Improvements in rotary intaglio printing machines

Abstract

Abstract 213,960. Johnston, T. R. Jan. 8, 1923. No Patent granted (Sealing fee not paid). Rotary intagliomachines.-In a a rotary intaglio sheetprinting machine, the printing-cylinder coacts with a larger impression cylinder having one or more heated, segmental, sheet-carrying impression surfaces whereby the ink is dried before the sheets are delivered. In multicolour printing several printing-cylinders are located around a large impression cylinder having one more heated surface than the number of printing-cylinders. An impression cylinder b<1> coacting with four colour-printing cylinders c<1> .. c<4> is provided with five heated surfaces b<2> . . b<6> each having grippers b<8> for carrying a sheet. The printing-cylinders rotate five times as fast as the impression cylinder, the former being lowered to print at every four-fifths revolution of the latter. Sheets are fed from a pile-table f<1>, each sheet receiving impressions from the cylinders c<1> . . c<4> in succession and being delivered by chains g' at the end of its fourth revolution. The feed-table f<1> is lowered to allow sheets lying against a front stop f<2> to be taken by the grippers b<8>, these being closed by an adjustable bolt h<9> carried by an oscillating member h<8> operated through a rod h<7> and lever h<6> from a gear-driven cam h<5>. The cam h<5> also operates an oscillating member h<11> carrying bolts for opening the grippers b<8> and for controlling the grippers of the delivery chains g<1>. A second cam lowers the feed table f through levers h<12>, h<13>, h<14>. In printing in one colour, the impression cylinder has one heated segmental surface and coacts with a printing-cylinder of half the diameter, or has two surfaces coacting with a cylinder of quarter diameter. Also described are arrangements comprising an impression cylinder having three surfaces and coacting with two cylinders and one having four surfaces and coacting with three cvlinders. The impression surfaces b<2> . . b<6> are heated electrically, or, as shown, by means of steam introduced via the centre of the impression cylinder shaft b<10> and pipes b<12> to segmental heating chambers b<13> and discharged through pipes b<14> to an annular chamber b<15> the condensed water escaping by orifices in the shaft b<10>. Specifications 2772/86, 2954/97, 3981/01, 3384/02, 19731/05, 17352/11, 10154/15, and 184,128 are referred to. Inking-apparatus.-The printing cylinders c .. c<4>, which are provided with etched plates or sleeves secured as described in Specification 117,888, are inked by rollers d<1>, superfluous inh being removed by spring-pressed scrapers e<1> carried by shafts e<2> reciprocated longitudinally by cams. Tripping-arrangements.-The printing cylinders c' .. c<4> are lowered on to the impression cylinder b<1> at every four-fifths of a revolution of the latter by means of cams loosely mounted on the shaft of the cylinder b<1> and driven by gearing at five-fourths the speed of that cylinder.

Inventors

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Bibliographic Details