Abstract:
A method and device for feeding elongated tobacco articles, whereby, on a wrapping machine, a mass of articles, oriented a given way, is fed along an annular path in a hopper connected to at least one channel for feeding the articles and in which the articles are fed in an orderly column.

Description:
The present invention relates to a method of feeding elongated articles on a wrapping machine. 
     The present invention is particularly advantageous for use in the tobacco industry, and specifically for feeding articles such as cigars, cigarettes or similar. 
     BACKGROUND OF THE INVENTION 
     In the following description, specific reference will be made purely by way of example to cigar wrapping machines. 
     Known cigar wrapping machines are equipped with a cigar feed device comprising a hopper with at least one channel underneath. The hopper has walls converging towards an outlet from which the channel extends, and houses a mass of cigars oriented a given way. Inside the hopper, the cigars drop by force of gravity towards the outlet and into the channel, along which they are arranged in an orderly column contacting one another, are guided by two opposite parallel walls of the channel, and travel under their own weight and the weight of the cigars inside the hopper. 
     Known feed devices have the drawback of the cigars possibly forming bridges, i.e. arc-shaped supporting structures defined by adjacent cigars resting on one another and on the walls of the hopper, and which clog the outlet, thus preventing the cigars from being fed into the channel, and preventing the cigars on top from exerting the weight force required to feed the cigars along the channel. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a method of feeding elongated articles on a wrapping machine, designed to eliminate the drawbacks of the known state of the art. 
     According to the present invention, there is provided a method of feeding elongated articles on a wrapping machine comprising a device in turn comprising a hopper for housing a mass of said articles oriented in a first direction, and at least one channel for feeding the articles and in which said articles are arranged in an orderly column; said channel being connected to an outlet of the hopper; and the method being characterized by comprising the step of feeding said mass of articles along an annular path inside said hopper; said outlet being located along said annular path. 
     The present invention also relates to a device for feeding elongated articles on a wrapping machine. 
     According to the present invention, there is provided a device for feeding elongated articles on a wrapping machine; the device comprising a hopper for housing a mass of said articles oriented in a first direction, and at least one channel for feeding the articles and in which said articles are arranged in an orderly column; said channel being connected to an outlet of the hopper; and the device being characterized by comprising conveying means housed inside said hopper to feed said mass of articles along an annular path inside said hopper; said outlet being located along said annular path. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The present invention will be described with reference to the accompanying drawing showing a nonlimiting embodiment of the present invention. In particular, the accompanying drawing shows a partly sectioned front view, with parts removed for clarity, of a cigar feed device in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Number  1  in the accompanying drawing indicates as a whole a device for feeding cigars  2  on a wrapping machine  3  for wrapping each cigar  2  in a respective sheet of wrapping material not shown. Device  1  comprises a hopper  4 , in turn comprising an inlet  5 , four outlets  6 , and four channels  7 , each of which is connected to a respective outlet  6  and guides cigars  2 , arranged in an orderly column  8 , to machine  3 . The cigars  2  inside hopper  4  and channels  7  are oriented in a direction D 1  perpendicular to the plane of the accompanying drawing. 
     Hopper  4  comprises a front wall and a rear wall not shown in the accompanying drawing; two lateral guides  9  and  10  having respective curved guide surfaces  11  and  12 ; four conveyors  13  associated with respective channels  7 ; and a conveyor  14  for recirculating cigars  2 . Conveyors  13  and  14  partly define a bottom wall  15  of hopper  4 , which has a compartment  16  occupied partly by a conveyor  17  dividing compartment  16  into a top portion and a bottom portion connected to the top portion by lateral guides  9  and  10 . 
     Conveyor  17  extends horizontally, and comprises a transmission pulley  18   a  located at guide  9 ; a drive pulley  18   b  located at guide  10 ; and a belt  19  looped about pulleys  18   a  and  18   b.  Pulleys  18   a  and  18   b  rotate about respective axes  20   a  and  20   b  parallel to direction D 1 , and conveyor  17  comprises a horizontal top branch  21  and a horizontal bottom branch  22  connected to each other at pulleys  18   a  and  18   b.  Conveyor  17  is rotated anticlockwise in the accompanying drawing to feed a mass of cigars  2  along an annular path P comprising a portion P 1  extending in a horizontal direction D 2  between bottom branch  22  and conveyors  13  and  14 . Guide surface  11  is a portion of a cylinder of radius Ra and axis  20   a,  and forms with pulley  18   a  a constant passage section Sa. Similarly, guide surface  12  is a portion of a cylinder of radius Rb and axis  20   b,  and forms with pulley  18   b  a constant passage section Sb. Pulleys  18   a  and  18   b  are equal in diameter, whereas radius Ra is greater than radius Rb so that passage section Sa is greater than passage section Sb. 
     Each conveyor  13  comprises two transmission pulleys  23   a,    23   b  and a drive pulley  23   c,  about which is looped a belt  24 , and comprises a top branch  25  sloping slightly downwards from left to right in the accompanying drawing and with respect to direction D 2 . That is, each branch  25  slopes towards respective channel  7  to assist the downward flow of cigars  2  into channel  7 . 
     Each channel  7  is defined by a vertical wall  26  tangent to pulley  23   b,  and by a wall  27  parallel to wall  26  and comprising an appendix  28 , which extends about pulley  23   b,  is substantially parallel to a portion of branch  25 , and is fitted on the free end with a revolving roller  29 . Wall  26  comprises a vertical surface  30  connected to pulley  23   b,  and wall  27  comprises a surface  31  having a portion parallel to and facing surface  30 , a portion extending about the axis of pulley  23   b,  and a portion parallel to a portion of branch  25 . Appendix  28  has an upper face  32  on which the cigars  2  in hopper  4  rest, and therefore defines a portion of channel  7  and a portion of bottom wall  15  of hopper  4 . Each outlet  6  of hopper  4  coincides with the inlet of a respective channel  7 , extends between roller  29  and respective branch  25 , and has a passage section S 6  sized according to the diameter of cigars  2  so as to permit access to respective channel  7  by one cigar  2  at a time. 
     Each channel  7  is therefore connected to the hopper by outlet  6 , and comprises, as of outlet  6 , a straight sloping portion extending between appendix  28  and branch  25 ; a curved portion extending between appendix  28  and pulley  23   b;  and a straight vertical portion extending between walls  26  and  27 . Passage section S 6  is substantially perpendicular to direction D 2  and path portion P 1  to intercept part of the mass of cigars  2 . 
     Recirculating conveyor  14  comprises a belt  33  looped about two transmission pulleys  34   a  and  34   b  and a drive pulley  34   c,  and comprises a branch  35  sloping upwards in direction D 2 . That is, branch  25  of the first conveyor  13 , on the left in the accompanying drawing, connects guide surface  11  to respective channel  7 ; branch  35  of conveyor  14  connects face  32  of appendix  28  of the last channel  7 , on the right in the accompanying drawing, to guide surface  12 ; and branches  25  of the central conveyors  13  connect the faces  32  of appendixes  28  of the respective upstream channels  7  to their own respective channels  7 . The bottom wall  15  of hopper  4  is therefore defined partly by branches  25  and  35 , and partly by appendixes  28 , and each outlet  6  defines a step in bottom wall  15  for intercepting the cigars  2  traveling along path P. 
     In actual use, cigars  2  are bulk fed continuously or discontinuously in direction D 3  into hopper  4  through inlet  5 . Conveyor  17  is fed continuously anticlockwise in the accompanying drawing, while conveyors  13  and  14  are fed continuously clockwise. Top branch  21  of conveyor  17  feeds cigars  2  through passage section Sa and between the bottom branch  22  of conveyor  17  and branch  25  of the first conveyor  13  in direction D 2 . The combined action of conveyor  17  and conveyor  13  feeds cigars  2  in bulk in direction D 2 , while the cigars  2  traveling in contact with branch  25  are intercepted by outlet  6  and fed through passage section S 6  into respective channel  7 . In the same way, each conveyor  13  supplies respective outlet  6  and feeds cigars  2  along the respective channel  7 ; and conveyor  14  cooperates with conveyor  17  to feed some of cigars  2  through passage section Sb and back onto top branch  21  of conveyor  17 . 
     Force feeding cigars  2  in bulk along path P prevents the formation of bridges and at the same time provides for feeding cigars  2  onto branches  25  leading into respective channels  7 , thus preventing any interruption in supply; while recirculating conveyor  14  provides for sending back into circulation along path P any cigars  2  failing to engage any channel  7  along portion P 1  of the annular path. 
     The number of channels  7  is a design parameter of machine  3 , may range from one to a very high number, and obviously determines the number of outlets  6  and conveyors  13 .