Sheet transport apparatus and sheet transport method

Abstract

Provided is a sheet folding apparatus including: a transport unit configured to transport a sheet bundle in a transport direction; a stopper arranged at a stop position, the front end of the sheet bundle being abutted against the stopper; a restriction part configured to restrict deformation in a height direction of the sheet bundle abutted against the stopper; a pushing roller configured to generate pushing force for pushing the front end of the sheet bundle against a transport face; and a roller motion mechanism configured to move the pushing roller between a protruding position upstream of the stop position and a retracted position spaced apart from the protruding position, and the roller motion mechanism moves the pushing roller from the protruding position to the retracted position after the front end of the sheet bundle transported by the transport unit reaches the pushing roller.

What is claimed is: 
     
         1 . A sheet transport apparatus comprising:
 a transport unit configured to hold a sheet bundle on a transport face and transport the sheet bundle in a transport direction;   a stopper arranged at a stop position in the transport direction, the front end of the sheet bundle transported by the transport unit being abutted against the stopper;   a restriction part forming a restriction face, the restriction face being arranged parallel to the transport face from a first position upstream of the stop position in the transport direction to a second position downstream of the stop position in the transport direction, and configured to restrict deformation in a height direction of the sheet bundle abutted against the stopper;   a pushing part arranged above the transport unit and configured to generate pushing force for pushing the front end of the sheet bundle against the transport face; and   a first motion mechanism configured to move the pushing part between a protruding position upstream of the stop position in the transport direction and a retracted position spaced apart from the protruding position,   wherein the first motion mechanism moves the pushing part from the protruding position to the retracted position after the front end of the sheet bundle transported by the transport unit reached the pushing part.   
     
     
         2 . The sheet transport apparatus according to  claim 1 , wherein the pushing part has a roller rotated in contact with the transport face that is moved in the transport direction. 
     
     
         3 . The sheet transport apparatus according to  claim 1  further comprising a second motion mechanism configured to move, in the transport direction, the stop position at which the stopper is arranged,
 wherein the first motion mechanism moves the pushing part in the transport direction in response to the second motion mechanism moving the stop position in the transport direction. 
 
     
     
         4 . The sheet transport apparatus according to  claim 1  further comprising an abutment part configured to press the rear end of the sheet bundle in the transport direction and abut the front end of the sheet bundle against the stopper after the first motion mechanism moves the pushing part from the protruding position to the retracted position. 
     
     
         5 . The sheet transport apparatus according to  claim 4  further comprising a sheet folding unit arranged in a width direction orthogonal to the transport direction and configured to fold the sheet bundle at an intermediate position between the front end and the rear end of the sheet bundle. 
     
     
         6 . The sheet transport apparatus according to  claim 1 , wherein the retracted position is a position downstream of the stop position in the transport direction. 
     
     
         7 . A sheet transport method to transport a sheet bundle by a sheet transport apparatus, wherein the sheet transport apparatus comprises
 a transport unit configured to hold the sheet bundle on a transport face and transport the sheet bundle in a transport direction,   a stopper arranged at a stop position in the transport direction, the front end of the sheet bundle transported by the transport unit being abutted against the stopper,   a restriction part forming a restriction face, the restriction face being arranged parallel to the transport face from a first position upstream of the stop position in the transport direction to a second position downstream of the stop position in the transport direction, and configured to restrict deformation of the sheet bundle abutted against the stopper, and   a pushing part arranged above the transport unit and configured to generate pushing force for pushing the front end of the sheet bundle against the transport face,   the sheet transport method comprising:   a transport step of transporting the sheet bundle in the transport direction toward the stopper by the transport unit; and   a retracting step of moving the pushing part from a protruding position upstream of the stop position in the transport direction to a retracted position spaced apart from the protruding position after the front end of the sheet bundle transported in the transport step reached the pushing part.   
     
     
         8 . The sheet transport method according to  claim 7 , wherein the pushing part has a roller rotated in contact with the transport face that is moved in the transport direction. 
     
     
         9 . The sheet transport method according to  claim 7  further comprising:
 a first motion step of moving, in the transport direction, the stop position at which the stopper is arranged; and 
 a second motion step of moving the pushing part in the transport direction in response to the first motion step moving the stop position in the transport direction. 
 
     
     
         10 . The sheet transport method according to  claim 7  further comprising an abutting step of pressing an abutment part against the rear end of the sheet bundle in the transport direction and abutting the front end of the sheet bundle against the stopper after the retracting step moves the pushing part from the protruding position to the retracted position. 
     
     
         11 . The sheet transport method according to  claim 10  further comprising a sheet folding step of pressing a sheet folding unit arranged in a width direction orthogonal to the transport direction against the sheet bundle at an intermediate position between the front end and the rear end of the sheet bundle and folding the sheet bundle. 
     
     
         12 . The sheet transport method according to  claim 7 , wherein the retracted position is a position downstream of the stop position in the transport direction.