Abstract:
A device for controlling a mass of cigarettes, and having a conveyor system for feeding the cigarettes in bulk along a path from a cigarette manufacturing machine to a cigarette packing machine; and an operating unit for both determining and at least partly compensating differences between the cigarette production and packing rates; the operating unit having an arm with a number of articulated segments.

Description:
[0001]     The present invention relates to a device for controlling a mass of cylindrical articles.  
         [0002]     More specifically, the present invention relates to a device for controlling a mass of cylindrical articles, and comprising conveying means for conveying the cylindrical articles transversely along a path from an input station to an output station via at least one intermediate station located between the input station and the output station. The device also comprises an operating unit located at the intermediate station to determine variations in the quantity of cylindrical articles along the path caused by differences between the number of cylindrical articles fed through the input station and unloaded through the output station.  
         [0003]     In the following description, said cylindrical articles are considered cigarettes, purely by way of a non-limiting example.  
       BACKGROUND OF THE INVENTION  
       [0004]     The device described above has the drawback of normally failing to effectively control relatively rapid variations in the quantity of cigarettes. In this respect, it is important to note that the device described above is often connected to a spiral compensating store, which has the advantage of relatively high maximum capacity, but the drawback of not always being able to compensate sharp differences in in-out quantities.  
         [0005]     To eliminate the above drawbacks, Patent Application GB 2133759 proposes using a further compensating store smaller in size and capacity than the spiral store but capable of more rapidly compensating sharp variations in the quantity of cylindrical articles. The presence of an additional store, however, makes the device more complex and therefore more expensive to produce.  
       SUMMARY OF THE INVENTION  
       [0006]     It is an object of the present invention to provide a device for controlling a mass of cylindrical articles designed to eliminate the aforementioned drawbacks, and which, in particular, is cheap and easy to produce.  
         [0007]     According to the present invention, there is provided a device as claimed in the attached Claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:  
         [0009]      FIG. 1  shows a schematic view of a device in accordance with the present invention;  
         [0010]      FIG. 2  shows a larger-scale detail of the  FIG. 1  device in different operating positions;  
         [0011]      FIG. 3  shows a larger-scale section along line III-III of the  FIGS. 1 and 2  device. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]     Number  1  in  FIG. 1  indicates as a whole a device for controlling a mass of cigarettes (not shown). Device  1  comprises a conveyor system  2  for conveying the mass of cigarettes transversely along a path P from an input station  3 —equipped with a manufacturing machine (not shown) for producing cigarettes (not shown)—through an intermediate station  4 —located at a curved portion of path P—to an output station  5 —equipped with a packing machine, of which a cigarette hopper  6  is shown.  
         [0013]     Device  1  also comprises an operating unit  7  located at intermediate station  4  to determine variations in the quantity of cigarettes along path P caused by differences between the number of cigarettes fed onto path P by the manufacturing machine (not shown) and the number of cigarettes used up by the packing machine.  
         [0014]     Operating unit  7  comprises a variable-volume store  8  bounded laterally by a fixed wall  9  and at the top by a movable arm  10 . Arm  10  rotates about an axis  11  substantially parallel to the cigarettes (not shown) along path P, and comprises a segment  12  hinged by an articulation  13  to a frame  14  (shown partly) of device  1 , and a segment  15  hinged by an articulation  16  to segment  12  to rotate about an axis  17  ( FIG. 2 ) substantially parallel to axis  11 . Frame  14  supports conveyor system  2 .  
         [0015]     Articulation  16  comprises a projection  18  integral with segment  15 , and which extends from segment  15  to a point beyond axis  17  to limit upward rotation of segment  15  about axis  17  by engaging a top surface of segment  12 .  
         [0016]     With reference to  FIG. 3 , at the opposite end to articulation  16 , segment  15  has a number of substantially parallel slits  19 .  
         [0017]     Wall  9  also has a number of slits  20  substantially parallel to slits  19 ; and wall  9  and segment  15  are positioned and designed to penetrate mutually. That is, arm  10  extends from axis  11  to a point beyond wall  9  and through wall  9 .  
         [0018]     With particular reference to  FIG. 2 , arm  10  also comprises a sliding member  21  (more specifically, a small wheel) located in a fixed position along segment  15 , on the opposite side of wall  9  to axes  11  and  17 , and which limits downward rotation of segment  15  about axis  17  by coming to rest on, and sliding along, wall  9 .  
         [0019]     Device  1  also comprises a known spiral compensating store  22  ( FIG. 1 ) of relatively high capacity greater than that of store  8 .  
         [0020]     Finally, device  1  comprises a control unit  23  (shown schematically in  FIG. 2 ) connected to operating unit  7 , to conveyor system  2 , and to compensating store  22  (the connection between control unit  23  and compensating store  22  is not shown), and which regulates operation of conveyor system  2  and of compensating store  22  on the basis of variations in the quantity of cigarettes (not shown) along path P as determined by operating unit  7 . More specifically, control unit  23  is connected to a sensor  24  (e.g. a potentiometer or encoder) of operating unit  7 , and sensor  24  is in turn connected to segment  12  at axis  11  to measure rotation of segment  12  about axis  11 .  
         [0021]     Operation of device  1  will now be described as of a balanced condition, i.e. in which the number of cigarettes (not shown) fed by the manufacturing machine (not shown) through input station  3  substantially equals the number of cigarettes (not shown) transferred from path P to the packing machine (shown partly) through output station  5 .  
         [0022]     In the above condition, arm  10  remains in a substantially fixed position (e.g. position A shown by the dash line in  FIG. 2 ), conveyor system  2  operates at substantially constant speed, and compensating store  22  remains idle.  
         [0023]     When the number of cigarettes (not shown) fed through input station exceeds the number of cigarettes (not shown) transferred through output station  5 , arm  10  moves up to allow an increase in the volume of cigarettes inside store  8 . More specifically, segment  12  rotates upwards about axis  11 , possibly into a maximum-rotation position B shown by the continuous line in  FIG. 2  and defined by stop members (not shown). If the cigarettes (not shown) along path P continue increasing, segment  15  rotates upwards about axis  17  until it reaches a maximum-rotation position C shown by the dash line in  FIG. 2 ; at which point, store  8  is filled to capacity.  
         [0024]     It should be pointed out that, as long as segment  12  rotates about axis  11 , sliding member  21  rolls along wall  9  to limit downward rotation of segment  15  about axis  17 . When arm  10  reaches position B and store  8  continues filling up, sliding member  21  is detached from wall  9  by rotation of segment  15  about axis  17 .  
         [0025]     When the number of cigarettes (not shown) transferred through output station  5  exceeds the number of cigarettes (not shown) fed through input station  3 , arm  10  moves down alongside the outflow of cigarettes (not shown) from store  8 . More specifically, segment  12  rotates downwards about axis  11 , possibly into a minimum-rotation position indicated D and shown by the dash line in  FIG. 2 . It should be pointed out that, even when arm  10  is in position D, the mass of cigarettes (not shown) can still be fed along path P. In other words, arm  10  in position D does not completely obstruct the passage from input station  3  to output station  5 .  
         [0026]     As segment  12  rotates about axis  11 , sensor  24  transmits a signal to control unit  23 , which, in known manner, accordingly regulates the speed of conveyor system  2  and possibly activates compensating store  22 . More specifically, when segment  12  rotates upwards, the speed of the conveyors upstream from intermediate station  4  is reduced, and the speed of the conveyors downstream from intermediate station  4  is increased. Conversely, when segment  12  rotates downwards, the speed of the conveyors upstream from intermediate station is increased, and the speed of the conveyors downstream from intermediate station  4  is reduced.  
         [0027]     By comprising an arm  10  with two articulated segments  12  and  15 , operating unit  7  is able to compensate fairly substantial variations in the quantity of cigarettes (not shown) along path P, and allows relatively gradual flow of the cigarettes to and from store  8 , thus reducing potential damage of the cigarettes (not shown).  
         [0028]     In this respect, it is important to note that compensating store  22  is only activated by control unit  23  upon sensor  24  indicating relatively sharp variations and/or when store  8  is almost completely full and/or completely empty.  
         [0029]     Though the above description relates to controlling cigarettes, device  1  may obviously be used to advantage for controlling other cylindrical articles, such as cigars and/or filters.