Printing plates

Claim 1

THE METHOD OF MAKING AN ACCURATELY CURVED MEMBER OF LESS THAN 360* EXTENT FROM A FLAT PLATE COMPRISING THE STEPS OF FORMING OPPOSITE EDGE PORTIONS OF THE FLAT PLATE WITH CURVATURES HAVING A PREDETERMINED RADIUS, FORMING THE PORTION OF THE PLATE BETWEEN THE CURVED EDGE PORTIONS IN AN ARCUATE SHAPE TO PRODUCE A PREFORM MEMBER OF A PARTIAL CYLINDRICAL CONFIGURATION HAVING A CONVEX OUTER SURFACE AND A CONCAVE INNER SURFACE, PLACING THE PREFORM MEMBER ENTIRELY WITHIN A FINISHING DIE HAVING A PREDETERMINED ARCUATELY CURVED AND LONGITUDINALLY EXTENDING INNER SURFACE WITH THE CONVEX SURFACE OF THE PREFORM MEMBER FACING THE INNER SURFACE OF THE DIE, EXERTING A RADIAL FORCE PROGRESSIVELY ALONG THE LENGTH OF THE INNER SURFACE OF THE PREFORM MEMBER TO FORM THE CONVEX OUTER SURFACE TO THE PREDETERMINED CONFIGURATION OF THE CURVED SURFACE OF THE FINISHING DIE BY MOVING A CIRCULAR FORMING MEMBER LONGITUDINALLY ALONG THE DIE FROM ONE END OF THE PREFORM MEMBER TO AN OPPOSITE END OF THE PREFORM MEMBER AND IN FORCED ENGAGEMENT THEREWITH TO EXERT SAID RADIAL FORCE, CONSTRAINING SAID PREFORM AGAINST ENDWISE MOVEMENT AND CONSTRAINING SAID PREFORM AGAINST RADIAL MOVEMENT AWAY FROM THE INNER SURFACE OF SAID DIE WHILE THE FORMING MEMBER IS BEING MOVED AS AFORESAID BY ANOTHER CIRCULAR MEMBER DISPOSED WITHIN ONE END OF THE PREFORM WHEREBY SAID ONE END OF THE PREFORM IS CONFINED BETWEEN SAID DIE AND THE OTHER CIRCULAR MEMBER THEREBY CONFINING SAID ONE END OF THE PREFORM AGAINST RADIAL DISTORTION IN THE COURSE OF MOVING THE FIRST-NAMED CIRCULAR MEMBER PROGRESSIVELY AS AFORESAID.

Claim 2

THE METHOD OF MAKING AN ACCURATELY CURVED MEMBER OF LESS THAN 360* EXTENT FROM A FLAT PLATE COMPRISING THE STEPS OF FORMING OPPOSITE EDGE PORTIONS OF THE FLAT PLATE WITH CURVATURES HAVING A PREDETERMINED RADIUS, FORMING THE PORTION OF THE PLATE BETWEEN THE CURVED EDGE PORTIONS IN AN ARCUATE SHAPE TO PRODUCE A PREFORM MEMBER OF A PARTIAL CYLINDRICAL CONFIGURATION HAVING A CONVEX OUTER SURFACE AND A CONCAVE INNER SURFACE, PLACING THE PREFORM MEMBER ENTIRELY WITHIN A FINISHING DIE HAVING A PREDETERMINED ARCUATELY CURVED AND LONGITUDINALLY EXTENDING INNER SURFACE WITH THE CONVEX SURFACE OF THE PREFORM MEMBER FACING THE INNER SURFACE OF THE DIE, EXERTING A RADIAL FORCE PROGRESSIVELY ALONG THE LENGTH OF THE INNER SURFACE OF THE PREFORM MEMBER TO FORM THE CONVEX OUTER SURFACE TO THE PREDETERMINED CONFIGURATION OF THE CURVED SURFACE OF THE FINISHING DIE BY MOVING A CIRCULAR FORMING MEMBER LONGITUDINALLY ALONG THE DIE FROM ONE END OF THE PREFORM MEMBER TO AN OPPOSITE END OF THE PREFORM MEMBER AND IN FORCED ENGAGEMENT THEREWITH TO EXERT SAID RADIAL FORCE, CONSTRAINING SAID PREFORM AGAINST ENDWISE MOVEMENT AND CONSTRAINING SAID PREFORM AGAINST RADIAL MOVEMENT AWAY FROM THE INNER SURFACE OF SAID DIE WHILE THE FORMING MEMBER IS BEING MOVED AS AFORESAID BY ANOTHER CIRCULAR MEMBER DISPOSED WITHIN ONE END OF THE PREFORM WHEREBY SAID ONE END OF THE PREFORM IS CONFINED BETWEEN SAID DIE AND THE OTHER CIRCULAR MEMBER THEREBY CONFINING SAID ONE END OF THE PREFORM AGAINST RADIAL DISTORTION IN THE COURSE OF MOVING THE FIRST-NAMED CIRCULAR MEMBER PROGRESSIVELY AS AFORESAID.