Sheet feeding apparatus and sheet separating apparatus

Abstract

Provided is a sheet folding apparatus including: a stacking unit configured to be stacked with a paper stack; a feeding roller configured to come into contact with a surface of the uppermost sheet of the paper stack and feed sheets in a feeding direction; and a sheet separating mechanism configured to separate the uppermost sheet of the paper stack from the remaining sheets. The sheet separating mechanism has a suction unit that sucks and pulls the uppermost sheet of the paper stack upward in upstream in a feeding direction and an injection mechanism that separates the uppermost sheet from the remaining sheets by injecting air toward a predetermined region including an end face in upstream in the feeding direction of the paper stack including the uppermost sheet. The injection mechanism has a rotary injection unit configured to inject air to change a first injection direction oriented to the predetermined region.

What is claimed is: 
     
         1 . A sheet feeding apparatus comprising:
 a stacking unit configured to be stacked with a paper stack including a plurality of sheets;   a feeding unit configured to come into contact with a surface of the uppermost sheet of the paper stack and feed the uppermost sheet in a feeding direction; and   a sheet separating mechanism configured to separate the uppermost sheet of the paper stack from the remaining sheets,   wherein the sheet separating mechanism comprises   a suction unit configured to suck and pull the uppermost sheet of the paper stack upward in upstream in the feeding direction, and   an injection mechanism configured to separate the uppermost sheet from the remaining sheets by a first injection unit configured to inject air so as to change a first injection direction oriented to a predetermined region including an end face in upstream in the feeding direction of the paper stack including the uppermost sheet of the paper stack.   
     
     
         2 . The sheet feeding apparatus according to  claim 1 ,
 wherein the first injection unit comprises   a nozzle portion that is formed in a cylindrical shape extending along an axis intersecting the height direction of the paper stack and having a closed tip and has an injection hole for injecting air toward the predetermined region formed in a side face of the nozzle portion, and   a rotary portion configured to rotate the nozzle portion in a predetermined direction about the axis, and   wherein air injected from the injection hole is supplied to an internal space of the nozzle portion.   
     
     
         3 . The sheet feeding apparatus according to  claim 2 , wherein the nozzle portion injects air from the injection hole within an injection region of an angle less than or equal to 180 degrees on the end face side of the paper stack in a circumferential direction about the axis. 
     
     
         4 . The sheet feeding apparatus according to  claim 3 ,
 wherein the first injection unit has a body that holds the nozzle portion,   wherein the body has an accommodation hole and a supply path, the accommodation hole accommodating the nozzle portion such that a part of the side face in which the injection hole is formed protrudes, and the supply path communicating with the accommodation hole and externally supplied with air, and   wherein in the nozzle portion, an opening communicating between the supply path and the internal space within a region of an angle less than or equal to 180 degrees in the circumferential direction is formed at a position facing the supply path of the side face.   
     
     
         5 . The sheet feeding apparatus according to  claim 2 , wherein the rotary portion generates driving force for rotation about the axis by externally supplied air. 
     
     
         6 . The sheet feeding apparatus according to  claim 1 , wherein the sheet separating mechanism has a second injection unit configured to fix a second injection direction oriented to the predetermined region and inject air. 
     
     
         7 . A sheet separating apparatus configured to inject air toward a predetermined region of an end face of a paper stack including a plurality of sheets to separate the sheets from each other, the sheet separating apparatus comprising:
 a nozzle portion that is formed in a cylindrical shape extending along an axis intersecting the height direction of the paper stack and having a closed tip and has an injection hole for injecting air toward the predetermined region formed in a side face of the nozzle portion; and   a rotary portion configured to rotate the nozzle portion in a predetermined direction about the axis,   wherein air injected from the injection hole is supplied to an internal space of the nozzle portion.   
     
     
         8 . The sheet separating apparatus according to  claim 7 , wherein the nozzle portion injects the air from the injection hole within an injection region of an angle less than or equal to 180 degrees on the end face side of the paper stack in a circumferential direction about the axis. 
     
     
         9 . The sheet separating apparatus according to  claim 8  further comprising a body that holds the nozzle portion,
 wherein the body has an accommodation hole and a supply path, the accommodation hole accommodating the nozzle portion such that a part of the side face in which the injection hole is formed protrudes, and the supply path communicating with the accommodation hole and externally supplied with air, and 
 wherein in the nozzle portion, an opening communicating between the supply path and the internal space within a region of an angle less than or equal to 180 degrees in the circumferential direction is formed at a position facing the supply path of the side face. 
 
     
     
         10 . The sheet separating apparatus according to  claim 7 , wherein the rotary portion generates driving force for rotation about the axis by externally supplied air.