US1654431A - Rotary intaglio printing machine - Google Patents

Description

@man 2'7", E92? 1,654,431

w. PICKUP Ef AL ROTARY INTAGLI PRINTINGV MACHINE Filed Feb. 19, 1926 Sheets-Sheet 1 W. PICKUP ET AL ROTARY INTAGLIO PRINTING MACHINE Filed Feb.'19. 1926 2 Sheets-Skaai 2 CTW ROTARY ZENTGLIIO PRINTING llllllllPllNE.A

Application tiled February i9, 1926, Serial No. 89,459, and in Great Britain March d, i925.

rll`his invention rela-tes to rotary intaglio printing machines and has for its obyect (inter alia) to provide a simple, eflicient and much less costly printing machine than heretofore, and one which is particularly well adapted for intaglio photogravure printing.

lUntil,l recently, photogravure printing has been done from an engraved solid cylinder, usually of copper. This was a very expensive method, especially where a variety of subjects had to be printed, since after the required number of prints had been made rof a subject, the surface of the'cylinder had to be ground down, polished and a fresh subject then vengraved thereon; or alternatively a large number of solid and expensive printing cylinders had to be kept.

More recently it has been proposed to wrap or mantle an engraved metal sheet on the printing cylinder, the sheet being capable of ready removal and replacement; and this arrangement has considerably lessened the cost of photogravure printing, but the machines themselves are still large, comparatively complicated and expensive. For

example, devices known as grippers are generally employed to feed the sheets of paper into the machine and to guide them through it so as to ensure correct registration and the desiredy margins etc.

The machine according to the present invention employs f a system of metal sheet mantling, dispenses with grippers, provides an arrangement whereby the printing and impression rollers are kept rotating con tinuously, the printing operation being performed only during alternate revolutions of the printing cylinder and the latter is automatically raised into and lowered out of contact with the impression roller duringv the printing and idle revolutions respectively. V

rlhe printing cylinder is mantled with a metal (usually copper) printing sheet by vany suitable method but preferably. in the manner hereinafter described, the construction including arrangements whereby the doctor is prevented from dipping into the joints between 4the edges of the capping piece employed to close the longitudinal gap in the printing cylinder and the turned in portions of the printing sheet.

Furthermore according to this invention, the doctor is preferably so geared that as it reciprocates along the printing surface it reverses each time at a diierent point on the periphery ofthe printing cylinder which has been found to improveits effectiveness.

@ne form of rotary intaglio printing maI chine in accordance with the present invention is illustrated in the accompanying drawings in which `Fig. l. is a View in side elevation of the complete machine.

lligs. 2 and 3 are transverse sectional views of the impression and the printing cylinders respectively.

i is an elevational View lonV a reduced scale of a printing cylinder illustrating one method of preventing the doctor dipping into the joints of the gap as aforesaid, and of securing the capping piece in position.

Referring to these drawings z- Mounted to slide vertically in the frame A of the machine are bearings B carrying a mantled printing cylinder C and resting through the medium of links D on cams E geared to rotate at half the speed of .the

printing cylinder C in such a manner that the latter is lifted by said cams at each alternate revolution into Contact with an im pression cylinder F carried in bearings Gr which are resiliently supported by .springs G1 and adjusted by screws H. The impres- 85 sion cylinder F is provided with a blanket F1 secured in any convenientgmanner for instance as shown in Fig. 2.

Mounted to rock in lugs I on the frame A is a double ended lever J, the lower end of able in the lengthwise direction of the printing cylinder C and the gearing of the cam L' is such that the block M through the medium of the lever J is caused to change 'its direction at a diiierent point onthe periphery of the printing cylinder C O is the ink retaining receptacle through the contents of which the printing c lnder C rotates continuously.

As illust-rated more particularly in Fig. 3 the mantled printing sheet C1 has its ends thickened or beaded at l?, in any suitable manner, for instance by turningover the ends one or more times, and these beads P are engaged by a ixing bar Q adapted to be screwed down by several screws R to apply unequal and Simultaneous, pull to both ends of the printing sheet. When the latter is bedded firmly on the cylinder the gap in its periphery is covered by a capping piece S provided with end portions S1 adapted to extend over the ends of the roller and be screwed to bosses T forming part of the cylinder as shown in Fig. 4.

Also as shown in Fig. 4 the longitudinal gap in the cylinder C is set at an angle to theaxis of the cylinder so that the narrow joints U along the edges of the capping piece cannot allow the doctor which is set parallel with the axis of the cylinder to drop into theiii during rotation of the cylinder.

Another suitable method ot' preventing this dipping of the doctor is that described in Berrys British patent specifica-v tion No. 238,402.

The machine is provided with any convenient inea-ns for feeding the paper 'sheets or other surfaces to be printed into the gap between the printing and impression cylinders in such a manner that the sheet is engaged between the cylinders when the printfaces are delivered on to tapes V, printed face downwards, and are conducted by said tapes4 to the desired place Where they are delivered in such a manner that they are caused to turn printed tace uppermost.

lWhat we claim is 1. ln a rotary intaglio printing machine, the combination of a driven printing' cylinder, a longitudinal gap in the siirrace of said cylinder, a securing device for hiring in said gap the ends of a detachable metal sheet constituting the rinting surface, a capping piece for covering the said gap to restore the circular contour of the cylinder, a driven impression cylinder yieldingly supported, means for raising and lowering the printing cylinder into and out of contact With the impression cylinder during alternate revolutions thereof, a cleaning knife or doctor arranged to be reciprocated lengthwise of the printing cylinder, and a system of tapes for deliveringthe printed surfaces from the machine.

2. ln a rotary intaglio printing' machine, the combination of a driven printing cylinder, a longitudinal gap in the surface ot said cylinder, a hitting bar adapted to engage the ends of a detachable .metal printing sheet and to be screw-ed into said gap to enert tension on said sheet to bed saine en the cylinder, a driven impression cylinder yieldingly suppnrted, iiicans ter raising and loivering the prii'iting cylinder' into and out of contact vri i the impression cylinder during alternate yevolutions thereof, a cleaning lirnife or doctor arranged tc be reciprocated lengtliivise o't the printing cylinder, and a. of tapes for delivering the printed surfaces frein the machine.

3. ln rotary intaglio printing ,.aaehine,

the combination of a driven rinting cylinder, a longitudinal gap in t e surface of said cylinder disposed at an angle tothe axis of the cylinder, a securing device for fixing in said gap the ends of a detcliable metal sheet constituting the printing surface, a capping piece adapted to cover the said gap above the iixing device to restore the circular contour of the cylinder, a driven impression cylinder yieldingly Supported, means for raising and lowering the printing cylinder into and out of Contact Witli'the impression cylinder during alternate revolutions thereof, a cleaning knife or doctor arranged to be reciprocated lengthwise of the printing cylinder, and a system or tapes for delivering the printed surfaces from the machine. 4. In a rotary intaglio printing machine, the combinationo a driven printingcylinder', a longitudinal gap in the surface of said cylinder, dis osed at an angle to the axis of the cyliner, a securing device for fixing in tliesaid gap the ends of a det-achable metal sheet constituting the printing surface, a capping piece for covering the said gap to restore the circular contour of the cylinder, a driven impression cylinder yieldingly supported, a set of driven cams, links reciprocated by said rcams to raise and lower ythe printing cylinder into and out of Contact with the impression cylinder during alternate revolutions, la cleaning knife or doctor arrangedA to be reciprocated lengthwise of the printing cylinder and geared to reverse at diitierent circumferential points on the cylinder in successive revolutions thereof, and a system of tapes tor delivering the printed surfaces from the machine.

v 5. ln a rotary intaglio printing machine, the combination ot a driven printing cyliiider, a longitudinal gap in the surface of said cylinder disposed atan angle to the axis thereof, a metal sheet constituting the printing surface Wrapped on the printing cylinder with the ends of said sheet lying in the gap in the cylinder, thickened portions at the ends ot said sheet, a iixing bar adapted to engage the thickened ends of said sheet and to be screwed dovvn into the gap in the cylinder to exert tension on said sheet, a capping piece covering the gap above the iixing bar to restore the contour of the cylinder, a driven vimpression cylinder yieldingly supported, means `lor .raising and lovvering the printing cylinder into and ont ot centactivith the impression cylinder daring alternate revffiiutions thereof, a cleaning lrniile or doctor arranged to he reciprocated iengthvvise o'if the pri ting cylinder, and to reverse at different ciiniinlerential points cn t." i cvli. fier in successive revolutions thereof, an `system olif 'tapes i'or delivering the printed surfaces trom the machine.

t @1M Plliallt BERRY.

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