A sheet folding apparatus includes a folding roller pair that forms a first fold line owing to that the folding roller pair nips a first position of the sheet, which has a loop to be formed on an upstream side of the folding roller pair due to continuous conveyance of the sheet by a conveyance roller pair in a stopped state in which a front end of the sheet being conveyed from the conveyance roller pair is nipped by the folding roller pair, as starting conveyance of the sheet while a pushing plate is pushing the sheet and moving toward the folding roller pair, and thereafter, forms a second fold line owing to that the folding roller pair nips a second position of the sheet with the loop formed as aligning with a rear end of the sheet.

A sheet folding device includes a sheet conveyance path, a first folding conveyance path, a first folding roller pair, a first folding guide, and a conveyance roller. The first folding roller pair is composed of a first roller and a second roller forming a first folding nip by being brought into pressure contact with an upstream side of the first roller. The first folding guide is movable between a folding position at which it approaches the first folding nip, guiding a to-be-folded part of a sheet to the first folding nip, and a retracted position at which it is away from the first folding nip. The conveyance roller forms, together with the second roller, a first assist roller pair that conveys the sheet along the sheet conveyance path. The first folding guide has a pivot fulcrum on a downstream side relative to the first folding nip in the conveyance direction.

A sheet processing device includes a first conveyance passage, a first conveyor, a second conveyor, a folder, a second conveyance passage, and circuitry. The circuitry is configured to (1) cause the first conveyor and the second conveyor to convey the sheet nipping the sheet to warp the sheet between the first conveyor and the second conveyor, (2) guide the warped sheet to form a first fold on the sheet by the folder and circulate the sheet to the first conveyance passage, (3) cause the first conveyor and the second conveyor to convey the sheet while nipping the sheet again to warp the sheet between the first conveyor and the second conveyor, (4) guide the warped sheet to form a second fold on the sheet by the folder, and (5) cause the second conveyor to convey the sheet with the first fold and the second fold.

An image forming apparatus includes an image forming unit, an input unit configured to receive input of folding unit information specifying either one of a first sheet folding unit and a second sheet folding unit, and a control unit configured to selectively perform a first mode and a second mode based on the folding unit information, the first mode being a mode in which the image forming unit forms the image on the sheet such that an orientation of the image becomes a first direction, the second mode being a mode in which the image forming unit forms the image on the sheet such that the orientation of the image becomes a second direction inverted from the first direction.

A sheet folding device, which is included in an image forming system and uses a sheet folding method, includes first and second drive motors, a first sheet conveyor driven by the first drive motor and configured to receive and convey a sheet toward a downstream side of a sheet conveying direction, a second sheet conveyor driven by the second drive motor and configured to receive the sheet conveyed from the first sheet conveyor and to convey the sheet to the downstream side of the sheet conveying direction, and a controller configured to fold the sheet to a predetermined folding length set according to an amount of conveyance of the sheet by the second sheet conveyor while the sheet is being held between the first and second sheet conveyors, and to perform a feedback control with an integral gain to the second drive motor.

A conveyor device for a folding apparatus for folding textiles includes an infeed region for a textile and an outfeed region for a folded textile. A first belt conveyor conveys the textile on a first conveyor plane from the infeed region to a first transfer unit, which feeds the textile to a second conveyor plane of a second belt conveyor. At least one second transfer unit and at least one additional belt conveyor having an additional conveyor plane are disposed downstream of the belt conveyor. At least two subassemblies, each configured as modular conveyor units are provided, into which one belt conveyor and at least one transfer unit are each integrated. The conveyor device is modularly configured, in that a plurality of modular conveyor units are disposed one atop the other and connected to each other.

A conveyor device for a folding apparatus for folding textiles includes an infeed region for a textile and an outfeed region for a folded textile. A first belt conveyor conveys the textile on a first conveyor plane from the infeed region to a first transfer unit, which feeds the textile to a second conveyor plane of a second belt conveyor. At least one second transfer unit and at least one additional belt conveyor having an additional conveyor plane are disposed downstream of the belt conveyor. At least two subassemblies, each configured as modular conveyor units are provided, into which one belt conveyor and at least one transfer unit are each integrated. The conveyor device is modularly configured, in that a plurality of modular conveyor units are disposed one atop the other and connected to each other.

A collation folding device comprising one or more fold rollers mounted in fixed positions. Below and adjacent to the fold rollers are adjustable nip rollers to form nip spacing between the rollers. The adjustable nip roller is mounted on a nip axis shaft. An adjustment mechanism is used for moving the nip axis shaft to adjust the nip spacing. The nip adjustment mechanism includes a bearing block cam follower on which the nip axis shaft is fixedly mounted and supported. An eccentric cam in operative contact with the bearing block cam follower. Rotation of the eccentric cam on the eccentric cam axis drives the bearing block cam follower in its linear motion to adjust the nip spacing.

The folding pocket device for a buckle folding machine includes a folding pocket having a feed-in aperture enabling a sheet to run therethrough in a running-in direction into a pocket space of the folding pocket. A sheet stop device includes a sheet stop extending essentially transversely to the running-in direction in the pocket space, which is displaceable in the running-in direction and in the opposite direction. A sheet directing device includes a diverting device, which is displaceable from a clearance position in which the diverting device opens up the way to the feed-in aperture into the folding pocket to a diverting position in which the diverting device blocks the feed-in aperture in order to divert a sheet. In order to achieve quick switching from the clearance position to the diverting position, the diverting device can be displaced from the clearance position to the diverting position by the sheet stop when the sheet stop is displaced opposite to the running-in direction.

A sheet folding apparatus for folding sheets comprising a curved conveyance path along which the sheets are moved successively in first and second opposite directions, the curved conveyance path being such that the sheets cannot naturally register to reach a folding position by simple effect of gravity, wherein to register the sheets before to fold them transport rollers having loaded the sheets in the first direction moves back in the second opposite direction for compressing the sheets against an adjustable low stop member to generate an elastic deformation of the sheets sufficient to compensate friction in the curved conveyance path and automatically register the sheets.