Patent ID: 11891263
Assignee: VALMET TISSUE CONVERTING S.R.L.
Field: Handling (Mechanical engineering)
Classification: CPC B | IPC B

Claim 21:
22. A method for producing stacks of interfolded sheets starting from a web of paper comprising:
feeding of said web of paper along a predetermined feeding direction;
cutting of said web of paper in a plurality of sheets of predetermined length;
folding by a first and a second folding rollers counter-rotating one with respect to the other said sheets at a folding zone to form said stack of interfolded sheets interfolded according to a predetermined interfolding configuration;
wherein:
said cutting of said web into said sheets is carried out on a cutting roller configured to alternately distribute said plurality of sheets to said first folding roller forming a first plurality of sheets arranged to reach said folding zone through a first feeding path, and to a transfer roller of transfer section forming a second plurality of sheets arranged to reach said folding zone through a second feeding path, said transfer roller being configured to transfer said second plurality of sheets to said second folding roller, said transfer roller is provided with third holding elements arranged to hold said second plurality of sheets on a respective portion of the external surface of said transfer roller to transfer said second plurality of sheets from said cutting roller to said second folding roller, and in that said cutting roller is provided with:
first holding elements configured to hold said sheets on a first portion of said external surface of said cutting roller; and

second holding elements configured to hold said sheets on a second portion of said external surface of said cutting roller positioned downstream of said first portion, in such a way that, when said second holding elements are arranged to hold said sheets on said second portion, a sheet of said plurality is transferred from said cutting roller to said transfer roller, whilst, when said second holding elements are not arranged to hold said sheets on said second portion, a sheet is transferred from said cutting roller to said first folding roller; and

deactivating said third holding elements of said transfer roller in such a way that all the sheets of said plurality of sheets are arranged to move from said cutting roller to said first folding roller reaching said folding zone through said first feeding path.