Photomechanical method for producing cutting dies

Claim 1

IN A METHOD FOR PRODUCING A CUTTING AND SCORING DIE FOR WORKING A SHEET MATERIAL ALONG A PRESELECTED PATTERN OF CUT LINES AND SCORE LINES, SAID DIE COMPRISING A PAIR OF OPPOSED, COACTING DIE MEMBERS, EACH MEMBER BEING ALL OF ONE HOMOGENEOUS PIECE AND INCLUDING AS WORKING ELEMENTS ON ITS WORKING SURFACE IN SHALLOW RELIEF ONE OF A COACTING PAIR OF CUTTING ELEMENTS AND ONE OF A PAIR OF COACTING SCORING ELEMENTS, SAID PAIRED CUTTING ELEMENTS HAVING THEIR LONGITUDINAL AXES SLIGHTLY DISPLACE ON OPPOSITE SIDES OF A DESIRED CUT LINE TO BE FORMED IN SAID SHEET MATERIAL AND SAID SCORING ELEMENTS INCLUDING A MALE SCORING ELEMENT THE LONGITUDINAL AXIS OF WHICH IS CENTERED ON A DESIRED SCORE LINE TO BE FORMED IN SAID SHEET MATERIAL AND A FEMALE SCORING ELEMENT COMPRISING TWO RAISED AREAS PARALLEL TO AND HAVING THEIR LONGITUDINAL AXES SLIGHTLY AND EQUALLY DISPLACED ON OPPOSITE SIDES OF SAID DESIRED SCORE LINE, WHICH METHOD COPRISES THE STEPS OF FORMING A PLAN IMAGE OF EACH OF SAID CUTTING AND SCORING ELEMENTS, OPTICALLY TRANSSFERRING THE PLAN IMAGE OF A FIRST MEMBER OF EACH OF SAID PARIS OF ELEMENTS ONTO A FIRST PHOTOSENSITIVE SURFACE AND THE PLAN IMAGE OF THE SECOND MEMBER OF EACH OF SAID PAIRS OFELEMENTS ONO A SECOND POHOTSENSITIVE SURFACE, REMOVING BY CHEMICAL MEANS MATERIAL FROM SAID SURFACES EXCEPT IN THE REGIONS BEARING SAID IMAGES TO PRODUCE A PAIR OF MATCHED OPPOSED COACTING CUTTING AND SCORING DIES HAVING SAID CUTTING AND SCORING ELEMENTS AS INTEGRAL PORTIONS THEREOF IN SHALLOW RELIEF ABOVE THE BACKGROUND AREAS OF SAID SURFACES, THE IMPROVEMENT WHICH COMPRISES: FORMING A SINGLE DRAWING INCLUDING THE PALN IMAGES OF BOTH MEMBERS OF EACH PAIR OF WORKING ELEMENTS OF THE FIRST OF PLAN IMAGE F THE WORKING ELEMENTS OF THE FIRST OF SAID PAIR OF DIE MEMBERS BEING MARKED ON SAID DRAWING IN THE COMBINATION OF A FIRST INDICATING MEDIUM AND A SECOND INDICATING MEDIUM, THE PLAN IMAGE OF THE WORKING ELEMENTS OF THE OTHER OF SAID PAIR OF DIE MEMBERS BEING MARKED ON SAID DRAWING IN THE COMBINATION OF THE SECOND INDICATING MEDIUM AND A THIRD INDICATING MEDIUM, THE SECOND INDICATING MEDIUM COMPRISING AN AREA COMMON TO THE PLAN IMAGES OF CERTAIN WORKING ELEMENTS OF BOTH DIE MEMBERS, SAID COMMON AREA BEING ALIGNED WITH AND SUBSTANTIALLY EQUIVALENT IN LENGTH TO A LINE OF WORKING IN SAID SHEET MATERIAL TO BE WORKED AND HAVING A CRITICAL WIDTH PRECISELY RELATED TO THE DISPLACEMENT OF THE LONGITUDINAL AXES OF THE WORKING ELEMENTS FROM THE DESIRED LINE OF WORKING AND TO THE DEGREE OF UNDERCUTTING RESULTING FROM CHEMICAL REMOVL OF MATERIAL IN FORMING SAID DIE, SAID FIRST AND THIRD INDICATING MEDIA BEING OPTICALLY SEPARABLE FROM EACH OTHER AND SAID SECOND INDICATING MEDIUM BEING OPTICALY COMBINABLE WITH EITHER OF SAID FIRST AND THIRD INDICATING MEDIA UNDER CONDITIONS WHICH EXCLUDE THE OTHER OF SAID FIRST AND THIRD MEDIA.