Forming assembly and method for forming a plurality of sealed packs for pourable food products starting from a tube of packaging material

A method for forming a plurality of sealed packs from a tube of packaging material, the tube extending in a direction along a tube axis, wherein the method comprises:

• advancing the tube along an advancing first direction;
• moving a sealing element along a track, the sealing element configured to seal a cross-sectional portion of the tube to form a sealed end of a respective pack,
• wherein the sealing element is configured to move, at different locations along the track, between a first position and a second position, the sealing element being situated closer to the tube axis when the sealing element is in the second position than when the sealing element is in the first position, and
• wherein the moving the sealing element along the track includes cyclically driving the sealing element along a cyclic path, the sealing element being movable between the first position thereof and the second position thereof as the sealing element moves along the cyclic path;
• moving a first shaping element along the track, the first shaping element including a first half-shell configured to contact and bound the tube to thereby control at least a portion of the shape of a first pack of the plurality of sealed packs during formation of the first pack, the first half-shell comprising a main wall and a pair of flaps hinged to the main wall, wherein the sealing element is arranged upstream of the first shaping element with respect to the advancing first direction thereof along the track and wherein the first shaping element comprises:
• a driving body configured to contact the track and comprising a motor configured to drive the first shaping element along the track,
• a first driven body which protrudes from the driving body, wherein the first driven body is staggered from the track, carries the main wall of the first half-shell, and comprises a first cam follower, and
• a second driven body, which is movable with respect to the first driven body, is operatively connected to the pair of flaps, and comprises a second cam follower,
• wherein movement of the main wall of the first half-shell towards or away from the tube is effected by cooperation between the first cam follower and a first cam surface, and
• wherein movement of the pair of flaps of the first half-shell with respect to the main wall is effected by cooperation between the second cam follower and a second cam surface;
• moving a second shaping element along the track, the second shaping element configured to contact and bound the tube to thereby control at least a portion of the shape of a second pack of the plurality of sealed packs during formation of the second pack, wherein the sealing element is located between the first shaping element and the second shaping element;
• contacting the tube with the first shaping element and the second shaping element while the sealing element is in the first position thereof, wherein the contacting of the tube includes cyclically moving the first shaping element between:
• a first rest position, in which the first half-shell is away from the tube axis and
• a first operative position, in which the first half-shell contacts and bounds the tube;
• moving the second shaping element towards the first shaping element along the track so as to decrease a distance therebetween while the first shaping element and second shaping element contact the tube and while the sealing element remains in the first position thereof;
• moving the sealing element from the first position thereof to the second position thereof while the first shaping element and the moved second shaping element contact the tube, so as to seal the first pack of the plurality of sealed packs, wherein the movement of the second shaping element towards the first shaping element is independent of the movement of the sealing element from the first position thereof to the second position thereof;
• maintaining the first shaping element in the first operative position and the sealing element in the first position thereof while the first shaping element and the sealing element are positioned along a first portion of an operative branch of the cyclic path, the operative branch having a main extension direction parallel to the advancing first direction;
• and
• maintaining the first shaping element in the first operative position and displacing the sealing element into the second position thereof while the first shaping element and the sealing element are positioned along a second portion of the operative branch, the second portion of the operative branch being arranged downstream of the first portion of the operative branch proceeding along the cyclic path, according to an advancing direction of the sealing element and the first and second shaping elements.

A packaging machine for forming a plurality of sealed packs from a tube of packaging material filled with a food product, wherein each sealed pack is filled with the food product and wherein the tube has an axis that extends in a vertical direction, the packaging machine comprising:

• a continuous track having a linear portion extending along a side of the tube in the vertical direction, wherein the track allows controlled movement of a plurality of carriages;
• a sealing carriage included as one of plurality of carriages, the sealing carriage being movable along the track and having a sealing element configured to seal a cross-sectional portion of the tube to form a sealed end of a first pack of the plurality of sealed packs,
• wherein the sealing element is configured to move, at different locations along the linear portion of the track, between a first position and a second position, the sealing element being situated closer to the tube axis when the sealing element is in the second position than when the sealing element is in the first position, and
• wherein the sealing element is cyclically drivable along a cyclic path and, as it moves along the cyclic path, the sealing element is movable between the first position thereof and the second position thereof;
• a first shaping carriage included as one of the plurality of carriages, the first shaping carriage having a first half-shell configured to contact and bound the tube to thereby control at least a portion of the shape of the first pack of the plurality of sealed packs during formation of the first pack, the first half-shell comprising a main wall and a pair of flaps hinged to the main wall,
• wherein the first shaping carriage is cyclically drivable along the cyclic path and, as it moves along the cyclic path, the first shaping carriage is movable between:
• a first operative position, in which the first half-shell contacts the tube so as to control the shape of the first pack;
• and
• a first rest position, in which the first half-shell is away from the tube, and
• wherein the first shaping carriage comprises:
• a driving body configured to contact the track and comprising a motor configured to drive the first shaping carriage along the track;
• a first driven body which protrudes from the driving body, wherein the first driven body is staggered from the track, carries the main wall of the first half-shell, and comprises a first cam follower;
• and
• a second driven body, which is movable with respect to the first driven body, is operatively connected to the pair of flaps, and comprises a second cam follower;
• a second shaping carriage included as one of the plurality of carriages, the second shaping carriage having a second half-shell configured to contact and bound the tube to thereby control at least a portion of the shape of a second pack of the plurality of sealed packs during formation of the second pack;
• a first cam surface, which cooperates with the first cam follower of the first shaping carriage, so as to move the main wall of the first half-shell towards or away from the tube;
• and
• a second cam surface, which cooperates with the second cam follower of the first shaping carriage, so as to move the pair of flaps of the first half-shell with respect to the main wall of the first half-shell,
• wherein the first pack is formed from a first portion of the tube and the second pack is formed from a second portion of the tube, wherein the first tube portion is located below the second tube portion with respect to the vertical direction,
• wherein the sealing carriage is located between the first shaping carriage and the second shaping carriage with respect to the vertical direction,
• wherein the second shaping carriage is configured to move towards the first shaping carriage along the track so as to decrease a distance therebetween while the first half-shell and the second half-shell contact the tube and while the sealing element is in the first position thereof, the movement of the second shaping carriage towards the first shaping carriage being independent of the movement of the sealing element from the first position thereof to the second position thereof,
• wherein the sealing element is configured to move from the first position thereof to the second position thereof while the first half-shell and the second half-shell contact the tube, so as to seal the first pack of the plurality of sealed packs, the second half-shell having been moved towards the first half-shell along the track by the movement of the second shaping carriage towards the first shaping carriage, and
• wherein the first shaping carriage is arranged downstream of the sealing carriage with respect to the cyclic path, the cyclic path comprising respective operative branches having a main extension direction which is parallel to the tube axis, wherein the operative branch comprises:
• a first portion, in which the first shaping carriage is in the first operative position and in which the sealing carriage is in the first position thereof, and
• a second portion, in which the first shaping carriage is in the first operative position and in which the sealing carriage is in the second position thereof,
• the second portion of the operative branch being arranged downstream of the first portion of the operative branch proceeding along the cyclic path, according to an advancing direction of the sealing carriage and the first shaping carriage.