Abstract:
A method of feeding cigars to a hopper of a wrapping machine, wherein the cigars are housed in bulk and in orderly manner inside containers; each container has a top opening by which to receive and unload the cigars in the aforementioned orderly manner; a full container of cigars is picked up and inverted at the hopper by means of a manipulating device so that the opening faces downwards; and the full container is rested on a supporting surface having a passage smaller than the opening, so as to partly close the opening and provide for controlled unloading of the cigars.

Description:
The present invention relates to a method of feeding elongated elements. 
   More specifically, the present invention relates to a method of feeding cigars to a wrapping machine hopper, to which the following description refers purely by way of example. 
   BACKGROUND OF THE INVENTION 
   Cigars are normally fed to a wrapping machine hopper in two ways: by connecting the manufacturing machine directly to the wrapping machine by a conveyor conveying the cigars in bulk; or by arranging the cigars coming off the manufacturing machine in orderly manner inside containers, which are then emptied into the wrapping machine hopper. 
   The first method is suitable for producing large batches of cigars, and binds the output rate of the manufacturing machine to that of the wrapping machine; while the second method is suitable for producing small batches, by the containers being easily stacked in a store and fed to the wrapping machine as required. 
   An example of feeding of rod-like articles according to the second method is given by U.S. Pat. No. 4,303,366, which discloses an apparatus for unloading rod-like articles from containers; in particular trays containing parallel rod-like articles are unloaded by rotation until the trays are at least partially inverted, the rotation being about an axis parallel to the articles. In one arrangement a pair of tray carriers is rotatable to successively invert a full tray over delivery conveyors and to return an empty tray; one of the conveyors is also rotatable about the same axis. A removable slat retains the articles in the full tray until it is completely inverted. In another arrangement a full tray is received in a bracket in which it is moved to a tilted position for unloading. A pivoted closure member is provided for the open top of the tray and this also serves as a barrier for the unloading articles. 
   Further examples of feeding of rod-like articles according to the second method are given by U.S. Pat. Nos. 4,366,895, 3,545,593 and 3,600,873. 
   In the case of the second method, the cigars must be unloaded from the containers into the wrapping machine hopper fairly quickly, but also carefully to avoid disarranging or damaging the cigars in the process. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a method of feeding elongated elements in accordance with the second method, but which also provides for extremely careful handling of the elongated elements. 
   According to the present invention, there is provided a method of feeding elongated elements to a hopper of a wrapping machine. 
   The above method of feeding elongated elements prevents the elongated elements in the container from being unloaded simultaneously in bulk, and so turning axially offset, thus resulting not only in damage to, but also in impaired outfeed of the elements. 
   In one embodiment, the method provides for varying the position of the passage with respect to the container and the opening; moving the passage with respect to the container ensures all the elongated elements are unloaded from the container. 
   The present invention also relates to a unit for feeding elongated elements. 
   According to the present invention, there is provided a unit for feeding elongated elements to a hopper of a wrapping machine. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: 
       FIG. 1  shows a side view, with parts in section and parts removed for clarity, of a unit for implementing the method according to the present invention and in the course of first operating steps; 
       FIG. 2  shows a side view, with parts in section and parts removed for clarity, of the  FIG. 1  unit in the course of second operating steps; 
       FIG. 3  shows a larger-scale view in perspective, with parts removed for clarity, of a detail of the  FIG. 1  unit; 
       FIG. 4  shows a larger-scale front view, with parts removed for clarity, of a further detail of the  FIG. 1  unit in the course of a first unloading step; 
       FIGS. 5 to 7  show smaller-scale front views, with parts removed for clarity, of the  FIG. 4  detail in the course of further unloading steps. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Number  1  in  FIGS. 1 and 2  indicates as a whole a unit for feeding cigars  2  to a hopper  3  of a wrapping machine  4 . 
   Cigars  2  have a length L 1  ( FIG. 1 ) and a width W 1  ( FIG. 4 ), and are housed in bulk and in orderly manner, side by side and parallel to one another, inside containers or so-called feedboxes  5 . Each container  5  comprises a rectangular bottom wall  6 ; a rectangular main wall  7  perpendicular to bottom wall  6 ; and two facing, parallel lateral walls  8  perpendicular to walls  6  and  7 . Each container  5  has no top wall and no wall facing main wall  7 , and comprises a top opening  9  and a main opening  10 . Top opening  9  has a width W 2  ( FIG. 4 ) substantially equal to the width of container  5  and greater than length L 1 ; and a length L 2  ( FIG. 1 ) slightly greater than length L 1  of cigars  2 , which rest on bottom wall  6  with the tips resting against main wall  7 . 
   With reference to  FIGS. 1 and 2 , unit  1  comprises a conveyor  11  for supplying full containers  5 ; a conveyor  12  ( FIG. 3 ) for removing empty containers  5 ; a manipulator  13  for manipulating containers  5 ; and an unloading device  14  for unloading cigars  2  from containers  5 . 
   With reference to  FIG. 3 , conveyors  11  and  12  are parallel, side by side belt conveyors, extend in a direction D 1 , comprise respective belts  15  and  16  looped about respective pulleys  17  and  18  (only two of which are shown in  FIG. 3 ), and have respective conveying branches  19  and  20  coplanar with each other. Conveyor  11  defines a pickup station  21  for picking up containers  5  and located at pulley  17 ; and conveyor  12  defines a release station  22  located at pulley  18  and alongside station  21 . 
   With reference to  FIGS. 1 to 3 , manipulator  13  is located at stations  21  and  22 , and comprises a frame  23 ; an arm  24  hinged to frame  23 ; an arm  25  hinged to arm  24 ; and a bar  26  integral with arm  25  and extending in a horizontal direction D 2  perpendicular to direction D 1 . Manipulator  13  also comprises two jaws  27  for picking up containers  5  at pickup station  21 , and feeding containers  5  to unloading device  14 ; two jaws  28  for removing containers  5  from unloading device  14  and releasing them at release station  22 ; and a cover  29  over jaws  27 . 
   Jaws  27  and  28  are hinged to bar  26  about respective axes perpendicular to direction D 2 , and grip containers  5  by lateral walls  8 ; cover  29  is fitted to bar  26 , and is adjustable in the directions indicated by arrow  30  to adapt its position to the length L 2  of container  5 ; and manipulator  13  comprises a number of known actuators (not shown) for rotating arms  24  and  25  about axes parallel to direction D 2 , and jaws  27  and  28  about their respective axes. 
   With reference to  FIGS. 1 and 2 , unloading device  14  is located over hopper  3 , on the opposite side of manipulator  13  to conveyors  11  and  12 , and comprises a frame  31 ; a vertical plate  32  integral with frame  31 ; an unloading conveyor  33 ; and a feed conveyor  34  for feeding hopper  3 . 
   With reference to  FIG. 4 , frame  31  comprises an inverted-U-shaped top portion  35  enclosing plate  32  and conveyor  33 , which comprises a belt  36  looped about a number of idle pulleys  37  fixed to portion  35 , about four idle pulleys  38  fitted to a movable carriage  39 , and about two drive pulleys  40  and  41  fixed to portion  35 . Pulleys  37 ,  38 ,  40  and  41  rotate about respective axes parallel to direction D 1 ; and carriage  39  is mounted to run inside a guide (not shown) extending in direction D 2 , and supports two top pulleys  38  separated by a distance W 3 , and two bottom pulleys  38  separated by a distance greater than distance W 3 . 
   Pulleys  37 ,  38 ,  40  and  41  are so located that endless belt  36  forms an inner branch  42  and an outer branch  43 . In other words, branches  42  and  43  are substantially parallel to each other along an open annular path at pulleys  38 , which define a passage  44  of a width equal to distance W 3  and smaller than length L 1  of the cigars, and of a length L 3  ( FIG. 1 ) greater than length L 1  of cigars  2 . 
   Inner branch  42  comprises two horizontal, coplanar portions  45   a  and  45   b  separated by passage  44  and defining a supporting surface for containers  5 ; a portion  46  parallel to portions  45   a  and  45   b ; and two vertical portions  47  and  48 . Similarly, outer branch  43  comprises two horizontal portions  49   a  and  49   b  parallel to and facing portions  45   a  and  45   b  respectively; a portion  50  parallel to and facing portion  46 ; and two vertical portions  51  and  52  parallel to and facing portions  47  and  48  respectively. 
   Drive pulley  40  engages inner branch  42 , and is located between portions  45   a  and  47 ; and drive pulley  41  engages outer branch  43 , and is located between portions  49   b  and  52 . 
   Conveyor  33  and plate  32  define a housing  53  for simultaneously housing two containers  5  located respectively at a hold station  54 , where manipulator  13  deposits full containers  5 , and at a hold station  55 , where manipulator  13  picks up the empty containers  5 . 
   Feed conveyor  34  extends beneath portions  45   a ,  45   b ,  49   a , and  49   b  to receive cigars  2  from passage  44  and to feed cigars  2  to hopper  3 . 
   In actual use, and with reference to  FIG. 1 , an orderly succession of containers  5  is fed by conveyor  11  in steps in direction D 1  to manipulator  13 . Containers  5  are positioned contacting one another, with respective main walls  7  facing manipulator  13 , so that cigars  2  are fed parallel to the traveling direction D 1  of conveyor  11 . 
   Conveyor  11  is stopped when the first container  5  in the succession reaches pickup station  21 . While conveyor  11  is stationary, manipulator  13  picks up the first container  5  by gripping lateral walls  8  of container  5  by means of jaws  27 , and positions cover  29  over opening  9 . Once container  5  is gripped, arm  24  is rotated anticlockwise into the position shown in  FIG. 2 , and arm  25  is rotated from the position shown by the dash line to the position shown by the continuous line in  FIG. 2 , so as to rest cover  29  on the supporting surface defined by portions  45   a  and  45   b  at hold station  54  of containers  5 . At this step, in normal operating conditions, an empty container  5  is located at station  55  alongside container  5  at station  54 , with jaws  27  on either side of the full container  5 , and jaws  28  on either side of the empty container  5 ; and jaws  27  are opened to release the full container  5 , and jaws  28  closed to pick up the empty container  5 . Manipulator  13  then withdraws cover  29  from housing  53 , together with the empty container  5 , which is deposited at release station  22  of conveyor  12  and carried off by conveyor  12 . The combined movement of arms  24  and  25  provides for withdrawing cover  29  parallel to direction D 1 . 
   With reference to  FIG. 2 , the full container  5  is rested against vertical plate  32 , with opening  10  facing and closed by plate  32 . 
   With reference to  FIG. 4 , once cover  29  is withdrawn, the full container  5  is positioned partly over portion  45   a  of unloading conveyor  33 , and partly over passage  44 , through which cigars  2  drop out of container  5  into a pile on conveyor  33 , which feeds cigars  2  to hopper  3 . The cigars  2  in container  5  drop partly out through passage  44  until a condition of equilibrium, depending on the natural slope angle of cigars  2 , is established inside container  5 . 
   To transfer container  5  from station  54  ( FIG. 4 ) to station  55  ( FIGS. 5 ,  6  and  7 ), pulley  40  is rotated anticlockwise, while pulley  41  is locked. That is, outer branch  43  is locked, while branch  42  is moved anticlockwise. Pulley  40  exerts pull on portions  47 ,  46 ,  48  and  45   b  to move carriage  39  (from left to right in  FIG. 4 ) and so exert pull on portion  45   a  to also move container  5  from left to right in  FIG. 4 . Since outer branch  43  is locked, portions  45   a  and  45   b , and obviously container  5 , move at twice the speed of carriage  39 , so that passage  44  changes position with respect to container  5  to unload further cigars  2  as container  5  is transferred from station  54  to station  55 . 
   With reference to  FIG. 5 , once container  5  is positioned at station  55 , pulley  40  is locked to lock inner branch  42 , and pulley  41  is rotated anticlockwise to move carriage  39  leftwards ( FIG. 7 ), and then clockwise to move carriage  39  rightwards ( FIG. 6 ) so that passage  44  successively covers the whole of opening  9 . Carriage  39  is moved repeatedly to unload all of cigars  2  from container  5 . In other words, passage  44  is moved by an amount greater than the width W 2  of the container, so as to cover all portions of opening  9  and ensure container  5  is unloaded completely. 
   During operation of pulley  41 , in fact, branches  45   a  and  45   b  are locked and impart no rotary movement to the cigars  2  still inside container  5 . 
   In addition to cigars  2 , unit  1  described may also be used for bulk feeding cigarettes or other types of elongated elements.