Patent ID: 7758486

Claim:
A folder operable in a first mode for forming a first fold in sheets cut from a web of material having an initial thickness to provide single-folded sheets having a double thickness portion thereof along a transport path of the sheets, and alternatively operable in a second mode for forming first and second folds in the sheets to provide double-folded sheets having a quadruple thickness portion thereof along a transport path of the sheets, wherein, the double thickness portion of the single-folded sheets has a doubled thickness of substantially twice the initial thickness, and the quadruple thickness portion of the double-folded sheets has a quadrupled thickness substantially four times the initial thickness of the web, the folder comprising: first, second and third folding rolls operatively mounted about substantially parallel respective axes of rotation defining respective surfaces thereof, and disposed relative to one another for defining a first nip between the surfaces of the first and second folding rolls, and a second nip between the surfaces of the second and third folding rolls; and a control arrangement operatively connecting the first, second and third folding rolls for selectively directing the sheets along at least portions of the respective surfaces of each of the first and second rolls in the first mode of operation, during rotation of at least the first and second rolls about their respective axes of rotation, and for directing the sheets along respective portions of the surfaces of each of the first, second and third rolls in the second mode of operation, during rotation of the first, second and third rolls about their respective axes of rotation; the control arrangement and rolls being operatively connected such that, in the first mode of operation, single thickness sheets are transferred from the surface of the first roll across the first nip to the surface of the second roll and folded a single time while at least partly attached to the surface of the second roll to form the single-folded sheets, with the single folded sheets being transported by the surface of the second roll to the transport path in such a manner that the single-folded sheets passing through the second nip remain on the second folding roll without transferring to the third folding roll in the first mode of operation; the control arrangement and rolls being further operatively connected such that, in the second mode of operation, single thickness sheets are transferred from the surface of the first roll across the first nip to the surface of the second roll and folded a first time while at least partly attached to the surface of the second roll to form single-folded sheets, and then the single-folded sheets are directed through the second nip and folded a second time by interaction of the second and third rolls downstream of the second nip to form the double-folded sheets, with the double-folded sheets being transported by the surface of the second roll to the transport path.