GB729561A - Improvements in or relating to inking rolls of rotary printing presses - Google Patents

Abstract

729,561. inking-apparatus. STRACHAN & HENSHAW, Ltd. May 7, 1953 [May 19, 1952], No. 12614/52. Class 100 (2). An inking roll has surface ink-carrying depressions 13 irregularly spaced over its whole operative surface 12 whereby, as compared with a roll having regularly spaced depressions (e.g. provided by circular grooves or one-way or criss - crossing helical grooves or lands), the inking of a forme bearing a half-tone &c. image may be carried out without harmonic variations arising from intermittent coincidence of the depressions and the screen pattern. The depressions 13, of uniform depth, may be formed in a metal roll by shot- or sand-blasting, by feeding emery, carborundum, sand, &c. with a liquid such as oil to the nip between two rolls rotating in rolling contact, by impressing with a hard-surfaced embossed wheel or roller, or by etching to expose the granular structure of the roll material. The roll may be used with a doctor roller or blade to remove ink completely or to a controlled extent from its surface 12; for use with quick-drying inks, the roll may be one of a pair of rolls providing an ink well in their nip, the contacting pressure being adjustable to control the ink film thickness applied by the surface 12 to an intermediate rubber roll in contact with the printing roll, or directly to a printing roll having rubber formes.