Packing method and unit for folding a blank on a packing machine

1. A packing method for folding a blank ( 4 ) on a packing machine ( 1 ); the packing method comprising the steps of:

engaging a first panel ( 11 ) of the blank ( 4 ), inside a store ( 20 ), by means of a first suction pickup head ( 21 );

engaging a second panel ( 13 ) of the blank ( 4 ), inside the store ( 20 ), by means of a second suction pickup head ( 22 );

moving the pickup heads ( 21 , 22 ) from a withdrawal position at the store ( 20 ) to a release position at a packing conveyor ( 17 ), to insert the blank ( 4 ) inside a pocket ( 18 ) on the packing conveyor ( 17 ); and releasing the blank ( 4 ), folded into a ‘U’, inside the pocket ( 18 ) on the packing conveyor ( 17 ); and

producing, as the pickup heads are moved from the withdrawal position to the release position, a relative movement between the first pickup head ( 21 ) and the second pickup head ( 22 ) to fold the blank ( 4 ) into a ‘U’ before the blank ( 4 ) is inserted into the pocket ( 18 ) on the packing conveyor ( 17 );

wherein a third panel ( 12 ) is interposed between the first panel ( 11 ) and the second panel ( 13 );

wherein the blank ( 4 ) is folded into a by rotating the first panel ( 11 ) 90° with respect to the third panel ( 12 ), and rotating the second panel ( 13 ) 90° with respect to the third panel ( 12 );

wherein the first and second panel ( 11 , 13 ) are rotated by more than 90° with respect to the third panel ( 12 ) before the U-folded blank ( 4 ) is inserted into the pocket ( 18 ) on the packing conveyor ( 17 ); and

wherein the first and second panel ( 11 , 13 ) are rotated in the opposite direction with respect to the third panel ( 12 ), to position the first and second panel ( 11 , 13 ) perpendicular to the third panel ( 12 ) once the U-folded blank ( 4 ) is inserted inside the pocket ( 18 ) on the packing conveyor ( 17 ).

2. A packing method according to claim 1 , wherein the relative movement between the first pickup head ( 21 ) and the second pickup head ( 22 ) comprises rotating the first pickup head ( 21 ) 180° with respect to the second pickup head ( 22 ).

3. A packing method according to claim 1 , and comprising the further step of folding down at least one flap ( 16 ), connected to the third panel ( 12 ), once the U-folded blank ( 4 ) is inserted inside the pocket ( 18 ) on the packing conveyor ( 17 ).

4. A packing method according to claim 3 , wherein the flap ( 16 ) is folded down by a movable folding device ( 47 ) located alongside the packing conveyor ( 17 ) and which rotates about an axis of rotation ( 48 ) parallel to the packing path (P) of the packing conveyor ( 17 ).

5. A packing method according to claim 4 , wherein the movable folding device ( 47 ) remains in a position engaging the flap ( 16 ) until, the movement of the packing conveyor ( 17 ) extracts the flap ( 16 ) from the movable folding device ( 47 ).

6. A packing method according to claim 4 , wherein, downstream from the movable folding device ( 47 ) along the packing path (P) of the packing conveyor ( 17 ), a fixed folding device ( 50 ) keeps the flap ( 16 ) in a down-folded position.

7. A packing method according to claim 1 , wherein:

the first pickup head ( 21 ) is fitted to a first actuating device ( 33 ), which controls the movement of the first pickup head ( 21 );

the second pickup head ( 22 ) is fitted to a second actuating device ( 34 ), which controls the movement of the second pickup head ( 22 ); and

the first and/or second actuating device ( 33 , 34 ) are/is moved perpendicularly to the packing path (P) of the packing conveyor ( 17 ) to adjust the position of the first and/or second pickup bead ( 21 , 22 ) to the format of the blank ( 4 ).

8. A packing method according to claim 1 , wherein the first pickup head ( 21 ) is moved by means of two degrees of rotational freedom.

9. A packing method according to claim 8 , wherein:

the first pickup head ( 21 ) is mounted for rotation on a supporting plate ( 35 ), and is rotated, with respect to the supporting plate ( 35 ), about a first axis of rotation ( 39 ) by a first motor ( 40 ); and

the supporting plate ( 35 ) is mounted for rotation on a fixed frame, and is rotated, with respect to the fixed frame, about a second axis of rotation ( 36 ), parallel to the first axis of rotation ( 39 ), by a second motor ( 37 ).

10. A packing method according to claim 1 , wherein the second pickup head ( 22 ) is moved by means of two degrees of rotational freedom.

11. A packing method according to claim 10 , wherein:

the second pickup head ( 22 ) is fitted rigidly to one end of a first arm ( 44 );

the first arm ( 44 ) is fitted in rotary manner to a second arm ( 41 ), and is rotated, with respect to the second arm ( 41 ), about a third axis of rotation ( 45 ) by a third motor ( 46 ); and

the second arm ( 41 ) is fitted in rotary manner to a fixed frame, and is rotated, with respect to the fixed frame, about a fourth axis of rotation ( 42 ), parallel to the third axis of rotation ( 45 ), by a fourth motor ( 43 ).

12. A packing method according to claim 11 , wherein the fourth motor ( 43 ) is coaxial with the third motor ( 46 ), and is connected mechanically to the first arm ( 44 ) by a mechanism comprising two mutually hinged third arms.

13. A packing method according to claim 1 , wherein the packing conveyor ( 17 ) comprises:

at least a first conveyor belt ( 23 ) defining a bottom wall of the pocket ( 18 );

a first retaining member ( 25 ), which projects perpendicularly from the first conveyor belt ( 23 ) and defines a front wall of the pocket ( 18 ) at least a second conveyor belt, which is separate from the first conveyor belt ( 23 ), is parallel to and positioned alongside the first conveyor belt ( 23 ), and, together with the first conveyor belt ( 23 ), defines the bottom wall of the pocket ( 18 ); and

a second retaining member ( 26 ), which projects perpendicularly from the second conveyor belt and defines a rear wall of the pocket ( 18 ).

14. A packing method for folding a blank ( 4 ) on a packing machine ( 1 ); the packing method comprising the steps of:

engaging a first panel ( 11 ) of the blank ( 4 ), inside a store ( 20 ), by means of a first suction pickup head ( 21 );

engaging a second panel ( 13 ) of the blank ( 4 ), inside the store ( 20 ), by means of a second suction pickup head ( 22 );

moving the pickup heads ( 21 , 22 ) from a withdrawal position at the store ( 20 ) to a release position at a packing conveyor ( 17 ), to insert the blank ( 4 ) inside a pocket ( 18 ) on the packing conveyor ( 17 ); and releasing the blank ( 4 ), folded into a ‘U’, inside the pocket ( 18 ) on the packing conveyor ( 17 ); and

producing, as the pickup heads are moved from the withdrawal position to the release position, a relative movement between the first pickup head ( 21 ) and the second pickup head ( 22 ) to fold the blank ( 4 ) into a ‘U’ before the blank ( 4 ) is inserted into the pocket ( 18 ) on the packing conveyor ( 17 );

wherein the second pickup head ( 22 ) is moved by means of two degrees of rotational freedom;

wherein the second pickup head ( 22 ) is fitted rigidly to one end of a first arm ( 44 );

wherein the first arm ( 44 ) is fitted in rotary manner to a second arm ( 41 ), and is rotated, with respect to the second arm ( 41 ), about a third axis of rotation ( 45 ) by a third motor ( 46 ); and

wherein the second arm ( 41 ) is fitted in rotary manner to a fixed frame, and is rotated, with respect to the fixed frame, about a fourth axis of rotation ( 42 ), parallel to the third axis of rotation ( 45 ), by a fourth motor ( 43 ).

15. A packing method according to claim 14 , wherein the fourth motor ( 43 ) is coaxial with the third motor ( 46 ), and is connected mechanically to the first arm ( 44 ) by a mechanism comprising two mutually hinged third arms.

16. A packing method for folding a blank ( 4 ) on a packing machine ( 1 ); the packing method comprising the steps of:

engaging a first panel ( 11 ) of the blank ( 4 ), inside a store ( 20 ), by means of a first suction pickup head ( 21 );

engaging a second panel ( 13 ) of the blank ( 4 ), inside the store ( 20 ), by means of a second suction pickup head ( 22 );

moving the pickup heads ( 21 , 22 ) from a withdrawal position at the store ( 20 ) to a release position at a packing conveyor ( 17 ), to insert the blank ( 4 ) inside a pocket ( 18 ) on the packing conveyor ( 17 ); and releasing the blank ( 4 ), folded into a ‘U’, inside the pocket ( 18 ) on the packing conveyor ( 17 ); and

producing, as the pickup heads are moved from the withdrawal position to the release position, a relative movement between the first pickup head ( 21 ) and the second pickup head ( 22 ) to fold the blank ( 4 ) into a ‘U’ before the blank ( 4 ) is inserted into the pocket ( 18 ) on the packing conveyor ( 17 );

wherein the packing conveyor ( 17 ) comprises:

at least a first conveyor belt ( 23 ) defining a bottom wall of the pocket ( 18 );

a first retaining member ( 25 ), which projects perpendicularly from the first conveyor belt ( 23 ) and defines a front wall of the pocket ( 18 ) at least a second conveyor belt, which is separate from the first conveyor belt ( 23 ), is parallel to and positioned alongside the first conveyor belt ( 23 ), and, together with the first conveyor belt ( 23 ), defines the bottom wall of the pocket ( 18 ); and

a second retaining member ( 26 ), which projects perpendicularly from the second conveyor belt and defines a rear wall of the pocket ( 18 ).