GB1065727A - Improvements in or relating to printing presses - Google Patents

Abstract

1,065,727. Printing-apparatus. HARRISINTERTYPE CORPORATION. Nov. 28, 1963, No. 47048/63. Heading B6C. A rotary letterpress printing machine, Fig. 1, comprises a plate cylinder 20 having a plurality of individually adjustable clamps 22 for holding the leading and trailing edges of relief printing plates 25 which are mounted in side-by-side relation and which carry image areas of substantially different extent, an inking roller 38 carrying a resilient rubber blanket 40 which is supplied with uniform layer of ink by an inking apparatus 45, an impression roller 12 carrying a tympan 15 and provided with grippers 14, to carry copy sheets 11 into contact with the plates 25 on the cylinder 20, packings 60a, 60b of different thicknesses under the relief plates 25a, 25b Figs. 7 and 8, respectively to' equalize the print lengths of the plates and render ineffective the difference in image areas thereof, and packings 65, 66 and 62, 63 under the blanket 40 and tympan 15 respectively complementary to the packings 60a, 60b in order to obtain proper ink transfer on to the image areas of the plates and from said areas on to the sheet 11. Without differential packing the heavily imaged plate 25b tends to iron out and print shorter than the lightly imaged plate 25a causing a lack of satisfactory register in multi-colour printing &c. The printed sheet is removed by grippers 32 on chains 33. No packing may be provided under one plate and a single plate may be used having the ability to stretch at the line where the packing height differs.