Retention device for retaining a blank, movement unit and process for moving said blank

1 . A retention device for retaining blanks, comprising:

a support,

a first gripping portion secured to said support, the first gripping portion comprising first retention elements of a blank,

a second gripping portion secured to said support or to said first gripping portion, the second gripping portion comprising second retention elements of said blank, and

a movement mechanism for said second gripping portion with respect to said first gripping portion, said movement mechanism being configured to perform a pure rotation of said second gripping portion about a virtual rotation axis defined outside said retention device,

wherein said movement mechanism comprises an articulated parallelogram secured to said first gripping portion and to said second gripping portion,

wherein said articulated parallelogram comprises:

a first rod secured by a first hinge to a first rotation point of said first gripping portion,

a second rod secured by a second hinge to a second rotation point of said first gripping portion,

a third rod comprising: a first pin rotatably secured to said first rod, a second pin rotatably secured to said second rod, and a third pin rotatably secured to a third rotation point of said second gripping portion,

a fourth rod comprising: a fourth pin rotatably secured to said first rod, a fifth pin rotatably secured to said second rod, and a third pin rotatably secured to a fourth rotation point of said second gripping portion,

wherein:

said first and second rotation points and said virtual rotation axis are aligned with each other; and

said third and fourth rotation points and said virtual rotation axis (V) being aligned with each other,

in such a manner that, when said first and second rods rotate with respect to said first and second rotation points with a same angle, said third and fourth rods follow a translational movement with respect to said first gripping portion while maintaining a mutual parallelism condition, thereby varying an angular orientation of said second gripping portion with respect to said first gripping portion by rotating about said virtual rotation axis.

2 . The retention device according to claim 1 , wherein said virtual rotation axis passes through said blank when said blank is retained by said retention elements.

3 . The retention device according to claim 2 , wherein said rotation axis coincides with a creased portion of said blank.

4 . The retention device according to claim 1 , wherein said rotation axis is close to an edge of said first gripping portion facing said second gripping portion.

5 . The retention device according to claim 1 , wherein said first gripping portion is fixedly secured to said support.

6 . The retention device according to claim 1 , further comprising a movement device configured to move in translation simultaneously with said first gripping portion and said second gripping portion.

7 . The retention device according to claim 1 , wherein said retention device is mounted on an arrangement selected from the group consisting of a drum, a runner, a track, and a belt.

8 . A movement unit for moving blanks comprising:

the retention device according to claim 1 , and

a drum, said retention device being secured to said drum.

9 . The movement unit according to claim 8 , wherein said first gripping portion and said second gripping portion are moveable in translation in a direction having a radial component of said drum.

10 . The movement unit according to claim 8 , comprising a plurality of said retention devices, equidistantly arranged one from another with uniform angular spacing in accordance with an axis of symmetry passing through the rotation axis of said drum.

11 . The movement unit according to claim 8 , comprising a plurality of said retention devices and a plurality of said drums, each drum secured to at least one of said retention devices, said plurality of retention devices being configured to exchange said blank between a first retention device and a second retention device of said plurality of retention devices, secured to different drums of said plurality of drums.

12 . A process for moving a blank, comprising:

providing the movement unit according to claim 8 ,

moving said drum to a removal position where a retention device of said movement unit faces said blank,

activating said retention elements of said retention device by securing said blank to said retention device,

rotating said drum in a rotation direction from said removal position to a release position,

rotating a second gripping portion of said retention device with respect to a first gripping portion of said retention device about a virtual rotation axis defined outside said retention device, while said drum rotates between said removal position and said release position, and

deactivating said retention elements by disengaging said blank from said retention device while said drum is in said release position.

13 . The process according to the claim 12 , further comprising:

retaining i) an abutment panel of said blank by said first gripping portion and ii) a lateral panel of said blank by said second gripping portion, in such a manner that said lateral panel is downstream with respect to said abutment panel in accordance with said rotation direction of said drum.

14 . The process according to claim 13 , further comprising:

while said drum rotates between said removal position and said release position, folding said blank between said abutment panel and said lateral panel by said retention device.

15 . The process according to claim 12 , further comprising:

rotating a first drum of said movement unit retaining said blank towards said release position,

rotating a second drum of said movement unit synchronously with said first drum and with an opposite rotation direction,

facing said second gripping portion of a first said retention device secured to said first drum with a second gripping portion of a second said retention device secured to said second drum,

facing said first gripping portion of said first retention device with a first gripping portion of said second retention device,

maintaining said retention elements of said first retention device activated while the retention elements of said second retention device are also activated, and

deactivating said retention elements of said first retention device while said retention elements of said second retention device are kept active.

16 . A packing apparatus for articles, comprising at least one blank movement unit, said blank movement unit being the movement unit of claim 8 .