A conveying unit 2including conveyor belts 7, a stopper 3positioning a sheet S at a folding position P on a conveying path 2, a knife-type folding unit 4, an anti-bounce roller unit 16having rollers 25a, 25b, and a motor 22 are provided. The rollers can be moved back and forth. A roller rotational speed monitoring unit 31 and a roller position setting unit 32 operatively connected to the motor are further provided. In setting mode, the rollers are moved from an upstream or a downstream of a tail end of the sheet positioned at the folding position P toward the tail end at a constant speed and stopped when the rotational speed of the rollers changes.

A conveying unit 2including conveyor belts 7, a stopper 3positioning a sheet S at a folding position P on a conveying path 2, a knife-type folding unit 4, an anti-bounce roller unit 16having rollers 25a, 25b, and a motor 22 are provided. The rollers can be moved back and forth. A roller rotational speed monitoring unit 31 and a roller position setting unit 32 operatively connected to the motor are further provided. In setting mode, the rollers are moved from an upstream or a downstream of a tail end of the sheet positioned at the folding position P toward the tail end at a constant speed and stopped when the rotational speed of the rollers changes.

A sheet folding device includes a folding path, a positioning member, a first folding roller, a second folding roller, a folding blade, a guide path, and a conveying roller. The positioning member is to support a leading edge of a sheet fed along the folding path and align the sheet at an initial folding position. The first folding roller is to engage with the second folding roller to form a folding nip. The folding blade is to move to an insertion position to push the sheet on the folding path into the folding nip. The guide path is provided around the first folding roller to return the sheet that has passed through the folding nip to the folding path. The conveying roller is to partially rotate around the first folding roller, to engage with the first folding roller to form a conveying nip and to feed the sheet along the guide path.

A sheet folding device includes a folding path, a positioning member, a first folding roller, a second folding roller, a folding blade, a guide path, and a conveying roller. The positioning member is to support a leading edge of a sheet fed along the folding path and align the sheet at an initial folding position. The first folding roller is to engage with the second folding roller to form a folding nip. The folding blade is to move to an insertion position to push the sheet on the folding path into the folding nip. The guide path is provided around the first folding roller to return the sheet that has passed through the folding nip to the folding path. The conveying roller is to partially rotate around the first folding roller, to engage with the first folding roller to form a conveying nip and to feed the sheet along the guide path.

A sheet folding apparatus includes: a rotor having a first peripheral surface and a second peripheral surface with a radius smaller than that of the first peripheral surface and configured to convey a sheet; and a guide member configured to be movable between a first position where it guides a sheet being conveyed by the rotor and a second position retracting from the first position. The guide member is disposed so as to move from the second position to the first position while passing within the rotation locus of the first peripheral surface of the rotor.

A sheet folding apparatus includes: a rotor having a first peripheral surface and a second peripheral surface with a radius smaller than that of the first peripheral surface and configured to convey a sheet; and a guide member configured to be movable between a first position where it guides a sheet being conveyed by the rotor and a second position retracting from the first position. The guide member is disposed so as to move from the second position to the first position while passing within the rotation locus of the first peripheral surface of the rotor.

A sheet separation device to open a two-ply sheet includes a rotator; a nipping member disposed opposite the rotator and configured to nip the two-ply sheet with the rotator; a conveyor configured to convey the two-ply sheet between the rotator and the nipping member, and a winding member disposed adjacent to the rotator. The conveyor conveys the two-ply sheet with a bonded portion of the two-ply sheet being an upstream end or a downstream end of the two-ply sheet in a conveyance direction of the two-ply sheet. The winding member winds the two-ply sheet around the rotator, to create a difference in winding circumferential length between the two sheets and separate the two sheets.

A sheet separation device to open a two-ply sheet includes a rotator; a nipping member disposed opposite the rotator and configured to nip the two-ply sheet with the rotator; a conveyor configured to convey the two-ply sheet between the rotator and the nipping member, and a winding member disposed adjacent to the rotator. The conveyor conveys the two-ply sheet with a bonded portion of the two-ply sheet being an upstream end or a downstream end of the two-ply sheet in a conveyance direction of the two-ply sheet. The winding member winds the two-ply sheet around the rotator, to create a difference in winding circumferential length between the two sheets and separate the two sheets.

The cross-fold module for a folding machine comprises a cross-fold knife which is movable in a reciprocating manner in a folding-knife movement direction, and a pair of folding rollers which form a folding roller gap in which a sheet that previously was fed in the feeding direction is creased for folding by the cross-fold knife. A delivery transport device for the folded product receives the folded product in a receiving portion close to an outlet of the folding roller gap and transports the folded product to a delivery portion. At least the cross-fold knife and the pair of folding rollers are adjustable horizontally, perpendicular to the folding-knife movement direction and perpendicular to the feeding direction.

A sheet folding device includes a folding rollers pair, a folding blade and a sheet guide. The folding rollers pair causes a sheet to pass through a first nip area to fold the sheet. The folding blade includes a blade portion and a pair of arm portions. The blade portion is selectively disposed in a folding position where the blade portion pushes a folded portion of the sheet into the first nip area and in a retracting position where the blade portion is retracted from the folding position. The pair of arm portions couples both end portions of the blade portion with the pivot shaft. The sheet guide can be passed between the pair of arm portions. Between the blade portion and the sheet guide, a retreating path in which a part of the sheet is retreated when the folded portion is pushed into the first nip area.