Machine and method for making a sub-unit of a smoking article

Abstract

A machine for making sub-units of smoking articles comprises a conveyor, a feed unit, cutting means and at least one rotary applicator. The conveyor is configured to feed a succession of tubular segments of the tobacco industry. The feed unit is configured to feed and convey at least one continuous web. The cutting means are configured to separate a succession of closing elements from a front end of the continuous web. The rotary applicator is operatively associated with the conveyor and is configured to pick up the succession of closing elements and to apply them, preferably by gluing, to an application end of a respective tubular segment, in such a way as to form closing walls to at least partly close the application ends.

1 . A machine for making sub-units of smoking articles, comprising:
 a conveyor configured to feed a succession of tubular segments of the tobacco industry;   a feed unit for feeding a continuous web;   cutting means configured to separate a succession of closing elements from a front end of the continuous web;   at least one rotary applicator, operatively associated with the conveyor and configured to pick up the succession of closing elements and to apply each closing element, preferably by gluing, to an application end of a respective tubular segment in such a way as to form closing walls to at least partly close the application ends.   
     
     
         2 . The machine according to  claim 1 , wherein the at least one applicator is configured and/or disposed to release each closing element on a front wall of the respective closing element, in particular an annular front wall of the respective closing element. 
     
     
         3 . The machine according to  claim 2 , wherein the at least one applicator is configured and/or disposed to cause a gradual movement of the closing elements towards the respective tubular segments in such a way as to release the closing elements so that they rest on the front surface of the respective tubular segment. 
     
     
         4 . The machine according to  claim 1 , wherein the at least one applicator is configured and/or disposed to move each closing element along a trajectory having at least one component parallel to an axial axis of symmetry of the respective tubular segment on which the closing element must be applied. 
     
     
         5 . The machine according to  claim 4 , wherein said trajectory is at a tangent to the trajectory followed by the application end of the respective tubular segment on which the closing element must be applied and is preferably circular. 
     
     
         6 . The machine according to  claim 1 , comprising folding means, disposed downstream of the applicator drum, which are configured to fold against an external cylindrical surface of the tubular segment end portions of the respective closing element, in particular end portions radially protruding beyond an external profile of the application end. 
     
     
         7 . The machine according to  claim 1 , comprising perforating means operating on the continuous web to make holes or perforations configured to allow air or gas to pass through them, the perforating means preferably comprising at least one laser. 
     
     
         8 . The machine according to  claim 1 , wherein the at least one rotary applicator comprises an applicator wheel. 
     
     
         9 . The machine according to  claim 8 , wherein the applicator wheel has an axis of rotation which is transversal, in particular perpendicular, to an axis of predominant extension of the tubular segments when these are being carried by the conveyor. 
     
     
         10 . The machine according to  claim 8 , wherein the applicator wheel has an axis of rotation that is inclined to an axis of predominant extension of the tubular segments when these are being carried by the conveyor, the axis of rotation being preferably inclined at an angle between 30° and 60° and, still more preferably, at an angle of 45°. 
     
     
         11 . The machine according to  claim 1 , comprising a gumming device configured to apply an adhesive substance on the application end of the tubular segment and/or on the closing element. 
     
     
         12 . The machine according to  claim 1 , comprising a pair of rotary applicators configured to apply respective successions of closing elements on respective application ends of each tubular segment. 
     
     
         13 . The machine according to  claim 1 , wherein the conveyor is configured to feed a succession of double-length tubular segments of the tobacco industry and the machine comprises a pair of rotary applicators configured to apply respective successions of closing elements on respective application ends of each double-length tubular segment. 
     
     
         14 . The machine according to  claim 13 , comprising separating means, disposed upstream or downstream of the pair of applicators and configured to cut the double-length tubular segment along a midplane to make a succession of pairs of tubular segments. 
     
     
         15 . The machine according to  claim 14 , wherein the separating means are disposed upstream of the pair of applicators, and also comprising retracting means disposed downstream of the separating means and configured to axially space the tubular segments of the pair of tubular segments in such a way that each tubular segment has a first end that is directed towards the other tubular segment and that is spaced from that tubular segment and a second end that is opposite to the first end. 
     
     
         16 . The machine according to  claim 15 , wherein the pair of rotary applicators is configured to apply respective successions of closing elements on respective application ends of the pair of tubular segments, the application ends being defined by the first ends. 
     
     
         17 . The machine according to  claim 15 , wherein the retracting means comprise a retracting drum and the rotary applicators are associated with the retracting drum to apply the closing elements on tubular segments disposed on the respective conveyor drum. 
     
     
         18 . The machine according to  claim 15 , wherein the retracting means comprise a retracting drum and a pair of conveyor drums disposed side by side and spaced from each other, the pair of conveyor drums being disposed downstream of the retracting drum to receive from the retracting drum respective successions of tubular segments, and wherein each rotary applicator is associated with a respective conveyor drum to apply the closing elements on tubular segments disposed on the retracting drum. 
     
     
         19 . The machine according to  claim 15 , wherein the folding means are axially fixed, disposed along a feed path of the pair of tubular segments in such a way as to be placed between the tubular segments of the pair of tubular segments and configured to fold against an external surface of the tubular segment portions of the respective closing element protruding beyond an edge of the application end, and also comprising movement means configured to axially move the pair of tubular segments towards each other in such a way as to engage the folding means. 
     
     
         20 . The machine according to  claim 1 , wherein the cutting means are configured to cut the continuous web across the full width of the continuous web. 
     
     
         21 . The machine according to  claim 1 , comprising detecting means configured to check the position of the closing element relative to the application end. 
     
     
         22 . A method for making a sub-unit of a smoking article, comprising the steps of:
 preparing a tubular segment of the tobacco industry, the tubular segment being internally provided with a through duct terminating with end openings of the tubular segment;   applying a closing element on at least one application end of the tubular segment by means of a rotary applicator in such a way as to form a closing wall to at least partly close that application end.   
     
     
         23 . The method according to  claim 22 , wherein the applying step is carried out by applying the closing element resting on a front wall of the respective tubular segment, in particular an annular front wall of the respective tubular segment. 
     
     
         24 . The method according to  claim 22 , wherein the applying step is carried out by moving the closing element along a trajectory having at least one component parallel to an axial axis of symmetry of the respective tubular segment. 
     
     
         25 . The machine according to  claim 24 , wherein said trajectory is at a tangent to the trajectory followed by the application end of the respective tubular segment and is preferably circular. 
     
     
         26 . The method according to  claim 22 , wherein the step of applying the closing element is preceded by the steps of:
 feeding at least one continuous web of material suitable for making the closing element;   cutting the continuous web to make a closing element suitable for being applied on the respective application end;   picking up the closing element by means of the rotary applicator.   
     
     
         27 . The method according to  claim 26 , wherein the step of cutting the continuous web to make the closing element is accomplished by cutting the continuous web across the full width of the continuous web. 
     
     
         28 . The method according to  claim 22 , comprising a step of applying an adhesive substance on the application end of the tubular segment and/or on the closing element according to a specific, predetermined pattern. 
     
     
         29 . The method according to  claim 22 , comprising a step of increasing the air and/or gas permeability of the closing wall, preferably by making a plurality of holes or perforations in the continuous web before cutting it. 
     
     
         30 . The method according to  claim 22 , wherein the step of applying the closing element is carried out by applying a pair of closing elements simultaneously on each application end of the tubular segments. 
     
     
         31 . The method according to  claim 22 , wherein the step of preparing a tubular segment is carried out by preparing a double length tubular segment and wherein the method further comprises, before or after the step of applying the closing element, a step of cutting the double-length tubular segment along a midplane to obtain two tubular segments of the tobacco industry having first ends abutted against each other at the midplane and second ends opposite the first ends. 
     
     
         32 . The method according to  claim 31 , wherein the step of applying the closing element is carried out by applying a pair of closing elements simultaneously on opposite application ends of the tubular segments of the pair of tubular segments, the application ends being defined by the second ends. 
     
     
         33 . The method according to  claim 31 , comprising a step of axially spacing the pair of tubular segments and wherein the step of applying the closing element is carried out by applying a pair of closing elements on facing application ends of the tubular segments of the pair of tubular segments, the application ends being defined by the first ends.