Abstract:
The outfeed unit of a cigarette maker establishes a feed path along which at least one cigarette rod is caused to advance in a predetermined direction from the outfeed end of a beam, on which the rod is formed, toward a cutter device by which the rod is divided into sticks constituting single cigarettes; the unit is equipped with a cut-off device located in close proximity to the outfeed of the forming beam, by which the rod is severed and diverted from the feed path, and, at a given point downstream of the cut-off device, with pinch rollers by which a portion of the rod separated through the action of the cut-off device is removed from a final stretch of the feed path between the cut-off device and the cutter device.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to an outfeed unit in a cigarette maker.  
           [0002]    Machines for making cigarettes comprise a unit serving to shape and advance a continuous ribbon of tobacco filler drawn from a tobacco feeder device, and a unit serving to feed a continuous strip of paper which is directed onto and along a forming beam and wrapped progressively around the ribbon of tobacco filler to form a continuous cigarette rod. On reaching an outfeed unit of the machine, the cigarette rod is advanced along a predetermined feed path at a predetermined speed, passing through a succession of quality control devices and into a cutting station where it is divided into cigarette sticks of predetermined length by a rotary cutter device.  
           [0003]    Conventionally, when the machine is started and stopped, and in certain circumstances during normal operation, the need may arise to activate a cut-off device located between the beam and the quality control devices, in order to separate a portion of the cigarette rod and divert it from the feed path toward a reject station.  
           [0004]    The cut-off device in question is interlocked to the aforementioned quality control devices and will be activated in the event of the selfsame devices detecting properties or defects in the cigarette rod such as render it unsuitable for the production of single cigarettes.  
           [0005]    Following the operation of the cut-off device, the length of cigarette rod remaining between the selfsame cut-off device and the rotary cutter must be removed manually so that normal operation of the machine can be resumed. The task of removing this fragment of cigarette rod is a complex one, since besides opening up the casing of the machine it may also be necessary to disturb the quality control devices, dismantling them in part and occasioning lengthy periods of inactivity as a result.  
           [0006]    The object of the present invention is to provide an outfeed unit for a cigarette maker such as will be unaffected by the aforementioned drawbacks.  
         SUMMARY OF THE INVENTION  
         [0007]    The stated object is duly realized according to the present invention in a cigarette maker outfeed unit comprising a feed path along which at least one cigarette rod is advanced in a predetermined direction, extending between the outfeed end of a beam on which the cigarette rod is formed and a cutter device by which the continuous cigarette rod is divided into discrete sticks constituting single cigarettes, also a cut-off device positioned in close proximity to the forming beam and capable of movement between a position of disengagement from the feed path, and a position of interference with the selfsame path in which the rod is cut and diverted from the path, characterized in that it comprises removal means by which a portion of the continuous cigarette rod separated through the action of the cut-off device is distanced from a final stretch of the feed path extending between the cut-off device and the cutter device.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which:  
         [0009]    [0009]FIG. 1 shows an outfeed unit of a cigarette maker, embodied in accordance with the present invention, viewed schematically in a side elevation with certain parts in section and others omitted for clarity;  
         [0010]    [0010]FIG. 2 is an enlarged detail of FIG. 1, viewed schematically in a side elevation and with certain parts omitted for clarity;  
         [0011]    [0011]FIG. 3 shows the enlarged detail of FIG. 2 in a second possible embodiment, viewed schematically in a side elevation and with certain parts omitted for clarity;  
         [0012]    [0012]FIGS. 4 and 5 show a detail of the unit as in FIG. 1 illustrated in two different embodiments, viewed schematically in front elevation and side elevation, respectively, and with certain parts omitted for clarity;  
         [0013]    [0013]FIG. 6 illustrates the detail of FIG. 5 in a different operating position.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    Referring to FIG. 1 of the drawings,  1  denotes a portion, in its entirety, of a machine serving to fashion a continuous cigarette rod  2 . The machine  1  is equipped with an outfeed unit denoted  3  in its entirety, which comprises an aspirating conveyor belt  4  looped around two pulleys  5  positioned one at either end (one only of which is illustrated in FIG. 1) and rotatable clockwise, as viewed in the drawing, about mutually parallel horizontal axes  6 . The endless loop described by the conveyor belt  4  compasses a chamber  7  connected to a source of negative pressure (not illustrated) and delimited at the bottom by a wall  8  pierced with suction holes  9 . As discernible in FIG. 1, the bottom branch  10  of the conveyor belt  4  runs in sliding contact with the wall  8  and is able to retain the particles  11  of tobacco by suction as they emerge from a riser (not illustrated) located beneath the branch  10 , thus forming a continuous ribbon  12  of tobacco.  
         [0015]    The ribbon  12  is directed by the branch  10  of the belt  4  in a substantially horizontal direction  13 , transverse to the axis  6  of the pulley  5 , onto a feed path  14  running through a station  15  at which the continuous cigarette rod  2  is formed.  
         [0016]    The forming station  15  is occupied by a running strip  16  of paper, directed along the feed path  14 , which is decoiled by a relative feeder unit  17  from a roll  18  through the action of a pair of pinch wheels  19 . The decoiling strip  16  is taken around a pulley  20  and routed toward the forming station  15 , which incorporates a belt conveyor  21  capable of retaining the strip  16  of paper by suction and advancing it along the feed path  14  together with the ribbon  12  of tobacco filler released onto the strip  16  by the bottom branch  10  of the conveyor belt  4 .  
         [0017]    The forming station  15  also comprises a beam  22  of conventional embodiment extending along the feed path  14 , of which the function is to wrap the paper strip  16  around the ribbon  12  of tobacco filler. The two longitudinal edges of the strip  16  are overlapped gradually along the beam  22  and glued together (in a conventional manner not indicated), thereby generating the aforementioned continuous cigarette rod  2 .  
         [0018]    The feed path  14  extends beyond the beam  22  and along a feed direction  23  followed by the rod  2  toward a cutting station  24 , at which a rotating cutter device  25  divides the continuous rod  2  into discrete cigarette sticks  26  of predetermined and constant length.  
         [0019]    The feed path  14  presents a final stretch  14   a  between the beam  22  and the cutting station  24 , coinciding with a table  27  along which the rod  2  is guided, and including a quality control device  28  by which the cigarette rod  2  is scanned in order to verify that it is correctly formed, and to reveal any possible defects. Also located between the quality control device  28  and the outfeed end of the beam  22  is a cut-off device  29  comprising a blade  30  capable of movement between a raised first position of disengagement from the feed path  14   a , illustrated in FIG. 1, and a second position of interference with the feed path  14 , illustrated in FIG. 2, in which the cigarette rod  2  is diverted by the device  29  toward a reject station  31 , having been cut during the passage of the blade from the first to the second position. The cut-off device  29  can come into operation either when the machine  1  is started up and shut down, or whenever a defect is detected in the cigarette rod  2  by the quality control device  28 , to which the cut-off device  29  is interlocked.  
         [0020]    Referring to FIG. 1 and FIG. 2, the outfeed unit  3  further comprises means  32 , located between the cutting station  24  and the quality control station  28 , of which the function is to remove a portion  2   a  of the cigarette rod  2  that may be left on the final stretch  14   a  of the feed path  14 , which extends from the cut-off device  29  to the rotary cutter device  25 , following the operation of the cut-off device  29 .  
         [0021]    Observing FIGS. 2, 5 and  6  it will be seen that the removal means  32  comprise gripping and feeding means  33  by which the aforementioned portion  2   a  of cigarette rod  2  is taken up and advanced along the final stretch  14   a  of the feed path  14 .  
         [0022]    The gripping and feeding means  33  comprise a pair of rollers  34  positioned one on either side of the final stretch  14   a  of the feed path  14  and mounted to respective mutually parallel shafts  35  extending transversely to the path  14 .  
         [0023]    In the example of FIGS. 5 and 6, the rollers  34  are mounted to respective shafts  35  carried in turn by the jaws  36  of a gripper  37  centered on a pivot denoted  38 .  
         [0024]    The gripper  37  is operated by respective drive means  39  comprising a lever  40  of which one end carries a pair of cams  41  acting on the gripper  37  by engagement with the free ends  42  of the jaws  36 , on either side of the pivot  38 . The remaining end of the lever  40  is connected to relative actuator means  43 , consisting in a cylinder, by which the jaws  36  are opened and closed through the agency of the lever  40 , the cams  41  and the free ends  42 . The rollers  34  are rendered capable thus of movement between a first non-operating position spread apart as illustrated in FIG. 5, and a second operating position, drawn together as illustrated in  6 , in which they combine to create a passage coinciding with a break  44  in the table  27  and presenting a transverse dimension substantially equal to the transverse dimension of the cigarette rod  2 .  
         [0025]    The rollers  34  are driven by a motor indicated by a block denoted  45 , and set in rotation in opposite directions so that the portion  2   a  of the cigarette rod  2  is caused to advance in the aforementioned direction  23  toward the rotary cutter device  25 . In particular, the gripper actuator  43 , the motor  45  and cutter device  25  are interlocked to a master control unit  46  which in turn is connected to the quality control device  28 . On receiving a signal from the quality control device  28 , the unit  46  will pilot the actuator  43  to draw the rollers  34  closer together and activate the motor  45  to set them in rotation about the respective shafts  35 , while causing the cutter device  25  (in the example of FIG. 2) to rotate at a prescribed frequency generally higher than during normal operation so as to chop up the portion  2   a  of the cigarette rod  2  advanced toward the device  25  by the rollers  34 .  
         [0026]    The fragments of cigarette rod thus produced are diverted toward a reject station, indicated as a block denoted  47 , by means of a movable flap  52  forming part of the table  27  and able to pivot about an axis transverse to the feed path  14 , between a raised position of substantial alignment with the plane occupied by the table  27  (FIG. 1) and a lowered position (FIG. 2) in which the fragments of cigarette rod are diverted away.  
         [0027]    In an alternative embodiment of the unit shown in FIG. 3, the rollers  34  are located between the cut-off blade  30  and the quality control device  28 , rather than beyond this selfsame device  28 .  
         [0028]    In this instance the motor  45  will be piloted to rotate the rollers  34  in the direction opposite to that described previously, so that the portion  2   a  of cigarette rod  2  is taken up and advanced along the final stretch  14   a  of the feed path  14  in the direction opposite to the predetermined direction denoted  23  toward the cut-off device  29 , which will then divert the portion  2   a  of rod toward the reject station  31 . In particular, the surface  29   a  of the cut-off device  29  directed toward the rollers  34  is fashioned in such a way as to provide an effective diverting element by means of which to guide the portion  2   a  of rod  2  toward the reject station  31 .  
         [0029]    In the example of FIG. 4, the two rollers  34  of the gripping and feeding means  33  are mounted to respective shafts  35  with respective fixed parallel axes  48  by which the rollers are carried in a fixed position, corresponding to the operating position described previously, and in which they combine to create a passage coinciding with a break  44  in the table  27  and presenting a transverse dimension substantially equal to the transverse dimension of the cigarette rod  2 . In this instance the motor  4  is coupled to a pair of gear wheels  49 , engaged in constant mesh, which during normal operation of the machine  1  will drive the rollers  34  at a tangential velocity identical to the linear velocity of the advancing rod  2 .  
         [0030]    In both the embodiments illustrated in FIGS. 4 and 5, the surface of revolution presented by each of the rollers  34  and engaging in contact with the cigarette rod presents a cross-section of U-shaped profile, and the gear wheels  49  and the motor  45  are included in both the solutions indicated (see FIGS. 4, 5 and  6 ). To advantage, as illustrated in FIGS. 1 and 2, the unit comprises pneumatic means  50  located along the final stretch  14   a  of the feed path  14 , by which a flow of pressurized air can be directed along the path  14  to eliminate any residual paper and tobacco filler.  
         [0031]    Importantly, the outfeed unit  3  described above might incorporate any number of variations without straying from the spirit of the present invention. For example, the shafts  35  of the rollers  34  can be oriented in any given direction, provided they are disposed transversely to the feed path  14 .  
         [0032]    Finally, in the event that the cigarette maker is of a type designed to fashion two cigarette rods simultaneously, the relative outfeed unit, embodied in accordance with the invention, will include a pair of rollers  34  for each one of the two rods.