Film dampening system for a rotary offset press

A method for applying dampening solution to a plate cylinder of a rotary press comprising the steps of:

• rotatably driving a pan roller, at least partially immersed in a container of dampening solution with a first motor;
• transferring dampening solution from the pan roller to a metering roller which rotates in contact with the pan roller;
• transferring the dampening solution from the metering roller to a dampening drum;
• rotatably driving the dampening drum at a speed corresponding to the speed of the metering roller to establish inter-roller differential slipping between the dampening drum and a dampening roller, or at a speed corresponding to the speed of a plate cylinder to establish inter-roller differential slipping between the dampening drum and the metering roller, thus making it possible to use either of two different dampening modes, with a means for selectively driving the dampening drum which includes a second motor coupled to the dampening drum for rotatably driving the dampening drum;
• and
• transferring the dampening solution from the dampening roller to the plate cylinder.

A dampening system for a rotary press, comprising:

• a pan roller rotatably driven by a first motor and including a hydrophilic covering and being at least partially immersed in a container of dampening solution;
• a metering roller including an elastomeric covering for rotation in contact with the pan roller;
• a dampening drum including a hydrophilic covering;
• a dampening roller including an elastomeric covering for rotation in contact with the dampening drum and a plate cylinder of the press;
• and
• a means for selectively driving the dampening drum at a speed corresponding to the speed of the metering roller to establish inter-roller differential slipping between the dampening drum and the dampening roller, or at a speed corresponding to the speed of the plate cylinder to establish inter-roller differential slipping between the dampening drum and the metering roller, thus making it possible to use either of two different dampening modes, wherein the means for selectively driving includes a disengagable coupling for selectively coupling the dampening drum to the first motor or to the plate cylinder for being driven with the plate cylinder, the disengagable coupling includes a first gear coupled to a shaft of the dampening drum for coupling to the first motor for driving the dampening drum with the pan and metering rollers, a second gear coupled to the shaft of the dampening drum for coupling to a shaft of the plate cylinder to drive the dampening drum with the plate cylinder, the disengagable coupling causing the dampening drum to be selectively rotated with one or the other of the first and second gears, whereupon rotation with one gear, the other gear remains idle on the shaft of the dampening drum, and two disks, each disk being coupled to an opposite end of the shaft of the dampening drum relative to the other disk for coupling to the first or second gears, respectively, wherein the dampening drum is coupled to the first motor by coupling the respective disk to the first gear and the dampening drum is coupled to the plate cylinder by coupling the respective disk to the second gear.

A dampening system for a rotary press, comprising:

• a pan roller rotatably driven by a first motor and including a hydrophilic covering and being at least partially immersed in a container of dampening solution;
• a metering roller including an elastomeric covering for rotation in contact with the pan roller;
• a dampening drum including a hydrophilic covering;
• a dampening roller including an elastomeric covering for rotation in contact with the dampening drum and a plate cylinder of the press;
• a means for selectively driving the dampening drum at a speed corresponding to the speed of the metering roller to establish inter-roller differential slipping between the dampening drum and the dampening roller, or at a speed corresponding to the speed of the plate cylinder to establish inter-roller differential slipping between the dampening drum and the metering roller, thus making it possible to use either of the different dampening modes, wherein the means for selectively driving includes a disengagable coupling for selectively coupling the dampening drum to the first motor or to the plate cylinder for being driven with the plate cylinder;
• and
• a means for displacing the pan roller relative to the metering roller, wherein the metering roller is at least partially immersed in the container of dampening solution, and the pan roller is spaced from the metering roller when the dampening drum is driven at a speed corresponding to the speed of the metering roller to establish differential slipping between the dampening drum and the dampening roller, and the pan roller is moved into contact with the metering roller when the dampening drum is driven at a speed corresponding to the speed of the plate cylinder to establish differential slipping between the dampening drum and the metering roller.

A method for applying dampening solution to a plate cylinder of a rotary press comprising the steps of:

• rotatably driving a pan roller, at least partially immersed in a container of dampening solution with a first motor;
• transferring dampening solution from the pan roller to a metering roller which rotates in contact with the pan roller;
• transferring the dampening solution from the metering roller to a dampening drum;
• rotatably driving the dampening drum at a speed corresponding to the speed of the metering roller to establish inter-roller differential slipping between the dampening drum and a dampening roller, or at a speed corresponding to the speed of a plate cylinder to establish inter-roller differential slipping between the dampening drum and the metering roller, thus making it possible to use either of two different dampening modes, with a means for selectively driving the dampening drum which includes a disengagable coupling for selectively coupling the dampening drum to the first motor or to the plate cylinder for being driven with the plate cylinder, the disengagable coupling includes a first gear coupled to a shaft of the dampening drum for coupling to the first motor for driving the dampening drum with the pan and metering rollers, a second gear coupled to the shaft of the dampening drum for coupling to a shaft of the plate cylinder to drive the dampening drum with the plate cylinder, the disengagable coupling causing the dampening drum to be selectively rotated with one or the other of the first and second gears, whereupon rotation with one gear, the other gear remains idle on the shaft of the dampening drum, and two disks, each disk being coupled to an opposite end of the shaft of the dampening drum relative to the other disk for coupling to the first or second gears, respectively, wherein the dampening drum is coupled to the first motor by coupling the respective disk to the first gear and the dampening drum is coupled to the plate cylinder by coupling the respective disk to the second gear;
• and
• transferring the dampening solution from the dampening roller to the plate cylinder.