Manufacturing machine and manufacturing method for the production of a filter for a tubular element

Abstract

Manufacturing machine and manufacturing method for the production of a filter for a tubular element for a smoking article. The following are provided: a folding drum which rotates around a rotation axis to move, along a circular folding path at least one holding head designed to accommodate a sheet having an inner portion and an outer portion; a feeding station where the holding head receives the sheet and engages the sole outer portion of the sheet leaving the inner portion of the sheet free; an insertion station where the holding head releases the sheet having the inner portion folded like a bellows; and a folding device which is arranged along the folding path between the feeding station and the insertion station and is configured to fold the inner portion of the sheet like a bellows. The holding head is mounted on the folding drum so as to radially translate outwards in the feeding station to receive the sheet and so as to radially translate outwards in the insertion station to release the sheet.

What is claimed is: 
     
         1 . A manufacturing machine ( 8 ) for the production of a filter ( 2 ) for a tubular element ( 1 ), in particular for a smoking article; the manufacturing machine ( 8 ) comprises:
 a folding drum ( 16 ), which rotates around a first rotation axis ( 17 ) to move, along a circular folding path (P), at least one holding head ( 18 ) designed to accommodate a sheet ( 4 ), preferably made of card stock, having an inner portion ( 5 ) and an outer portion ( 6 );   a feeding station (S 2 ), where the holding head ( 18 ) receives the sheet ( 4 ) and engages the sole outer portion ( 6 ) of the sheet ( 4 ), leaving the inner portion ( 5 ) of the sheet ( 4 ) free;   an insertion station (S 1 ), where the holding head ( 18 ) releases the sheet ( 4 ) having the inner portion ( 5 ) folded like a bellows; and   a preferably fixed folding device ( 25 ), which is arranged along the folding path (P) between the feeding station (S 2 ) and the insertion station (S 1 ) and is configured to fold the inner portion ( 5 ) of the sheet ( 4 ) like a bellows;   wherein the holding head ( 18 ) is mounted on the folding drum ( 16 ) so as to radially translate outwards in the feeding station (S 2 ) to receive the sheet ( 4 ) and so as to radially translate outwards in the insertion station (S 1 ) to release the sheet ( 4 ).   
     
     
         2 . The manufacturing machine ( 8 ) according to  claim 1 , wherein the folding drum ( 16 ) supports two and precisely two holding heads ( 18 ) and, with every rotation step, the folding drum ( 16 ) rotates around the first rotation axis ( 17 ) by 180° so as to switch the position of the two holding heads ( 18 ). 
     
     
         3 . The manufacturing machine ( 8 ) according to  claim 2 , wherein, when the folding drum ( 16 ) is standing still, a holding head ( 18 ) in the feeding station (S 2 ) is radially moved towards the outside of the folding drum ( 16 ) so that it can retrieve a new sheet ( 4 ) and, at the same time, the other holding head ( 18 ) in the insertion station (S 1 ) is radially moved towards the outside of the folding drum ( 16 ) so that it can release a previously retrieved sheet ( 4 ). 
     
     
         4 . The manufacturing machine ( 8 ) according to  claim 2 , wherein the folding drum ( 16 ) comprises:
 two linear guides ( 21 ), which are radially oriented;   two slides ( 22 ), each sliding along a respective linear guide ( 21 ) and supporting a respective holding head ( 18 ); and   an actuation device ( 24 ), which pushes the slides ( 22 ) back and forth along the respective linear guides ( 21 ).   
     
     
         5 . The manufacturing machine ( 8 ) according to  claim 4 , wherein the actuation device ( 24 ) comprises:
 a secondary shaft ( 33 ), which is mounted so as to rotate around the first rotation axis ( 17 ); a pinion ( 34 ) integral to the secondary shaft ( 33 ); and   two racks ( 35 ), which mesh with the pinion ( 34 ), are arranged at opposite ends of the pinion ( 34 ) and are integral to the corresponding slides ( 22 ).   
     
     
         6 . The manufacturing machine ( 8 ) according to  claim 5  comprising a main shaft ( 32 ), which is mounted so as to rotate around the first rotation axis ( 17 ), is coaxial to the secondary shaft ( 33 ), is arranged around the secondary shaft ( 33 ) and determines the rotation of the folding drum ( 16 ). 
     
     
         7 . The manufacturing machine ( 8 ) according to  claim 6  comprising:
 a main electric motor, which causes the rotation of the main shaft ( 32 ); and 
 a secondary electric motor, which causes the rotation of the secondary shaft ( 33 ) and is separate from and independent of the main electric motor. 
 
     
     
         8 . The manufacturing machine ( 8 ) according to  claim 1 , wherein the holding head ( 18 ) has a support body ( 19 ), where there is obtained a sucking seat ( 20 ), which reproduces, in negative, the shape of the outer portion ( 6 ) of the sheet ( 4 ). 
     
     
         9 . The manufacturing machine ( 8 ) according to  claim 1  comprising a feeding system ( 26 ) provided with a preferably horizontal hopper ( 27 ), which accommodates a series of stack of sheets ( 4 ). 
     
     
         10 . The manufacturing machine ( 8 ) according to  claim 9 , wherein the hopper ( 27 ) has a support drum ( 28 ), which is mounted so as to rotate, in a stepped manner, around a second rotation axis ( 29 ) and has a series of preferably horizontal channels ( 30 ), which are evenly distributed around the rotation axis ( 29 ) and are each shaped so as to accommodate a stack of sheets ( 4 ). 
     
     
         11 . The manufacturing machine ( 8 ) according to  claim 10 , wherein the rotation of the support drum ( 28 ) around the rotation axis ( 29 ) cyclically causes a channel ( 30 ) to be aligned with the feeding station (S 2 ). 
     
     
         12 . The manufacturing machine ( 8 ) according to  claim 11 , wherein the feeding system ( 26 ) comprises a pushing element ( 31 ), which is aligned with the feeding station (S 2 ) and is horizontally movable so as to push the stack of sheets ( 4 ) located in the channel ( 30 ) aligned with the feeding station (S 2 ) towards the feeding station (S 2 ). 
     
     
         13 . The manufacturing machine ( 8 ) according to claim comprising:
 a tubular inserting body ( 11 ), in particular with the shape of a truncated cone, which is arranged in the area of the insertion station (S 6 ) and is shaped so as to be inserted into the tubular element ( 1 ); and   a pushing element ( 12 ), which is designed to push the filter ( 2 ) along the entire inserting body ( 11 ) until it comes out of the inserting body ( 11 ), so as to insert the filter ( 2 ) into the tubular element ( 1 ) surrounding the inserting body ( 11 ).   
     
     
         14 . The manufacturing machine ( 8 ) according to  claim 13 , wherein the pushing element ( 12 ) is configured to place a row of filters ( 2 ) inside the inserting body ( 11 ) so that a new filter ( 2 ), by entering the inserting body ( 11 ), pushes out another filter ( 2 ) on the opposite side of the inserting body ( 11 ). 
     
     
         15 . A manufacturing method for the production of a filter ( 2 ) for a tubular element ( 1 ), comprising:
 moving, by means of a folding drum ( 16 ), which rotates around a first rotation axis ( 17 ), along a folding path (P), at least one holding head ( 18 ) designed to accommodate a sheet ( 4 ), preferably made of card stock, having an inner portion ( 5 ) and an outer portion ( 6 );   inserting, in a feeding station (S 2 ), the sheet ( 4 ) into the holding head ( 18 ), which engages the sole outer portion ( 6 ) of the sheet ( 4 ), leaving the inner portion ( 5 ) of the sheet ( 4 ) free;   transferring, in an insertion station (S 1 ), the sheet ( 4 ) having the inner portion ( 5 ) folded like a bellows from the holding head ( 18 ); and   folding the inner portion ( 5 ) of the sheet ( 4 ) like a bellows by means of a folding device ( 25 ) arranged, preferably in a fixed manner, along the folding path (P) between the feeding station (S 2 ) and the insertion station (S 1 );   wherein the holding head ( 18 ) is radially translated outwards in the feeding station (S 2 ) to receive the sheet ( 4 ) and is radially translated outwards in the insertion station (S 1 ) to release the sheet ( 4 ).