The present invention relates to a device for replacing the printing roller in a printing unit, in particular for in line rotary flexographic machines.

The present invention relates to a device for replacing the printing roller in a printing unit, in particular for in line rotary flexographic machines.

Variable format offset printing machine having a central impression cylinder The printing machine comprises a central impression cylinder (1) on which a web printable substrate (B) is supported and a plurality of printing stations arranged around the central impression cylinder (1). Each printing station comprises a blanket cylinder (2) of variable diameter, a plate cylinder (3) of variable diameter, and an offset inking unit (4). Said blanket cylinder (2), plate cylinder (3) and offset inking unit (4) are individually movable between respective withdraw positions and respective multiple working positions for different diameters of the blanket and plate cylinders (2, 3). At least one of said printing stations has the axis of the blanket cylinder (2) and the axis of the plate cylinder (3) comprised in an inclined first plane (P1) which does not comprise the axis of the central impression cylinder (1) at any of said multiple working positions for different diameters of the blanket and plate cylinders (2, 3).

Variable format offset printing machine having a central impression cylinder The printing machine comprises a central impression cylinder (1) on which a web printable substrate (B) is supported and a plurality of printing stations arranged around the central impression cylinder (1). Each printing station comprises a blanket cylinder (2) of variable diameter, a plate cylinder (3) of variable diameter, and an offset inking unit (4). Said blanket cylinder (2), plate cylinder (3) and offset inking unit (4) are individually movable between respective withdraw positions and respective multiple working positions for different diameters of the blanket and plate cylinders (2, 3). At least one of said printing stations has the axis of the blanket cylinder (2) and the axis of the plate cylinder (3) comprised in an inclined first plane (P1) which does not comprise the axis of the central impression cylinder (1) at any of said multiple working positions for different diameters of the blanket and plate cylinders (2, 3).

An adjuster for first and second print rollers carried on respective first and second supports has a first spindle extending along and rotatable about an axis between the supports and formed with a pair of axially spaced screwthreads of the same hand but of different pitches. One of the screwthreads is threaded into the first support and the other into a first nut rotatable about the axis and axially fixed in the second support. A mechanism serves for either arresting the nut against rotation relative to the second support and or rotating the nut relative to the second support.

An adjuster for first and second print rollers carried on respective first and second supports has a first spindle extending along and rotatable about an axis between the supports and formed with a pair of axially spaced screwthreads of the same hand but of different pitches. One of the screwthreads is threaded into the first support and the other into a first nut rotatable about the axis and axially fixed in the second support. A mechanism serves for either arresting the nut against rotation relative to the second support and or rotating the nut relative to the second support.

The present invention relates to a device for replacing the printing roller in a printing unit, in particular for in line rotary flexographic machines.