A sheet folding device includes a sheet conveyance path, first and second side plates, a first folding roller pair, a first folding guide, and a guide drive mechanism. The first folding guide is reciprocatable between a folding position and a retracted position, and includes a guide main body and first and second arms provided respectively at both ends of the guide main body. The guide drive mechanism includes a drive source provided on the first side plate, a first drive transmission portion that transmits a drive force of the drive source to the first arm, a second drive transmission portion that transmits the drive force to the second arm, and a drive coupling portion that couples the first drive transmission portion to the second drive transmission portion and transmits the drive force from the first drive transmission portion to the second drive transmission portion.

An enclosing apparatus for enclosing an enclosure into an envelope at an enclosing position includes a conveyance roller that conveys the envelope to the enclosing position and an envelope conveyance path through which the envelope is conveyed. An enclosing support is disposed in the envelope conveyance path and supports enclosing of the enclosure into the envelope. The enclosing support retracts a flap of the envelope from the envelope conveyance path while the conveyance roller conveys the envelope to the enclosing position.

An apparatus for treating a stack of sheets of sheet material includes a means for moving the stack of sheets of sheet material towards a first and second fold roller means. The first and second fold roller means are arranged to assist with folding of the stack of sheets of sheet material. The apparatus also includes a first and a second clamping jaw defining a gap. The first and second clamping jaws are arranged to be movable relative to each other to increase and decrease the gap for selective application of a clamping force to the stack of sheets of sheet material having passed between the first and second fold roller means. The first and second fold roller means are mounted in a manner allowing for an increase and decrease in separation and thus between a stack-guiding configuration and a stack compressing configuration.

An apparatus for folding and receiving book documents comprises a main conveying device arranged and adapted to convey unfolded book documents in a main conveying direction and a secondary conveying device arranged and adapted to receive the book documents conveyed by the main conveying device and to convey them in a secondary conveying direction and/or against the secondary conveying direction, wherein the secondary conveying direction is transverse to the main conveying direction. Further, the apparatus comprises a receiving device arranged at a spatial distance from the first and/or the second conveying surface and configured to receive folded book documents. The device folds the conveyed book documents respectively with a movement in the secondary conveying direction and/or against the secondary conveying direction. Furthermore, a lifting device is arranged to convey the folded book documents from the main conveying device and/or from the secondary conveying device into the receiving device.

A sheet post-processing apparatus includes a stacker, a pair of folding rollers having a nip portion therebetween, and a blade. A sheet is stacked on the stacker. The blade is configured to fold the sheet in half by pushing the sheet stacked on the stacker into the nip portion of the pair of folding rollers. The pair of folding rollers are configured to switch between a first posture and a second posture. In the first posture, the sheet is pushed into the nip portion by the blade. In the second posture, a feeding direction of the sheet is different from that in the first posture.

A sheet processing apparatus includes a roller pair configured to convey a sheet, a sheet bundle conveyer configured to convey a sheet bundle to the roller pair, and circuitry configured to cause the sheet bundle conveyer to contact leading edges of sheets of the sheet bundle to the roller pair and cause the roller pair to rotate in reverse to align the leading edges of the sheets of the sheet bundle.

A sheet folding device includes a sheet loading unit, a folding processing unit, and an ejection roller. The folding processing unit includes a folding roller pair. A sheet alignment part and a sheet moving part are provided. A sheet loading tray includes an upstream-side loading part and a downstream-side loading part. The sheet alignment part includes an upstream-side alignment part and a downstream-side alignment part. The downstream-side alignment part includes a side plate, a fixed guide plate, and a movable guide plate supported on the side plate in such a manner as to be swingable between a retreat position and a regulation position.

A sheet folding apparatus folds two portions of a first folding position of a sheet and a second folding position existing between one end of the sheet and the first folding position to perform Z-fold on the sheet. Then, in a state in which a one-end side portion of the sheet and a folded portion folded in the first folding position are overlapped with each other, the apparatus adjusts a distance between one end of the sheet and the first folding position.

An apparatus for folding and receiving book documents comprises a main conveying device arranged and adapted to convey unfolded book documents in a main conveying direction and a secondary conveying device arranged and adapted to receive the book documents conveyed by the main conveying device and to convey them in a secondary conveying direction and/or against the secondary conveying direction, wherein the secondary conveying direction is transverse to the main conveying direction. Further, the apparatus comprises a receiving device arranged at a spatial distance from the first and/or the second conveying surface and configured to receive folded book documents. The device folds the conveyed book documents respectively with a movement in the secondary conveying direction and/or against the secondary conveying direction. Furthermore, a lifting device is arranged to convey the folded book documents from the main conveying device and/or from the secondary conveying device into the receiving device.

A sheet processing apparatus includes a roller pair configured to convey a sheet, a sheet bundle conveyer configured to convey a sheet bundle to the roller pair, and circuitry configured to cause the sheet bundle conveyer to contact leading edges of sheets of the sheet bundle to the roller pair and cause the roller pair to rotate in reverse to align the leading edges of the sheets of the sheet bundle.