An example method comprises identifying, by a processor, a gap in a housing of a printing apparatus and positioning an inlet of a conduit inside the housing proximate the gap. The inlet is fluidly connected to a fan, and the fan is powered to create a pressure differential across the housing to minimize the amount of air inside the housing being able to escape the housing via the gap.

A printing machine includes a sliding carriage to provide isolation between internal volumes, to enable a print medium container to be exchanged without disrupting a print operation. Convective air flow between the volumes is maintained during normal operation.

An example method comprises identifying, by a processor, a gap in a housing of a printing apparatus and positioning an inlet of a conduit inside the housing proximate the gap. The inlet is fluidly connected to a fan, and the fan is powered to create a pressure differential across the housing to minimize the amount of air inside the housing being able to escape the housing via the gap.

A printing press (10) has at least one electric motor (14), which is arranged at a distance of less than 0.5 m from an emission source (18). At least one explosion protection wall (22) is provided, such that the thread measure (F) between the emission source (18) and the electric motor (14) is greater than 0.5 m.

A printing press (10) has at least one electric motor (14), which is arranged at a distance of less than 0.5 m from an emission source (18). At least one explosion protection wall (22) is provided, such that the thread measure (F) between the emission source (18) and the electric motor (14) is greater than 0.5 m.

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.

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.

A liquid transfer apparatus includes: rollers configured to transfer supplied liquid to a blanket cylinder; a roller holding device configured to detachably hold the rollers and perform a rotating operation to move any one of the rollers to a predetermined position facing the blanket cylinder; and a contact-separation unit configured to bring the roller held by the roller holding device and disposed at the predetermined position into and out of contact with the blanket cylinder.

A liquid transfer apparatus includes: rollers configured to transfer supplied liquid to a blanket cylinder; a roller holding device configured to detachably hold the rollers and perform a rotating operation to move any one of the rollers to a predetermined position facing the blanket cylinder; and a contact-separation unit configured to bring the roller held by the roller holding device and disposed at the predetermined position into and out of contact with the blanket cylinder.

The invention relates to a method of protecting a camera (2) for inspecting printed work during printing from soiling. A transparent protective element (7) is placed here between the camera (2) and the printed work for inspection, and the protective element (7) is replaced when the transparency thereof decreases. The transparent protective element (7) can form part of a strip of transparent film (7) which is unwound from a supply reel (9) and wound onto a take-up reel (10). The decrease in transparency can be determined on the basis of a recording made by the camera (2). The invention also relates to a device (1) for protecting such a camera (2) from soiling, comprising a transparent protective element (7) to be placed between the camera (2) and the printed work for inspection; and means ( ) for replacing the protective element (7) when the transparency thereof decreases. The replacing means (8) can comprise a strip of transparent material (7) supplied on a supply reel (9) and be configured to unwind the film (7) from a supply reel (9) and wind it onto a take-up reel (10). The supply reel (9) and the take-up reel (10) can be received in a cassette (3) which has between the supply reel (9) and the take-up reel (10) an opening (4) along which the transparent film (7) is moved. Finally the invention further relates to a printing installation in which a camera (2) with such a protective device (1) is applied.