Method and apparatus for controlling rotary presses in power failure

A method for controlling, in a power failure, a rotary press having a printing section and a folding section separately driven by independent drive sources, with a printing material, while being braked by a paper feeding section, being pulled by at least the folding section and brought into contact with a blanket cylinder of the printing section to produce printing impressions on the printing material;

• the method comprising steps of:
• changing over the braking of the printing material in the paper feeding section to a braking mode with a constant braking force that is greater than the braking force before the power failure upon interruption of power feeding due to a main power failure;
• outputting a power failure signal upon detection of a voltage drop as the result of the power failure and changing over the power supply to a battery power supply;
• separating the blanket cylinder that is at press from the printing material by applying the power failure signal and a power from the battery power supply;
• and
• decelerating and bringing to a halt a printing material pulling mechanism in the folding section by applying the power failure signal and the power from the battery power supply.

An apparatus for controlling, in a power failure, a rotary press having independent drive sources in a printing section and a folding section, a printing material braking mechanism for braking the pulling of the printing material in the paper feeding section, a blanket cylinder moving mechanism for selectively moving the blanket cylinder in the direction making contact with, or separating from, the printing material in the printing section, and a printing material pulling mechanism for pulling the printing material by the rotation of the drag roller at least on the upstream side of the folding section, the apparatus comprising:

• a printing material braking mechanism adapted so that braking force can be changed over to a braking mode with a constant braking force upon interruption of power feeding in a main power failure;
• an uninterruptible power supply having a power failure signal output section whose power input side connected to an external power supply for outputting a power failure signal by detecting a voltage drop on the power input side thereof in the event of a power failure, and a battery power supply for outputting a power to the power output side thereof along with the voltage drop on the power input side in a power failure;
• a drive source control section provided for each drive source for the printing section and the folding section for controlling the rotation of the drive sources;
• a rotation control signal output section for outputting a signal for synchronously controlling the rotation of each drive source;
• a moving mechanism controlling section for operating the blanket cylinder moving mechanism so as to selectively causing the blanket cylinder to make contact with, or separate from, the printing material, and
• at least a drag roller drive source control section of the printing material pulling mechanism on the most upstream side of the folding section, the rotation control signal output section, and the moving mechanism control section being connected to the power output side of the uninterruptible power supply,
• at least the rotation control signal output section and the moving mechanism control section being connected to the power failure signal output section of the uninterruptible power supply so that the blanket cylinder is separated from the printing material based on the signal output by the power failure signal output section, and the printing material pulling mechanism on the most upstream side of the folding section is controlled with the output signal output by the rotation control signal output section and brought to a halt.