Abstract:
Single cigarettes selected as samples at the outfeed stage of a manufacturing line undergo a systematic quality control operation, performed by a testing unit, that consists in verifying a given number of characteristics for each cigarette and generating a set of signals each reflecting the quality of a respective characteristic; the succession of signals, each assigned a value on a predetermined scale, is represented in the form of a graph. Once a significant sample has been processed, the values assigned to all the characteristics of the tested cigarettes are displayed in a table, ordered such that each column will serve effectively as a production report on an individual cigarette.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a method and a unit for testing production quality in a line for manufacturing tobacco products.  
         [0002]     The invention is applicable to the art field of systems for the manufacture of tobacco products, and of cigarettes in particular, comprising both cigarette maker and filter tip attachment machines, albeit no limitation is implied.  
         [0003]     More exactly, the invention is concerned with testing the various characteristics or properties of cigarettes sampled at the outfeed of the line during the course of the production cycle.  
         [0004]     Among the characteristics of cigarettes subjected to such tests, certain items are notably important: the weight, the consistency of the filler at the cut ends, the degree of ventilation, the quality of the print, the integrity of the paper wrap, and the soundness of the join between filter and cigarette.  
         [0005]     Conventionally, sample cigarettes taken at the outfeed end of the manufacturing line for quality control purposes will undergo tests conducted by a specialist operator who selects single cigarettes at regular intervals. The samples are subjected to a quality control procedure implemented in part visually and manually by the operator, and in part instrumentally by dedicated testing devices.  
         [0006]     In practice, the procedure in question serves to verify whether or not the different characteristics of the sample cigarettes are within given limits, which in the case of certain characteristics, at least, will be determined by the experience and judgement of the operator.  
         [0007]     In the event of at least one among the tested characteristics failing to meet the standards of acceptance, the operator will identify those parts of the cigarette maker or the filter tip attachment machine to which any defects found in the finished product are attributable, and proceed to take the appropriate action.  
         [0008]     It will be appreciated from the foregoing that the quality control procedure in question depends to a large extent on the experience and judgement of the operator. Consequently, the evaluation of certain characteristics presented by the cigarettes is necessarily subjective and may not always be made uniformly, even within the scope of a single production run.  
         [0009]     The object of the present invention is to provide a method and a unit whereby all the characteristics of products turned out by a manufacturing line of the above noted type are evaluated on the basis of rigorously objective criteria that remain constant over time.  
       SUMMARY OF THE INVENTION  
       [0010]     The stated object is realized, according to the present invention, in a method for testing the quality of production in a line for manufacturing tobacco products that consists in sampling a given number of finished products taken from the outfeed stage of the line, then subjecting each of the sampled products to a step, performed by a testing unit, in which the quality of a predetermined number of characteristics is evaluated in such a way as to obtain a plurality of signals each reflecting the quality of a single characteristic.  
         [0011]     The stated object is realized likewise in a unit for testing the quality of production in a line for manufacturing tobacco products, typically a line equipped with a cigarette maker and a filter tip attachment machine, comprising a unit such as will test the quality of a given number of characteristics presented by single products sampled at the outfeed stage of the line and generate output signals reflecting the quality assignable respectively to each of the single characteristics of each sampled product, also a central processing and sorting unit by which the output signals are received from the testing unit, processed, and used to create video displayable graphs. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which:  
         [0013]      FIG. 1  is a block diagram representing a line for the manufacture of tobacco products, equipped with a unit for testing the quality of production such as will implement the method according to the present invention;  
         [0014]      FIG. 2  is a schematic perspective representation of the line for manufacturing tobacco products as illustrated diagrammatically in  FIG. 1 ;  
         [0015]      FIGS. 3 and 4  show two graphs obtainable using the unit of  FIG. 1 ;  
         [0016]      FIGS. 5 and 6  show a table and a corresponding graph, respectively, obtainable using the unit of  FIG. 1 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     With reference to  FIGS. 1 and 2 , numeral  1  denotes a production line, in its entirety, for the manufacture of tobacco products such as cigarettes, denoted  2 , comprising a cigarette maker  3  and a filter tip attachment machine  4 .  
         [0018]     The cigarette maker  3  incorporates a plurality of devices and machine units and, more exactly, is equipped at the upstream end with a carding unit  5  in receipt of tobacco from an infeed hopper (not illustrated); proceeding downstream, the tobacco is taken up onto a carding drum  6  and projected by an impeller roller  7 , operating in conjunction with the carding drum  6 , into a descent duct or chute  8 , thence onto a belt conveyor  9  and into an ascent duct or chimney  10 .  
         [0019]     The top end of the chimney  10  is enclosed by an aspirating belt  11  on which the tobacco particles collect and are formed gradually into a continuous stream  12  that will ultimately provide the filler for the cigarettes  2 .  
         [0020]     The stream  12  of tobacco is released onto a strip of paper  13  decoiling from a roll  14  along a path that passes initially through a printing device  15 , and advances into a garniture section  16  where it is enveloped longitudinally by the aforementioned strip  13  to form a continuous cigarette rod  17 .  
         [0021]     The continuous rod  17  is fed toward and through a cutting station  18  where it will be divided up by a rotary cutter device  19  into discrete segments of predetermined and constant length, and more exactly into sticks  20  of length measuring twice the length of a stick making up a single cigarette  2 .  
         [0022]     Numeral  21  denotes a device by which the double length sticks  20  are transferred, through a set of infeed rollers  22  forming part of the filter tip attachment machine  4 , to a cutting station  23  where each successive double length stick  20  is separated into two single cigarette sticks  24  by the action of a roller  25  and a disc cutter  26 .  
         [0023]     The single cigarette sticks  24  are directed from the roller  25  of the cutting station  23 , first onto a distancing roller  27  on which the two sticks  24  separated by each cutting stroke are spaced apart axially one from the other, then onto an assembling roller  28 , whereupon a double length filter plug  29  supplied by a respective feed unit, denoted  30  in its entirety, is interposed between the two single sticks  24  of each advancing pair.  
         [0024]     The resulting assemblies, each consisting of two single cigarette sticks  24  and one double length filter plug  29  placed between them, are released from the assembling roller  28  onto a roller  31  that forms part of a finishing station  32 , comprising a unit  33  by which tipping papers  34  are cut and fed to the selfsame station  32 , and a rolling device  35  such as will take up the stick/double-filter/stick assemblies and the tipping papers  34  and roll each successive tipping paper  34  about a corresponding assembly to fashion a double length cigarette  2 .  
         [0025]     The double length cigarettes  2  are fed by way of an intermediate roller  36  to a cutter device  37  and divided by a cutting stroke made through the double length filter  29  to generate two successions of single filter cigarettes  2  appearing identical one to another.  
         [0026]     The two successions of filter cigarettes  2  are directed toward an outfeed stage  38  of the filter tip attachment machine  4 , advancing first onto an overturning roller  39  by which a single succession of cigarettes  2  is established, then passing onto a final train of rollers denoted  40  in its entirety, along which the cigarettes  2  will undergo further finishing steps of a familiar nature.  
         [0027]     As illustrated in  FIG. 2  for example, the final train  40  of rollers, supported together with the aforementioned rollers  22 ,  25 ,  27 ,  28  and  31  by a vertical bulkhead  41  associated with the frame  42  of the filter tip attachment machine  4 , comprises a roller denoted  43  on which ventilation holes are pierced in the cigarettes  2  by a laser generator device  44 , and a roller denoted  45  on which the cigarettes are scanned.  
         [0028]     Referring again to  FIG. 1 , the manufacturing line  1  comprises a unit  46  by means of which to test the production quality of the cigarettes  2 , connected on the input side by way of a single cigarette sampling device, indicated as a block  47 , to a roller  48  coinciding with the outfeed stage  38  of the filter tip attachment machine  4 .  
         [0029]     The unit  46  in question is designed to test the quality of a plurality of characteristics presented by the single cigarette  2 , and in particular, the integrity of the paper wrap, the consistency of the end fill, the degree of ventilation obtained with the holes pierced by the laser generator  44 , the quality of the print, the weight, and so forth.  
         [0030]     With reference in particular to  FIG. 1 , the quality testing unit  46  is connected on the output side to a central data processing and sorting unit or CPU  49 , connected in turn to a keyboard  50 , a video display unit  51  and a printer  52 . The CPU  49  can also be connected by way of a web network  53  to the Internet, represented schematically by a block denoted  59 .  
         [0031]     Once the quality testing unit  46  has inspected a significant number of single cigarettes  2  (say 10, for example) selected at the outfeed station  38 , the CPU  49  will receive signals relating to each of the characteristics tested, which it processes and outputs in the form of graphs, as illustrated by way of example in  FIGS. 3 and 4 , viewable on the video display unit  51 .  
         [0032]     The CPU  49  comprises processing means  54  by which each signal received from the testing unit  46  is assigned a value on a predetermined scale common to all of the tested characteristics.  
         [0033]     In the graphs of  FIGS. 3 and 4 , the “x” axis represents the succession of cigarettes  2  subjected to quality testing, whilst the “y” axis is marked  0  to  10 , denoting the values on the aforementioned scale.  
         [0034]     Observing the graphs relative to a succession of cigarettes  2  sampled from the outfeed stage  38 , the quality of production as reflected in each of the tested characteristics will be readily discernible. Self-evidently, a substantially flat line indicates that the quality of the tested characteristic has remained substantially constant over time, whilst an upward trend toward the higher numbers on the scale indicates an improvement and a downward trend indicates a deterioration.  
         [0035]     In the latter instance, the information provided will enable the operator to take corrective action on the devices of the line  1  to which the negative trend is attributable.  
         [0036]     The action in question might occur automatically, triggered by feedback control circuits indicated schematically in  FIG. 1  as blocks denoted  55  and  56 , by way of which the CPU  49  is connected to the various devices and units of the cigarette maker  3  and of the filter tip attachment machine  4 .  
         [0037]     The CPU  49  further comprises sorting means  57  by which the signals reflecting the characteristics of each single cigarette  2  tested can be represented as numerical values in a table as illustrated in  FIG. 5 .  
         [0038]     Accordingly, each column in the table of  FIG. 5  provides information amounting effectively to a “report” on a respective cigarette.  
         [0039]     The central data processing and sorting unit  49  is equipped with computing means  58  able to produce an overall assessment of the tested characteristics for each cigarette  2  sampled. In the example of  FIG. 5 , each of the overall assessments indicated on the bottom line of the table is attributed by computing the average of the values assigned for the single characteristics.  
         [0040]     On the basis of the overall assessments produced by the computing means  58 , the processing means  54  are able to generate a graph of the type shown in  FIG. 6 , which indicates the trend of the overall assessments relating to a given series of sampled cigarettes  2 .  
         [0041]     It will be seen that the line  1  is equipped in conventional manner with a succession of devices serving to monitor the cigarette-making process, and devices serving to reject any cigarettes  2  of which the characteristics may not register within prescribed limits. Thus, all of the cigarettes  2  scrutinized by the quality testing unit  46  will be identifiable, at least in theory, as conforming to an acceptance threshold defined in the graphs of  FIGS. 3, 4  and  6 , by the line A parallel to the “x” axis.  
         [0042]     Thus, with the graphs described above providing an index as to the quality of a given production cycle, the manufacturer will be able, on the basis of these same graphs, to select the most suitable market for a particular type of production lot.  
         [0043]     Accordingly, selection means might be installed at the outfeed stage  38  of the line  1 , with the end in view of organizing the tobacco products into distinct lots destined for different markets.  
         [0044]     As illustrated in  FIG. 1 , the system might also comprise a printing device  60 , associated with the quality testing unit  46  and driven by the computing means  58  and/or the processing means  54 , such as will impress the sampled cigarettes  2  with marks  61  serving to indicate the overall quality assessment attributed by averaging the values assigned for all of the characteristics tested, or to indicate the value assigned for one such characteristic.