Abstract:
In a method and an apparatus for filling containers with rod-shaped articles a hopper for feeding the articles includes at least two mouths for dispensing the articles through respective lower ends, a conveyor device located in the vicinity of the at least two dispensing mouths The conveyor device includes two conveyors placed side by side and designed to operate independently on the containers supported by the conveyor device, and respective motors mechanisms are associated with the two conveyors so that one of the two conveyors moves towards the hopper the empty containers carried on the conveyor device from the dispensing apparatus, and the other of the two conveyors moves away from the hopper the containers full of rod-shaped articles.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates to a method and an apparatus for filling containers with rod-shaped articles. 
         [0002]    More specifically, this invention addresses the tobacco industry and has for its objects a method and an apparatus for filling containers, in particular cardboard boxes, with rod-shaped articles consisting, for example, of cigarettes, filters, filter tubes (tubes of paper with a filter at one end and designed to be filled with tobacco by the smoker). 
         [0003]    Hereinafter in this description, reference is made to the handling of rod-shaped articles consisting of cigarettes, without thereby restricting the scope of the invention. 
         [0004]    In apparatuses of known type for filling containers with cigarettes, the groups of cigarettes to be packaged are usually formed using a vertical hopper into which the cigarettes are fed through an opening at the top of it. The bottom portion of the hopper is divided into a plurality of mouths arranged side by side horizontally and each divided by a plurality of walls into substantially vertical channels arranged side by side horizontally and designed to receive respective stacks of cigarettes reciprocally superposed. Groups of cigarettes, or layers which are then placed on top of one another to form the groups, are removed from the bottom portion of each hopper mouth by suitable pick-up and transport elements and these groups or layers are directed to a packaging station where they are packed in boxes intended to contain a plurality of layers of cigarettes on top of one another. In the packaging station there is usually a plurality of boxes which are filled with cigarettes simultaneously while they occupy respective dwell positions, so that the apparatus can attain as high a production speed as possible. 
         [0005]    Apparatuses of this kind present critical situations connected with synchronizing the movements of the empty boxes which must be conveyed to the packaging station and of the full boxes which must remain stationary at the station for a relatively extended length of time during filling. Indeed, it is normal practice for a single conveyor to support and move both the empty boxes and those being filled, and the relatively extended length of time during which the boxes being filled need to remain stationary does not allow the conveyor to be supplied with the necessary quantity of empty boxes, since the conveyor does not move during this time. For the empty boxes to be supplied, therefore, it is normally necessary to wait for the conveyor start moving again after the boxes present at the packaging station have been filled completely. This necessity contrasts with endeavors to allow prior art apparatuses to operate at high production speeds. 
       SUMMARY OF THE INVENTION 
       [0006]    This invention has for an aim to provide a method and an apparatus for filling containers with rod-shaped articles capable of overcoming the above mentioned drawback. 
         [0007]    The invention accordingly provides a method and an apparatus for filling containers with rod-shaped articles, as described in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The invention is described below with reference to the accompanying drawings, which illustrate a non-limiting embodiment of it, and in which: 
           [0009]      FIG. 1  is a schematic front view of an apparatus for filling containers with rod-shaped articles, made according to this invention; 
           [0010]      FIG. 2  is a schematic plan view of the apparatus of  FIG. 1 ; 
           [0011]      FIG. 3  is a schematic elevation view of certain details of the apparatus of  FIGS. 1 and 2 ; 
           [0012]      FIG. 4  is a schematic perspective view of certain details of the apparatus of  FIGS. 1 and 2 ; and 
           [0013]      FIG. 5  is an axonometric view of a container for rod-shaped articles to be filled by the apparatus of  FIGS. 1-4 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    The numeral  1  in  FIG. 1  denotes in its entirety an apparatus for filling containers  8  with rod-shaped articles, consisting for example of cigarettes  2 . 
         [0015]    By way of an example and with reference to  FIG. 5 , the containers  8  comprise a parallelepiped shaped box  8   a  whose hollow interior faces up and which is defined by a base  8   b,  a rear wall  8   c,  a front wall  8   d  and two side walls  8   e.  The walls  8   c,    8   d  and  8   e  are vertical, and the upper edges of the side walls Se are integral, by way of respective folding lines of weakness, with two side flaps  8   f  folded squarely towards each other. The upper edge of the rear wall  8   c  is integral, by way of a folding line of weakness, with a lid  8   g  which is the same size as the base  8   b  and which is integral, at the front by way of a folding line of weakness, to a flap  8   h  folded squarely and designed to be tucked into the mouth at the top of the box  8   a.    
         [0016]    The apparatus  1  comprises a vertical hopper  3  operating at a station  3 ′ for filling the containers  8  and whose lower portion comprises at least two mouths  4  for dispensing cigarettes  2  and is preferably subdivided into a plurality of mouths  4  positioned side by side horizontally (three in the embodiment illustrated). Each mouth  4  is subdivided by a plurality of walls  5  substantially vertical and parallel to each other in a plurality of substantially vertical channels  6  positioned side by side horizontally, each of which is designed to accommodate internally a stack  2  of cigarettes reciprocally superposed; 
         [0017]    Transfer or extractor elements, denoted in their entirety by the numeral  11  ( FIG. 2 ) extract layers  12  of cigarettes  2  in succession from the bottom ends of the channels  6 , at the bottom portion of each mouth  4  of the hopper  3  and insert these layers  12  into containers  8  carried by a conveyor  9 , which directs the containers  8 , in a manner described in more detail below, to a further handling station of essentially known type schematically represented as a block  10 . The transfer elements  11  may be of any suitable type and are not illustrated or described since they do not form the object of this invention. 
         [0018]    The station  10  comprises (for example) a station  13  for folding the side flaps  8   f,  followed by a station  14  (optional) for inserting coupons (not illustrated) into the boxes  8   a,  a station  15  for closing the lids  8   g  of the boxes  8   a,  and a station  16  for stabilizing the full, closed boxes  8   a  and comprising, for example, a compressing roller conveyor (not illustrated) designed to facilitate drying of the adhesive on the boxes  8   a  and to stabilize the shape of the boxes  8   a.    
         [0019]    As shown in  FIGS. 3 and 4 , the conveyor  9  comprises two identical belt conveyors  17  and  18  running side by side along identical paths comprising respective upper horizontal transport paths  17 ′,  18 ′ wound in a loop around respective pairs of pulleys  19  and  20  (only the ones on the right being shown in  FIG. 4 ) rotatable about horizontal axes. The pulleys  19  of the two conveyors  17  and  18  are coaxial and are power driven by respective motor means  21  and  22 . Similarly, the pulleys  20  are coaxial. Each of the motor means  21  and  22  comprises a stepping motor not illustrated (or other kind of motor offering similar performance) driven by a control circuit of known type (also not illustrated) which allows variable motion to be imparted to the motors  21  and  22  independently of each other, with respective laws of motion which are better specified below. As shown in  FIG. 3 , the upper transport branches  17 ′,  18 ′ run side by side along respective contiguous flanks, whilst the other flanks run alongside respective strips  23  having an L-shaped cross section and extending parallel to the upper transport branches  17 ′,  18 ′ themselves, and each having a horizontal wing  24  lying in the same plane as the transport branches  17 ′,  18 ′ and an upwardly directed vertical wing which, in use, runs alongside and in contact with one side of the containers  8  being carried. 
         [0020]    The belt conveyors  17  and  18  are provided, on their peripheral transport surfaces  25 , with a plurality of projections or accompanying elements  26  which follow each other along the direction of extension of the peripheral transport surfaces  25 . The accompanying elements  26  are not distributed uniformly along the peripheral transport surface  25  since on each peripheral surface  25  there are stretches  27  of predetermined length having on them a sequence of accompanying elements  26  equal in number to the number of mouths  4  of the hopper  3 , alternated with stretches  28  of the same length without any accompanying elements  26  on them Further, the stretches  27  with accompanying elements  26  on each of the conveyors  17 ,  18  are placed alongside the stretches  28  without accompanying elements  26  on the other conveyor  18 ,  17 . It should be noted that each accompanying element  26  might be associated with a positioning element  26 ′ ( FIG. 1 ) comprising a projection positioned downstream of the accompanying element  26  with reference to the direction of feed of the belt conveyors  17 ,  18 , at a distance from the accompanying element  26  which is slightly greater than the dimension of the containers  8  measured according to the direction of feed. The function of each positioning element  26 ′ is to act in conjunction with an accompanying element  26  associated therewith in order to better define the position of the containers  8  carried by the conveyors  17 ,  18 . 
         [0021]    Upstream of the hopper  3  with reference to the transporting direction of the conveyor  9 , alongside and in the proximity of the conveyor  9  itself, there is an apparatus  29  for forming and dispensing the containers  8 , capable of forming containers  8  from cardboard blanks (not illustrated) and feeding them one at a time towards the conveyor  9 , in a manner that will become clearer as this description continues, to a dispensing station  30 . For reasons that will become clearer as this description continues, the outfeed section of the apparatus  29  is located, with reference to the feed direction of the conveyor  9 , at a distance from the hopper  3  not less than the length of a portion of the conveyor  9  carrying a number of consecutive containers  8  equal to the number of mouths  4  of the hopper  3  itself. 
         [0022]    Described below is the operation of the apparatus  1  starting from the moment when three containers  8 , which have been brought by the conveyor  9  to the filling station  3 ′, are stationary in the proximity of respective mouths  4  of the hopper  3 , and the conveyor  9  has no other containers  8  on it. The lids  8   g  of the containers  8  being filled are raised and, if necessary, directed backwards, and the container sidewalls  8   e  are directed upwards. 
         [0023]    In this situation, the transfer elements  11  extract the layers  12  of cigarettes  2  from the bottom ends of the channels  6 , at the bottom portion of each mouth  4  of the hopper  3 , and place the layers  12  into the waiting containers  8  in front of the hopper  3 . Respective accompanying elements  26  associated with the conveyor  17  are adjacent to the containers  8  being filled and the conveyor  17  is stationary. 
         [0024]    While these containers  8  are being filled, the apparatus  29  erects other containers  8  and delivers a first one immediately downstream of, and in contact with, the most advanced (with reference to the feed direction of the conveyor  9 ) of the accompanying elements  26  of the conveyor  18  forming part of a sequence of accompanying elements  26  which are stationary at the dispensing station  30 . After that container  8  has been placed in contact with an accompanying element  26 , the motor means  22  set the conveyor  18  in motion and cause it to move forward one step whose length is such that the accompanying element  26  immediately following the one just associated with a container  8  is brought to the dispensing station  30 . A container  8  is then dispensed by the apparatus  29  and brought into contact with the accompanying element  26  and the motor means  22  are started once again in the same way as just described to move another accompanying element  26  into the dispensing station  30  so that it, too, is associated with a container  8 . 
         [0025]    During these movements of the conveyor  18 , the filling of the stationary containers  8  at the filling station  3 ′ is in no way disturbed since the stretch of the conveyor  18  under these containers  8  has no accompanying elements  26  on it and does not act on these containers  8  in any way. 
         [0026]    When the containers  8  in the station  3 ′ have been filled and the apparatus  29  has placed three containers  8  in contact with respective accompanying elements  26  forming part of the sequence of the accompanying elements  26  waiting in the proximity of the dispensing station  30 , the conveyor  17  is started by the motor means  21  and pushes the containers  8  just filled towards the further handling station  10 , whilst the conveyor  18  is started to bring into the filling station  3 ′ the containers  8  which were placed on the conveyor  9  of the apparatus  29 . 
         [0027]    In practice, the latter operations cause the roles of the conveyors  17  and  18  to be temporarily reversed compared to what has been described up to now, since the containers  8  which are now located in the proximity of the dispensing station  30 , that is, in front of the hopper  3 , are in contact only with a sequence of accompanying elements  26  associated with the conveyor  17  itself, while in the proximity of the dispensing station  30  there is a sequence of accompanying elements  26  associated with the conveyor  18  and downstream of which, with reference to the feed direction of the conveyor  9 , there is a stretch of the conveyor  18  without accompanying elements  26  on it. Thus, the operations described above of filling three containers  8  with cigarettes  2  and placing three empty containers  8  on the conveyor  9  occur, during this operating cycle, with the conveyor  18  acting on the containers  8  being filled and the conveyor  17  acting on the empty containers  8  arriving from the apparatus  29 . When this operating cycle has been completed in the same way as described above, the apparatus  1  is back to the operating situation the above description started from. 
         [0028]    From the foregoing, it is evident that the apparatus  1  described overcomes in a simple and effective manner the drawback described above with reference to the prior art, since the presence, design and operating mode of the conveyors  17  and  18  allow the apparatus  1  to minimize idle time, thereby appreciably increasing production speed.