Inking unit pre-adjustment method

For rotary printing machine having a plate cylinder carrying a printing plate, an inking unit for receiving ink from an ink duct and applying the ink to the printing plate, the inking unit including a plurality of inking unit rollers including applicator rollers engaging said plate cylinder during continuous printing and means for selectively throwing the applicator rollers on and off the plate cylinder, said ink duct including a duct roller and a plurality of adjustable ink metering elements for regulating respective amounts of ink applied zonally across the surface of said duct roller, said printing machine having a vibrator driven by a vibrator drive to transfer ink from the surface of said duct roller to the inking unit rollers, said adjustable ink metering elements being adjustable to regulate the respective amounts of ink fed to printing zones across said printing plate, said vibrator drive being controllable to turn on and off the flow of ink from the ink duct to the inking unit rollers, and means for driving the inking unit rollers in the absence of continuous printing when the applicator rollers are thrown off the plate cylinder,

• a method of pre-adjusting the inking unit before printing starts prior to continuous printing for which said ink metering elements are adjusted to obtain a desired zonal ink profile based upon the ratio of printing area to total area in each of the zones comprising the steps of:
• initially adjusting the ink metering elements to regulate approximately the same predetermined amounts of ink, controlling said vibrator drive to turn on the flow of ink from the ink duct to the inking unit rollers and driving the inking unit rollers for a first predetermined amount of time in the absence of continuous printing when the applicator rollers are thrown off of the plate cylinder so that an accurately defined quantity of ink is fed to the inking unit rollers approximating the amount of ink stored in the inking unit during continuous printing, and
• throwing the applicator rollers onto the plate cylinder and starting continuous printing.

A method of pre-adjusting the inking unit of a rotary printing machine of the kind having an ink duct including a duct roller and a plurality of zonal ink metering elements along the length of the duct roller for setting up an ink profile on the duct roller, a vibrator for transferring the ink profile from the duct roller to the inking unit, the inking unit having applicator rollers for engagement with a plate cylinder carrying a printing plate and a plurality of other inking unit rollers for receiving the ink profile from the vibrator and transferring the ink profile to the applicator rollers and the printing plate during continuous printing, the ink metering elements being remotely adjustable by an ink control computer, the vibrator being driven by a vibrator drive controllable by said computer to turn on and off the vibrator and the flow of ink to the inking unit rollers, the applicator rollers having a throw-off mechanism controllable by said computer to throw the applicator rollers onto and off of the plate cylinder, said inking unit rollers capable of being driven when the applicator rollers are thrown on as well as off of the plate cylinder, said computer executing a predetermined procedure to perform said method of pre-adjusting the inking unit comprising the steps of:

• (1) adjusting said ink metering elements to set up a substantially uniform first ink profile along the length of the duct roller,
• (2) turning on said vibrator and driving said inking unit rollers with the applicator rollers thrown off of the plate cylinder for a predetermined time period selected in accordance with said first ink profile and the ink capacity of said inking unit so that the inking unit is filled at the end of said first predetermined period with an amount of ink approximately equal to the base level of ink in said inking unit when equilibrium is established during continuous printing,
• (3) turning off said vibrator and so that the ink in the inking unit to become substantially uniformly distributed among the inking unit rollers,
• (4) adjusting the ink metering elements to set up a second ink profile along the length of the duct roller responsive to the content of the printing plate, and when the ink in the inking unit is substantially uniformly distributed, turning on the vibrator for a predetermined time period sufficient for the second ink profile to propagate to the applicator rollers and when the ink profile substantially reaches the applicator rollers throwing the applicator rollers onto the plate cylinder and starting continuous printing.