Abstract:
A dampening water spraying device includes: a nozzle for spraying dampening water; a nozzle holder including, an end surface connectable to the nozzle, and an outer peripheral portion provided with at least one groove; and a nozzle fixing member including, an opening portion adapted to expose at least a spout of the nozzle, and an inner peripheral portion provided with a nozzle attachment/detachment moving portion opposed to and engageable with the groove, the nozzle fixing member being adapted to be fastened to the nozzle holder while clamping the nozzle between the nozzle fixing member and the nozzle holder; wherein the nozzle fixing member includes an outer peripheral portion provided with a handhold portion for making it possible to to manually rotate the nozzle fixing member, thereby allowing to rapidly and readily conduct replacement of the nozzle.
Abstract:
A control system for regulating the composition of an emulsion ink made from an oil-based ink and a water-based fountain solution using a mixing and dispersing apparatus includes a liquid level sensor, means responsive to the liquid level sensor for maintaining a proper liquid level in the mixing and dispersing apparatus, and means for producing an emulsion ink with a water content value which is within a predetermined range from a desired water content value. The producing means includes a feedforward controller and a feedback controller for regulating water-based fountain solution input rate to the mixing and dispersing apparatus.
Abstract:
A coating system for coating print carriers includes at least one pump, at least one selection valve, a first metering device and a second metering device. The first metering device and the second metering device are constructed differently from one another with respect to metering principles thereof. The pump and the selection valve are assembled into a modular supply unit constructed so as to be compatible both with the first and with the second metering device. A coating machine, such as a printing or varnishing machine which includes the coating system, is also provided.
Abstract:
A rotary printing press has one or two inking rollers each in rolling engagement with both an ink supply cylinder and a plate cylinder. Each inking roller is identically supported by means comprising a first pair of roller support members mounted one adjacent each end of the ink supply cylinder for pivotal motion about the axis of that cylinder, and a second pair of roller support members mounted to the first pair for pivotal motion about an axis parallel to the axis of the ink supply cylinder, the second pair of roller support members rotatably supporting one inking roller therebetween. Adjusting screws act between the two pairs of roller support members for adjustably varying the nip width between the ink supply cylinder and each inking roller. The axis of each inking roller, and the axis of the pivotal motion of the second pair of roller support members relative to the first, are both so positioned that the width of the nip between the ink supply cylinder and each inking roller is adjustably variable without substantially varying the nip width between the inking roller and the plate cylinder.
Abstract:
An offset printing press having a plate cylinder, a dampening unit and an inking unit. The dampening unit comprises a rotatable dampening form roller, a rotatable dampening fluid feed roller, and a rotatable auxiliary dampening roller. The rotatable dampening form roller is in removable contacting engagement with the plate cylinder along a contact stripe, and transfers dampening fluid to the plate cylinder. The rotatable dampening fluid feed roller is in removable contacting engagement with the dampening form roller and transfers dampening fluid thereto. The dampening fluid feed roller is in fluid flow communication with a dampening fluid source. The rotatable auxiliary dampening roller is in contacting engagement with the dampening form roller immediately upstream of the contact stripe.
Abstract:
A combination used in an offset printer comprises a water pickup roller having an outside surface and mounted so that the roller is able to rotate within an offset printer frame adjacent to a water pan for pickup of water. A tape strip has plural holes spaced along the length of the strip. The strip may be coiled to form a roll of material that can be dispensed as needed. A portion of the roll is removed and adhesively attached to the roller's outer surface at positions on the roller where it is desired to limit the amount of water picked-up by the roller.
Abstract:
Apparatus for an offset lithographic printing press having a master cylinder on which a lithographic printing plate may be mounted for rotating contact with the surface of a blanket cylinder and having a set of dampening rollers for applying a fountain solution to the printing plate and a separate set of ink rollers for applying ink to the printing plate. The set of ink rollers has at least one ink form roller for engagement with the printing plate for applying ink thereto prior to engagement of the printing plate with the blanket cylinder. The set of dampening rollers has a dampening form roller which engages the printing plate after engagement by the ink form roller for applying fountain solution thereto prior to engagement of the printing plate with the blanket cylinder.
Abstract:
A method of feeding dampening water includes a density measuring step for measuring densities of first and second detecting patches 101 and 102 printed adjacent each other on printed matter 100 and presenting a difference in density variations after printing with varied feed rates of damping water and ink, a dampening water feeding step for controlling the feed rate of dampening water based on the densities of the first and second detecting patches 101 and 102 measured in the density measuring step, and an ink feeding step for controlling the feed rate of ink based on the densities of the first and second detecting patches measured in the density measuring step, and the feed rate of dampening water.
Abstract:
A seal apparatus is disclosed for sealing dampening solution which is disposed within a reservoir extending from a nip defined between a form roller and a metering roller of a lithographic printing machine. The apparatus includes a source of pressurized air and device for directing a flow of air from the source of pressurized air towards an edge of the reservoir and between the form and metering rollers such that the flow of air generates an air dam for sealing the reservoir so that leakage of the dampening solution from the edge of the reservoir is inhibited.
Abstract:
The invention relates to a spray damping unit for printing machines, with a spray housing attached to a machine frame which extends parallel to and along the roller to be dampened, and a spray bar carrying spray valves, which is adjustably attached on the spray housing in a direction radial to the roller. The spray bar can be additionally adjusted in its longitudinal direction parallel to the roller.