US 4,570,539 AGranted

Method of adjusting the inking unit of a printing machine and a measuring device for performing the same

AssigneeMAN Roland Druckmaschinen AG

InventorHans-Jurgen Rottstedt

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Abstract

The ink dosing elements in the ink fountain of a printing machine are adjusted to reference positions in response to measurement of the amount of ink applied to the fountain roller at the respective inking zones. The reference positions are stored in a data memory for future use or are adjusted in accordance with predetermined values to arrive at the settings of the ink dosing elements for obtaining a desired ink profile. Preferably an optical densitometer mounted on a rail parallel to the fountain roller measures the amount of ink, and the densitometer is initially calibrated at an ink-free zone on the fountain roller. According to a manual embodiment, a first one of the ink dosing elements is brought to a reference position by an operator while viewing the respective inking zone, for example, to obtain a permissible minimum of ink. The densitometer is moved to measure the ink at the first inking zone, and is successively moved to measure the ink at the other inking zones while the respective ink dosing elements are adjusted to obtain substantially the same measured values for all of the inking zones. Alternatively, the method is performed by a remote control computer.

Claims3

Dependent claims

A method of adjusting the inking unit of a printing machine having a plurality of ink dosing elements disposed along the length of an ink fountain roller, means for adjusting the distances of the ink dosing elements from the fountain roller independently of one another to thereby regulate the amount of ink applied to a plurality of inking zones along the length of the fountain roller corresponding to respective ones of the ink dosing elements, and an optical densitometer having a sensing head for measuring by light-dark sensing the amount of ink applied to the fountain roller, the optical densitometer being slidably mounted on a rail mounted substantially parallel to the fountain roller, said method comprising the steps of:

(a) manually positioning the densitometer so that its sensing head is aligned with an ink-free zone of the fountain roller and using the measured response of the densitometer for calibration by adjusting the densitometer to register a predetermined maximum light intensity,
(b) bringing a first one of said ink dosing elements to a reference position with respect to said fountain roller by manually adjusting said first ink dosing element so that a slight application of ink is just detectable by the human eye in the entire inking zone regulated by said first ink dosing element,
(c) manually positioning the densitometer to a first one of the inking zones regulated by said first ink dosing element and using a locating mechanism engaging said rail at periodically spaced positions along said rail corresponding to the inking zones including a position along said rail corresponding to the first inking zone for aligning the sensing head with the first inking zone,
(d) obtaining the densitometer measurement for the amount of ink applied to said fountain roller at the first inking zone,
(e) successively and manually positioning the densitometer to each of the other of said inking zones and using said locating mechanism engaging the rail at corresponding positions for aligning the sensing head with each of the other of said inking zones, obtaining densitometer measurements and adjusting each of the other ink dosing elements until the measured amount of ink applied to the fountain roller at the other of said inking zones corresponds to the measured amount of ink applied to the fountain roller at the first one of said inking zones, so that said ink dosing elements are adjusted to corresponding reference positions, and
(f) adjusting the ink dosing elements by respective predetermined amounts from the reference positions obtained in steps (b) and (e), in order to obtain a desired ink profile.

3 more elements

A method of adjusting the inking unit of a printing machine having a plurality of ink dosing elements disposed along the length of an ink fountain roller and means for adjusting the distances of the ink dosing elements from the fountain roller independently of one another to thereby regulate the amount of ink applied to a plurality of inking zones along the length of the fountain roller corresponding to respective ones of the ink dosing elements, said fountain roller also having at least one ink-free zone, said method comprising the steps of:

(a) traversing the sensing head of an optical densitometer along a rail mounted substantially parallel to the axis of the fountain roller to align the sensing head with said ink-free zone of said fountain roller,
(b) measuring the response of the optical densitometer to the ink-free zone to obtain an ink-free measured value,
(c) moving the sensing head of the optical densitometer along the rail to align the sensing head with a first one of said inking zones,
(d) adjusting the ink dosing element corresponding to said first inking zone to obtain a response X from said densitometer differing from the ink-free measured value by a predetermined value responsive to the thickness of the ink film applied to the first inking zone by the corresponding ink dosing element,
(e) successively moving the sensing head of the optical densitometer along the rail to align the sensing head with the other of said inking zones, and adjusting the respective ink dosing elements to obtain responses of approximately X from the optical densitometer for each inking zone, so that said ink dosing elements are adjusted to corresponding reference positions,
(f) measuring said reference positions of the ink dosing elements obtained after steps (a), (b), (c), (d) and (e) and storing the measured values of the reference positions in a data memory,
(g) reading the stored reference values from said data memory,
(h) offsetting the reference values read from said data memory by respective predetermined values, and
(i) moving the ink dosing elements to positions indicated by the offset reference values, so that a desired ink profile is obtained.

6 more elements

Dependencies are inferred from the claim text.