Abnormality detector for nozzle type dampening systems

Abstract

An abnormality detector for nozzle-type dampening systems in offset printers, for injecting dampening solution through nozzles onto a receiving part by intermittently opening nozzles with nozzle opening signals generated by a nozzle operation controller, which detects the abnormal injection of dampening solution through the dampening system nozzles is disclosed. The abnormality detector comprises electrically conductive members provided in a dampening solution flying zone between the nozzles and the receiving part, a dampening solution stream detecting means for detecting a voltage generated in accordance with the state of dampening solution injection between the nozzles and the electrically conductive members, a comparing means for comparing a detecting signal generated from the injected dampening solution detecting means with a predetermined threshold value, an intermediate processing means that is brought into a signal outputt state with a nozzle opening signal generated from a nozzle operation controller, and releases the signal output state with an output signal from the comparing means, and an abnormality judgment means for generating an abnormality judgment signal when a nozzle opening signal is received from the nozzle operation controller under the state where the output signal is being received from the intermediate processing means.

Dependencies are inferred from the claim text.