Patent ID: 7975999
Filing Date: 2011-07-12
Classification: B42C,B65H,G03G

Abstract:
1. A sheet post-processing apparatus comprising: a sheet carry-in path having a carry-in port and a first sheet discharge port; a switch back conveying path for guiding a sheet from the carry-in port of the sheet carry-in path fed through the first sheet discharge port to a downstream post-processing position, said switch back conveying path having a sheet approaching path, a switch back approaching path and a sheet processing path, wherein the sheet approaching path branches off from the sheet carry-in path and extends downwardly from the sheet carry-in path to a second sheet discharge port; the sheet processing path extends further downwardly from the second sheet discharge port; and the switch back approaching path branches from the second sheet discharge port separately from the sheet approaching path, a collecting guide device for setting and collecting the sheet transferred through the sheet approaching path into a bunch of sheets, the collecting guide device being located on the sheet processing path; a post-processing device for executing at least one of a stapling process and a folding process on the bunch of sheets collected on the collecting guide device in the sheet processing path; a sheet leading end regulating device for regulating a position of leading end of the bunch of sheets collected on the collecting guide device, the sheet leading end regulating device being formed to be movable so that a trailing end of the bunch of sheets supported on the collecting guide device is transferred from a position of being at least placed in the second sheet discharge port to a position of being placed in the switch back approaching path to stack a carried-in sheet transferred through the sheet approaching path onto an uppermost sheet of the bunch of sheets at the collecting guide device; a guide member provided at the second sheet discharge port so that the carried-in sheet transferred through the sheet approaching path is guided onto the uppermost sheet supported on the collecting guide device where the trailing end of the bunch of sheets is located at the second sheet discharge port; and a shift device for moving a position of the sheet leading end regulating device along the sheet processing path; wherein the switchback approaching path is arranged so as to move the bunch of sheets supported on the collecting guide device to an overlap position where the trailing end of the bunch of sheets overlaps the leading end of the carried-in sheet from the sheet approaching path complying with a position of the sheet leading end regulating device, and wherein the guide member comprises a plate guide member, the plate guide member having a base end supported via a shaft so as to be pivotable above the collecting guide device, and a leading end configured to retract from an operative position where the carried-in sheet is guided onto the uppermost sheet on the collecting guide device, along a surface of the uppermost sheet and then to pivot onto the carried-in sheet, and a driving device for rotating the guide member is coupled to the plate guide member.