A leveler device (200) is proposed for use in a bookbinding sewing machine (100) adapted to sew signatures (115) into book blocks (155) with one or more sewing threads (415). The leveler device (200) is used to level each signature (115) loaded onto amovable saddle (150). The leveler device (200) has at least one inlet (215) for receiving a gas jet and one or more nozzles (220) for ejecting the gas towards corresponding free ends of the threads (415) projecting from a last signature (115) of each completed bookblock (155). A bookbinding sewing machine (100) comprising the leveler device (200) is also proposed. Moreover, a corresponding method for operating a bookbinding sewing machine (100) is proposed.

Provided is a saddle stitch folding apparatus including: a stitcher unit; a reel support unit configured to support a reel rotatably about the axis with a support shaft being inserted in a through-hole formed in the reel; and a rotation detecting mechanism configured to detect a rotation state of the reel, and the rotation detecting mechanism has an adhering member that is rotated while adhered to a bottom face of the reel, a rotating member having an insertion hole inserted in the support shaft, and a rotation detecting unit configured to detect the rotation state of the rotating member.

Provided is a stitching and folding apparatus in which a stitch mechanism has a transport unit, a stitcher that binds a sheet bundle at a binding position in the transport direction, a pair of guide members that restrict a position in the width direction of the sheet bundle, and a guide motion unit that moves the pair of guide members in the width direction, the transport unit is arranged in a region where the sheet bundle transported from a collating machine is arranged, and a control unit controls the guide motion unit so that the stitcher is arranged at an intermediate position in the width direction between the pair of guide members and controls the stitcher to bind the sheet bundle at the binding position with the stitcher being arranged at the intermediate position and arranged at a different position from a region where the transport unit is arranged.

Provided is a stitching and folding apparatus in which a stitch mechanism has a transport unit, a stitcher that binds a sheet bundle at a binding position in the transport direction, a pair of guide members that restrict a position in the width direction of the sheet bundle, and a guide motion unit that moves the pair of guide members in the width direction, the transport unit is arranged in a region where the sheet bundle transported from a collating machine is arranged, and a control unit controls the guide motion unit so that the stitcher is arranged at an intermediate position in the width direction between the pair of guide members and controls the stitcher to bind the sheet bundle at the binding position with the stitcher being arranged at the intermediate position and arranged at a different position from a region where the transport unit is arranged.

A stapling unit with an improved stitching head drive apparatus includes a bunch sensor that senses the absence of the bunch of sheets and send a signal to the PLC, which actuates a lever operating device. The lever operating device opens the toggle lever by pushing the toggle release lever to disengage the driving lever from the pivot lever. The disengagement of the toggle lever with the pivot lever and the driving lever results in free pivotal movement of the pivot lever and the driving lever will not transfer the motion to the shaft which is responsible to drive the stitching head. Thus, the controllable movement of the stitching head results in improved cycle time of machine and minimum rejection.

A stapling unit with an improved stitching head drive apparatus includes a bunch sensor that senses the absence of the bunch of sheets and send a signal to the PLC, which actuates a lever operating device. The lever operating device opens the toggle lever by pushing the toggle release lever to disengage the driving lever from the pivot lever. The disengagement of the toggle lever with the pivot lever and the driving lever results in free pivotal movement of the pivot lever and the driving lever will not transfer the motion to the shaft which is responsible to drive the stitching head. Thus, the controllable movement of the stitching head results in improved cycle time of machine and minimum rejection.

Provided is a saddle stitch folding apparatus including: a stitcher unit; a reel support unit configured to support a reel rotatably about the axis with a support shaft being inserted in a through-hole formed in the reel; and a rotation detecting mechanism configured to detect a rotation state of the reel, and the rotation detecting mechanism has an adhering member that is rotated while adhered to a bottom face of the reel, a rotating member having an insertion hole inserted in the support shaft, and a rotation detecting unit configured to detect the rotation state of the rotating member.