摘要:
In a high speed sheet printing or coating machine there is a tendency for the sheets to move about as they are being fed to the datum stops, so that precise registration is not achieved. This is remedied by exerting a damping force which pulls each sheet continuously towards a fixed support surface 12 before and during registration and during printing or coating. The damping force comprises vacuum and/or magnetic forces which settle each sheet rapidly on the fixed support surface as it is fed into contact with the datum stops. The vacuum force is provided by drawing air through an array of holes 26 in the fixed support surface into an underlying chamber 24 evacuated through a pipe 28 by a vacuum pump, and is adjustable either by controlling the flow rate through the pump or by controllably venting the chamber or pipe to atmosphere. The magnetic force is provided by a row of permanent or electro-magnets 22 in the fixed support surface, and can be adjusted by varying their position perpendicular to that surface. Alternatively, in the case of electro-magnets, the magnetic force is adjustable by varying their supply of electrical power.
摘要:
A printing device for printing elements in sheet fond: a platen press 310 for depositing onto each sheet 10, by stamping, colored or metalized film from at least one stamping foil; a conveyor using a succession of gripper bars for moving each sheet 10 individually through the platen press 310; a blower member separates each stamping foil from each sheet as it leaves the platen press, the blower member being movable between a work position, in which it is able to operate from the transfer region in which the gripper bars 610 run to the exit of the platen press 310, and a withdrawn position, in which it keeps away from said transfer region.
摘要:
A printing device for printing elements in sheet fond: a platen press 310 for depositing onto each sheet 10, by stamping, colored or metalized film from at least one stamping foil; a conveyor using a succession of gripper bars for moving each sheet 10 individually through the platen press 310; a blower member separates each stamping foil from each sheet as it leaves the platen press, the blower member being movable between a work position, in which it is able to operate from the transfer region in which the gripper bars 610 run to the exit of the platen press 310, and a withdrawn position, in which it keeps away from said transfer region.
摘要:
An air dispenser attached to a printing press has a tube with a plurality of holes for directing air toward sheet material moving toward the gripper of the printing press to ensure registration and accurate feeding of the sheet material to the gripper of the printing press.