Method for positioning engraving organs

A method for positioning engraving elements in an electronic engraving machine for engraving a printing cylinder for rotogravure, where at least two engraving lanes are engraved in the form of cups with a respectively allocated engraving element, the engraving elements being positioned axially relative to the engraving cylinder before the engraving, comprising the steps of:

• with the engraving elements, implementing an axial feed motion along the printing cylinder during engraving;
• predetermining axial reference positions for the engraving elements, axial spacings thereof from one another corresponding to lane widths of the respective engraving lane;
• successively positioning an electronic position measuring system to the axial reference positions;
• identifying an axial deviation of a reference point of the allocated engraving element from the reference position with the position measuring system;
• and
• axially displacing the engraving elements with their reference points by the identified deviations onto the corresponding reference positions.

An engraving machine for engraving at least two engraving lanes of predetermined lane widths lying next to one another in an axial direction of a printing cylinder with a respectively allocated engraving element, comprising:

• a rotationally seated printing cylinder turned by a first drive;
• an engraving carriage moveable in the axial direction of the printing cylinder with a second drive;
• engraving elements for engraving the engraving lanes, these being arranged displaceable and lockable on the engraving carriage;
• a position measuring system displaceable in the axial direction of the printing cylinder and positionable to predetermined, axial reference positions for the engraving elements for determining exact positioning of the engraving elements to their reference positions;
• and
• a displacement unit for each engraving element on the engraving carriage controlled by the position measuring system for automatic displacement of the engraving elements to their reference positions.

An engraving machine for engraving at least two engraving lanes with a respectively allocated engraving element, comprising:

• a rotationally seated printing cylinder turned by a first drive;
• an engraving carriage moveable in an axial direction of the printing cylinder with a second drive;
• engraving elements for engraving the engraving lanes, these being arranged displaceable and lockable on the engraving carriage;
• a position measuring system displaceable in the axial direction of the printing cylinder and positionable to predetermined, axial reference positions for the engraving elements for determining exact positioning of the engraving elements to their reference positions;
• and
• a displacement unit for each engraving element on the engraving carriage controlled by the position measuring system for automatic displacement of the engraving elements to their reference positions.

A position measuring system for an engraving machine for engraving cups on a printing cylinder with engraving elements, comprising:

• a video camera mounted on a measuring carriage for registering video images of engraving stylus tips of the engraving elements or of cups engraved as trials with the engraving elements as actual axial positions of the engraving elements roughly shifted onto predetermined reference positions;
• the measuring carriage being displaceable in an axial direction of a printing cylinder and positionable to the predetermined reference positions for the engraving elements;
• and
• an image evaluation unit for determining axial deviations of the actual positions of the engraving elements from the reference positions by interpreting the registered video images.