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.

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.

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 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.

In order to enable a sheet to be properly guided to a nip portion in performing folding processing, a sheet processing apparatus for performing folding processing on a sheet is provided with a rotating body pair which nips the sheet by a nip portion to rotate, and thereby draws the sheet to perform folding processing, a folding blade that pushes the sheet to the nip portion of the rotating body pair, and a blade guide member including a guide portion for pushing the sheet to the nip portion when the folding blade pushes the sheet to the nip portion, where the folding blade and blade guide member are relatively shifted so that a distance from a push front edge portion to the guide portion when the folding blade pushes the sheet to the nip portion is longer than a distance from the front edge portion to the guide portion.

In order to enable a sheet to be properly guided to a nip portion in performing folding processing, a sheet processing apparatus for performing folding processing on a sheet is provided with a rotating body pair which nips the sheet by a nip portion to rotate, and thereby draws the sheet to perform folding processing, a folding blade that pushes the sheet to the nip portion of the rotating body pair, and a blade guide member including a guide portion for pushing the sheet to the nip portion when the folding blade pushes the sheet to the nip portion, where the folding blade and blade guide member are relatively shifted so that a distance from a push front edge portion to the guide portion when the folding blade pushes the sheet to the nip portion is longer than a distance from the front edge portion to the guide portion.

A plurality of folding units is arranged in a circumferential direction R of a drum that rotates about an axis. Each of the folding units includes: a pad for holding each workpiece while a center portion of the workpiece as viewed in a lengthwise direction is placed on the pad; and a first folding member and a second folding member arranged adjacent to both end portions of the workpiece respectively as viewed in the lengthwise direction and used for folding the workpiece so as to stack the both end portions over the center portion. The first folding member and the second folding member are arranged at the same position as the pad of each of the folding units as viewed in the circumferential direction, and a width direction of the drum parallel to the axis is defined in the lengthwise direction of the workpiece.

A plurality of folding units is arranged in a circumferential direction R of a drum that rotates about an axis. Each of the folding units includes: a pad for holding each workpiece while a center portion of the workpiece as viewed in a lengthwise direction is placed on the pad; and a first folding member and a second folding member arranged adjacent to both end portions of the workpiece respectively as viewed in the lengthwise direction and used for folding the workpiece so as to stack the both end portions over the center portion. The first folding member and the second folding member are arranged at the same position as the pad of each of the folding units as viewed in the circumferential direction, and a width direction of the drum parallel to the axis is defined in the lengthwise direction of the workpiece.

A sheet post-processing device includes a folding portion, a discharge portion, a stacking tray, a shift unit, a pair of alignment members, and a controller. The pair of alignment members include first and second alignment members at one and the other side of sheets stacked on the stacking tray. When a sheet bundle sorted and stacked on the stacking tray includes a folded sheet, executes a second alignment mode in which it performs, for sheets shifted to a first position at one side on the stacking tray, alignment with only the first alignment member and, for sheets shifted to a second position at the other side, alignment with only the second alignment member, or does not perform alignment process.

A folding machine for folding fiber products and fiber products formed and stacked thereby are disclosed. The folding machine includes two folding devices, each of which includes a cutting device, a delivery wheel, a folding-line wheel, a platen wheel, and a folding wheel. The cutting device cuts the fiber product and transports the cut fiber product to the delivery wheel. The folding-line wheel is adjacent to the delivery wheel for making a first folding line on the fiber product carried by the delivery wheel, and then the platen wheel folds the fiber product along the first folding line. Subsequently, the once-folded fiber product is transported to the folding wheel. The folding wheels of the two folding devices are adjacent to each other and are used to fold the fiber product passing therethrough for a second time, and thus fiber products with three folds are formed.