Patent Publication Number: US-2018035707-A1

Title: A cleaning unit

Description:
TECHNICAL FIELD 
     The present disclosure relates to a cleaning unit, designed for removing contaminations from a train of rod-like elements, for use in tobacco industry machines. 
     BACKGROUND 
     Tobacco industry products, such as cigarettes, may comprise segment filters with various filtering materials, such as activated charcoal in a form of a loose granulate located between other segments having a solid form. The segment with activated charcoal can be formed by placing the charcoal between the solid segments, which typically have a form of rod-like elements. The solid segments may have filtering properties or non-filtering properties, for example they may comprise aromatic capsules. The manufacturers of filters comprising charcoal or other loose materials aim for placement of the portions of the loose material such that the neighboring segments are not contaminated with that material or such as to eliminate the loose particles from the solid segments before wrapping the train of segments in a wrapper. 
     A U.S. Pat. No. 3,482,488 discloses a device for removing contaminations from rod-like elements by means of a rotary brush. Such solution has relatively low cleaning efficiency. A significant problem is that contamination remains inside grooves formed along the edge of contact of the rod-like elements with the wrapper, because the particles of the loose material have a tendency to chock in the grooves and are difficult to be removed. 
     There is a need to provide a device for manufacturing multi-segment filtering rods comprising loose material, which will enable cleaning such as to not remove the loose material from the locations wherein the loose material is supplied, and which will provide high cleaning efficiency of the rod-like elements. 
     SUMMARY 
     There is disclosed herein a cleaning unit for machines used in tobacco industry, configured to remove contaminations of a loose material from rod-like elements arranged in a moving train, the train comprising rod-like elements separated with spaces filled with the loose material, the train being partially wrapped by a wrapper, wherein the cleaning unit comprises at least one suction nozzle for collecting the contaminations of the loose material. The cleaning unit further comprises a shifting mechanism configured to shift covering elements to positions in which the covering elements at least partially cover spaces filled with the loose material between the rod-like elements during the movement of the train in a vicinity of the suction nozzle. 
     The shifting mechanism may comprise a wheel and the covering elements mounted around a circumference of the wheel. 
     The shifting mechanism may comprise a belt and the covering elements mounted on an outer surface of the belt. 
     The shifting mechanism may be configured to move the covering elements along an elliptical track. 
     The covering elements may be made of a resilient material. 
     The covering elements may be mounted slidably with respect to the shifting mechanism of the covering elements. 
     The covering elements may have a pressing surface that is permeable to air. 
     The covering elements may have a pressing surface that is impermeable to air. 
     The covering elements may have a pressing surface in a shape of a portion of a cylinder. 
     The covering elements may further have a surface with at least one opening for collecting the contaminations of the loose material through a duct in the covering element. 
     There is also disclosed a machine for manufacturing multi-segment filter rods, comprising: a feeding unit for arranging, in a spaced relationship, rod-like elements in a train on a wrapper placed on a garniture belt; a filling unit for supplying a loose material to spaces between the rod-like elements; a cleaning unit for removing contaminations of the loose material from the rod-like elements; a garniture unit for wrapping the wrapper around the rod-like elements and the loose material to form a continuous rod; and a cutting head for cutting the continuous rod into multi-segment filter rods. The cleaning unit is the unit as described above. 
     There is also disclosed a method for cleaning, by removing contaminations of a loose material from rod-like elements, for use in machines in tobacco industry for manufacturing multi-segment filter rods, during a movement of a train comprising the rod-like elements separated by spaces filled with loose material and partially wrapped in a wrapper, the method comprising collecting the contaminations of the loose material from the rod-like elements by a suction nozzle. The method comprises the steps of: covering, by a covering element, at least partially the space filled with the loose material and not covered by the wrapper; removing the contaminations from the rod-like elements of the train of elements; and uncovering the previously covered part of the space. 
     The presented unit allows to manufacture filtering rods having compartments filled with loose material at a level close to 100%, which results in a high quality of the manufactured rods. An additional advantage is relatively low contamination of the machine for manufacturing the rods with loose material. Furthermore, the unit can operate at a high speed. Tests that have been performed have proven that the covering elements may be used to compress the loose material, in particular the loose material of a low bulk density that is problematic to fill the space between the rod-like elements. 
    
    
     
       BRIEF DESCRIPTION OF FIGURES 
       The unit is shown by means of example embodiments in a drawing, in which: 
         FIGS. 1 and 2  show fragments of various examples of continuous multi-segment rods; 
         FIG. 3  shows an example of a multi-segment rod; 
         FIG. 4  shows schematically a fragment of a machine for manufacturing multi-segment filtering rods; 
         FIG. 5  shows a first embodiment of a cleaning unit; 
         FIG. 6  shows a second embodiment of the cleaning unit; 
         FIG. 7  shows an enlarged view of a region of covering a loose material; 
         FIG. 8  shows a third embodiment of the cleaning unit; 
         FIG. 9  shows a fourth embodiment of the cleaning unit; 
         FIG. 10  shows suction nozzles; 
         FIG. 11  shows the suction nozzles in a form of separate pipes; 
         FIG. 12  shows sliding covering elements. 
         FIG. 13  shows an embodiment of a covering element. 
         FIG. 14  shows a plurality of covering elements. 
         FIG. 15  shows another embodiment of the covering element. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  present fragments of various examples of continuous multi-segment rods CR 1  and CR 2  formed from a train of rod-like elements S 1 , S 2  and SC formed by the presented unit, wherein the segments are wrapped in a wrapper  101 . The segments S 1  and S 2  have a solid shape, typically cylindrical, whereas the segment SC is formed from a loose material  102  which is located between the segments S 1  and S 1  or between the segments S 1  and S 2 . The presented continuous rods are cut into multi-segment rods.  FIG. 3  shows an example of a multi-segment rod R 2  formed from the continuous rod CR 2 . 
       FIG. 4  shows schematically a fragment of a machine for manufacturing the multi-segment filtering rods. The machine comprises a feeding unit  1 , which is configured to arrange the rod-like elements S 1  and S 2  as a train ST 1 , wherein the rod-like elements S 1  and S 2  are transported in a substantially preset spaced relationship. The rod-like elements S 1  and S 2  are fed to a garniture belt  5 . A wrapper, such as a wrapping paper, is fed on a belt of the garniture belt  5  and the elements S 1  and S 2  are placed on the wrapper  101 . The elements S 1  and S 2  received by the garniture belt  5  form a train ST 2  of the rod-like elements S 1  and S 2 , wherein the elements are arranged in a spaced relationship. Over the moving train ST 1  there is located a filling unit for supplying the loose material, for example activated charcoal, in order to form the segment CS. Lifted edges of the wrapper  101  and front surfaces of the elements S 1  and S 2  form compartments, into which the loose material  102  is supplied from the filling unit  103 . The train ST 2  of the rod-like elements S 1 , S 2  and CS that moves on the garniture belt  5  belt is wrapped in the wrapper  101  by a garniture unit  6 , wherein the edges of the wrapper  101  are lifted before the final formation of the rod in the garniture unit  6 . The garniture belt  5  typically forms a part of the garniture unit  6 . Next to the filling unit  103  there is located a cleaning unit  104  for removing contamination from the rod-like elements i.e. particles of the loose material which fall on the surface of the rod-like elements S 1  and S 2  in the preceding step, i.e. when the loose material is supplied from the filling unit  103 . The manufactured continuous rod CR is transported further and, after the wrapper  101  is glued in the garniture unit  6 , it is cut by a cutting head  8  into individual multi-segment rods R. 
       FIG. 5  shows a first embodiment of the cleaning unit  104 .  FIG. 5  also shows a fragment of the filling unit  103 , wherein a portion of a loose material  41  located in a pocket  42  is placed in a space  43  between the elements S 1  and S 2 , for example through a filling channel  44 . Behind the filling unit  103  there is located the cleaning unit  104 , comprising a wheel  51  having on its circumference a plurality of covering elements  52 . A rotary motion of the wheel  51  is synchronized with the motion of a belt  53  of the garniture unit  6 , on which the wrapper  101  is transported, with the train ST 2  placed thereon. The cleaning unit  104  is arranged with respect to the garniture unit  6  such that pressing surfaces  54  of the covering elements  52  touch the loose material accumulated in the consecutive spaces  43  between the rod-like elements S 1  and S 2 . Alternatively, the pressing surface  54  of the covering elements  52  may constitute an upper wall of the space  43  in case the space  43  is not entirely filled. The pressing surfaces  54  can be made of an air permeable or impermeable material, depending on the type of the loose material. The covering elements  52  are resilient, for example they may be made of a sponge-like material. The covering elements  52  may be used to compress the loose material. Furthermore, the cleaning unit  104  is equipped with suction elements supplying negative pressure to the zone in which the covering elements  52  have contact with the loose material or enclose the loose material. The suction elements may have a form of pipes or openings  55 , for example made in a bar located in parallel to the direction of motion of the train ST 2 . 
       FIG. 6  shows a second embodiment of the cleaning unit  104 ′, comprising a belt  61  which is mounted on two wheels  62  and  63 , with a plurality of covering elements  64  configured to cover the spaces  43  with the loose material by means of the pressing surfaces  69 . The pressing surfaces  69  may have a shape of a concave portion of a cylinder. 
       FIG. 7  shows an enlarged top view (with the belt  61  not shown for clarity) of a region of covering a loose material by the covering elements  64 , and a region of removing contaminations (view A shown in  FIG. 6 ). The covering element  64  has dimensions a and b, wherein the dimensions a and b are smaller than the distance d of the space between the rod-like elements S 1  and S 2  and the diameter D of the rod-like elements respectively, or equal to these dimensions. Alternatively, considering that the covering element  4  may be subject to deformations, it may be necessary to use the covering element having the dimensions a and b greater than the distance d and the diameter D respectively, in order to appropriately cover the space between the elements S 1  and S 2  after the deformation. The covering element  64  may be used to compress the loose material. The above remarks correspond to all embodiments. Along the region of covering the loose material, there are located suction nozzles  65  and  66  in a form of bars equipped with suction openings  67  and ducts  68  for supplying negative pressure. The suction nozzles  65  and  66  are shown in a cross-section B_B in  FIG. 10 . It is possible to use a plurality of neighboring suction nozzles, for example in a form of separate pipes  71  (as shown in  FIG. 11 ). During the unit operation, edges  101 A and  101 B of the wrapper  101  (as shown in  FIG. 7 ) are drawn aside outwards the suction nozzles  65  and  66  to enable access to the regions of the rod-like elements S 1  and S 2  where contaminations may accumulate. 
       FIG. 8  shows a third embodiment of the cleaning unit  104 ″, wherein covering elements  81  are mounted, in a manner equivalent to the second embodiment, on a belt  82 , whereas the covering elements  81  consist of two sliding elements  83  and  84  as shown in  FIG. 12 .  FIG. 13  shows another embodiment of the covering element  81 ′, which may be used in the cleaning unit  104 ″ as shown in  FIG. 8 . The covering element  81 ′ has a form of a cube  85 , a bottom surface  86  having a form of a concave cylinder surface adapted to cover the loose material  102  between the rod-like elements S 2 . The surface  86  may be used to compress the loose material  102 . The cube  85  is shown in a working position, in which the surface  86  covers the loose material  102 . The cube  85 ′ is shown in a position spaced from the loose material  102 . The covering element  85 ′ comprises a duct  88 ′ ended at an opening  87 ′, through which the particles of the loose material which lie on the rod-like element S 2  are drawn in.  FIG. 14  shows a plurality of covering elements  81 ′, which move along the bar  89  comprising a plurality of suction nozzles which supply negative pressure to the ducts  88 ′ through the openings  88 A. The bar  89  may be connected to the ducts  88 ′ of the covering elements  85 ′ by means of openings or a longitudinal duct in the bar on the side of the covering elements  85 ′. The negative pressure may be supplied to the bar  89  using various known methods.  FIG. 15  shows another embodiment of the covering element  85 ″. The duct  88 ″ connected with the opening  88 A splits and supplies the negative pressure through two openings  87 ″ made in a surface  86 A. The surface  86 A of the element  85 ′ or  85 ″ may be flat or cylindrically concave. In a position, in which the surface  86  covers the loose material, the surface  86 A is located right next to the side surface of the rod-like element S 2 , and the openings  87 ″ are located above recesses between the paper wrapper  101  and the side surface of the rod-like elements S 2 . In case when the surface  86 A is flat, it is possible for the surface  86 A to touch the upper surface of the rod-like element S 2 . Preferably, there is a small space, at least 1.5 times bigger than the size of particles of the applied loose material, for example from 0.1 mm to 0.3 mm, between the upper surface of the rod-like element S 2  and the lowest point of the surface  86 A. 
     Similarly, openings such as the openings  87 ′,  87 ″ for receiving the loose material contaminations through a duct such as the ducts  88 ′ and  88 ″, may be comprised in the covering elements  52 ,  64 ,  84  of the other embodiments. 
       FIG. 9  shows a fourth embodiment of the cleaning unit  104 ′″, wherein covering elements  91  are mounted on a mechanism, in which ends of supports move on an elliptical track, wherein the horizontal arrangement of the covering elements  91  is maintained. 
     Other embodiments may comprise combinations of the elements of the embodiments described above.