Sheet handling apparatus

Abstract

According to one embodiment, a pickup device includes a separation mechanism for applying, to a to-be-subsequently-fed mail item picked up from accumulated mail items, a separation force exerting in a direction opposite to a mail item pickup direction. The separation mechanism comprises an outer drum with suction holes that face the to-be-subsequently-fed mail item during rotation, an inner drum provided inside and concentric with the outer drum and having air holes that overlap with the suction holes during rotation, a pump for drawing air through the suction holes facing the to-be-subsequently-fed mail item and the air holes overlapping with them to attach the to-be-subsequently-fed mail item to the outer peripheral surface of the outer drum. A controller rotates the inner and outer drums in association with each other to apply a sufficient separation force to the to-be-subsequently-fed mail item.

1 . A sheet handling apparatus comprising:
 a pickup mechanism which is brought into contact with an outermost sheet of a plurality of accumulated sheets, and rotates to pick up the outermost sheet in a direction parallel to a surface of the outermost sheet;   a separation mechanism which applies a separation force to a to-be-subsequently-fed sheet included in the accumulated sheets and picked up by the pickup mechanism simultaneously with the outermost sheet, the separation force being exerted in a direction opposite to the direction of pickup of the outermost sheet;   the separation mechanism comprising:
 an outer rotation body including a plurality of columns of suction holes, the columns of suction holes sequentially facing the to-be-subsequently-fed sheet when the outer rotation body rotates in the opposite direction; 
 an inner rotation body rotatably provided inside and concentric with the outer rotation body, the inner rotation body including a plurality of columns of air holes, the columns of air holes overlapping with the respective columns of suction holes when the inner rotation body rotates; 
 a suction unit which draws air through at least one column of suction holes included in the columns of suction holes and through at least one column of air holes included in the columns of air holes and overlapping with the at least one column of suction holes, when the at least one column of suction holes face the to-be-subsequently-fed sheet, thereby attaching the to-be-subsequently-fed sheet to an outer peripheral surface of the outer rotation body; and 
 a control unit which rotates the outer and inner rotation bodies in association with each other. 
   
     
     
         2 . The sheet handling apparatus according to  claim 1 , wherein the control unit rotates the inner rotation body with a relative angular position thereof deviated from a relative angular position of the outer rotation body to prevent the drawn air from leaking through a subsequent column of suction holes which are included in the columns of suction holes and subsequently face the to-be-subsequently-fed sheet in accordance with the rotation of the outer rotation body in the opposite direction. 
     
     
         3 . The sheet handling apparatus according to  claim 2 , wherein the control unit rotates the outer rotation body at a constant speed in the opposite direction, and accelerates and decelerates the inner rotation body. 
     
     
         4 . The sheet handling apparatus according to  claim 1 , wherein the control unit rotates the outer rotation body and the inner rotation body to adjust a degree of overlap between the at least one column of suction holes facing the to-be-subsequently-fed sheet and the at least one column of air holes, thereby to adjust the separation force applied to the to-be-subsequently-fed sheet. 
     
     
         5 . A sheet handling apparatus comprising:
 a pickup mechanism which is brought into contact with an outermost sheet of a plurality of accumulated sheets, and rotates to pick up the outermost sheet in a direction parallel to a surface of the outermost sheet;   a separation mechanism which applies a separation force to a to-be-subsequently-fed sheet included in the accumulated sheets and picked up by the pickup mechanism simultaneously with the outermost sheet, the separation force being exerted in a direction opposite to the direction of pickup of the outermost sheet;   the separation mechanism comprising:
 an outer rotation body including a plurality of columns of suction holes, the columns of suction holes sequentially facing the to-be-subsequently-fed sheet when the outer rotation body rotates in the opposite direction; 
 an inner rotation body rotatably provided inside and concentric with the outer rotation body, the inner rotation body including a plurality of columns of air holes, the columns of air holes overlapping with the respective columns of suction holes when the inner rotation body rotates; 
 a chamber defined in the inner rotation body and communicating with an outside of the outer rotation body through the columns of suction holes and the respective columns of air holes overlapping therewith; 
 a suction unit which draws air from the chamber through at least one column of suction holes included in the columns of suction holes and through at least one column of air holes included in the columns of air holes and overlapping with the at least one column of suction holes, when the at least one column of suction holes face the to-be-subsequently-fed sheet, thereby attaching the to-be-subsequently-fed sheet to an outer peripheral surface of the outer rotation body; and 
 a control unit which rotates the outer and inner rotation bodies in association with each other. 
   
     
     
         6 . The sheet handling apparatus according to  claim 5 , wherein when the to-be-subsequently-fed sheet is attached to an outer peripheral surface of the outer rotation body, the control unit rotates the inner rotation body with a relative angular position thereof deviated from a relative angular position of the outer rotation body to prevent the chamber from communicating with a subsequent column of suction holes which are included in the columns of suction holes and subsequently face the to-be-subsequently-fed sheet in accordance with the rotation of the outer rotation body in the opposite direction. 
     
     
         7 . The sheet handling apparatus according to  claim 6 , wherein the control unit rotates the outer rotation body at a constant speed in the opposite direction, and accelerates and decelerates the inner rotation body in the opposite direction. 
     
     
         8 . The sheet handling apparatus according to  claim 5 , wherein the control unit rotates the outer rotation body and the inner rotation body to adjust a degree of overlap between the at least one column of suction holes facing the to-be-subsequently-fed sheet and the at least one column of air holes, thereby to adjust the separation force applied to the to-be-subsequently-fed sheet. 
     
     
         9 . A sheet handling apparatus comprising:
 a pickup mechanism which is brought into contact with an outermost sheet of a plurality of accumulated sheets, and rotates to pick up the outermost sheet in a direction parallel to a surface of the outermost sheet;   a separation mechanism which applies a separation force to a to-be-subsequently-fed sheet included in the accumulated sheets and simultaneously picked up by the pickup mechanism with the outermost sheet, the separation force being exerted in a direction opposite to the direction of pickup of the outermost sheet;   the separation mechanism comprising:
 an outer rotation body including at least one suction hole temporarily facing the to-be-subsequently-fed sheet when the outer rotation body rotates in the opposite direction; 
 an inner rotation body rotatably provided inside and concentric with the outer rotation body, the inner rotation body including at least one air hole that at least partially overlaps with the at least one suction hole when the inner rotation body rotates; 
 a suction unit which draws air through at least one suction hole and through at least one air hole, the at least one air hole at least partially overlapping with the at least one suction hole when the at least one suction hole faces the to-be-subsequently-fed sheet, thereby attaching the to-be-subsequently-fed sheet to an outer peripheral surface of the outer rotation body; and 
 a control unit which rotates the outer and inner rotation bodies to adjust a degree of overlap between the at least one suction hole and the at least one air hole.