Cylinder throwing-off/throwing-on controller for a multicolor lithographic rotary press

A cylinder throwing-off/throwing-on controller for a multicolor lithographic rotary press which comprises a plurality of printing units each having paired blanket cylinders movable between a printing position and a non-printing position and adapted to successively perform printing on a supplied paper web in different colors;

• and a paper feed unit adapted to supply a paper web of a paper roll and to splice a leading end of a new paper roll to the paper web of the currently used paper roll in response to a paper splicing signal which is output from splicing signal output means when the currently used paper roll runs out due to printing operation of the printing units, the cylinder throwing-off/throwing-on controller comprising:
• a pulse generator connected to a member rotating due to operation of the rotary press and adapted to output a pulse signal every time the paper web travels a predetermined distance during the operation of the rotary press;
• cylinder throwing-off timing adjustment means including count means and setting means for setting a target count value in advance, the count means starting in response to the paper splicing signal from the splicing signal output means, counting the pulse signal from the pulse generator, and outputting a cylinder throwing-off signal when the counted value reaches the target count value;
• cylinder throwing-on timing adjustment means provided for each of the printing units, the cylinder throwing-on timing adjustment means starting in response to the cylinder throwing-off signal and outputting a cylinder throwing-on signal after elapse of a preset period of time;
• and
• cylinder throwing-off/throwing-on means for simultaneously moving the blanket cylinders of the plurality of printing units from the printing position to the non-printing position in response to the cylinder throwing-off signal and for sequentially moving the blanket cylinders of the plurality of printing units from the non-printing position to the printing position in response to the cylinder throwing-on signal, from the furthest-upstream printing unit toward the furthest-downstream printing unit.