Abstract:
A method of conveying articles provides for feeding an article to a pocket travelling along a conveying path; gripping the article by means of suction holes located along a plate of the pocket; feeding the article and the pocket along the path; releasing and pushing the article against a locating member of the pocket as the article and the pocket are advanced; and gripping the article to the plate by means of the suction holes.

Description:
[0001]    The present invention relates to a method of conveying articles.  
           [0002]    More specifically, the present invention relates to a method of conveying blanks by which to produce packets of cigarettes, to which the present invention refers purely by way of example.  
         BACKGROUND OF THE INVENTION  
         [0003]    Blanks are normally supplied successively to respective pockets on a packing machine conveyor, and are fed along a given path, along which, they are paired with respective groups of cigarettes wrapped beforehand in sheets of foil. Once paired with a respective group, the blank is folded about the group by folding members on the packing machine.  
           [0004]    The blank is made of cardboard, and comprises tabs and flaps defined by cuts and crease lines. The crease lines are defined by incisions made in the cardboard, and which act as hinges about which the tabs and flaps are folded.  
           [0005]    It is essential, therefore, that each blank be set to a given position with respect to the group and the folding members to prevent the group from being placed on the crease lines, or the folding members from folding portions of the blank not meant to be folded.  
         SUMMARY OF THE INVENTION  
         [0006]    It is an object of the present invention to provide a method of conveying articles, designed to eliminate the aforementioned drawbacks, and which provides for positioning each article correctly with respect to the pocket.  
           [0007]    According to the present invention, there is provided a method of conveying articles, comprising the steps of feeding an article to a pocket travelling along a given path; retaining said article by gripping means associated with said pocket; and feeding the article along said path in a given direction by means of said pocket; the method being characterized by releasing said article from said gripping means, and pushing the article against a locating member of said pocket as said article is advanced.  
           [0008]    The present invention also relates to a conveyor for conveying articles.  
           [0009]    According to the present invention, there is provided a conveyor for conveying articles, the conveyor comprising a pocket movable in a direction along a given path, and gripping means associated with said pocket to retain said article; and the conveyor being characterized by comprising folding devices located along the path and cooperating with said gripping means and with a locating member associated with said pocket. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:  
         [0011]    [0011]FIG. 1 shows a schematic side view of a conveyor for implementing the present invention;  
         [0012]    [0012]FIG. 2 shows a larger-scale view in perspective, with parts in section and parts removed for clarity, of a detail of the FIG. 1 conveyor;  
         [0013]    [0013]FIG. 3 shows a plan view, with parts in section and parts removed for clarity, of the FIG. 2 detail;  
         [0014]    [0014]FIGS. 4, 5 and  6  show side views, with parts in section and parts removed for clarity, of the FIG. 1 conveyor at different operating steps;  
         [0015]    [0015]FIG. 7 shows a view in perspective of an article conveyed by the FIG. 1 conveyor. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]    Number  1  in FIG. 1 indicates as a whole a conveyor of a packing machine (not shown) for packing cigarettes (not shown).  
         [0017]    Conveyor  1  is supported by a frame T, and comprises a drum  2  rotating about an axis  3 ; a number of gripping members  4  equally spaced about axis  3  (perpendicular to the FIG. 1 plane) and movable in a direction D 1  along a conveying path P of cardboard blanks  5 ; a guide  6  parallel to a portion of path P; and folding members  7  located along path P at guide  6 . Each blank  5  is fed to a gripping member  4  of conveyor  1  at a feed station  8  located upstream from guide  6  in direction D 1 , and is paired with a group  9  of cigarettes, wrapped beforehand in a sheet of foil, at a pairing station  10  located downstream from guide  6  in direction D 1 .  
         [0018]    With reference to FIG. 7, blank  5 , when flat, extends along and is symmetrical with respect to an axis A, and comprises a front panel  11 , a bottom panel  12 , a rear panel  13 , a top panel  14 ; and a front lid panel  15 . Tabs  16 ,  17 ,  18 ,  19  and  20  extend from panels  11 ,  13  and  15 ; panels  11 - 15  and tabs  16 - 20  are bounded by crease lines  21  parallel to axis A, and by crease lines  22  perpendicular to axis A; and a flap  23  extends from each tab  17 , and is bounded with respect to tab  17  by a crease line  24 . Similarly, a flap  25  extends from each tab  18 , and is bounded with respect to tab  18  by a crease line  26 . Crease lines  21 ,  22 ,  24  and  26  are substantially incisions made in the cardboard of blank  5 , and serve to fold panels  11 - 15 , tabs  16 - 20 , and flaps  23  and  25  easily with respect to adjacent panels  11 - 15  and/or tabs  17  and  18 . In other words, crease lines  21 ,  22 ,  24  and  26  act as hinges.  
         [0019]    With reference to FIGS. 2 and 3, each gripping member  4  comprises a rod  27  connected to drum  2 ; a plate  28  fitted to rod  27  and having suction holes  29 ; two folding devices  30  and  31  hinged to plate  28  about respective axes  32  and  33  parallel to axis  3 ; and a locating member  34  integral with plate  28 . Gripping member  4  comprises known mechanisms, not shown, for rotating the two folding devices  30  and  31  about respective axes  32  and  33 . That is, member  4  comprises a variable-configuration pocket  35  defined by plate  28  and the two folding devices  30  and  31 , which can be positioned substantially coplanar with plate  28 , perpendicular to plate  28 , or in intermediate positions between the coplanar and perpendicular positions.  
         [0020]    Locating member  34  comprises three teeth  36  located downstream from plate  28  in direction D 1 , and each having a free end  37  bent outwards of drum  2  and engaging a respective opening  38  in folding device  31 .  
         [0021]    Guide  6  is in the form a cylindrical shell sector, which has an inner face  39  facing drum  2 . Two grooves  40  are formed along face  39 , extend parallel to path P, and provide for housing flaps  23  and  25  folded with respect to the rest of blank  5 , and part of folding member  7 ; and three grooves  41  are also formed along face  39 , extend parallel to path P, between grooves  40 , and provide for housing ends  37  of teeth  36 . That is, face  39  faces plates  28  of gripping members  4  travelling along guide  6 .  
         [0022]    With reference to FIG. 2, folding member  7  comprises a drive member  42 ; a shaft  43  parallel to axis  3  and rotated by drive member  42 ; and two shafts  44  parallel to and rotated by shaft  43 , and having a folding devices  45  having lobes  46  for squarely folding flaps  23  and  25 . Each folding device  45  is located between guide  6  and drum  2 , and is synchronized with pockets  35  so that each lobe  46  folds a respective flap  23  or  25 .  
         [0023]    In actual use, each blank  5  is fed to a respective pocket  35  at feed station  8 , and is gripped by plate  28  by means of suction holes  29 , as shown in FIG. 1. With reference to FIGS. 2 and 3, the blank  5  feed step comprises seating blank  5  inside the open pocket  35  with axis A of blank  5  substantially parallel to axis  3  of drum  2 , with panel  13  on plate  28 , and with tabs  17  and  18  at the two folding devices  30  and  31 . Drum  2  is rotated continuously, and blank  5  is fed to pocket  35  without stopping gripping member  4  at feed station  8 , so that blank  5  is positioned substantially accurately in a direction parallel to axis  3 , but not so in travelling direction D 1 .  
         [0024]    When pocket  35  faces guide  6 , the suction through holes  29  is cut off, and blank  5  is kept along path P by guide  6  and is free to move with respect to pocket  35 . One movement along path P may be induced by the drag of blank  5 , so as to push blank  5  against ends  37  of teeth  36  of locating member  34 . Since, however, the drag of blank  5  may not be enough to produce a sliding movement in direction D 1  between blank  5  and pocket  35 , blank  5  is conveyed without being retained by respective pocket  35  through the region occupied by folding member  7 , which folds flaps  23  and  25 .  
         [0025]    Flaps  23  and  25  total four in number, and comprise two front flaps  23  and  25 , i.e. upstream from plate  28  in direction D 1 , and two rear flaps  23  and  25 , i.e. downstream from plate  28  in direction D 1 . More specifically, and with reference to FIG. 4, lobes  46  are timed with front flaps  23  and  25  of a blank  5  theoretically positioned correctly. In FIG. 5, lobes  46  gradually come into contact with and begin folding front flaps  23  and  25  about lines  24  and  26 . At this stage, even if blank  5  is still some distance from ends  37 , i.e. is not positioned correctly inside pocket  35 , blank  5  is pushed against ends  37  by lobes  46  as they begin folding front flaps  23  and  25 .  
         [0026]    Since both lobes  46  act simultaneously on the two front flaps  23  and  25 , there is no danger of misalignment of axis A of blank  5  with respect to axis  3  of drum  2 . Once the two front flaps  23  and  25  are folded, the suction through holes  29  is reactivated to grip blank  5  in the definitely correct position, so that lobes  46 , as shown in FIG. 6, are timed with the two rear flaps  23  and  25 , which are folded squarely with respect to the rest of blank  5 .  
         [0027]    Subsequently, a group  9  is paired with blank  5  at station  10 , and tabs  17  and  18  are folded by folding devices  30  and  31 , together with flaps  23  and  25  already folded squarely with respect to tabs  17  and  18 . In addition to folding flaps  23  and  25 , folding devices  45  therefore also act as contrasting members by which to push blank  5  against locating member  34 .