A system with an interfolding machine, a method and an interfolding machine

A system comprising an interfolding machine for production of interfolded packs of sheet articles from strips which comprises a frame and an interfolding unit, for cutting sheet articles from strips and for arranging the sheet articles so as to realise interfolded packs, which comprises a set of roller units, having a first roller unit and a second roller unit the rollers of which are configured for moving sheet articles, and folding elements cooperating with the first roller unit and the second roller unit in order to arrange the sheet articles in an interfolded way, wherein:

• each roller unit of the set comprises a first part, a second part and, between them, a roller which is rotatable with respect to the first part and to the second part about a respective rotation axis;
• the first part and the second part of a roller unit of the set are distinct respectively from the first part and from the second part of another roller unit of the set;
• the frame comprises, for each roller unit of the set, a first seat which removably houses a respective first part and a second seat which removably houses a respective second part;
• the system comprises a second set of roller units which is interchangeable, in the interfolding machine, with the set and which comprises a third roller unit and a fourth roller unit interchangeable respectively with the first roller unit and the second roller unit so as to cooperate with the folding elements, each roller unit of the second set comprising a first part removably engageable with a respective seat of the first seats, a second part removably engageable with a respective seat of the second seats and, between them, a roller which is rotatable with respect to the first part and to the second part about a respective rotation axis and the first part and the second part of a roller unit of the second set being distinct respectively from the first part and from the second part of another roller unit of the second set;
• the rollers of the third roller unit and of the fourth roller unit differ from the rollers of the first roller unit and of the second roller unit so as to operate with a different length of sheet articles;
• the system being characterised in that it comprises a first coupler for reciprocally coupling the roller units of the set and a second coupler for reciprocally coupling the roller units of the second set, wherein:
• the first coupler comprises a structure which is configured to support the weight of the roller units of the set and connecting means for connecting the first part and the second part of each roller unit of the set to the structure so as to be able to move the roller units of the set together;
• the second coupler comprises a second structure which is configured to support the weight of the roller units of the second set and second connecting means for connecting the first part and the second part of each roller unit of the second set to the second structure so as to be able to move the roller units of the second set;
• the first coupler is configured in such a way as to maintain the first parts and the second parts of the roller units of the set in the positions they reciprocally occupy when they engage the first seats and the second seats;
• the second coupler is configured in such a way as to maintain the first parts and the second parts of the roller units of the second set in the positions they reciprocally occupy when they engage the first seats and the second seats.