Printer ductor roller and electromagnetic valve protection member built into ductor roller

A ductor roller for a printing machine, the ductor roller comprising:

• a shaft provided with an air supply pipe;
• a plurality of individual ductor rollers;
• and
• a plurality of electromagnetic valves, wherein
• the individual ductor rollers and the electromagnetic valves are connected to the shaft, and the individual ductor rollers are advanced pneumatically by said electromagnetic valves,
• the individual ductor rollers are provided with housings associated with the shaft and configured to move forward and backward;
• roller members configured to contact an ink fountain roller and an ink distribution roller;
• and bearing members connecting the roller members to the housings,
• said electromagnetic valves are located in said housings, and
• protection members for the electromagnetic valves are located within a clearance between the individual ductor rollers, are oil-resistant, are associated with and supported by the shaft, and are provided with circularly cylindrical covers covering at least upper portions of side ends of said housings, and
• said circularly cylindrical covers have a trough on an outer circular face of the circularly cylindrical covers and, in an axial direction of said shaft, the trough is lower at a central portion of the circularly cylindrical covers and higher at side end portions of the circularly cylindrical covers.