Abstract:
The object of the invention is a unit for conveying filter segments ( 2 ) for the machines of tobacco industry, comprising a chain conveyor ( 10 ) in a horizontal arrangement on which the lugs ( 21 ) are disposed, the working ends ( 28 ) of which are deflected from the vertical. The unit comprises guides ( 23, 33 ) of the filter segments ( 2 ) provided with an inclined channel ( 27 ) guiding the lug ( 21 ).

Description:
BACKGROUND 
     The object of the application is a unit for conveying filter segments for the machines of the tobacco industry, in particular for manufacturing multi-segment filters for cigarettes. 
     One of known methods of manufacturing multi-segment filters is placing individual filter segments onto a grouping tape, whereas the said segments are pushed down in order to form a continuous filter segment stream which after wrapping into cigarette paper is cut into multi-segment rods. The said segments are delivered by modules in which the filter rods are cut on multi-flute cutting drums into filter segments which, in the form of sets of segments, are conveyed by lugs in the direction of the grouping tape. From the patent GB 915 203, a module delivering filter segments is known wherein the sets of filter segments are conveyed by vertically positioned lugs and the said lugs move along slots above which filter segments in the form of sets of segments move, whereas the lugs are mounted on a chain situated in a vertical plane. From the publication WO2009074540, a module is known wherein the lugs for conveying the sets of segments are mounted on a chain situated in a horizontal plane. 
     A problem which filter manufacturers have to deal with is damaging filter elements conveyed by lugs, the working elements of which are situated vertically, that is when the segments are conveyed above the channels in the form of slots along which the lugs are guided, which occurs most frequently when the plane in which the chain works is situated vertically. The segments move then on sharp edges of the guiding channel, which can lead to damage of the segments. In addition, if the cigarette paper wrapping the filter material is not perfectly glued, a deflected part of the cigarette paper easily slides into the slot, which can lead to a blockage of the segments or to the destruction thereof, whereas the blockage of fed segments can lead to the damage or deformation of the lugs. 
     SUMMARY 
     The object of the invention is a unit for conveying filter segments for the machines of the tobacco industry, comprising a chain conveyor in a horizontal arrangement on which the lugs are disposed. 
     A unit according to the invention is characterized in that the working end of the lug is deflected from the vertical, and in addition comprises guides of filter segments provided with an inclined channel guiding the lug. 
     A unit according to the invention is characterized by additionally comprising a unit detecting the position of the working end of the lug. 
     A unit according to the invention is characterized in that the lugs can be dismounted from the chain conveyor without the necessity of opening the chain. 
     A favorable effect of using the invention is shifting the point of contact of a guided filter segment from the edge of a channel guiding a lug to a flat surface. In the solution according to the invention the filter segments are guided along three smooth walls of a guide, which allows avoiding the contact of a filter segment with the sharp edge of the channel guiding the lug. If the cigarette paper is not correctly glued, the risk that an unstuck fragment of the cigarette paper slides into the guiding slot is clearly reduced. A unit according to the invention allows detecting of deformations of all lugs e.g. before the start of the machine, which eliminates the risk of damage to the elements of the machine if it is started at the moment when the lugs are damaged or deformed. In addition, a fast replacement of a lug without the necessity of dismounting the chain is possible. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The object of the invention is shown in a preferred embodiment in a drawing in which: 
       FIG.  1 —shows a view of the guides of a filter segment known in the state of the art in a cross-section and a known lug mounted on a chain guided in a vertical arrangement, 
       FIG.  2 —a view of the guides of a filter segment known in the state of the art in a cross-section and a lug mounted on a chain guided in a horizontal arrangement, 
       FIG.  3 —a view of the guides of a filter segment in a cross-section and a lug according to the invention, 
       FIG.  4 —a view of the guides of a filter segment in a cross-section and a lug according to the invention, 
       FIG.  5 —a top view of the path of a chain conveyor with the shown detection zone of the end of a lug, 
       FIG.  6 —a simplified perspective view of a lug with a fastening element. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a lug  1  known in the state of the art, fastened to a chain working in a vertical arrangement, used in units for conveying filter segments. The lug  1  drags and pushes filter segments  2  along guides  3 , whereas the plane of the drawing is principally perpendicular to the direction of movement of the lug  1  and the segment  2 , and the motion of the segments takes place in a horizontal plane. The guides  3  have surfaces  4  being lateral guides of the segment  2  and surfaces  5  being bottom guides of the segment  2 . The surfaces  5  on the side of the lug  1  terminate in edges  6  which restrict the space of a guiding channel  7  in the form of a slot along which the lugs  1  move. A working end  8  of the lug  1  which comes into contact with the segment  2  moves above the slot  7 , whereas a gripping part  9  moves beneath the slot  7 , with the gripping part  9  being fastened to a link of a chain conveyor  10 . The drive chain of the lugs is a closed loop, and the axis of rotation  11  of each of the pins of the chain conveyor is situated perpendicular to a vertical plane A, in other words the chain is guided in a vertical arrangement. 
       FIG. 2  also shows a known lug  1 ′, whereas the chain is guided in a horizontal arrangement. The gripping part  9  of the lug  1 ′ is fastened to a link of the chain conveyor  10 , whereas the axes of rotation  11  of each of the pins of the chain conveyor are situated vertically perpendicular to a horizontal plane B, in other words the chain conveyor is guided in a horizontal arrangement. 
       FIG. 3  shows a solution according to the invention wherein a segment  2  is dragged and pushed by a lug  21 , whereas the segment  2  is guided between guides  23  and  33 . The guides  23  and  33  have surfaces  24  and  34  being lateral guides of the segment  2 . From below the segments are guided along a surface  25  belonging to the guide  23  and being the bottom guide of the segment. The guides  23  and  33 , which can be constructed as one element, have surfaces  41  and  42 , respectively, constituting guides of the lug  21 , whereas the surfaces  41  and  42  form a guiding channel  27  along which a working end  28  of the lug  21  moves, with the said working end being deflected from the vertical. The surfaces  41  and  42  intersect with the surfaces  25  and  34 , respectively; the edges  26  and  36  lying along the intersection of the said surfaces are situated in the corner of a channel along which the filter segments  2  are guided and they do not come into contact with the segments  2 . In a solution according to the invention wherein the working end  28  of the lug  21  is deflected from the vertical, the segments  2  are guided only along the smooth surfaces  24 ,  25  and  34  which constitute the guides of the segments  2 . A horizontally situated gripping part  29  of the lug is fastened to a chain conveyor working in a horizontal arrangement, the axes  11  of the pins of the chain conveyor  10  are situated perpendicular to the horizontal plane B. 
     Despite the lugs are guided in the channel  27  in the area of the greatest danger of deformation of the lugs, that is beneath a cutting drum  43  ( FIG. 5 ) from the flutes of which cut filter rods in the form of filter segments are fed, the lugs  21  disposed on the chain conveyor can be exposed to incidental untypical loads in different places of the path of motion of the lugs  21  and the chain conveyor  10  as a result of which the working ends  28  can be damaged or deformed. A example of a deformation of the working end  28  is shown in  FIG. 4  in broken lines. Deformations of the working end  28  can affect the correct operation of the machine for manufacturing multi-segment filters, they can be also a source of damage to the machine.  FIG. 5  shows the path of motion of the chain conveyor  10  with the lugs  21  which is determined by circles around which the chain  10  is guided and a fragment of the guides  23  and  33  shown in broken lines. In a unit for conveying the segments according to the invention, for example optical elements for the detection of positions of the working end of the lug are disposed. The working end  28  is illuminated by a illuminating element  51  ( FIG. 5 ) in the area of detection  50 , whereas a receiver  52  is an element which collects information about the shape of the working end  28  of the lug  21 . The receiver  52  can be constructed as a matrix of known light-sensitive elements, whereas the control system can have stored model image of the shape of the working end  28  with which the images created on the receiver  52  will be compared. For instance, the area  50  of detection of the position of the working end  28  of the lug  21  can comprise at least two sets of kits consisting of the illuminating element  51  and the receiver  52 . The chain of the unit for conveying the segments can move along its path of motion, feeding successive lugs  21  into the area  50  in order to record the images of the working ends  28  of all lugs  21 , collect and analyze them in the control system, as well as to report faults. If any deformations of the working ends  28  of the lugs  21  are detected, a further operation will be possible for example only after the replacement of a damaged or deformed lug. 
       FIG. 6  shows a simplified representation of a chain  10  with pins  60  onto which a lug  21  is put. The lug  21  is fastened from above by means of a clip  61  put onto the pins  60 . Such fastening method allows the replacement of the lugs  21  without opening the chain  10 .