Unit and method for packaging articles in boxes
A packaging unit of articles in boxes includes a mandrel, a movement device, a feeding device, a folding device, and a first retaining device. The mandrel is configured to accommodate at least one of the articles therein. The movement device is configured to move the mandrel along a movement trajectory. The feeding device is configured to feed at least one blank towards the mandrel. The folding device is configured to cooperate with the mandrel to fold at least one panel of the blank being wound around the mandrel, and to form one of the boxes. The first retaining device is movably guided parallel to the movement trajectory and is configured to cooperate with the mandrel, along a section of the movement trajectory, retaining the at least one panel of the blank, wound on the mandrel, against an abutment surface of the mandrel extended parallel to the movement trajectory. A packaging method of articles into boxes by means of such a unit is also described.
1 . A packaging unit for packaging articles in boxes, comprising:
a mandrel configured to accommodate at least one of said articles therein,
a movement device configured to move said mandrel along a movement trajectory,
a feeding device configured to feed at least one blank towards said mandrel,
a folding device configured to cooperate with said mandrel to fold at least one panel of said blank being wound around said mandrel, to form one of said boxes,
a first retaining device movably guided parallel to said movement trajectory and configured to cooperate with the mandrel along a section of said movement trajectory, the first retaining device retaining said at least one panel of the blank wound on said mandrel against an abutment surface of the mandrel, the abutment surface of the mandrel extended parallel to the movement trajectory, and
a second retaining device, arranged downstream of the first retaining device, and configured to retain said at least one panel of the blank against said abutment surface of the mandrel in an advancement movement of the mandrel downstream of said section of said movement trajectory,
wherein the second retaining device is spaced apart from the folding device along said movement trajectory and the first retaining device is movable between the folding device and the second retaining device in a direction of said movement trajectory.
2 . The packaging unit according to claim 1 , wherein the first retaining device is mounted on the second retaining device.
3 . The packaging unit according to claim 1 , wherein said second retaining device comprises a pair of spaced apart plates, parallel, and constrained to a fixed structure of said packaging unit.
4 . The packaging unit according to claim 1 , further comprising an actuation device configured to displace said first retaining device along a first stroke of said section of said movement trajectory towards the folding device with approach to the mandrel, and along a second stroke in an opposite direction.
5 . The packaging unit according to claim 4 , wherein, along at least part of the second stroke, the first retaining device is carried to accompany the mandrel with a same advancement speed as the mandrel.
6 . The packaging unit according to claim 4 , wherein the first stroke extends along at least part of the section of the movement trajectory between the folding device and the second retaining device.
7 . The packaging unit according to claim 4 , wherein:
the actuation device is further configured to displace the first retaining device along the first stroke between a first position and a second position,
in the first position the first retaining device is spaced apart from the advancing mandrel, and
in the second position the first retaining device is positioned in proximity to a first folding edge of the mandrel facing the folding device.
8 . The packaging unit according to claim 7 , wherein:
in said first position, said first retaining device approaches the second retaining device, and
in said second position, said first retaining device is displaced to a remote position from said second retaining device.
9 . The packaging unit according to claim 4 , wherein said first retaining device comprises an arm operatively associated with the actuation device, said arm bearing at one end thereof a head capable of retaining the at least one panel of the blank against the abutment surface of the mandrel.
10 . The packaging unit according to claim 9 , wherein said head is configured to extend, in contact with the blank, along the at least one panel of the blank and a first folding edge of the mandrel.
11 . The packaging unit according to claim 1 , said mandrel comprising a pair of abutment surfaces parallel and opposed to each other with respect to a median plane of the mandrel extended parallel to the trajectory,
wherein:
said blank is wound against each of said abutment surfaces, and
said first retaining device is configured to retain said blank against each of said abutment surfaces.
12 . The packaging unit according to claim 4 , wherein the folding device comprises an abutment element,
wherein:
the abutment element is configured to retain the at least one panel of the blank against the abutment surface of the mandrel in an advancement of said mandrel at least up to a third position along the first stroke,
the third position located between said first position and second position, and
the first retaining device reaches the mandrel and contacts the at least one panel of the blank.
13 . A method for packaging articles in boxes comprising:
(a) providing a mandrel and accommodating at least one of said articles in said mandrel,
(b) moving said mandrel along a movement trajectory,
(c) feeding at least one blank towards the mandrel,
(d) providing a folding device configured to cooperate with said mandrel to fold at least one panel of said blank around the mandrel for the formation of one of said boxes,
(e) moving a first retaining device to cooperate with the mandrel along a section of the movement trajectory,
(f) retaining said at least one panel of the blank, wound on the mandrel, against an abutment surface of the mandrel extended parallel to the movement trajectory, by said first retaining device,
(g) providing a second retaining device arranged downstream of the first retaining device, to retain the at least one panel of the blank against said abutment surface of the mandrel, during an advancement movement of the mandrel downstream of said section of said movement trajectory, and
(h) spacing the second retaining device from the folding device along said section of said movement trajectory and moving the first retaining device between the folding device and the second retaining device in a direction of said movement trajectory.
14 . The packaging method according to claim 13 , further comprising:
(e1) moving the first retaining device along said section of movement trajectory, in a first stroke, towards the folding device, with approach to the mandrel being advanced, and continuing said moving in a second return stroke, in the opposite direction.
15 . The packaging method according to claim 14 , further comprising:
(e2) carrying the first retaining device, along at least part of the second stroke, accompanying the mandrel with the same speed as the mandrel.
16 . The packaging method according to claim 14 , further comprising:
(e3) moving said first retaining device, along said first stroke, between a first position, in which the first retaining device is spaced apart from the advancing mandrel, and a second position, in which the first retaining device is positioned in proximity to a first folding edge of the mandrel facing the folding device.