function of the reference signal so as to obtain an effective measurement signal by eliminating from the measurement signal a component which is due to the suction belt 13. According to a first possible embodiment, schematically illustrated in Figures 1 -2, wherein the method disclosed is performed using a single electromagnetic detecting device 20, the step corresponding to the first configuration is performed before or after the step corresponding to the second configuration.
That is to say, the single electromagnetic detecting device 20 is configured to be operated alternatively in the first configuration or in the second configuration.
In particular, according to that embodiment, the step corresponding to the first configuration will be performed by causing the suction belt 13 to slide through the detecting channel of the electromagnetic detecting device 20 for one full turn of the suction belt 13.
Simultaneously, by means of the electromagnetic detecting device 20, there is detecting of at least one property of the suction belt 13 sliding through the detecting channel.
The expression full turn means that the suction belt 13 is made to rotate until each of its portions has passed through the detecting channel and at least one of its properties has been suitably detected by the electromagnetic detecting device 20.
Then, the at least one property measured is associated with the successive portions of the suction belt 13 and in this way the reference signal is generated which, since the suction belt 13 has performed a full turn, takes into account the influence of each portion of the suction belt 13 on the measuring process.
According to a further possible embodiment, schematically illustrated in Figures 3-4, the method disclosed is carried out using a pair of electromagnetic detecting devices 40a, 40b, therefore making it possible for the apparatus 100 to simultaneously operate in both the first configuration and the second configuration, since each of them is associated respectively with a different electromagnetic detecting device 40a, 40b. In particular, that embodiment comprises the step of providing at least one electromagnetic detecting device.
In particular that step comprises preparing a first electromagnetic detecting device 40a and a second electromagnetic detecting device 40b. Each of the two sensors is therefore for performing a respective inspection, that is to say, either for detecting only the suction belt 13 or for measuring both the suction belt 13 and the semi-finished product which it holds on it.
In particular, the method comprises detecting, by means of the second electromagnetic detecting device 40b, at least one property of the suction belt 13 as it passes through the second detecting channel.
Then, the method comprises measuring, by means of the first electromagnetic detecting device 40a, at least one property of the semi finished product and of the suction belt 13 as they pass through the first detecting channel.
Advantageously, that embodiment allows the step of detecting to be performed simultaneously with the step of measuring, since it involves the use of two different sensors, each for performing a single respective step.
In other words, the use of two distinct and separate sensors for performing respective inspection steps allows simultaneous generation of the reference signal and of the measurement signal.
In this way, it is possible to promptly assess any variations/deterioration of the suction belt 13 and how they influence the process for assessment of the properties of the semi-finished product.
Indeed, the reference signal is continuously updated while the suction belt 13 slides through the second electromagnetic detecting device 40b and sent to the control unit“C”, so as to allow correction of the measurement signal using a reference signal which is effectively representative of the influence that the suction belt 13 has on the inspection process at a predetermined moment.

Claims

1. An apparatus for the conveying and inspection of a semi-finished product of the tobacco industry, comprising:
- a conveyor (10) with a suction belt (13) configured to hold and convey the semi-finished product along a conveying path, the conveyor (10) comprising at least one guide channel (1 1 ) for the semi-finished product, delimited at the sides by two side walls (12) and at the top by a suction belt (13);
- at least one electromagnetic detecting device (20, 40a, 40b) defining at least one detecting channel configured to slidably receive the suction belt (13) and at least one portion of the semi-finished product held on the suction belt (13), the electromagnetic detecting device (20, 40a, 40b) comprising at least one electromagnetic sensor for detecting at least one property of the semi-finished product and of the suction belt (13) passing through the detecting channel;
the conveying apparatus being configured to operate in a first configuration, in which the detecting unit detects at least one property of the suction belt (13) passing through the detecting channel and generates a reference signal, and in a second configuration, in which the detecting unit detects at least one property of the semi-finished product and of the suction belt (13) passing through the detecting channel and generates a measurement signal;
the conveying apparatus comprising, or being associated with, a control unit (C) configured to receive and process the measurement signal, correcting or varying the measurement signal as a function of the reference signal so as to obtain an effective measurement data item relating only to the semi-finished product by eliminating from the measurement signal a component due to the suction belt (13).
2. The apparatus according to claim 1 , wherein the suction belt (13) has at least one distinctive element defined by a portion of the suction belt (13) having at least one distinctive property and wherein the conveying apparatus comprises at least one position detector (30, 50a, 50b) configured to detect the at least one distinctive element and generating an identification signal representing the distinctive property and the time instant the distinctive element passes through the detecting channel.
3. The apparatus according to claim 2, wherein the control unit (C) is configured to receive the identification signal and the reference signal, associating them with each other to define a spatial and/or temporal match between the reference signal and the distinctive element.
4. The apparatus according to claim 2 or 3, wherein the control unit (C) is configured to modify the reference signal as a function of the identification signal.
5. The apparatus according to one or more of claims 1 -4, wherein the apparatus comprises:
- a first electromagnetic detecting device (40a) defining a first detecting channel configured to slidably receive at least a portion of the semi finished product and of the suction belt (13), the first electromagnetic detecting device (40a) comprising at least one electromagnetic sensor for detecting at least one property of the semi-finished product and of the suction belt (13) passing through the first detecting channel;
- a second electromagnetic detecting device (40b) defining a second detecting channel configured to slidably receive at least a portion of the suction belt (13), the second electromagnetic detecting device (40b) comprising at least one electromagnetic sensor for detecting at least one property of the suction belt (13) passing through the second detecting channel;
the first and second electromagnetic detecting devices (40a, 40b) being located on distinct stretches of the conveyor (10), preferably the first electromagnetic detecting device (40a) being located on an operating section of the conveyor (10) and the second electromagnetic detecting device (40b) being located on a non-operating section of the conveyor (10) or upstream of an entry point of the semi-finished product in the guide channel (1 1 ).
6. The apparatus according to claim 5 when dependent on any one of claims 2 to 4, comprising:
- a first position detector (50a) associated with the first electromagnetic detecting device (40a) and configured to detect the at least one distinctive element and to generate an identification signal representing a time instant at which the distinctive element passes through the first detecting channel;
- a second position detector (50b) associated with the second electromagnetic detecting device (40b) and configured to detect the at least one distinctive element and to generate an identification signal representing a time instant at which the distinctive element passes through the second detecting channel.
7. The apparatus according to claim 6, wherein the first position detector (50a) is positioned downstream of the first electromagnetic detecting device (40a) along the conveying direction and the second electromagnetic detecting device (40b) is positioned upstream of the first electromagnetic detecting device (40a).
8. The apparatus according to one or more of claims 2-7, wherein each position detector comprises an encoder (E, 32, 52a, 52b) configured to generate a position signal representing a position of each portion of the suction belt (13) relative to the at least one electromagnetic detecting device (20).
9. The apparatus according to one or more of claims 2-8, wherein each position detector comprises a discontinuity sensor (31 , 51 a, 51 b) configured to detect the at least one distinctive property by identifying when the distinctive element passes by the position detector.
10. The apparatus according to claim 9, wherein the distinctive element is a graphical sign, an incision or a notch or a joint on the suction belt (13) and the discontinuity sensor (31 , 51 a, 51 b) is an optical inspection device, preferably an image capturing device or a photocell designed to detect the passage of the distinctive element.
11. The apparatus according to claim 9, wherein the distinctive element is a metal insert and the discontinuity sensor (31 , 51 a, 51 b) is an electromagnetic sensor designed to detect the passage of the distinctive element.
12. The apparatus according to one or more of the preceding claims, wherein the at least one electromagnetic detecting device (20, 40a, 40b) is an electromagnetic microwave detecting device, preferably configured to operate at between 108 and 1012 Hz.
13. A method for the conveying and inspection of a semi-finished product of the tobacco industry, comprising the following steps:
- holding and conveying the semi-finished product along a guide channel (1 1 ) delimited at the sides by two side walls (12) and at the top by a suction belt (13);
- providing at least one electromagnetic detecting device (20, 40a, 40b) defining at least one detecting channel configured to slidably receive the suction belt (13) and at least one portion of the semi-finished product held on the suction belt (13);
- detecting at least one property of the suction belt (13) passing through the detecting channel and generating a reference signal;
- measuring at least one property of the semi-finished product and of the suction belt (13) passing through the detecting channel and generating a measurement signal;
- processing the measurement signal and correcting or varying it as a function of the reference signal so as to obtain an effective measurement data item relating only to the semi-finished product by eliminating from the measurement signal a component due to the suction belt (13).
14. The method according to claim 13, wherein the step of detecting is performed before or after the step of measuring.
15. The method according to claim 14, wherein the step of detecting comprises the following steps:
- causing the suction belt (13) to slide through the at least one detecting channel for one full turn of the suction belt (13);
- simultaneously detecting, by means of the electromagnetic detecting device (20, 40a, 40b), at least one property of the suction belt (13) sliding through the at least one detecting channel;
- associating the at least one property measured with successive portions of the suction belt (13) and generating the reference signal.
16. The method according to claim 13, wherein the step of providing comprises the following steps:
- providing a first electromagnetic detecting device (40a) defining a first detecting channel configured to slidably receive the suction belt (13) and at least one portion of the semi-finished product held on the suction belt (13);
- providing a second electromagnetic detecting device (40b) defining a second detecting channel configured to slidably receive the suction belt (13);
the step of detecting comprising the step of:
- detecting, by means of the second electromagnetic detecting device (40b), at least one property of the suction belt (13) passing through the second detecting channel;
and the step of measuring comprising the step of:
- measuring, by means of the first electromagnetic detecting device (40a), at least one property of the semi-finished product and of the suction belt (13) passing through the first detecting channel;
the step of detecting being performed simultaneously with the step of measuring.
PCT/IB2019/057907 2018-09-21 2019-09-19 Apparatus for the conveying and inspection of a semi-finished product of the tobacco industry WO2020058897A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB781042A (en) * 1951-08-15 1957-08-14 Desmond Walter Molins Improvements in or relating to machines for manipulating cut tobacco
US3127899A (en) * 1958-07-17 1964-04-07 Philip Morris Inc Cigarette making machine
US5103086A (en) * 1989-05-19 1992-04-07 Korber Ag Method of and apparatus for ascertaining the density of a stream of fibrous material
DE102015105353A1 (en) * 2015-04-09 2016-10-13 Hauni Maschinenbau Gmbh Suction belt conveyor and rod machine of the tobacco processing industry, use and method for measuring material properties of a material strand of the tobacco processing industry

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB781042A (en) * 1951-08-15 1957-08-14 Desmond Walter Molins Improvements in or relating to machines for manipulating cut tobacco
US3127899A (en) * 1958-07-17 1964-04-07 Philip Morris Inc Cigarette making machine
US5103086A (en) * 1989-05-19 1992-04-07 Korber Ag Method of and apparatus for ascertaining the density of a stream of fibrous material
DE102015105353A1 (en) * 2015-04-09 2016-10-13 Hauni Maschinenbau Gmbh Suction belt conveyor and rod machine of the tobacco processing industry, use and method for measuring material properties of a material strand of the tobacco processing industry

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EP3852557A1 (en) 2021-07-28
EP3852557B1 (en) 2023-09-06

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