US3044396A

US3044396A - Inking mechanism for intaglio printing machines

Info

Publication number: US3044396A
Application number: US135A
Authority: US
Inventors: Claes B Aller
Original assignee: CARL ALLERS A S Ets
Current assignee: CARL ALLERS A S Ets
Priority date: 1959-01-02
Filing date: 1960-01-04
Publication date: 1962-07-17
Anticipated expiration: 1979-07-17

Description

July 17, 1962 c. B. ALLER 3,044,396

INKING MECHANISM FOR INTAGLIO PRINTING MACHINES Filed Jan. 4, 1960 4 Sheets-Sheet 1 Fly. 1.

In ventor Attorney:

July 17, 19 2 c. B. ALLER 3,044,396

INKING MECHANISM FOR INTAGLIO PRINTING MACHINES 4 Sheets-Sheet 2 Filed Jan. 4. 1960 5" O, 8 O 2/ Q I 2 H 4 4 -1" 5 ,'//F II\ V 27 7 ,4 2

Inventor Clauflm vw,

MMzi/W c. B. ALLER 3,044,396

INKING MECHANISM FOR INTAGLIO PRINTING MACHINES Jul 17, 1962 4 Sheets-Sheet 3 Filed Jan. 4, 1960 I l l l l l l l I I I i l l x I -l l n 4A W M B July 17, 1962 c. B. ALLER 3,044,396

INKING MECHANISM FOR INTAGLIO PRINTING MACHINES Filed Jan. 4, 1960 4 Sheets-Sheet 4 l n ven tor pazdwow A ftorney:

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3,044,396 INKING D/[ECHANISM FOR INTAGLIO PRINTING MACHINES Claes B. Aller, Copenhagen, Denmark, assignor to Carl.

In intaglio printing as practised commercially with rotary printing machines, the image to be reproduced is formed in the curved face of a printing surface by a series of cells; ink is initially applied in one way or another to the whole area of the printing surface which then, as it moves towards the printing or impress-ion zone, passes under a doctor blade which is supported by the outer faces of the walls of the cells, this blade being intended to remove the ink in excess of that contained in the cells themselves.

The tone values of the image are controlled by the depth or the area or both of the cells, these factors being established at the time the printing surface is produced; to retain the same tone values in the printed image demands firstly that the cells shall be adequately charged with ink and secondly that the outer faces of the cell walls shall be devoid of ink. This imposes a heavy duty on a single doctor blade and in some cases it is necessary to cause the printing surface, :after leaving the doctor blade, to pass under wiper cloths or pads for the purpose of wiping clean the outer faces of the cell walls before they pass to the printing or impression zone in which the ink in the cells is transferred to the material tobe printed.

The main object of this present invention is to provide an inking mechanismwhich while being simple, will ensure that the cells are fully charged with ink and that the outer faces of the cell walls shall be adequately cleaned.

The present invention comprises providing, in advance of the doctor blade (regarded in the sense of movement of the printing surface from an ink applying zone to the impression zone) a roller which not only operatesto reduce the ink applied to the printing surface to a thin film but operates to force the ink into the cells; by this action the duty imposed on the subsequently acting doctor blade is considerably reduced since it is now called upon to remove only the thin film or trace to which the ink is reduced and the doctor is therefore enabled easily to clean the outer faces of the cell walls without the necessity for any further cleaning action. The tone values are thus maintained since it is ensured that the cells are properly charged with ink and the outer surfaces of the cell walls are adequately cleaned.

In order to maintain the doctor blade clear of any accumulation of the ink which it removes,'it is preferred that the doctor blade shall operate in a region of subatmospheric pressure created by a duct connected to the suction side of a pump; in this way the ink which is removed by the doctor blade is constantly sucked away leaving the blade in a continuously clean condition able to clear the faces of the cell walls of all traces of ink. The roller is supported for rotation in bearings which are adjustable to enable the roller to be set radially with respect to the axis about which the printing surface rotates so as to enable the thickness of the film of ink left on the surface after it has passed. the roller to be regulated.

The ink can initially be applied to the whole area of printing surface in any of the usual ways; e.g. by providing a pool of ink in an ink fountain in which the printing surface dips or by providing an inking head which directs a spray or film of ink to the printing surface. The ink may, however, be caused to circulate in a path which atent O being forced into the cavities in the plate to ensure theirs Patented July '17 1962 "ice . 2 includes the printing surface as it passes to the roller; the circulation of ink can be produced by a pump in which case the pressure side of the circulation would be used to supply the ink to the printing surface and the suction side to remove the excess ink from the doctor blade.

The term printing surface is employed to denote either the periphery of a printing cylinder-prepared for the pur-1 pose or the outer face of a shell or plate mounted on a cylinder. 7 i g I The doctor blade is arranged as closely as practicable to the impression zone which would be formed in the usual way by an impression roller backed by a counterpressure cylinder on the diameter opposite that at which the roller is applied to the printing surface, the material to be printed passing between the impression roller and the printing surface. p 1

The invention is illustrated in the accompanying drawing in which FIGURE 1 is a somewhat diagrammatic view showingthe essential working parts and FIGURES 2, 3 and 4 are views of a practical form of the apparatus, FIGURE 2 being a fragmentary view,.partly in end elevation and partly in transverse, vertical section, FIGURE 3 being a side elevation looking in the direction of thearrow III, FIGURE 2, and FIGURE 4 being a plan view. ,In FIGURES 2-4 of the drawing the parts corresponding to those shown in FIGURE 1 are given similar reference numerals. '7 7 Referring to -the drawings, the printing cylinder of an intaglio printing machine is indicated at-l, the printing surface applying the printing image to a web '2where it passes over an impression cylinder or roller 3 backed by a counter-pressure cylinder 4. f f

The printing surface of thecylinder 1 is inked by ink supplied to a chamber 5 through aQsup ply connection 6; in this chamber is a roller 7 which operates to force the. ink into the cells constituting thep'rinting surface.on.. the. cylinder 1 and at the same time to limit the thickness the coating of ink which is on the printing surface. .Sur-I plus ink (i.e. ink which is' squeezedaway by the roller 7 is removed by connecting the chamber 5 to a suction -re-.

regulating action of the roller 7 has now only the small duty of removing the regulated thickness of ink from the outer walls of the cells leaving them charged by the injecting action of the roller 7. j The doctor blade operates in a region of suction which is created by extending the suction duct. 8 as shown at 11 so that ink removed by the doctor itself is drawn away.

Referring now to the practical as it is sh'own'in FIGURES 2-4, the roller 7 .is carried by arms 24 which are fast with stub'spindles 25 so mounted on stationary brackets 26 that the spindles can be rocked by adjusting screws 27 operating on arms 27' so that t he pressure created by the roller 7 can be adjusted.

In this practical form, the ink supplied to the-connec-f tion '6 flows to an inking head 28 having an'arrow flow passage 28' which extends the length of the printing cylinder ,1 so that the ink is applied as a sheet to theperiphery of the cylinder prior to itspassing below the roller 7; thus, the printingrsurface is pre-inked and the] ink is subjected to the pressure, of the roller 7 so as to be levelled and regulated in thickness by it as well as being fully charged with the ink. r

The doctor blade 10 is carried by a holder 12, clampedform of the invention" 3 on a hollow rail component 13 which provides the suction duct 8; this component 13 is itself provided withlugs 14 which are pivotably mounted at the ends of the component 13 on pivots 15' carried by brackets 16 clamped in selected positions on brackets 17 clamped to the upper edge of the wall 18 of the usual fountain disposed below the printing cylinder 1.

- The pivots 15 provide for the lifting of the suction duct and doctor blade assembly to enable the printing cylin der to be fitted and its surface to be examined. This lifting operation can be effected by power via pneumatic ram" and cylinder arrangements the cylinders 19 of which are carried by brackets 20 pivoted at 21 and the farms of which are connected by their rods 22 to swivels 23 onthe duct component 13, the arrangement enabling the cylinders to oscillate as the duct swings.

The ink which is drawn away by the suction applied vla the duct 8 is returned to the supply duct 6 so estab lishing a circulation of'ink which will wash over the printing surface where it is exposed between the ink applying chamber or the head 28 and the roller 7. The roller 7 is a free running roller relying on traction irnparted to it by the printing surface of the cylinder 1 but alternatively the roller could be positively driven to have a peripheral speed equal to'that of the printing surface slightly less or greater than that of the printing surface so as to produce a working action on the ink promoting the cell-charging action.

Although reference has been made to only a' single roller 7, two or more rollers could be used in series'and set progressively to reduce the thickness of the ink film before it passes to the doctor: in most cases however, a single roller is sufiicient and is desirable on the score of simplicity and cost.

The suction ink removing action can be extended close to the operating zone of the doctor blade by ducts or pipes 30 carried by the rail 13 and open to its interior.

Provision can be made to remove ink which passes over the end walls of the printing cylinder 1: this can be efiected by extending down those end walls suction boxes 29 which are also connected to the suction to which the interior of the rail 13 is connected. These suction boxes are open at their faces which are presented to the end walls of the cylinder 1 so that ink which passes over' I the end walls is collected and returned.

As is usual in such printing machines the cylinder '1 is disposed over a fountain 31 and this fountain will catch any ink falling from the mechanism, the fountain being conveniently also connected to the suction supply.

I claim:

1. A rotary intaglio printing machine comprising a rotary printing cylinder having an etched printing surface formed with cells extending into the cylinder below the cylinder surface, an'impres'sioncylinder with which the printing cylinder cooperates to effect a printing impression; at an impression zone, means to apply ink to the surface of the printing cylinder as it moves toward the impression zone, a doctor blade disposed to operate on the printing cylinder as it passes from the ink-applying means to the impression zone to remove the ink from the outer walls of the cells but leave the cells charged with ink; and, in combination therewith, a roller disposed adjacent the printing cylinder between the inkapplying means and the doctor blade, the roller operating on the inked surface of the printing cylinder to force the ink into the etched printing surface cells and to remove surplus ink from said printing cylinder prior to the etched surface passing to the doctor blade.

2. A rotary intaglio printing machine comprising a rotary printing cylinder having an etched printing surface formed with cells extending into the cylinder below the cylinder surface, an impression cylinder cooperating at an impression zone with the printing surface to effect a printing impression on material passed between the cylinders, an inking head to apply a film of ink to the etched surface of said printing cylinder as it passes to the impression zone, means to supply ink under pressure to the said head, a doctor blade disposed to operate on the etched printing surface of said printing cylinder as it passes from the inking head to the impression zone to remove the ink from the outerwalls of the cells but leave the cells charged with ink; and, in combination therewith, a roller disposed adjacent said printing cylinder to operate on the etched printing surface as it passes from the inkinghead to the doctor blade, the said roller operating on the inked printing surface to force the ink into the etched printing surface cells and to remove surplus ink, thereby relieving the duty of the doctor blade.

.3. A rotary intaglio printing machine comprising a rotary printing cylinder having an etched printnig surface formed with cells extending into the cylinder below the cylinder surface, an impression cylinder with which the printing cylinder cooperates to effect a printing impression at an impression zone, means to apply ink to the surface of the printing cylinder as it moves toward the impression zone, a doctor blade disposed to operate on the printing cylinder as itpasses from the ink-applying means to the impression zone to remove the ink from the outer walls of the cells but leave the cells charged- With ink; and, in combination therewith, a roller disposed adjacent the printing cylinder between the ink-applying means and the doctor blade, the roller operating on the inked surface of the printing cylinder to force the ink into the etched printing surface cells and to remove surplus ink from said printing cylinder prior to the etched surface passing to the doctor blade, and means to adjust the setting of said roller radially of the etched printing surface of the printing cylinder.

4. A rotary intaglio printing machine comprising a rotary printing cylinder having an etched printing surface formed with cells extending into the cylinder below the cylinder surface, an impression cylinder cooperating at an impression zone with the printing surface to effect a printing impression on material passed between the cylinders, an inking head to apply a film of ink to the etched surface as it passes to the impression zone, means to Supply inkunder pressure to the said head, a doctor blade disposed to operate on the etched printing surface of said printing cylinder as it passes from the inking head to the impression zone to remove the ink from the outer walls of the cells but leave the cells charged with ink; and, in combination therewith, a roller disposed adjacent said printing cylinder to operate. on the etched printing surface as it passes from the inking head to the doctor blade, the said roller operating on the inked printing surface to force the ink into the etched printing surface cells and to remove surplus ink, thereby relieving the duty of the doctor blade, and means to adjust the setting of the said roller radially of the etched printing surf-ace of the printing cylinder.

5. A rotary intaglio printing machine comprising a rotary printing cylinder having an etched printing surface formed with cells extending into the cylinder below the cylinder surface, an impression cylinder with which the printing cylinder cooperates to eflect a printing impression at an impression zone, means to apply ink to the surface of the printing cylinder as it moves toward the impression zone, a doctor blade disposed to operate on the printing cylinder as it passes from the ink-applying means to the impression zone to remove the ink from the outer walls of the cells but leave the cells charged with ink; and, in combination therewith, a roller disposed adjacent the printing cylinder between the inkapplying means and the doctor blade, the roller operating on the inked surface of the printing cylinder to force the ink into the etched printing surface cells and to remove surplus ink prior to the etched surface passing to the doctor blade, and means to withdraw surplus ink removed by the roller and the doctor blade and to supply it to the ink-applying means.

6. A rotary intaglio printing machine comprising a rotary printing cylinder having an etched printing surface formed with cells extending into the cylinder below the cylnider surface, an impression cylinder cooperating at an impression zone with the printing surface to eifect a printing impression on material passed between the cylinders, an inking head to apply a film of ink to 'the etched surface as it passes to the impression zone, means to supply ink under pressure to the said head, a doctor blade disposed to operate on the etched printing surface of said printing cylinder as it passes fro-m the inking head to the impression zone to remove the ink from the outer Walls of the cells but leave the cells charged. with ink; and, in combination therewith, a. roller dis posed adjacent said printing surface to operate on the etched printing surface as it passes from the inking head to the doctor blade, the said roller operating on the inked printing surface to force the ink into the etched printing surface cells and to remove surplus ink, thereby relieving the duty of the doctor blade, suction means to remove the surplus ink removed by the said roller and the said doctor blade, and means to re-supply the removed ink to the said inking head so as thereby to create a circulation of ink.

7. A rotary intaglio printing machine comprising a rotary printing cylinder having an etched printing surface formed with cells extending into the cylinder below the cylinder surface, an impression cylinder cooperating at an impression zone with the printing surface to effect a printing impression on material passed between the cylinders, an inking head to apply a film of ink to the etched surface of said printing cylinder as it passes to the impression zone, means to supply ink under pressure to the said head, a doctor blade disposed to operate on the etched printing surface of said printing cylinder as it passes from the inking head to the impression zone to remove the ink from the outer walls of the cells but leave the cells charged with ink; and, in combination therewith, a roller disposed to operate on the etched printing surface as it passes from the inking head to the doctor blade, the said roller operating on the inked printing surface to force the ink into the etched printing surface cells and to remove urplus ink, thereby relieving the duty of the doctor blade, means to adjust the setting of the said roller radially of the etched printing surface of the printing cylinder, suction means to remove the surplus ink removed by the said roller and thesaid doctor blade, and means to re-supply the removed ink:

to said inking head so as thereby to create a circulation of ink.

8. A rotary intaglioprinting machine comprising a rotary printing cylinder having an etched printing surface formed with cells extending into the cylinder below the cylinder surface, an impression cylinder cooperating with the printing cylinder to print on material passed between the cylinders in a printing impression zone, means to apply ink to the printing surface as it moves toward the impression zone, a roller disposed adjacent the printing cylinder to operate on the inked printing surface after inking thereof and before said surface moves to the impression zone so as to force the ink into the etched surface cells and to remove surplus ink from the cylinder surface around said cells, and wiping means disposed to operate on the printing surface between the roller and the impression zone finally to clean the outer face of the printing surface as it passes to the impression zone but leave the cells charged with ink.

9. A machine as claimed in claim 8 including a chamber to which the ink is supplied and wherein said roller is disposed in said chamber, a wall of the chamber having an extension cooperating with the periphery of the roller to remove ink from it, the said chamber having means for connection to a source of suction to withdraw the removed ink.

10. A machine as claimed in claim 8 and having means to adjust the setting of the roller radially of the printing cylinder.

FOREIGN PATENTS Great Britain Nov. 9, 1916 Great Britain Ian. 10, 1940