Abstract:
Printed slips are applied to packets in a cigarette packer by a unit comprising a first device designed to feed slips procured as single items and ordered in a stack, or a second device designed to feed slips obtainable as cuts generated from a continuous strip; the two feed devices are conceived as mutually interchangeable accessory components that can be mounted in identical manner to a universal pickup and application device that is installed permanently in the machine and able to take up the slips with equal facility from either the first or the second feed device at a pickup station.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a unit intended for the application of printed slips to packets in packaging machines. 
   In particular, and to advantage, the invention finds application in machines for manufacturing packets of cigarettes, the field to which reference is made explicitly in the following specification albeit with no limitation implied, whilst the term “printed slip” is used to indicate a coupon, plain or folded, or a label or revenue stamp, of the kind typically associated with such packets. 
   Printed slips of the type in question are in most cases either cut from a continuous strip or drawn from a stack of diecuts. The machines by which the slips are applied will obviously be equipped with different feed devices according to the manner in which the slips are procured. In the case of folded coupons, in particular, these can be cut from a continuous strip folded previously along one or more longitudinal crease lines and decoiled thus from a roll, or alternately, the folding operation can be carried out at the moment when the strip is decoiled and fed to the machine. 
   Conventionally, a cigarette packer can be used both for the production of articles furnished with printed slips cut from a continuous strip, and for the production of articles furnished with slips procured in the form of diecuts. Obviously, given the high operating speeds and outputs of machines in use today, and the high profitability expected of them, the changeover from one type of production to another on the same packer will be economically justifiable only when the conversion of the machine from the one type of operation to the other can be accomplished in a relatively short time. 
   The prior art embraces packer machines equipped with devices designed to feed printed slips either from a continuous strip or from the bottom of a vertical magazine, operating in conjunction with respective devices by which the slips are picked up and applied to the packets, wherein the changeover from one type of feed system to another is effected by replacing both the feed and the pickup devices. 
   As a result, cigarette packers currently in use are rendered less adaptable to different types of slips and to their corresponding feed systems, and consequently less profitable. 
   The object of the present invention is to provide a unit for the application of printed slips in packaging machines, from which the aforementioned drawbacks can be eliminated. 
   SUMMARY OF THE INVENTION 
   The stated object is realized, according to the invention, in a unit for applying printed slips to packets in packaging machines, which comprises first means by which to feed slips procurable as single items and ordered in a stack, or second means by which to feed slips obtainable as cuts made from a continuous strip, and is equipped with a universal pickup and application device installed permanently in the machine, such as will take up the slips with equal facility from either the first or the second feed means at a pickup station. 

   
     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: 
       FIG. 1  shows a portion of a packer machine, viewed schematically in elevation with certain parts omitted and comprising a unit for applying printed slips to packets embodied in accordance with the present invention, in which the slips can be supplied by two different and interchangeable feed devices; 
       FIG. 2  illustrates the portion of the packer as in  FIG. 1 , viewed schematically in elevation and with certain parts omitted for clarity, showing the application unit associated with the first device for feeding the printed slips; 
       FIG. 3  illustrates the portion of the packer as in  FIG. 1 , viewed schematically in elevation and with certain parts omitted for clarity, showing the application unit associated with the second device for feeding the printed slips; 
       FIGS. 4 and 5  show a detail of the second feed device in two different operating steps, viewed in elevation; 
       FIG. 6  shows a detail of the unit of  FIG. 1 , illustrated in an alternative embodiment and viewed in perspective; 
       FIGS. 7 and 8  show part of the unit of  FIG. 1  associated respectively with the first and with the second device for feeding the printed slips, viewed in perspective; 
       FIGS. 9 ,  10  and  11  illustrate three different types of printed slip, viewed in perspective; 
       FIG. 12  is the enlarged perspective view of a packet furnished with a printed slip. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 1  of the drawings,  1  denotes a portion, in its entirety, of a packaging machine, and  2  denotes a unit, likewise in its entirety, for the application of detachable printed slips  3  to packets  4  of substantially parallelepiped shape, for example of the type with a hinged lid. 
   The portion  1  of the machine is equipped with a conveyor denoted  5  in its entirety, by which the packets  4  are received at an infeed section  6  and advanced in succession along a predetermined feed path P in a given direction F toward a station  7  at which a slip  3  is applied to each packet  4  by the unit  2  aforementioned, and thereafter toward an overwrapping machine represented schematically as a block  8 , by which the packets  4  are overwrapped in transparent plastic material (a familiar operation not illustrated in the drawings). 
   The application unit  2  comprises a pickup and application device denoted  9  in its entirety, which is positioned immediately above the application station  7 . 
   The device  9  is of universal design, installed permanently on the machine in a fixed position, and can be supplied with slips  3  at a pickup station  10  by first feed means  11  or by second feed means  12  consisting respectively in a first feed device  11  or a second feed device  12 . The devices  11  and  12  in question are interchangeable accessories, shown schematically in  FIG. 1  in positions not as yet fitted to the application unit  2 , so as to indicate the facility of using one or other device  11  or  12  according to the requirement. 
   Observing  FIGS. 1 and 2 , the first device  11  for feeding the printed slips  3  will be seen to include a magazine  13  with a substantially vertical axis  14  positionable on a vertical bulkhead  15  of the application unit  2 , and more exactly fixed to a mounting point  16  indicated by a phantom outline in  FIG. 1 . 
   The magazine  13  is designed to hold a stack  17  of slips  3  removable one by one from a bottom end  18  of the selfsame magazine when fixed to the mounting point  16  and positioned thus with the bottom end  18  facing the pickup station  10 . 
   Observing  FIGS. 1 and 3 , the second device  12  for feeding the printed slips  3  will be seen to include a decoiling unit  19  by which a continuous strip  20  of material is drawn from a roll  21 , and a feed unit  22  comprising a suction roller  23  located downstream of the decoiling unit  19 , in relation to the direction of the running strip  20 , by which the selfsame strip  20  is diverted along a substantially horizontal direction D coinciding with a plane  24  that lies parallel with and in close proximity to a reference plane  25  of the pickup station  10   
   Importantly, it will be observed also that the position of the reference plane  25  relative to the pickup station  10  remains the same in the event of the first feed device  11  being utilized. 
   The second device  12  further comprises a cutter unit  26  presenting a fixed blade  27  and a movable blade  28 , positioned in sequence along the feed direction D followed by the advancing strip  20 , respectively below and above the plane  24  occupied by the strip  20 . 
   The movable blade  28  of the cutter unit  26  is pivotable about an axis  29  normal to the vertical bulkhead  15  between a raised non operating position indicated in  FIG. 4 , distanced from the plane  24  and affording a passage to a portion  30  of the strip  20  indexed forward by the suction roller  23 , and a lowered operating position of interaction with the fixed blade  27 , indicated in  FIG. 5 , in which the aforementioned portion  30  of strip  20  constituting one slip  3  is cut and transferred into a position occupying the same plane as the pickup station  10 . 
   With reference to  FIGS. 1 ,  2 ,  3 ,  7  and  8 , the aforementioned pickup and application device  2  includes a pickup assembly  31  of the type disclosed in U.S. Pat. No. 5,775,062, to which reference may be made for a full description. Such an assembly  31  comprises at least one pickup mechanism  32  with an aspirating sector  33  having a cylindrical outer pickup surface  33   a  centered on an axis  34  normal to the vertical bulkhead  15 , which is designed to pick up a single slip  3  from the first feed device  11  or alternatively from the second feed device  12 , at a point coinciding with the reference plane  25  of the pickup station  10 . The pickup mechanism  32  is made to advance at constant speed along a predetermined path P 1 , through the agency of a carrier device  35  mounted to a power driven shaft  36  of which the axis is denoted  37 . The mechanism  32  comprises a plurality of suction cups  38  occupying a part of the aspirating sector  33  of the outer surface  33   a , aligned parallel with the aforementioned axis  34  and connected to a conventional source of negative pressure (not indicated), and able thus to attract and retain a single slip  3  on the surface  33   a . More exactly, and as described in U.S. Pat. No. 5,775,062, the pickup mechanism  32  is caused to rotate about the axis  37  of the carrier device  35  in such a way that the outer surface  33   a  rolls tangentially to the reference place  25  of the pickup station  10 , engaging progressively in contact with a slip  3  positioned at the bottom end  18  of the magazine  13  or under the movable blade  28  of the cutter unit  26  when in the lowered operating position. Thus, the suction cups  38  make contact by degrees with the slip  3 , which is transferred gradually away from the station  10 . 
   Thereafter, the mechanism  32  is advanced by the carrier device  35  along the aforementioned path P 1 , moving clockwise as viewed in the drawing, toward a release position  39 . 
   The unit  2  disclosed also presents an application assembly  40  located below the pickup assembly  31 , interposed between the latter assembly  31  and the conveyor  5 . This further assembly  40  operates in conjunction with the pickup assembly  31  and is equipped with a drum  41  rotatable about an axis  42  parallel to the axis  37  of the pickup assembly  31  between the release position  3  and a position  43 , coinciding with the application station  7 , in which a slip  3  is applied to the relative packet  4 . The drum  41  carries three angularly equidistant second pickup mechanisms  44 , pneumatic in operation, which as discernible in  FIGS. 2 ,  3 ,  7  and  8  comprise a cylindrical surface  45  concentric with the axis  42  of rotation, and two suction cups  46  positioned one on either side of the surface  45 , connected to a source of negative pressure not illustrated in the drawings. 
   The second pickup mechanisms  44  are designed to interact with the aspirating sector  33  of the first pickup mechanism  32  at the release position  39 , where the slips  3  are transferred from the suction cups  38  of the first mechanism  32  to the suction cups  46  of the second mechanisms  44 . 
   During the course of the transfer, the suction cups  38  and  46  describe a rolling movement relative to the slip  3 , devoid of sliding contact not least by virtue of their elastic deformability, and are also offset one from the another rather than being mutually opposed. 
   More particularly, the drum  41  rotates about its axis  42  in a counterclockwise direction, as viewed in the drawing, in such a manner as to transfer the slips  3  along a path P 2  tangential to the path P followed by the packets  4  on the conveyor  5  and affix one slip  3  to a corresponding face of each packet  4  at the application station  7 , at least one dab of adhesive having been deposited on the slip  3  by a gumming device  47  positioned along the path P 2  followed by the mechanisms  44  (see  FIG. 1 ). 
   As discernible in  FIGS. 1 and 12 , the packets  4  lie flat on the conveyor  5  as they proceed along the feed path P, advancing with their longitudinal axes  48  set transversely to the feed direction F, whilst the printed slips  3 , which in  FIGS. 9 ,  10  and  11  appear substantially rectangular and are referable to a relative longitudinal axis  49 , are applied to the packets  4  each with the longitudinal axis  49  parallel to the longitudinal axis  48  of the packet  4 . 
   Assuming that the slips  3 , whether picked up from the magazine  13  by the first feed device  11  or cut from a strip  20  and picked up consequently by the second feed device  12 , are directed into the pickup station  10  with their longitudinal axes  49  disposed parallel to the axes  49  of the packets  4  advancing along the conveyor  5 , then the subsequent transfer of each slip  3  from the pickup station  10  to the application station  7  can be effected without any need for a change of orientation. 
   Conversely, in the event that the slips  3  enter the pickup station  10  with their respective axes  49  disposed transversely to the longitudinal axes  48  of the packets  4 , and therefore parallel to the feed direction F followed by the packets  4  on the conveyor  5 , then the orientation must be changed during the passage from the pickup station  10  to the application station  7  in order to bring the axes  49  into a position substantially of parallel alignment with the axes  48  of the single packets  4 . 
   To this end, the drum  41  can be equipped as in the alternative embodiment of  FIG. 6  with three angularly equidistant second pickup mechanisms  50 , pneumatic in operation and comprising two suction cups  46  similarly to the first mechanisms  44 , but differing from the first in that they are mounted to respective shafts  51  rotatable about respective radial axes  51   a  through the agency of conventional mechanical linkages (not illustrated) in such a way as to maneuver the suction cups  46  from a position of alignment on a line  60  parallel to the transfer path P 2  to a position in which the selfsame line  60  is disposed transversely to the transfer path P 2 , thereby rotating the slips  3  through 90°. 
   This would be the procedure in case of the slip  3  illustrated in  FIG. 10 , which is folded along crease lines extending parallel to the longitudinal axis  49  and cut from a continuous strip  20  along lines transverse to the selfsame axis  49 . 
   In the case of the slip  3  shown in  FIG. 11 , which is folded along crease lines transverse to the longitudinal axis  49  and for example cut from a strip  20  along lines parallel to the axis  49 , or cut previously and stacked in a magazine  13 , the orientation of the axes  49  on entering the pickup station  10  will be transverse to the feed path P 1  and thus parallel to the axes  48  of the packets  4 ; in this instance the unit  2  comprises first and second guiding and locating means  52  and  53 , as illustrated in  FIG. 8 , positioned between the pickup station  10  and the release position  39 , serving to ensure that the folded slips  3  are transferred correctly. 
   In particular, the first such guide means  52  comprise an arcuate element  54  associated with the end of a bracket  55  rigidly attached to the carrier device  35  and designed to prevent the overlapping leaves of the folded slip  3  from opening out and becoming detached, whilst the second guide means  53  comprise an L-shaped plate  56  fixed at one end to the frame  57  of the relative feed device  11  or  12 . 
   The plate  56  in question presents a free end  58  disposed parallel to the feed path P 1 , of which the function is to prevent relative movement between the overlapping leaves of the folded slip  3 . 
   It will be observed that the second vacuum pickup mechanisms  50  might be mounted permanently to the second pickup assembly  40  and activated only when effectively necessary for the reasons indicated. 
   In addition, the aspirating sector  33  of the first pickup assembly  31  might present a plurality of holes  59  rather than suction cups  38 , as in the example of  FIG. 7 , connected likewise to a source of negative pressure (not illustrated).