Folding, or interfolding, unit for folding, or interfolding sheets of paper for a machine for paper converting

A folding, or interfolding, unit, for folding, or interfolding a first and a second plurality of sheets of paper of a predetermined length and arranged to be folded, or interfolded, at a predetermined folding, or interfolding, zone, of a machine for converting paper, or similar product, said folding, or interfolding, unit comprising:

• first and second folding, or interfolding, counter-rotating rolls between which said folding, or interfolding, zone is defined, each said first and second folding, or interfolding, rolls, providing:
• a tubular body configured to rotate about a respective longitudinal rotational axis, and a plurality of suction holes being provided organized according to a predetermined number of longitudinal rows close to each other;
• a vacuum generation device configured to produce a predetermined vacuum degree;
• a vacuum distribution device configured to selectively put into pneumatic communication said vacuum generation device with at least a row of said plurality of rows of suction holes, at predetermined angular positions of said tubular body, in such a way to cause said plurality of processed sheets of paper to be sucked and to adhere at predetermined portions of said first, or second, folding, or interfolding, roll;
• a separation unit arranged to operate downstream of said folding, or interfolding, unit, said separation unit comprising a first and a second plurality of separator members configured to enter from opposite sides in a finished stack of folding, or interfolding, sheets, and to separate the same from a following forming stack of folded, or interfolded, sheets;
• a displacement unit configured to move said first plurality of separator members and said second plurality of separator members;
• a first and a second cutting device respectively associated to said first and to said second folding, or interfolding, roll said first and second cutting device, providing, respectively, at least a first and a second cutting blade,
• wherein:
• each said first and second folding, or interfolding, roll provides, respectively, a first and a second plurality of counter-blades distributed along said respective tubular body and configured to operate, respectively, in combination with said first and second cutting blades to divide a first and a second web of paper, or similar product, in said first and said second plurality of sheets, and
• said displacement unit is configured to move said first and second plurality of separator members between a first position and a second position along a respective displacement trajectory positioned outside the encumbrance of said first and second folding, or interfolding, rolls during the formation of said stack of folded, or interfolded, sheets in such a way not to intersect said first and second plurality of counter-blades.