Patent Publication Number: US-7712286-B2

Title: Machine for packing cylindrical articles

Description:
The present invention relates to a machine for packing cylindrical articles, and to a group-forming device for forming groups of cylindrical articles. 
   The present invention may be used to advantage for packing cigarettes, to which the following description refers purely by way of example. 
   More specifically, the present invention relates to a machine for packing cylindrical articles in the tobacco industry, and which comprises a group-forming device for forming a group of cylindrical articles. The group-forming device in turn comprises a substantially vertical hopper; a conveying device comprising at least one pocket for housing the group of cylindrical articles; and a transfer device for transferring the cylindrical articles from the hopper to the conveying device. The transfer device comprises a push member for pushing a first and at least a second subgroup of cylindrical articles, crosswise to the feed direction, into the pocket at a first and second insertion station respectively; and the second subgroup is inserted, in use, into the pocket on top of the first subgroup to define the group of cylindrical articles. 
   Examples of machines of the above type for packing cylindrical articles are described in U.S. Pat. No. 3,707,219 and EP1002722A1. 
   U.S. Pat. No. 5,590,513 describes a cigarette packing machine comprising a group-forming device for forming a group of cigarettes. The group-forming device in turn comprises a substantially vertical hopper housing a mass of downward-fed cigarettes; and a transfer device for transferring a group of cigarettes from the hopper into a folding spindle. And the folding spindle has movable lateral walls for compressing the group of cigarettes. 
   BACKGROUND OF THE INVENTION 
   Known cigarette packing machines of the above types have the drawback of being unable to satisfactorily pack substantially triangular groups of cigarettes. 
   In this connection, it is important to note that, being highly unstable, on account of the relative positions of the cigarettes, triangular groups of cigarettes are relatively difficult to handle. To produce packets of triangular groups of cigarettes, therefore, it is essential that means be provided—which are not, on known machines—to maintain the relative positions of the cigarettes, while at the same time adequately preparing the groups for wrapping (normally in a foil wrapping). 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a machine for packing cylindrical articles, and a group-forming device for forming groups of cylindrical articles, designed to at least partly eliminate the aforementioned drawbacks, and which at the same time are cheap and easy to produce. 
   According to the present invention, there are provided a machine for packing cylindrical articles, and a group-forming device for forming groups of cylindrical articles, as claimed in the attached Claims. 

   
     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 schematic front view of a cigarette packing machine in accordance with the present invention; 
       FIG. 2  shows a view in perspective of a packet of cigarettes producible on the  FIG. 1  machine; 
       FIG. 3  shows a schematic top plan view, with parts removed for clarity, of a portion of the  FIG. 1  machine; 
       FIG. 4  shows a schematic front view of a portion of the  FIG. 1  machine; 
       FIGS. 5 and 6  show sections along lines V and VI, respectively, of the  FIG. 3  portion; 
       FIG. 7  shows a view in perspective of a detail of the  FIG. 1  machine; 
       FIG. 8  shows a view in perspective of an alternative embodiment of the  FIG. 7  detail; 
       FIGS. 9 to 11  show schematics of a portion of the  FIG. 1  machine at different operating stages; 
       FIGS. 12 and 13  show top plan views of groups of cigarettes of two further shapes packable on a machine in accordance with the present invention; 
       FIGS. 14 and 15  show sections along lines XIV and XV, respectively, of the  FIG. 3  portion. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Number  1  in  FIG. 1  indicates as a whole a machine for packing cylindrical articles, in particular cigarettes  2 , to form a packet  3  of cigarettes  2  ( FIG. 2 ). With particular reference to  FIGS. 3 and 4 , machine  1  comprises a group-forming device  4  for forming a group  5  of cigarettes  2 , and which comprises a substantially vertical hopper  6  for housing and feeding a mass of cigarettes  2  downwards to a transfer station  7 , a conveyor  8  for feeding group  5  from station  7  along a path P in a given direction A, and a transfer device  9  for transferring cigarettes  2  from hopper  6  to conveyor  8 . 
   Device  9  comprises a number of—in the example shown, two—seats  10  and  11  located at the transfer station, and each for receiving from hopper  6  a respective subgroup  12 ,  13  of cigarettes  2 ; each subgroup  12 ,  13  comprising at least one cigarette  2 . 
   At the bottom, hopper  6  comprises a number of channels  14 , along each of which a column  15  of single cigarettes  2  travels, in use. Each seat  10 ,  11  is located beneath at least one channel  14 , and contains a respective number of cigarettes  2  different from the number of cigarettes  2  in the other seat  11 ,  10 . In the embodiment shown, seat  10  is located beneath two channels  14 , and houses a subgroup  12  comprising three cigarettes  2 ; and seat  11  is located beneath four channels  14 , and houses a subgroup  13  comprising seven cigarettes  2 . 
   The fact that each seat  10 ,  11  contains a respective number of cigarettes  2 , different from the number of cigarettes  2  in the other seat  11 ,  10 , provides for forming group  5  relatively easily. 
   Each seat  10 ,  11  comprises two lateral walls  16 , each of which is substantially vertical and has an inner surface  17 . And each seat  10 ,  11  comprises a bottom wall  18  having a substantially horizontal top supporting surface  19  and a substantially horizontal bottom supporting surface  19   a  connected to each other by a respective substantially vertical surface  19   b.    
   An optional known vibrating member (not shown) is provided at seats  10 ,  11  to vibrate seats  10 ,  11  to ensure correct insertion of cigarettes  2  inside seats  10 ,  11 . 
   Conveyor  8  comprises a belt  10  travelling in direction A and looped about two pulleys (not shown); and at least one pocket  21  fitted integrally to belt  20  to travel along path P in direction A. 
   With particular reference to  FIG. 7 , pocket  21  comprises two lateral walls  22 , each having an inner lateral surface  23 ; a bottom wall  24  having an inner bottom surface  25 ; and a top wall  26  having an inner top surface  27 . Surfaces  23  are crosswise to the given direction, and slope towards each other so that group  5  assumes a substantially triangular shape inside pocket  21 . More specifically, surfaces  23  slope so that the space defined inside pocket  21  by surfaces  23 ,  25  and  27  tapers downwards. 
   Pocket  21  comprises a slit  28  crosswise to surfaces  23 , substantially parallel to direction A, and defining openings in lateral walls  22  and top wall  26 ; and a slit  29  crosswise to slit  28  and defining an opening in top wall  26 . 
   With particular reference to  FIGS. 3 ,  5  and  6 , device  4  also comprises a push member  30  for pushing subgroups  12 ,  13  longitudinally, and crosswise to direction A, through respective insertion channels  31 ,  32  into pocket  21 . Push member  30  comprises two pushers  33  comprising a number of push fingers  33   a  (some of fingers  33   a  are shown in  FIG. 3 ); and each finger  33   a  is movable longitudinally, and crosswise to direction A, to push a respective cigarette  2  into pocket  21 . 
   Each channel  31 ,  32  is located at a respective insertion station  34 ,  35 , and comprises two lateral walls  36 , each having an inner surface  37 ; a bottom wall  38  having an inner bottom surface  39 ; and a top wall  40  having an inner top surface  41 . 
   Inner top surfaces  41  are designed to exert downward pressure on cigarettes  2  in respective subgroups  12 ,  13 , as subgroups  12 ,  13  are pushed, in use, towards path P. 
   Each channel  31 ,  32  is shaped so that the inner cavity  42  defined by surfaces  37 ,  39 ,  41  tapers towards path P, and the cigarettes  2  in subgroup  12 ,  13  are therefore brought closer together and/or compacted as they travel along relative insertion channel  31 ,  32  towards conveyor  8 . 
   Channel  32  has one end  43  facing path P at a higher level than a similar end  44  of channel  31 , so that, in use, subgroup  13  is inserted into pocket  21  on top of subgroup  12 . 
   It is important to note that the cross sections, parallel to direction A, of cavities  42  vary. More specifically, the respective cross sections, parallel to direction A, of cavities  42  are substantially T-shaped ( FIGS. 5 and 6 ) at ends  43  and  44 , and are substantially L-shaped ( FIGS. 14 and 15 ) at the opposite ends to ends  43  and  44 . This particular design of cavities  42  provides for positioning cigarettes  2  in each subgroup  12 ,  13  correctly with respect to one another, as cigarettes  2  are fed from hopper  6  to conveyor  8 . 
   With particular reference to  FIGS. 9 to 11 , device  4  also comprises a stabilizing device  45  for keeping subgroup  12  positioned correctly inside pocket  21  as pocket  21  travels, in use, along path P between stations  34  and  35 . Device  45  has the same structure and operates in the same way as the stabilizing device described in U.S. Pat. No. 3,642,112, to which full reference is made herein. More specifically, device  45  comprises a retaining member  46 , which at least partly engages slit  28  to define the top of a portion  47  of pocket  21  housing subgroup  12 . And retaining member  46  has a bottom pressure surface  48  for pressing down on subgroup  12 . 
   Device  45  also comprises actuating members (not shown) for moving retaining member  46 , in time with pocket  21 , along path P from station  34  to station  35  ( FIG. 9 ), and, once pocket  21  reaches station  35  ( FIG. 10 ), for returning retaining member  46  to station  34  ( FIG. 11 ). 
   Device  4  preferably comprises a known control unit (not shown) for coordinating push member  30  and the actuating members (not shown), so that retaining member  46  begins disengaging the slit when subgroup  13  is at least partly inserted inside pocket  21 . 
   Operation of machine  1  will now be described briefly, as of the instant in which subgroup  12  is correctly positioned inside seat  10 . 
   At this point, push member  30  pushes subgroup  12  through insertion channel  31  into pocket  21 ; and subgroup  12  is kept positioned correctly inside pocket  21  by retaining member  46 , which moves together with pocket  21  from station  34  to station  35 . 
   When pocket  21  reaches station  35 , subgroup  13 , formed in the meantime inside seat  11 , is pushed through channel  32  into pocket  21  and on top of subgroup  12  to form group  5 . As subgroup  13  begins engaging pocket  21 , retaining member  46  is withdrawn from station  35  to station  34  to disengage slit  28  and avoid interfering with insertion of subgroup  13 . 
   In the above embodiment, group  5  of cigarettes  2  is substantially triangular with its apex facing downwards. 
   In a further embodiment, group  5  is formed with its apex facing upwards. In which case, hopper  6  is equipped with mechanical fingers (not shown) for selectively closing some of channels  14  to form, inside seats  10  and  11 , superimposed layers (not shown) of decreasing numbers of cigarettes  2  (i.e. layers in which the top layer comprises a smaller number of cigarettes  2  than the underlying layer). The pocket  21  of this further embodiment is shown in  FIG. 8 . 
   Though the above description relates to a packet  3  of ten cigarettes  2 , the teachings of the present invention obviously also apply to packets containing a different number of cigarettes  2 . 
   Purely by way of example,  FIGS. 12 and 13  show respective groups  5 ′ and  5 ″ of cigarettes  2  of two further shapes that can be produced and packed in accordance with the present invention. More specifically, group  5 ′ comprises twenty-one cigarettes  2 , and group  5 ″ twenty cigarettes  2 . 
   The above embodiments may also obviously be modified to form subgroups  12 ,  13  comprising a different number of layers of cigarettes  2 . More specifically, in an embodiment not shown, to form groups  5 ″ of twenty cigarettes  2 , each subgroup  12 ,  13  comprises three layers of cigarettes  2 . In which case, subgroup  12  comprises six, and subgroup  13  fourteen, cigarettes  2 .