Patent ID: 7198264
Filing Date: 2007-04-03
Classification: B65H

Abstract:
1. A sheet supplying device for feeding a sheet from a sheet stack configured by stacking plural sets of sheets collated by page order, each of which corresponds to one volume, for each set of sheets, in a state where the sheets are superimposed on one another so as to be sequentially offset from one another in a fore-to-aft direction, the sheet supplying device comprising: a frame; a sheet table arranged in the frame for vertical movement, the sheet stack being placed on said sheet table; a front vertical plate attached to the frame and arranged in proximity to the front of the sheet table with the sheet stack placed thereon; a sensor attached to the frame in the rear of the sheet table for detection of a sheet; first transport means attached to the frame above a rear end of the sheet table for sucking a rear end of a sheet in an uppermost position of the sheet stack placed on the sheet table so as to move the sheet to a detection position of the sensor toward the rear of the sheet table; second transport means arranged adjacent to the front of the transport means above the sheet table and attached to the frame for sucking the sheet in the uppermost position moved to the detection position of the sensor by the first transport means so as to transport the sheet forward beyond the front vertical plate; and control means controlling suction operations of the first and second transport means, wherein each of the first and second transport means includes: a suction roller rotatably supported on the frame above the sheet table and having plural suction holes on a periphery extending horizontally across the sheet table; a drive belt rotating the suction roller for guiding a sheet sucked up by the suction roller in a tangent direction of the suction roller; a drive pulley arranged for rotating the drive belt; a motor attached to the frame so as to rotate the drive pulley; a common vacuum pump; an intake pipe connecting the suction roller with the vacuum pump; and a solenoid valve arranged in the middle of the intake pipe, and wherein the suction roller of the first transport means is always rotated in a direction for transporting a sheet toward the rear of the sheet table by the related motor while the suction roller of the second transport means is always rotated in a direction for transporting a sheet toward the front of the sheet table by the related motor, and wherein the control means (i) allows the first transport means to start the suction operation by opening the solenoid valve of the first transport means, and allows the first transport means to suck the sheet in the uppermost position of the sheet stack so as to move the sheet to the detection position of the sensor, (ii) when it is determined on the basis of a detection signal from the sensor that the sheet in the uppermost position has reached the detection position of the sensor, allows the first transport means to stop the suction operation by closing the solenoid valve of the first transport means and, also, the second transport means to start the suction operation by opening the solenoid valve of the second transport means, allows the second transport means to suck the sheet in the uppermost position so as to transport the sheet beyond the front vertical plate, and allows the second transport means to stop the suction operation by closing the solenoid valve of the second transport means after completion of the transportation, and (iii) repeats the operations (i) and (ii) for the subsequent sheets of the sheet stack, until the sheets in a set of sheets, which corresponds to one volume, are all transported.