Printing – Rolling contact machines – Rotary
Patent
1991-12-05
1993-05-25
Fisher, J. Reed
Printing
Rolling contact machines
Rotary
B65H 3112, B65H 502
Patent
active
052130363
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a sheet feeding apparatus to feed sheets of corrugated cardboard and the like piled up in a hopper to a printing press piece by piece.
BACKGROUND TECHNOLOGIES
Conventional sheet feeding apparatus have, at bottom of a hopper, a kicker moving back and forth to push out the lowest bottom sheet in the hopper, or an apparatus having a suction conveyor and controlling only conveyor speed with motor.
A sheet feeding apparatus of the type having a kicker has such disadvantages that sheets are damaged at their surfaces contacting with the kicker in case of sheets of lower stiffness and that sheets are not always timely fed to the printing press. A sheet feeding apparatus of the type having a suction conveyor and controlling only conveyor speed with a motor has such a disadvantage that the accuracy to feed a sheet to the printing press is poor due to the untimely suction of sheets.
DISCLOSURE OF THE INVENTION
It is an object of this invention to provide a sheet feeding apparatus enabling the elimination of the said disadvantages of conventional apparatuses and to feed sheets without vacancies of shoot feeding and without damage to sheets.
Another object of this invention is to provide a sheet feeding apparatus enabling the improvement of sheet feeding accuracy by correction of mechanical error caused by suction of sheets by the conveyor.
A further object of this invention is to provide a sheet feeding apparatus enabling the correction of parallel error against a plate cylinder.
The sheet feeding apparatus of the first invention for feeding sheets piled up in a hopper, piece by piece, to a printing press from a suction conveyor installed at bottom of the hopper, comprising, sheets being transferred, and cylinder of printing press and for adjusting phase of the sheet to phase of a press plate on the plate cylinder with a detection signal of the sensor, errors at suction of sheets.
The sheets feeding apparatus of the second invention for feeding sheets piled up in a hopper, piece by piece, to a printing press from first and second suction conveyors installed in parallel at bottom of the hopper, comprising, front edges of sheets being transferred, front edges of sheets being transferred, a plate cylinder of printing press and for adjusting phase of the sheet to phase of a press plate on the plate cylinder with a detection signal of the first sensor, and of the plate cylinder of printing press for adjusting phase of the sheet to phase of the press plate with the detection signal of the first sensor, and for correcting parallel error of the sheet against the press plate with detection signals of the first and second sensors, error and parallel error at suction of sheets.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows the construction of an embodiment of the first invention.
FIG. 2 is a plan view of the embodiment shown in FIG. 1.
FIG. 3 is a plan view of an embodiment of the second invention.
FIG. 4 and FIG. 5 show the construction of the embodiment shown in FIG. 3.
BEST MODE FOR EXECUTING THE INVENTION
FIG. 1 and FIG. 2 are a construction drawing and a plan view, respectively, of an embodiment where a sheet feeding apparatus of the first invention was applied to a flexographic printing press.
This sheet feeding apparatus includes a hopper 1 to pile up corrugated cardboard sheets 5, a suction conveyor 3 extending from a bottom of the hopper to a plate cylinder 2 of a printing press, a servo motor 4 for driving the suction conveyor 3, and a sensor 6 provided to detect front edges of sheets for information of the suction conveyor 3.
A timing belt is used for the suction conveyor 3, and non-slippery material is adhered to surface of the belt. Because the suction conveyor is not a feature of this invention, a usual suction conveyor can be used.
The servo motor 4 for driving the conveyor is controlled by a control unit as shown in FIG. 1, and this control unit comprises a servo amplifier 17 to control speed of the servo motor 4, a pulse tacho-generator (PG) 13 installed at the
REFERENCES:
patent: 4232859 (1980-11-01), Tokuno
patent: 4541624 (1985-09-01), Sasage et al.
patent: 4774446 (1988-09-01), Salazar et al.
Miyagawa Tatsuyuki
Tokuno Masateru
Fisher J. Reed
Reliance Electric Ltd.
SK Engineering Ltd.
LandOfFree
Sheet feeding apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sheet feeding apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sheet feeding apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-890970