US3303779A - Rotary intaglio perfecting press - Google Patents

Description

Feb. 14, 1967 s. GIORI 3,303,779

ROTARY INTAGLIO PERFECTING PRESS Filed Nov. 19, 1964 3 Sheets-Sheet 1 Feb. 14, 1967 G. GlORl 3,363,779

ROTARY INTAGLIO PERFECTING PRESS Filed Nov. 19, 1964 3 Sheets-Sheet z Feb, 14, 1967 G. GiORH 3,33,779

ROTARY INTAGLIO PERFECTING PRESS Filed Nov. 19, 1964 3 Sheets-Sheet 3 United StatesPatent 3,3e3,779 ROTARY lNTAGLlO PERFECTlNG PRESS Gualtiero Giori, 4 Rue de la Pain, Lausanne, Switzerland Filed Nov. 19, 1964, Ser. No. 412,352 Claims priority, application Germany, Feb. 4, 1964, G 39,7ti8 1 flaint. (Cl. 101-152) In all prior intaglio printing methods, the paper or the like suitable material to be printed is conventionally urged in the form of webs or sheets through the agency of a so-called pressure cylinder provided with an outer elastic surface against the corresponding rigid inked printing plate or engraved cylinder, while the ink carried in the grooves of the printing plate or of the engraved cylinder, is removed and transferred onto the material to be printed. The required value of the compression is selected in accordance with the depth of the engraved grooves and consequently with the amount of ink to be transferred out of said grooves and this, in its turn, defines the fineness of the printed picture.

The intaglio printing procedure allows executing very intricate pictures and letter press in one or more colours, which pictures and letter press may be accurately reproduced in the successive prints. Since however this procedure forms the most expensive, the most difiicult and also the slowest of all known printing methods, it is used generally only for the execution of prints of a very high grade, preferably of securities and banknotes, which must satisfy very strict requirements, principally as a guarantee against forgery.

Since the paper used for securities and banknotes must be very resistant and firm and therefore has a comparatively hard upper surface, it is necessary to urge the paper under a high pressure during its printing against the printing plate or the engraved cylinder so that a perfect transfer of ink out of the engraved grooves may be obtained. For this reason, it is necessary for the pressure cylinder rolling over the printing plate or the engraved cylinder to be urged under an adjustable pressure against said printing plate or engraved cylinder. Said pressure cylinder is provided on its outer cylindrical surface, as already proposed, with a yielding material such as cardboard, rubberized canvas, cork, felt or any other suitable material, which is urged with a more or less intense elastic deformation against the paper running between the pressure cylinder and the printing plate or engraved cylinder.

The pressure cylinders used hitherto exclusively for obtaining the necessary printing pressure leads to the necessity of printing at a time only one side of the paper during its passage through the printing press. If, as in the case of securities and banknotes, it is necessary to print both sides of the sheet or web of paper, the second printing has to be executed, after the drying of the ink on the first printed side and the necessary turning round of the paper, during a second passage of the paper through the press. This increases the time required for the execution of a carrier material printed on both sides through intaglio printing and therefore the actual procedure becomes still more expensive when applied to both sides of the paper.

Our present invention has now for its object to remove this drawback of the intaglio printing procedures as known hitherto and it covers a method which allows printing simultaneously both sides of a sheet or web of paper of any suitable material, whether in one or in more colours.

In order to solve this problem, the method according to my invention consists in the use of two cylinders having parallel axes and facing each other, said cylinders being provided each with at least one sector carrying a printing plate or with an engraved sheath and being urged against each other under an adjustable pressure, while the material to be printed is fed between the cylinders for the simultaneous impression of both its sides in a compressed condition.

When the paper to be printed has, by reason of its actual composition, a sufficient elasticity, this elasticity is sufiicient for the obtention, during the printing procedure, of the required elastic pressure, between the outer surface of the paper and the rigid printing plate or rigid cylinder sheath, whereas such a pressure was hitherto considered only obtainable in the printing of one side by means of a pressure cylinder having an elastic outer surface.

However, if the paper or material to be printed is hard or very thin and consequently, its elasticity is not suflicient, my improved method is executed in an arrangement wherein at least one of the two cylinders, having parallel axes and facing each other, is provided with elastic means which ensure an elasticity for the printing plate or engraved sheath with reference to the printing plate or engraved sheath of the other cylinder.

This elasticity may be obtained for instance by providing the printing plate or engraved sheath on one at least of the two cylinders with elastic means with reference to the cylinder axis.

To this end, it is of advantage to insert under said printing plate or engraved cylinder a layer of an elasti cally yielding material which may be constituted say by felt, rubber, cardboard, cork or any synthetic material showing elastic properties.

In the case of cylinders provided with an engraved sheath, it is possible to ensure the desired elasticity by securing at least one of the two cylinders on its carrier spindle by means of radially acting springs.

Lastly, we may according to a further feature of the invention, set at least one of the cylinder-carrying spindles which is in any case adapted to move perpendicularly to the longitudinal axis of the spindle so as to adjust the pressure applied and must therefore be subjected to a corresponding pressure, under the action of an elastic stress whereby the cylinder considered and its spindle are elastically fitted with reference to the other cylinder.

These different improvements are such that the part played by the pressure cylinder used hitherto for intaglio printing on a single side is now played by at least one cylinder carrying the printing plates or engraved sheath with a view to obtaining a perfect elastic compression. Since the compression exerted on the paper is obviously distributed on both sides of the paper, the conditions for a simultaneous printing of both sides of the paper are thus satisfied.

The following disclosure will allow a better understanding of the means for the execution of the invention, reference being made to the accompanying drawings wherein:

FIG. 1 is a diagrammatic view from above showing the terminal surfaces of two cylinders carrying the printing plates, all other well known arrangements providing for intaglio printing being removed,

FIG. 2 is a diagrammatic cross-section through two cylinders provided each with an engraved sheath,

FIG. 3 is a diagrammatic view of a rotary press adapted to print with a single colour both sides of the sheets in association with wiping cylinders,

FIG. 4 is a diagrammatic view of a press similar to that illustrated in FIG. 3, incorporating conventional endless wiping webs for wiping the ink off the outer surface of the printing plates or of the engraved sheath.

Turning to FIG. 1, the twocylinders 1 and 2 the axes of which are parallel face each other and are adapted to revolve round their axes, respectively shown at 7 and 8. Each of thecylinders 1 and 2 is subdivided into four peripheral sectors carrying the printing plates, respectively 3 and 4. The two cylinders rotate at the same peripheral speed in the direction of the arrows, that is in opposite directions, so that the peripheral surfaces of the cylinders move in their contacting area in the same direction. Between the cylinders, the material, generally paper, to be printed on both sides and which is not illustrated, is introduced as a sheet or a web.

In order to obtain a sufficient compression of the paper to be printed, the two cylinders are urged against each other with an adjustable pressure, by means known per se as shown on FIGURE 3, such means can for example consist ofcylinder 121 to whosepiston 122 is mounted the spindle of one of the rotating cylinders. Such a cylinder can be hydraulic and can have fluid inlet andoutlet 123, 124.

Now, if the actual elastic yieldingness of the paper is not sufiicient for the obtention of a good elastic pressure, this necessary elasticity is obtained in the example illustrated in FIG. 1 by laying, according to the invention, theprinting plates 3 and 4 on a layer ofelastic material 5 and/or 6. This carrier layer, which may be given for instance a thickness ranging between 1 and 5 mm., according to the pressure required, is constituted for instance by felt, cork, rubber or cardboard; such a layer allows laying the rigid printing plates in a suitable elastic manner on the cylinder.

According to a modification which is not illustrated, only one of the twocylinders 1 and 2 is provided with an elastic layer and obviously, in this case also, the pressure is distributed equally over both sides of the paper.

In order to prevent the compression from being applied too harshly at the moment at which twosectorshaped printing plates 3 and 4 carried by the corresponding cylinders engage each other, the leadingedges 3a and 4a of the printing plates on both cylinders are correspondingly bevelled. By reason of the presence of this inwardly directed slope, which slope may advantageously be incurved and merge gradually into the periphery of the plate provided with engraved grooves, there is obtained a smooth application of the pressure upon engagement between the cooperating printing plates and the paper to be printed. A similar arrangement may also be incorporated with thetrailing edges 3a and 4b of the printing plates so that a sudden outing out of the pressure exerted on the output ends of the printing plates may be avoided.

FIG. 2 illustrates diagrammatically two cylinders and 11 adapted to rotate round thecorresponding axes 12 and 13. In order to obtain an elastic compression, the rigid cylindrical shell is suspended radially round the cylinder-carrying spindle through radially actingsprings 16 and 17. This leads to the possibility of shifting radially and outwardly the cylindrical shell of either cylinder as a unit with reference to itsspindle 12 or 13, to an extent depending on the elasticity of the spring, in a direction facing away from the cooperating cylinder.

Thus, while the two cylinders show permanently in the case illustrated in FIG. 2 a constant diameter d, thespacing 11 between the cylinder shell in the contacting area with the other cylinder and the cylinder spindle is always slightly shorter than thedistance 12 between the diametrically opposed peripheral area of the same cylinder shell and the cooperating cylinder spindle. The spacing between the spindles "12 and 13 of the two cylinders is thus somewhat smaller than the sum of the radii of the cylinders considered in their free condition. Consequently, whatever may be the position of a cylinder, thesprings 16 or 17 operating radially on the cylinder shell in a direction facing the other cylinder are subjected to compression, while the springs facing away from said other cylinder are subjected to a corresponding expansion.

According to a modification which is not illustrated, it is also possible to set the engraved shell of thecylinders 10 and 11 over an elastic layer distributed over the inner periphery of the outer shall forming the engraved sheath in a manner such that the rigid cylinder shell may be elastically shiftable on said layer with reference to the cylinder spindle.

FIG. 3 illustrates diagrammatically a rotary printing press designed in accordance with the invention so as to allow the simultaneous printing on both sides of a sheet of paper with a single colour intaglio impression. Thecylinders 1 and 2 are constituted in this case by platecarryiru cylinders provided with four sector-shaped engravedprinting plates 3 and 4 in a manner similar to those illustrated in FIG. 1, with the interposition, if required, of an elastic layer which is not illustrated.

From a conventional stack 21 carrying the sheets, the paper to be printed on both sides is fed over the feeding table 22 and is taken hold of by the oscillating gripping member 23 so as to be laid over the lower plate-carryingcylinder 3 and to be guided between the latter and the upper plate-carryingcylinder 2. Theprinting plates 3 and 4 on the two cylinders are subjected in a conventional manner to the well-known wiping operation after they have been inked by theinking means 27.

The wiping system cooperating in the case illustrated with thewiping cylinders 28 and 29 is designed so that unengraved upper surface areas of the plates are perfectly freed of any superfluous ink, while the ink is still more energetically urged into the engraved grooves so as to cut out any undesired splashing effect upon engagement of paper sections inside said engraved grooves.

The preliminary wiping system 23 is advantageously provided with an ink-recovering system which allows recovering the valuable printing ink.

The sheets printed on both sides are fed off the periphery of the lower plate-carryingcylinder 1 over the outlet chain system gripping the paper sheets and leading them onto the output table 2-5.

Instead of the one-colour printing illustrated, it is obviously possible to provide one or both sides of the sheets with a multicolour printing. In particular, it is possible to execute simultaneously a multi-colour printing on one side and a single colour printing on the other side of the sheet.

The arrangement illustrated diagrammatically in FIG. 4 for the execution of our improved printing procedure incorporates again twocylinders 39 and 31 which may be constituted by plate-carrying cylinders provided with sector-shaped printing plates as already illustrated in the case of FIG. 3, or else, it is possible to resort to cylinders carrying an engraved sheath. The web or sheet of paper to be printed reaches as precedingly, over an inlet table 32 and anoscillating gripping system 33, the periphery of the lower cylinder 39 and it is then urged under a suit-able compression into the gap between the two cylinders so that the simultaneous printing of both sides may be executed, the paper being finally conveyed by anoutput chain system 34 adapted to take hold of the paper so as to feed it onto an output table which is not illustrated.

In contradistinction with the wiping system cooperating with the cylinders as illustrated in FIG. 3, the wiping is executed in the case of FIG. 4 by the usual endless web of paper, fabric or the like suitable wiping material. These endless wiping webs are wound off feed rollers, overwiping bars 36a, 36b and 360 which urge them against the outer plate surface to be cleaned, after which said webs are wound on take-up rollers. These feed and take up rollers are designated generally by thereference number 36. The inking of the printing plates or of the engraved sheaths on the cylinders is again provided by inkingsystems 35.

in both embodiments illustrated in H65. 3 and 4, and with a view to increasing, as required by the case considered, the elastic pressure exerted by reason of the more or less elastic yieldingness of the paper, it is possible to resort to any of the inventive steps already disclosed with reference to FIGS. 1 and 2 in the case of a plate-carrying cylinder and of a cylinder carrying an engraved sheath. Furthermore, the invention provides for at least one cylinder spindle, which is shiftable perpendicularly to its longitudinal direction, so as to allow adjustment of the pressure exerted on it and must be subjected to the necessary pressure, to be stressed by an elastic force so that the unit including the cylinder and its spindle may be urged elastically against the other cylinder.

The method according to the invention allows for the first time the simultaneous one-colour or multi-colour intaglio printing on both sides of the material to be printed, which leads to a cheaper execution of expensive intaglio prints and also to a substantial saving of time in comparison with the double passage of the paper through the printing press as required hitherto.

What I claim is:

Device for producing sheets and web printed on both sides by single or multi-colour intaglio printing comprising (A) a pair of coacting oppositely rotating cylinders facing each other at their peripheries and each carrying similarly dimensioned rigid I intaglio printing plates,

(13) means for inking and wiping the surface of said intaglio plates on each of said cylinders,

(C) means for guiding the material to be printed between said cylinders at their coacting area to thus simultaneously print both sides of said material,

(D) spindles carrying said cylinders, at least one of said spindles having means for moving perpendicularly to the longitudinal axi thereof for adjusting the pressure between said plates and thereby guiding the material to be printed under pressure between said plates,

(E) at least one of said cylinders having an elastically yielding surface for supporting the said intaglio plates carried thereby,

(F) each of said rigid plates being sector-shaped and having bevelled leading and trailing edges,

(G) said plates on said coacting cylinders being oriented so that at least said bevelled leading edges of said cylinders coact to form an inwardly directed slope therebetween so that upon engagement between two oooperating printing plates carried by the two cylinders a gradual rise in pressure is obtained and similarly a gradual release of said pressure is ensured at the end of said engagement between said plates.

References Cited by the Examiner UNITED STATES PATENTS 1,970,809 8/1934 Marguardt 101156 2,085,323 6/1937 Leash 101376 2,234,726 3/1941 Frazier 10l220 2,310,788 2/1943 Hummelchen 101350 2,333,172 11/1943 Grupe 101-157 2,585,617 2/1952 Battey 101156 2,659,305 11/1953 Giori 101423 X 2,987,993 6/1961 Giori 101-155 3,030,883 4/1962 Shacklett 101-156 3,136,672 6/1964 Prongay 10140.1 X 3,161,127 12/1964 Lime 101-153 FOREIGN PATENTS 542,586 1/1932 Germany.

18,055 12/1915 Great Britain.

OTHER REFERENCES Hackleman, C. W., Commercial Engravings and Printing, Commercial Engraving Publication Company, Indiana, page 550, lines 912.

ROBERT E. PULFREY, Primary Examiner.

I. R. FISHER, Assistant Examiner.

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