Patent ID: 6257568
Filing Date: 2001-07-10
Classification: B65H

Abstract:
An apparatus adapted to be used for the automatic handling of sheets from which leaflets are formed, said apparatus comprising:a transfer unit for conveying sheets having printed subject matter thereon from a printer;an accumulator station disposed adjacent said transfer unit, said accumulator station being adapted to receive sheets from said transfer unit and to accumulate said sheets in a stack, said accumulator station having a plurality of air-pressure apertures to supply pressurized air against a portion of said stack of sheets;a sensor associated with said accumulator station, said sensor being adapted to generate a signal indicative of whether the height of said stack of sheets in said accumulator station is at least a minimum height;a folder being adapted to make at least one fold in each of said sheets so that said sheets are formed into leaflets;a sheet feeder being adapted to periodically remove sheets from said stack of sheets and feed said sheets from said accumulator station to said folder at a substantially constant rate; anda control mechanism operatively coupled to said sensor and said sheet feeder, said control mechanism being adapted to cause said sheet feeder to remove said sheets from said accumulator station and feed said sheets to said folder as long as the height of said stack of sheets is at least said minimum height as determined by said sensor, said control mechanism being adapted to cause said sheet feeder to cease removal of said sheets from said accumulator station and feed of said sheets to said folder if the height of said stack of sheets falls below said minimum height as determined by said sensor,wherein said sheet feeder comprises a rotatable vacuum roll adapted to remove a sheet from the bottom of said stack of sheets at said accumulator station, a vacuum generator operatively coupled to said vacuum roll for creating a suction pressure within an interior portion of said vacuum roll, and a motor for causing said vacuum roll to be rotatably driven at a substantially constant rate, andwherein said control mechanism comprises an actuator mechanism operatively coupled to said vacuum generator for selectively eliminating said suction pressure, in response to said signal generated by said sensor, while said vacuum roll is being rotatably driven by said motor.