US 6,802,256 B1 · Method and device for preventing uncontrolled spread of powder in a printing machine

Abstract

A method for conveying sheets, which have been printed in a printing machine, through a sheet delivery system above a sheet deposit pile by a sheet conveying device and, at the same time, dusting the sheets with a powder, and preventing uncontrolled spread of excess powder, includes interrupting a powder-laden air flow extending in a direction towards the printing machine along an empty strand of the sheet conveying device in a housing of the sheet delivery system at least at one interruption location between a free end of the sheet delivery system and the printing machine, so that transport of entrained powder in a direction towards the printing machine is prevented; a prevention device for performing the method; a sheet delivery system including the prevention device; and a sheet-fed printing machine in combination with the sheet delivery system.

Claims46

Dependent claims

A method for conveying printed sheets, which comprises:

conveying printed sheets through a delivery housing of a printing machine with a chain conveyor having gripper systems, a conveyor transport-run operatively running along a first conveyor path in a sheet transport direction and a conveyor return-run running along a second conveyor path in a reverse direction, and simultaneously dusting the printed sheets with a powder by using a dusting device and preventing uncontrolled spread of excess powder borne by an air flow induced by the conveyor return-run;
limiting the air flow by using side walls of the delivery housing and an upper limiting device disposed above the conveyor return-run and a lower limiting device disposed below the conveyor return-run between the conveyor transport-run and the conveyor return-run;
defining an interruption location with the upper and lower limiting devices at the second conveyor path;
and
interrupting the air flow at the interruption location.

2 more elements

A sheet-fed printing machine, comprising:

at least one printing unit;
a sheet delivery including a housing having side walls;
a piling station for piling a stack of sheets;
a dusting device disposed within said housing for powdering printed sheets;
an operatively revolving chain conveyor mounted within said housing and having gripper systems and a conveyor transport-run operatively running in a direction towards said piling station, said conveyor transport-run transporting printed sheets from said printing unit to said piling station;
a conveyor return-run operatively running along a conveyor path in a reverse direction, causing a dust laden air flow directed towards said printing unit in the surroundings of said conveyor return-run;
an upper limiting device adapted for limiting the dust laden air flow above said conveyor return-run;
a lower limiting device adapted for limiting the dust laden air flow below said conveyor return-run;
said lower limiting device being disposed below said conveyor return-run between said conveyor transport-run and said conveyor return-run;
said limiting devices extending across the width of said housing and defining an interruption location at said conveyor path of said conveyor return-run;
and
interrupting devices adapted for interrupting the dust-laden air flow at said interruption location.

9 more elements

Dependencies are inferred from the claim text.

Method and device for preventing uncontrolled spread of powder in a printing machine

Life of this patent

Method and device for preventing uncontrolled spread of powder in a printing machine

Life of this patent

Abstract

Claims46