Harris Corporation

Man Roland Druckmaschinen Ag

Harris-intertype Corporation

James N Crum

Sung C Lee

Ernest H Treff

Webster C Roberts

Earl M Landis

To rapidly and reliably remove foreign objects from rotating plate cylinders (10, 10'; 10a, 10a') of a printing machine, a carriage (12) is mounted on a keyboard (21) having keys associated with predetermined axial positions or zones on the plate cylinder, controls via a control unit (CU) rotation of the stepping motor to the respective axial zone which is selected by operation of one of the keys (20) of the keyboard. A solenoid then projects the wiper blade to remove a foreign object or hickey from the plate. In a multi-cylinder machine, the removal apparatus including the spindle, carriage, wiper blade and solenoid, is placed in association with each one of the cylinders, one keyboard and one control unit operating all the wiper blades in unison, thereby eliminating the need to determine on which one of the plate cylinders of, for example, a multi-color press, a foreign object has lodged. After removal of a foreign object, or a number of foreign objects, as counted by keyboard operation, the carriage is returned to a rest or cleaning position where a motor-operated brush, upon sensing the presence of the carriage, removes the objects from the blade.

System for removing foreign matter from a plate cylinder of a printing

A low-inertia, fast-acting servo motor (40) coupled through a gear to a fountain roll (20) of an inker is controlled and energized by an electronic control unit (45). The control unit controls acceleration of the fountain roll (20) during the period of time when a ductor roller (21) is in contact therewith, from speed 0 to the required speed which is necessary to rotate the fountain roll (20) about a predetermined angle (.phi.s) which, for example, is between 0.degree. and 90.degree.. During the second half of the ductor roller cycle (T), that is, when the ductor roller (21) is separated from the fountain roll (20) and in engagement with an ink transfer roller (22) of the inker, the angular speed of the fountain roll is braked to zero speed. The system permits remote command of the angle of rotation (.phi.s) of the fountain roll (20) during the half cycle (T/2) of the ductor roller (21) as the ductor roller oscillates at a speed depending on printing press machine speed. The rotation of the freely rotatable ductor roller (21) imparted thereto by the ink transfer roller (22) assists in accelerating the fountain roll (20). The closed servo loops ensure operation of the system, as commanded.

Electronically controllable ink fountain roll drive system, and method

An offset lithographic web printing press capable of printing a series of relatively short runs without interruption and with minimum waste of web material. The press includes a plurality of printing units. During a given run, some of the printing units are in a printing mode, while others are in a nonprinting or thrown-off mode. The web moves freely through the units which are thrown-off while those units are made ready for a succeeding run. Each unit includes a motor which has adequate capacity to drive such auxiliary equipment as a web infeed and folder, in addition to the unit, itself. Each unit motor may be clutched into a common drive line passing through all the units in order to drive the infeed and folder. Each printing unit also includes apparatus for throwing the printing cylinders of the unit to and from the web, and for changing the attitude of the web as it passes through the unit. A control system is included which controls the throw-off of the engaged printing units at the end of a preset count and also controls start-up of the units which are to be engaged in the next run. The control system includes a circuit for selecting the printing mode of the units so that any one or all of the printing units may be used for printing a given job.

Web printing press

In a printing press, a remote control apparatus for adjusting ink keys to control ink film thickness at various lateral portions of the ink fountain has an inspection table for supporting paper printed with an image by the press and a plurality of switches mounted at the leading edge of the paper on the table. Each switch is aligned with a respective portion of the printed image corresponding to a respective ink key wich can be adjusted by the switch. A display such as a cathode ray tube simultaneously displaying the settings of all of the ink keys is combined with the inspection table and switch arrangement, with the setting of each ink key being displayed in a different horizontal location, arranged in the same horizontal order as the switches that control them. A respective portion of the display image is vertically deflected for each respective key position, with increasing deflection corresponding to increasing ink film thickness, to create an image of the shape of the ink film distribution. Each of the switches is operable from a neutral position to far and near positions to adjust the respective ink key and consequently change the deflection of the respective portion of the display image. The geometrical relationship of image, keys, switches, and display provides great operating convenience.

Ink key control system

A web tension control system for a reel stand used with a web-fed printing press in which web material is pulled into the press and unwound from a roll on a reel and having a dancer engaging a loop in the web material intermediate the roll and the press. The dancer applies a constant force to the web material at the loop irrespective of the position of the dancer within its range of travel. The reel is equipped with a friction brake whose retarding torque is controlled by a resultant control signal to which several signals contribute. A first signal contributing to the resultant control signal is proportional to the instantaneous radius of the roll of web material and is produced by digitally dividing the press speed by the angular speed of the reel. A second contributing signal is a negative feedback signal that is proportional both to the computed roll radius and to the dancer position. Torque applied by the brake in response to the resultant signal tends to maintain the dancer in a predetermined central position. When the press is coming to a stop a predetermined web tension is achieved by controlling the brake torque in proportion only to the first signal.

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Stonington, CT, United States of America

James N Crum