Abstract:
A machine for producing packets of cigarettes, each packet having a group of cigarettes enclosed in packaging material, has a number of conveyors, each having a respective given number of respective members which are brought into contact with the groups and/or the packaging material, and cooperate with the members of at least one adjacent conveyor; the number of members of each conveyor being equal to a multiple or to a divisor of the number of members of an adjacent conveyor.

Description:
The present invention relates to a machine for producing packets of cigarettes. 
     BACKGROUND OF THE INVENTION 
     A packet of cigarettes comprises a group of cigarettes, and packaging material folded about the group; and machines for producing packets of cigarettes comprise a number of conveyors, each having a given number of members arranged in series and for manipulating the groups and/or the packaging material and for performing the operations by which the packets are produced. The members of each conveyor also cooperate with those of adjacent conveyors to transfer the groups and/or the packaging material—unfolded, partly folded, or folded into the form of the packet—from one conveyor to another. The number of members of each conveyor is normally determined on the basis of design parameters, which fail to take into account the adjustments required by the members of each conveyor, and the control methods implemented on the machine itself. 
     As a result, known machines of the above type for producing packets of cigarettes involve a painstaking setup procedure to adjust each member to cooperate effectively with all the members on the adjacent conveyor, and which must be repeated whenever the size of the packet is changed, thus resulting in prolonged stoppage of the machine. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a machine for producing packets of cigarettes, designed to eliminate the drawbacks of the known state of the art. 
     According to the present invention, there is provided a machine for producing packets of cigarettes; each packet comprising a group of cigarettes enclosed in packaging material; the machine comprising a number of conveyors, each having a respective number, greater than one, of members which are brought into contact with said groups and/or the packaging material, and cooperate with the members of at least one adjacent conveyor; in particular, said members comprising outlets for the groups, pockets for conveying the groups and/or packets, conveying heads for conveying the packaging material, and folding devices for folding said packaging material; and the machine being characterized in that the number of members of each conveyor is equal to a multiple or to a common divisor of the number of members of an adjacent conveyor. 
     The present invention also relates to a method of controlling a machine for producing packets of cigarettes. 
     According to the present invention, there is provided a method of controlling a machine, characterized by comprising the steps of extracting a given number of packets from said machine; and determining, for each extracted packet, which members have been brought into contact with the group and with the packaging material used to produce each extracted packet. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: 
     FIG. 1 shows a side view, with parts removed for clarity, of a machine in accordance with the present invention; 
     FIGS. 2 and 3 show sections of a detail of the FIG. 1 machine in a first and second operating position respectively. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Number  1  in FIG. 1 indicates as a whole a machine for producing hinged-lid packets  2  of cigarettes. 
     Each packet  2  comprises an orderly group  3  of cigarettes  4  wrapped in a sheet of packaging material  5 ; a collar  6  about group  3  and on top of the sheet of packaging material  5 ; and a blank  7  folded about group  3 . 
     Machine  1  comprises a frame  8 , shown by the dash line in FIG. 1, which supports a device  9  for forming groups  3 , a packaging device  10 , and a device  11  for unloading the finished packets  2 . Device  9  for forming groups  3  comprises a hopper  12  for conveying cigarettes  4 ; a pocket conveyor  13  for feeding groups  3  of cigarettes in a substantially horizontal direction D 1 ; and a conveyor  14  for feeding cigarettes  4  in bulk to hopper  12 . Conveyor  13  is a magnetic conveyor comprising an annular track  15 , in turn, comprising a straight top branch  16  and along which four trains  17  of pockets  18  travel along an annular path P 1 . Each train  17  comprises six pockets  18 , one of which is shown by the dash line in the enlarged detail in FIG. 1; hopper  12  comprises six outlets  19  arranged along top branch  16 , and an inlet  20  communicating with conveyor  14 ; and cigarettes  4  extend crosswise to direction D 1 . 
     With reference to FIGS. 2 and 3, hopper  12  comprises two parallel, facing walls  21 ; and partitions  22  located between walls  21  to divide the stream of cigarettes  4  inside hopper  12 . Walls  21  are vertical, are parallel to direction D 1 , and are located a fixed distance A 1  apart in a horizontal direction D 2  perpendicular to direction D 1  and to walls  21 . At inlet  20 , an ordering device  23  is provided to align cigarettes  4 , and comprises two walls  24  parallel to each other and to walls  21 , and an actuator  25  for transmitting a back and forth movement to walls  24  in direction D 2 . Walls  24  are located a given distance A 2  apart in direction D 2 , and are supported by pins  26  parallel to direction D 2  and having respective appendixes engaged in respective guides  27  integral with frame  8 . Actuator  25  comprises a motor  28 , and a crank mechanism  29  connecting motor  28  to one of walls  24 . Distance A 1  equals the length of cigarettes  4  plus clearances B 1  and B 2  at opposite ends of each cigarette  4 , and distance A 2  is greater than distance A 1 . At each outlet  19 , device  9  comprises a respective extractor (not shown) movable back and forth in direction D 2  and controlled by a respective linear electric motor (not shown) to cyclically expel a group  3  from outlet  19 . 
     With reference to FIG. 1, packaging device  10  comprises a packaging wheel  30 , along which each group  3  is wrapped in a respective sheet  5  and partly enclosed in a respective collar  6 ; and a packaging wheel  31 , along which each group  3  is enclosed in a blank  7 . Wheel  30  rotates about an axis  32 , and comprises twelve pockets  33 , which are equally spaced about axis  32 , house respective groups  3 , and have respective movable folding walls  34 . Each pocket  33  travels along an annular path P 2 , along which are located in succession a station S 1  for supplying groups  3  and sheets  5 ; a station S 2  for folding sheet  5 ; a further station S 3  for folding sheet  5 ; a station S 4  for transferring groups  3  onto wheel  31 ; and a station S 5  for supplying collars  6 . At station S 2 , there is provided a folding wheel  35  rotating about a respective axis  36 , and comprising three folding tools  37  equally spaced about axis  36  and cooperating with the groups  3  conveyed by pockets  33  to fold sheet  5 . Similarly, at station S 3 , there is provided a folding wheel  38  rotating about an axis  39 , and comprising three folding tools  40  equally spaced about axis  39  and cooperating with the groups  3  conveyed by pockets  33  to fold sheet  5 ; and, at station S 5 , there is provided a wheel  41  rotating about an axis  42  parallel to axis  32 , and comprising six pickup heads  43  equally spaced about axis  42  and for feeding collars  6  to pockets  33 . 
     Wheel  31  rotates about an axis  44  parallel to axis  32 , and comprises twelve pockets  45 , which are equally spaced about axis  44 , have respective movable walls  46 , and are fed along a path P 3 , along which are located transfer station S 4  for receiving groups  3  from wheel  30 , a station S 6  for transferring packets  2 , and a station S 7  for supplying blanks  7 . At station S 7 , there is provided a wheel  47  rotating about an axis  48  parallel to axis  32 , and comprising six heads  49  equally spaced about axis  48  and for feeding blanks  7  to pockets  45 . 
     Unloading device  11  comprises a conveyor  50 , which, in turn, comprises a chain  51  looped about two pulleys  52 , extends in a vertical direction D 3 , and comprises twenty-four pockets  53  equally spaced along chain  51  and each for selectively retaining a respective packet  2  by means of a known actuator not shown. Conveyor  50  is supplied by a wheel  54 , which rotates about an axis  55  parallel to axis  32 , comprises six pockets  56 , and is located between station S 6  and conveyor  50  to transfer packets  2  from wheel  31  to conveyor  50 , which comprises a straight upflow branch  57 , along which packets  2  are fed in direction D 3 , and a downflow branch  58  parallel to branch  57 . Unloading device  11  also comprises two suction-belt conveyors  59  and  60 . Conveyor  59  has a portion located along upflow branch  57  to receive packets  2  from conveyor  50  and continue feeding packets  2  in direction D 3 , and is further connected to suction-belt conveyor  60  facing a portion of conveyor  59 . In other words, conveyor  59  retains each packet  2  by suction on one face of packet  2 , while conveyor  60  retains packet  2  by suction on the opposite face of packet  2 . 
     Machine  1  comprises a control device  61  for checking groups  3  are complete, cigarettes  4  are undamaged, and packets  2  are formed properly. Control device  61  comprises a control unit  62 ; a camera  63  located along branch  16  to check groups  3  are complete and cigarettes  4  undamaged; and two cameras  64  and  65  facing conveyors  59  and  60  respectively, to check correct formation of packets  2  from two opposite angles. Control unit  62  is connected to wheel  54  to release packets  2  from wheel  54  into a bin  66 , shown by the dash line in FIG. 1, and is connected to conveyor  60  to activate an extractor  67  for extracting packets  2  from conveyor  60  and feeding packets  2  into a bin  68  shown by the dash line in FIG.  1 . Unit  62  emits an error signal E 1  as a function of the values detected by camera  63 , and uses error signal E 1  to reject any packets  2  containing incomplete groups  3  or faulty cigarettes  4 , and to activate pockets  56  of wheel  54  to feed such packets  2  into bin  66 . Similarly, unit  62  emits an error signal E 2  as a function of the values detected by cameras  64  and  65 , to reject any packets  2  with flawed outer surfaces by means of extractor  67 . 
     Unit  62  comprises a control member  69  for disabling transfer of packets  2  from conveyor  50  to conveyor  59 , so that packets  2  are fed along downflow branch  58  of conveyor  50  and released successively onto a table  70  shown by the dash line in FIG.  1 . 
     Each outlet  19  has a respective identification mark to distinguish it from the other outlets  19 . And similarly, each of pockets  18 ,  33 ,  45 ,  53  and  56 , each of pickup heads  43  and  49 , and each of tools  37  and  40  have respective identification marks—normally numbers—so as to easily identifiable on machine  1 . 
     In actual use, cigarettes  4  are fed in bulk to hopper  12  by conveyor  14 , and are deposited between walls  24  of ordering device  23  at inlet  20  of hopper  12 . Walls  24  are moved back and forth in direction D 2  between the two positions shown in FIGS. 2 and 3 respectively, and are oscillated by an amount equal to “A 2 −A 1 +B 1 +B 2 ”, so that cigarettes  4  are aligned perfectly by device  23  before dropping down between walls  21  of hopper  12 , and so that the ends of cigarettes  4  are prevented from sliding against walls  21 . 
     Inside hopper  12 , cigarettes  4  are fed by gravity to outlets  19 , from which groups  3  are extracted as described previously. One group  3  is extracted from each outlet  19  and deposited inside a respective pocket  18  of a train  17  arrested at outlets  19 . Conveyor  13  is operated to feed trains  17  continuously past wheel  30 , and to stop at outlets  19  to receive groups  3  from outlets  19 . Each pocket  18  of trains  17  cooperates with only one respective outlet  19  of hopper  12 , and each train  17  is activated independently of the other trains  17 . 
     The groups  3  fed by pockets  18  along branch  16  are controlled by camera  63  to ensure each group  3  is complete and cigarettes  4  undamaged. When the values detected by camera  63  depart from given threshold values, control unit  62  emits error signal E 1  to expel the packet  2  containing an incomplete group  3  or faulty cigarette, as the packet  2  is fed by wheel  54  past bin  66 . That is, control unit  62  provides for expelling the faulty packet  2  from pocket  56  in known manner. 
     Groups  3  are transferred successively from conveyor  13  onto wheel  30  at station S 1 , and are transferred between pockets  18  and pockets  33  so that each pocket  18  transfers a group  3  to a respective pocket  33  on wheel  30 . That is, at each cycle, each pocket  18  of each train  17  always cooperates with the same pocket  33  on wheel  30 . At station S 1 , each pocket  33  is supplied with a sheet  5  of packaging material, which is wrapped about group  3  along path P 2 ; and, at station S 5 , each pocket  33  is supplied with a respective collar  6 , which is folded about group  3  and on top of packaging material  5 . 
     Collar  6  and part of sheet  5  of packaging material are folded by the movable folding walls  34  of each pocket  33 , and the folding of sheet  5  of packaging material is completed by wheels  35  and  38 . Collars  6  are supplied to pockets  33  by heads  43 , so that each of the six heads  43  only cooperates with two of the twelve pockets  33 . Similarly, each folding tool  37  and  40  of respective wheels  35  and  38  only cooperates with a given four of the twelve pockets  33 . 
     At station S 4 , each group  3 , complete with a respective folded sheet  5  and with a respective folded collar  6 , is transferred onto wheel  31 . In this case, since pockets  33  are equal in number to pockets  45 , each given pocket  33  only cooperates with a given pocket  45 . At station S 7 , each pocket  45  is supplied with a blank  7  by a head  49  on wheel  47 , and each head  49  only cooperates with two pockets  45  on wheel  31 . At station S 6 , packets  2  are transferred to pockets  56  on wheel  54 , which in turn transfers packets  2  to pockets  53  on conveyor  50 . Each pocket  56  only cooperates with two pockets  45  on wheel  31 , and with four pockets  53  on conveyor  50 . Packets  2  are then fed along upflow branch  57  of conveyor  50 , are engaged by conveyor  59 , are released to conveyor  59  by pockets  53 , and are fed successively by conveyor  59  past camera  64 . Conveyor  59  then releases packets  2  to conveyor  60 , which feeds packets  2  successively past camera  65 . When the images picked up by cameras  64  and  65  fail to fall within given threshold values, unit  62  emits error signal E 2  to activate extractor  67 , which feeds packets  2  into bin  68 . 
     When control member  69  is activated, twelve successive, adjacent pockets  53  are disabled from releasing respective packets  2  to conveyor  59 ; the respective packets  2  are fed along downflow branch  58 ; and the disabled pockets  53  are activated to release packets  2  successively onto table  70  for inspection. The packets  2  collected on table  70  are numbered according to the sequence in which they are released. 
     Inspection consists in taking packets  2  apart to determine whether the group  3  forming, packaging and conveying operations on machine  1  have been performed properly, i.e. without damaging group  3 , blank  7 , collar  6 , or sheet  5 . Control unit  62  is able to identify the pocket  53  on conveyor  50  from which a given packet  2  has been extracted for inspection, and, on the basis of the structure of the machine, supplies the identification mark of the pocket  56  by which the packet  2  was conveyed; the identification mark of the pocket  45  by which blank  7  was folded to form the packet  2 ; the identification marks of pockets  18  and  33  by which the group  3  in the packet  2  was conveyed; the identification marks of heads  43  and  49  by which collar  6  and blank  7  were supplied to form the packet  2 ; and the identification numbers of tools  37  and  40  by which sheet  5  of the packet  2  was folded. 
     That is, by inspecting and detecting a flaw in a packet  2 , it is possible to work out immediately which machine  1  member  18 ,  19 ,  33 ,  45 ,  37 ,  40 ,  43 ,  49 ,  53 ,  56  is responsible, and to change, repair or adjust the member  18 ,  19 ,  33 ,  45 ,  37 ,  40 ,  43 ,  49 ,  53 ,  56  in question. In other words, for each packet extracted, control unit  62  processes a predetermined algorithm relative to the relationships between the numbers of members  18 ,  19 ,  33 ,  45 ,  37 ,  40 ,  43 ,  49 ,  53 ,  56 , in which the input data item is represented by the identification mark of the pocket  53  from which the packet  2  was extracted, and the variables are defined by the identification marks of members  18 ,  19 ,  33 ,  45 ,  37 ,  40 ,  43 ,  49 ,  56 . The algorithm comprises a number of equations, which comprises the relationships between the numbers of members  18 ,  19 ,  33 ,  45 ,  37 ,  40 ,  43 ,  49 ,  53 ,  56  of adjacent conveyors  12 ,  13 ,  30 ,  31 ,  35 ,  38 ,  41 ,  47 ,  50 ,  54 . 
     For example, on machine  1 , given relationships exist between the numbers of members  18 ,  19 ,  33 ,  45 ,  37 ,  40 ,  43 ,  49 ,  53 ,  56 , and which are determined by machine  1  comprising three tools  37  and three tools  40 , six outlets  19 , six heads  43 , six heads  49  and six pockets  56 , twelve pockets  33  and twelve pockets  45 , twenty-four pockets  18  and twenty-four pockets  53 . In the case of machine  1  described, said numbers form part of a geometric progression of ratio  2 . 
     In the example described, control unit  62  provides for extracting twelve packets  2 , but may control the number of packets  2  to be extracted, which should advisably form part of said geometric progression. For example, extracting three packets  2  provides for a complete check of three tools  37  and three tools  40 ; extracting six packets  2  provides for a complete check of pockets  56 , heads  43  and  49 , and outlets  19 ; extracting twelve packets  2  provides for a complete check of twelve pockets  45  and twelve pockets  33 ; and extracting twenty-four packets provides for a complete check of twenty-four pockets  53  and twenty-four pockets  18 .