Sheet stack loader and sheet loading method

Abstract

A sheet stack loader includes a loading table to support a first folded sheet bundle, an elevator to lift the first folded sheet bundle from the loading table, and a conveyer to convey a second folded sheet bundle into a space between the loading table and the first folded sheet bundle, wherein the space is created by the elevator.

1 . A sheet stack loader comprising:
 a loading table to support a first folded sheet bundle;   an elevator to lift the first folded sheet bundle from the loading table; and   a conveyer to convey a second folded sheet bundle into a space between the loading table and the first folded sheet bundle, the space being created by the elevator.   
     
     
         2 . The sheet stack loader according to  claim 1 , wherein the elevator includes a motor. 
     
     
         3 . The sheet stack loader according to  claim 2 , wherein the elevator includes:
 a shaft attached to the motor;   an elevating member attached rotatably to the shaft to lift the first folded sheet bundle on the loading table; and   a controller provided at a connection portion of the shaft and the elevating portion to restrict a rotation range of the elevating member.   
     
     
         4 . The sheet stack loader according to  claim 3 , wherein the elevating member is restricted by the controller so as not to be inclined below from almost the horizontal direction. 
     
     
         5 . The sheet stack loader according to  claim 4 , wherein the elevator includes a spring attached to the shaft so as to return the elevating member almost to its original horizontal state when the elevating member is rotated. 
     
     
         6 . The sheet stack loader according to  claim 3 , wherein the elevating member and the loading table have respectively a comb shape so as to make opposite sides thereof mesh with each other. 
     
     
         7 . A sheet stack loader for saddle-stitching a sheet bundle conveyed from a sheet output apparatus at a central part, folding the sheet, then conveying the sheet bundle by conveying means, and loading the sheet bundle on a folded sheet bundle stacker, the sheet stack loader comprising:
 a loading table for loading the sheet bundle conveyed from the conveying means;   elevating means arranged on both sides of the loading table for lifting the sheet bundle on the loading table from the loading table and setting a space between themselves and the loading table; and   driving means for driving vertically the elevating means.   
     
     
         8 . The sheet stack loader according to  claim 7 , wherein the elevating means includes:
 a shaft attached to the driving means;   an elevating member attached rotatably to the shaft for lifting the sheet bundle on the loading table; and   control means installed at a connection portion of the shaft and the elevating member for restricting a rotation range of the elevating member.   
     
     
         9 . The sheet stack loader according to  claim 8 , wherein the elevating member is restricted by the control means so as not to be inclined below almost the horizontal direction. 
     
     
         10 . The sheet stack loader according to  claim 8 , wherein the sheet bundle elevating means includes posture control means for returning the elevating member almost to its original horizontal state when the elevating member is rotated. 
     
     
         11 . The sheet stack loader according to  claim 8 , wherein a side of the elevating member opposite to the loading table has a comb structure and a side of the loading table has a comb structure for meshing with the comb portion of the elevating member. 
     
     
         12 . The sheet stack loader according to  claim 11 , wherein depending on a length of teeth of the comb of the elevating member, a distance between the opposite teeth of the comb of the elevating member is set smaller than a width of sheets to be loaded. 
     
     
         13 . The sheet stack loader according to  claim 7  further comprising:
 a sensor installed at a top end of the folded sheet bundle stacker for detecting that the sheet bundle lifted by the elevating member is loaded up to the top end of the folded sheet bundle stacker,   wherein on the basis of detection results of the sensor, a limit loading amount is controlled.   
     
     
         14 . A sheet loading method comprising:
 supporting a first folded sheet bundle on a loading table;   lifting the first folded sheet bundle from the loading table to form a space between the first folded sheet bundle and the loading table; and   conveying a second folded sheet bundle into the space.   
     
     
         15 . A sheet loading method for saddle-stitching a sheet bundle conveyed from a sheet output apparatus at a central part, folding the sheet, then conveying the sheet bundle by conveying means, and loading the sheet bundle on a loading table in a folded sheet bundle stacker, the method comprising:
 moving up sheet bundle elevating means installed on both sides of the loading table, setting a space between the sheet bundle elevating means and the loading table, and then conveying the folded sheet bundle into the space;   moving down the sheet bundle elevating means after conveying the sheet bundle to the loading table and rotating the sheet bundle elevating member of the sheet bundle elevating means in contact with the sheet bundle loaded on the loading table;   moving down the sheet bundle elevating means until the sheet bundle elevating member reaches under the loading table by rotating the sheet bundle elevating member and returning the rotated sheet bundle elevating member almost to the horizontal state; and   loading the sheet bundle from bottom by repeating a series of operations of moving up the sheet bundle elevating means and lifting the sheet bundle on the loading table by the sheet bundle elevating member of the sheet bundle elevating means.   
     
     
         16 . The sheet loading method according to  claim 15 , wherein a sheet bundle sensor is installed at a top end of the folded sheet bundle stacker, and when the sheet bundle elevating means moves up, an uppermost sheet bundle of a plurality of sheet bundles lifted by the sheet bundle elevating means is detected.