GB971399A - Improvements in or relating to rotary multi-colour printing machinery - Google Patents

Abstract

971,399. Rotary printing machines. SCHNELLPRESSENFABRIK A. G. HEIDELBERG. Sept. 14. 1962 [May 2, 1962], No. 35074/62. Heading B6C. A rotary multi-colour printing machine having a plurality of printing units arranged in series with the cylinder trips of the units inter-connected is characterized by the feature that for each successive printing unit a reduction gearing for delaying the tripping of a cylinder on or off is provided, the reduction ratio of the gearing corresponding to the number of the sheets which are on the way from an impression cylinder of one printing unit to the impression cylinder of the next unit. When a lever 1 is moved in a direction to trip the plate cylinder into co-operation with the impression cylinder of a first unit, rods 2 and 4, lever 3 and a pawl 5 cause, via a roller lever 8 and a cam 7, a pawl lever 9 to rotate and move a switching rod mechanism 10. The rod 10 rotates the eccentric bushes 14 of the plate cylinder by means of toothed segments 11 and 12 and a connecting rod 13. The simultaneous rotation of a toothed segment 16 displaces a rod 29 and a lever 30 to the right, compresses a spring 32, and causes a resilient roller 27 to engage the outer surface of a cam or control disc 25. The movement of the lever 30, via a cam and lever linkage, couples a single tooth clutch 38 to a gea-rwheel 39 which engages a gear-wheel 40 rigidly connected to a second cam or control disc 41. The disc 41 is rotated clockwise with a reduction ratio of 1 : 4, there being four sheets travelling on the chain conveyer between the printing units. After one revolution of the disc 41 four sheets have travelled between the units and a roller 42 drops into a slot in the disc 41 under the action of the spring 32 and a guide 43 is displaced to the right. The eccentric bushes 57 of the plate cylinder of the second unit are thus rotated so that the cylinder co-operates with its impression roller by means including a switching rod mechanism 53 similar to that which rotates the bushes of the first unit. The drive of the disc 41 is disengaged by a cam 58 and the disc is braked by pawls 60 and 61 and locked. Clutch pins 15 and 62 may be removed if the plate cylinders are not required to co-operate with the impression cylinders. The first plate cylinder is tripped off when the control disc 25 is actuated by the clutch 22. When the apparatus is not being used for direct letterpress but for indirect relief or lithographic offset printing the tripping rods may act on the eccentric bearings of the impression cylinders.