Patent Publication Number: US-6666321-B2

Title: Conveying unit for transferring a mass of cigarettes

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a conveying unit for the transfer of cigarettes en masse, and more exactly to the conveying units used typically to link a cigarette maker with a cigarette packer. 
     Conventionally, in conveying units of the type in question, the means by which the cigarettes are supported and conveyed consist in bands or belts combining to create at least one channel, or in at least one channel element equipped with a conveyor by which the cigarettes are advanced. In both cases the cigarettes are disposed horizontally and en masse along the channel, and made thus to advance continuously in a direction transverse to their longitudinal axes. The channel originates from the cigarette maker and extends along a path composed generally of horizontal and vertical stretches and bends, and sometimes inclines, leading ultimately into a hopper from which the cigarettes are fed to the packer. 
     One condition necessary for the correct operation of the conveying unit, and therefore of the system as a whole, is that the quantity of cigarettes occupying the channel at any one time will be such as to exclude the risk of a break in continuity at the infeed of the packer, while ensuring also that the orderly arrangement of the cigarettes is not disrupted, especially along the bends and descent stretches of the conveyor. 
     Another condition necessary for correct operation is that there will be no pressures within the mass of cigarettes flowing along the channel that might occasion a jam in the channel and/or cause damage to the cigarettes. 
     The object of the present invention is to provide a conveying unit unaffected by the aforementioned drawbacks. 
     SUMMARY OF THE INVENTION 
     The stated object is realized in a conveying unit for transferring a mass of cigarettes, comprising at least one feed channel embodied at least in part as a conveyor by which the mass of cigarettes is advanced along a predetermined path and in a given direction toward the infeed stage of a user unit. 
     To advantage, the conveying unit according to the present invention is embodied with at least one movable wall defining at least one section of the channel and compassed between two ends of which one is fixed and the other movable. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which: 
     FIGS. 1 and 2 are two schematic side elevations of a conveying unit equipped with a movable wall embodied in accordance with the present invention, disposed respectively in two different operating conditions, illustrated with certain parts shown in section and others omitted for clarity; 
     FIG. 3 is a schematic sectional view taken on III—III in FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the drawings, FIGS. 1 and 2 show a conveying unit, denoted  1  in its entirety, by which a mass  2  of cigarettes  3  is transferred along a path P and in a direction D transverse to the longitudinal axes of the selfsame cigarettes, from a cigarette maker, not illustrated, to a user unit which in the particular example illustrated is represented by the infeed hopper  4  of a cigarette packer, likewise not illustrated. 
     It will be observed in FIGS. 1 and 2 that some cigarettes  3  of the mass  2  are omitted, purely in the interests of simplified graphic representation; the mass  2  in effect is essentially compact and homogeneous, and flows from the cigarette maker to the hopper  4  substantially without voids or gaps attributable to the absence of single cigarettes  3 . 
     The unit  1  comprises a feed channel  5  presenting a substantially rectilinear and horizontal first section  6  originating from the cigarette maker, a substantially vertical second section  7  leading to the mouth of the hopper  4 , and a curved section  8  interconnecting the aforementioned first and second sections  6  and  7 . The first rectilinear section  6  is delimited at the bottom by the top branch  9  of a belt conveyor  10  looped around pulleys of which one only, denoted  11 , is illustrated in the drawings, located near the mouth of the curved section  8  and mounted to a shaft  12  with a transversely disposed axis driven by a relative motor  13 . The conveyor  10  serves to advance a continuous flow of cigarettes  3  along the path P and into the mouth of the curved section  8 . The channel  5  is delimited uppermost by a fixed wall  14  of which only the final part can be seen in the drawings, and thereafter, considered in the conveying direction D along which the flow of cigarettes  3  is advanced, by a movable rectilinear restraint  15  coinciding with the end portion of the rectilinear horizontal first section  6 . The curved section  8  and the successive vertical section  7  are delimited on the inside by respective fixed curved and vertical walls  16  and  17 , and on the outside by a second movable restraint  18  of arched profile, associated pivotably at the upstream end by way of an intermediate hinge  19  with the free end of the first movable restraint  15 , of which the remaining end directed toward the fixed wall  14  is pivotably associated with a movable hinge  20  connected to the top end of a bracket  21  mounted to a guided slide device  22  capable of movement parallel to the top branch  9  of the conveyor  10 . Finally, the end of the arched second restraint  18  remote from that connected to the intermediate hinge  19  is anchored pivotably to a fixed hinge  23  located near to the connection between the end of the channel  5  and the mouth  24  of the hopper  4 . 
     As discernible from FIGS. 1,  2  and  3 , the aforementioned guided slide device  22  comprises a pair of rods  25  extending parallel to the branch  9  of the conveyor  10  and occupying a common vertical plane, each fixed to the bracket  21  at one end. The rods  25  slide internally of a guide block  26  fixed to a lateral bulkhead  27  of the unit  1 . 
     The two restraints  15  and  18  combine to create a movable wall  28  which in its turn constitutes an articulated mechanism  29  able to assume infinitely variable intermediate positions between a first limit position in which the first restraint  15  lies substantially parallel with the top branch  9  of the conveyor  10 , and a second limit position in which the selfsame restraint  15  is inclined at a given angle as a result of rotating clockwise, as seen in FIGS. 1 and 2, about the aforementioned movable hinge  20 . In the first of the two limit positions assumed by the rectilinear first restraint  15 , the bracket  21  occupies a retracted position and the arched second restraint  18  is disposed with an initial rectilinear portion aligned on a terminal portion of the first restraint  15 , as illustrated in FIG. 1, whilst in the second, the bracket  21  occupies a forward position and the arched second restraint  18  is rotated counterclockwise relative to the fixed hinge  23 , as seen in FIGS. 1 and 2, to the point at which an angle of predetermined width, centered on the intermediate hinge  19 , is compassed between the initial portion of the arched second restraint  18  and the terminal portion of the rectilinear first restraint  15 . The two resulting limit positions of the movable wall  28  correspond respectively to configurations of minimum capacity and maximum capacity afforded by the relative part of the channel  5 . 
     In particular, the unit  1  comprises a sensor  30  associated with the guided slide device  22 , wired on the output side to a master controller  31  which is connected in turn to the motor  13 . The sensor  30  is able at any given moment to detect the position of the rods  25  in relation to the guide block  26 , hence the position assumed by the movable hinge  20 , and thus to furnish the controller  31  with a signal that indicates the current position of the movable wall  28 . On the basis of these same signals, the controller  31  will proceed to regulate the speed of the motor  13 , hence also of the conveyor  10 , and in this way control the rate at which the cigarettes  3  are advanced along the channel  5 . 
     Regarding operation, it will be appreciated that the articulated mechanism  29  incorporating the two movable restraints  15  and  18 , embodied in rigid material and presenting a smooth inner surface to the mass  2  of cigarettes  3 , is structured in such a manner as to shift between the two limit positions without offering resistance and without applying any significant pressure to the flow of the mass  2  of cigarettes advancing along the channel  5 . 
     The invention thus affords an extremely sensitive system that allows the articulated mechanism  29  to move toward the limit position corresponding to the maximum capacity of the channel  5  in the event of the mass  2  of cigarettes  3  swelling in volume along the section occupied by the movable wall  28 , and then to return toward the position corresponding to the minimum capacity of the channel  5  when there is a reduction in volume of the mass  2  of cigarettes  3  along the selfsame section occupied by the wall  28 . These movements will be generated swiftly, and in response to the slightest variations in flow. 
     To increase the sensitivity and speed of response afforded by the system, the unit  1  can be equipped with spring means of suitable design operating in conjunction with the aforementioned guided slide device and serving to assist the movement of the device toward the limit positions described above, in one direction and/or in the other. 
     To this end, for the sole purpose of clarifying the concept in question, FIGS. 1 and 2 indicate a spring  33  operating between the bracket  21  and a fixed point on the guide block  26 , such as will exert a pulling force parallel to the flow path P and in the conveying direction D, favoring the movement of the wall  28  toward the position that coincides with maximum capacity of the channel  5 . Clearly, the spring  33  could also be installed so as to operate between the bracket  21  and a fixed point on the side of the bracket opposite to that illustrated, in such a way as to exert a force parallel to the flow path P but in the direction opposite to the conveying direction D, favoring the return of the wall  28  to the position coinciding with the minimum capacity of the channel  5 . 
     Moreover, during the movements of the articulated mechanism  29  described above, the slide device  22  functions also as a device  32  serving to support and stabilize the movable wall  28  in each of the positions assumed, so that the selfsame wall will not exert any significant pressures on the mass  2  of cigarettes  3 .