In a digital inking system having an anilox member that carries a patterned metered layer of ink to a digital imaging member, and a doctor blade that removes excess ink from the surface of the anilox member resulting in the patterned metered layer, an overfill form roller in rolling contact with the anilox member adds an overcoat layer of ink on the patterned metered layer for transfer of both layers of ink to the digital imaging member. The overcoat layer of ink uniformly covers all regions of the anilox member and the mattered metered layer of ink, including lands of the anilox cell walls to make the combined layers of ink pattern-free.

The present subject matter describes a system for ink pumping. In an example implementation, the system comprises a tube having a first end and a second end, a peristaltic pump to pump ink through the tube, a first ink port, and a second ink port. The system includes a first fluid chamber between the first end of the tube and the first ink port. The first fluid chamber is configured to hold the ink entering and exiting the tube through the first end to dampen flow of the pumped ink. The system also includes a second fluid chamber between the second end of the tube and the second ink port. The second fluid chamber is configured to hold the ink entering and exiting the tube through the second end to dampen flow of the pumped ink.

The present subject matter describes a system for ink pumping. In an example implementation, the system comprises a tube having a first end and a second end, a peristaltic pump to pump ink through the tube, a first ink port, and a second ink port. The system includes a first fluid chamber between the first end of the tube and the first ink port. The first fluid chamber is configured to hold the ink entering and exiting the tube through the first end to dampen flow of the pumped ink. The system also includes a second fluid chamber between the second end of the tube and the second ink port. The second fluid chamber is configured to hold the ink entering and exiting the tube through the second end to dampen flow of the pumped ink.

There is disclosed a selective wetting apparatus (2) comprising a roller (20) rotatable about a roller axis (24) and comprising a wettable roller surface (22); an applicator unit (10) having a lip (12) which extends parallel to the roller axis (24) and is radially spaced apart from the roller surface (22) by a gap (30), wherein the applicator unit (10) is to convey liquid agent (14) towards the roller (20) so that the liquid agent (14) forms a liquid bridge (32) over the gap (30) to wet a wettable axial portion of the roller surface (22); and a flow guide (50) to direct a gas flow (56) into a regulated axial portion of the gap (30) to locally prevent formation of a liquid bridge (32), and thereby prevent wetting of a corresponding axial portion of the roller surface (22).

There is disclosed a selective wetting apparatus (2) comprising a roller (20) rotatable about a roller axis (24) and comprising a wettable roller surface (22); an applicator unit (10) having a lip (12) which extends parallel to the roller axis (24) and is radially spaced apart from the roller surface (22) by a gap (30), wherein the applicator unit (10) is to convey liquid agent (14) towards the roller (20) so that the liquid agent (14) forms a liquid bridge (32) over the gap (30) to wet a wettable axial portion of the roller surface (22); and a flow guide (50) to direct a gas flow (56) into a regulated axial portion of the gap (30) to locally prevent formation of a liquid bridge (32), and thereby prevent wetting of a corresponding axial portion of the roller surface (22).

The present subject matter describes a system for pumping ink. In an example implementation, the system includes a piston assembly having a lower chamber and an upper chamber. The lower chamber has an inlet port to receive ink. The upper chamber has a passage to receive ink from the lower chamber and an outlet port to dispense ink. The upper chamber is enclosed by a bellow. An actuating member is engaged with the piston assembly. The actuating member is configured to linearly move the piston assembly. The piston assembly is configured to compress and relax the bellow by the linear movement to pump ink from the lower chamber to the upper chamber and from the upper chamber to the outlet port.

The present subject matter describes a system for pumping ink. In an example implementation, the system includes a piston assembly having a lower chamber and an upper chamber. The lower chamber has an inlet port to receive ink. The upper chamber has a passage to receive ink from the lower chamber and an outlet port to dispense ink. The upper chamber is enclosed by a bellow. An actuating member is engaged with the piston assembly. The actuating member is configured to linearly move the piston assembly. The piston assembly is configured to compress and relax the bellow by the linear movement to pump ink from the lower chamber to the upper chamber and from the upper chamber to the outlet port.

A printing press makes an ink reservoir between an ink fountain and an ink fountain roller and supplies ink to the plate cylinder via a ductor roller advancing and retracting towards and from the ink fountain roller. The printing press is provided with the ink fountain, a base supporting the ink fountain, a slide mechanism sliding the ink fountain along the base in order to control the clearance between the tip of the ink fountain and the ink fountain roller, a cleaner removing the ink from the ink fountain roller, an advancement and retraction mechanism for advancing and retracting the cleaner between a contact position to the ink fountain roller and a non-contact position, and a controller. The controller controls the slide mechanism and the advancement and retraction mechanism, enlarges the clearance in order to pass the dirt with the ink through the clearance, and makes the cleaner in contact with the ink fountain roller to remove the dirt with the ink.

A printing press makes an ink reservoir between an ink fountain and an ink fountain roller and supplies ink to the plate cylinder via a ductor roller advancing and retracting towards and from the ink fountain roller. The printing press is provided with the ink fountain, a base supporting the ink fountain, a slide mechanism sliding the ink fountain along the base in order to control the clearance between the tip of the ink fountain and the ink fountain roller, a cleaner removing the ink from the ink fountain roller, an advancement and retraction mechanism for advancing and retracting the cleaner between a contact position to the ink fountain roller and a non-contact position, and a controller. The controller controls the slide mechanism and the advancement and retraction mechanism, enlarges the clearance in order to pass the dirt with the ink through the clearance, and makes the cleaner in contact with the ink fountain roller to remove the dirt with the ink.

A printing device, a printing machine, and a box making machine are provided with printing cylinders on which printing plates can be mounted, ink supply rolls that are placed on the upstream or downstream sides of the printing cylinders in a sheet-conveying direction and that can be in contact with the printing cylinders, ink supply units that can supply ink to the ink supply rolls, first covers that cover the upper parts of the printing cylinders in the vertical direction and that can be opened and closed, and footholds that cover the vertically upper parts of the ink supply rolls and that can be operated by an operator.