Patent ID: 11292244

Abstract:
A ductor roller for printing machines has a shaft provided with an air supply pipe, plural individual ductor rollers, and plural electromagnetic valves, both connected to the shaft. The individual ductor rollers advance pneumatically by the electromagnetic valves. The individual ductor rollers have housings that are associated with the shaft and configured to move forward and backward; roller members configured to contact with the ink fountain roller and an ink distribution roller; and bearings connecting the roller members to the housings. The electromagnetic valves are placed in the housings. Protection members for the electromagnetic valves are oil-resistant, have circularly cylindrical or arc-like covers, and are associated with the shaft. They cover the side ends of the housings and are placed in the clearance between the individual ductor rollers. The protection members do not need an exchange, discharge cleaning liquid for printing machines along troughs and prevent the electromagnetic valves from being contaminated by the cleaning liquid.