US2276662A - Inking mechanism for printing machines - Google Patents

Description

March 17, 1942. w -rusc I 2,276,662

INKING MEC JHAN ISM FOR PRINTING MACHINES Original Filed March 4, 1939 2 Sheets-Sheet l TIT /z "H '5 INVENTOR O D 0 Wu March 1942- w. MATuscHKE INKING MECHANISM FOR PRINTING MACHINES Original Filed March 4, 1939 Sheets-Sheet 2 INVENTOR r- W ATTORNEYS I Patented Mar. 17, 1942 INKING MECHANISM FOR PRINTING MACHINES Walter Matuschke, Berlin, Germany Continuation of application Serial No. 259,890, March 4, 1939. This application July 22, 1939, Serial No. 285,889. In Great Britain and Germany March 2, 1938 3 Claims.

This invention relates to printing machines of the type utilizing water-thin aniline printing inks, and is described in my application Serial No. 259,890 filed March 4, 1939, of which the instant application is a continuation. As is well known in machines of this character, the ink is taken from an ink trough by a rotatable fountain roller arranged to dip into the ink as it rotates, and delivered through the medium of a distributing rollerto a printing roller and by the latter to a paper web which is pressed in contact with the printing roller by an impression cylinder. The amount of ink conveyed by the fountain roller to the distributing roller is ordinarily controlled by the pressure with which the distributing roller is urged against the fountain roller during the operation of the press. Control of the amount of ink transferred from the fountain roller to the distributing roller has also been effected by the use of a separate squeezing roller located'in advance of the distributing roller and which acts in a similar way to remove excess ink from the fountain roller, the ink thus removed being allowed to flow or drop back into the ink trough in which the fountain roller dips.

In the operation of these presses it has been found. that in increase in the speed of rotation of the fountain roller is accompanied by an increase in the amount of ink carried along by it from the ink trough. Because of'this fact, the speed of rotation of the fountain roller is limited since for the higher speed: it is impossible to remove the excess ink merely by the application of pres sure to the squeezing roller or to the distributing roller as the case might be. In other-words, beyond certain limiting speeds, pressure on the distributing roller or on the squeezing roller ceases to be an effective control of the amount of ink transmitted from the fountain roller for distribution.

In explanation of this phenomenon, the following theory is offered. Due to the friction or drag between the ink which is water-thin, and the fountain roller, the latter causes the ink to pile up at the point where the roller emerges therefrom, which piling up of ink is increased with increases in the speed of rotation of the fountain roller. This in turn increases the volume of the ink carried along by the fountain roller to the bight between it and the distributing roller or the squeezing roller should one be used. As the volume is thus increased, the amount of ink necessarily rejected by the rollers is likewise in-' creased, assuming the thickness of the film of ink to be passed for distribution remains constant. The result is that a considerable amount of ink partaking of a. swirling motion is built up at the bight of the rolls and as both rollers, being positively driven, tend to pull the ink through the bight, an excessive pressure is built up causing the rubber surface of the squeezing roller or the distributing roller, as the case may be; to be compressed or deformed out of true cylindrical conformation. This deformation of the rubbercovered roll under high speeds of operation permits the passage of ink in excess of that desirable for proper printing. The present improvements are designed to eliminate the effect just alluded to and thereby allow the press to be operated at very high rates of speed.

According to the present improvements, there is provided in the ink duct, a series of Walls or bafiles extending parallel to the axis of the fountain roller and having their upper edges near to but not touching the cylindrical surface thereof. These baflies act as weirs allowing the desired amount of ink to be carried along by .the roller. At the same time the baiiies act to break up the flow of ink in the ink trough which otherwise would be caused by the rapid rotation of the fountain roller, were it not for the presence of preventive means such as herein described. The 'baiile plates are perforated near their lower edges in order to permit the free flow of ink between the compartments formed thereby so as to equalize the level of the ink throughout the ink trough. The baflles may consist either of flat plates 'extending upwardly toward the fountain roller or may be bent near their upper edges whichever is desired.

It may be that, with certain speeds of rotation of the fountain roller, the baiiles just alluded to will not permit of a sufficiently accurate control of the amount of ink carried along by the fountain roller. Consequently, the present improvements also contemplate the provision of a strickle or doctor blade cooperating with the fountain roller and located close behind the position where the surface of the fountain roller emerges from the ink reservoir. This doctor blade does not effect a complete scraping of the ink oil? the fountain roller, that is, where the latter is provided with a smooth cylindrical surface, but has its edge located with respect to the fountain roller so as to leave a narrow gap therebetween. This strickle or doctor blade acts somewhat in the manner of a sluice or a weir controlling the amount of ink flowing through the gap. By making the doctor blade adjustable, the width of gap between it and the fountain roller can be regutween the latter and the fountain roller will be somewhat less than that between the former and the fountain roller. 1 v V A further control of the amount of ink supplied to the distributing roller may be obtained by employing a fountain roller having its surface formed with closely spaced etched ink retaining wells similar to those of an lntaglio printing cylinder used in rotogravure work, except that the depth of the etched wells will be uniform throughout the cylindrical surface. When such a fountain roller is used, the doctor blade is held in contact with the cylinder so that all of the ink is strickled or scaped off, except that located in the ink retaining wells. The ink from the wells is transferred to the distributing roller which has an India rubber surface and thence transferred to the printing roller.

The various improvements described herein may be used eitheralone or in combination. For

fountain roller may be preferred with, of course,

the doctor blade which could be used alone for moderate speeds or in conjunction with the baille plates where the printing speeds are high.

Referring to thedrawings:

Fig. 1 is an end sectional elevation in diagrammatic illustration, of a printing machine equipped with the present improvements;

Fig. 2 is a vertical'sectional view on line 22 of Fig. 1;

Fig. 3 is a vertical sectional view on line 3-4 Fig. 1;

Fig. 4 is a detail view showing a doctor blade adjusting and locking device suitable for use in the improved machine;

Fig. 5 is a diagrammatic view similar to Fig. 1 of a printing machine equipped with an etched fountain roller; 7

Fig. 6 is a partial vertical sectional view through an etched cylinder of the type'used in the machine illustrated in Fig. 5; and

Fig. 7 is a partial elevational view of the cylin- .der shown in Fig. 6.

In the form of the invention shown in Figs. 1

' able means not shown and as thus far described the machine is known. During the rotation of the fountain roller in a machine as thus constituted, there is considerable tendency for the ink to be dragged along with the fountain roller, causing it to pile up at the point where the fountain roller emerges from the ink, this tendency being augmented as the speed of the fountain roller is increased, and the greater, the extent to which the ink piles up, the greater is the volume of ink carried up into the bight of the rollers 21 and d. Since these rollers must reject all but a given amount of ink, it is apparent that the rejected ink meeting the large volume of rising ink will .produce a swirling motion at the bight so that there is a substantial volume of ink upon which the squeezing roller and the fountain roller can act at this point. When the speeds are high,

' this large volume of ink at the bight, attempting improvements, a series of transverse bailies 9 exto 3, there is provided an ink trough a, a rotatable urged thereagainst by an impression roller f. In

this embodiment of the invention, there is also provided a squeezing roller d arranged in advance of the distributing roller and which is pressed by suitable means, not shown, against the fountain roller, the function of this roller being to determine the amount of inkthat is passed onto the roller c for distribution. All of the rollers are rotated in well known manner by suittending from one end of the trough a to the other, and which likewise extendsfrom the bottom of the trough up to a point near to but not in engagement with the cylindrical surface of the fountain roller. These bailles g act to the tendency of the ink in the trough to flow in a continuous current under the influence of the fountain roller movement and consequently'will eliminate to a great extent the piling up of the ink at the point where the fountain roller emerges from the ink. The space between the upper edges of the baiiles and the fountain roller is, however, suflicient to permit the fountain roller to drag along with it a suflicient amount of ink for proper printing without, however, causing the excess swirling motion at the bight of the rollers.

Near their lower edges the baflies g areprovided with perforations a giving communication. past all of the bailles in order that the level of the ink throughout the trough will be equahzed.

- The .baflles g may be bent near their upper edges,

as shown, or if desired, could extend straight upwardly toward the cylindrical surface of the fountain roller.

For a finer degree of ink regulation, a doctor blade h is provided extending toward the fountain roller but located so that its free edge is in spaced relation with the surface thereof. The gap provided at this point is somewhat smaller than that between the battles and the fountain roller and will accordingly act to remove an additional amount of ink. The doctor blade 11. is preferably adjustable to accommodate different speds of press operation and for this purpose is fixedupon a pivotal shaft h joumalled in the walls at the opposite ends of the ink trough a (see Fig. 4) and provided at one ,end with a handle it through which the blade can be adjusted and a locking device it for securing the blade in its different positions of adjustment.

Also for fine regulation of the ink supply, a ma chine may be used employing a fountain roller 1 having its surface etched with small ink cells 5 similar to those used in roto'gravure work, except that the cells are etched substantially to the same depth throughout the surface of the roller (see Figs. 5, 6 and 7). The machine itself is substantially the same as that heretofore described,- except that the squeezing roller is omitted and the ink cells, this ink being picked up or transferred to the distributing roller which in turn inks the The actual printing of the paper printing roller. web is the same as that in the machine heretofore described. Since only th ink in the ink retaining cells is transferred to the distributing roller, it is apparent that a very accurate control of the ink supply can be obtained with a fountain roller of this type. Such a machine could be operated with the doctor blade alone,

although for high speeds of operation it maybe desirable to employ bafile plates 9 for the same purpose as heretofore described.

Inthe accompanying drawings, the invention has been shown merely in preferred form and by way of example, but obviously many variations and modifications may be made therein which will still be comprised within its spirit. It is to be understood, therefore, that the invention is not limited to any specific form or embodiment v except insofar as such limitations are specified in the appended claims.

Having thus described my invention, what I claim is:

l. In or for a printing machine adapted to be used with thin fluid inks, an inking mechanism including, in combination, an ink trough, a rotatable fountain roller arranged during its rotation to dip into the ink, a second rollercooperating constantly with the fountain roller to control the amount of ink passed along for use in printing, said fountain roller being adapted as it rotates to carry along to said second roller an even supply of ink from the ink trough, and baffling means including a plurality of walls arranged in the ink trough parallel with the axis of the fountain roller, and each having one of its edges in Slightly spaced relation with the cylin-' drical surface of the roller. I

=2. In or for a'printing press adapted to be used with thin fluid inks, an inking mechanism including, in combination, an ink trough, a' rotatable -fountain roller arranged during its rotation to dip into the ink, a second roller cooperating constantly with the fountain roller to control the amount of ink passed along for use in printing, said fountain roller being adapted as it rotates to carry along to said second roller an even supply of ink from the ink trough, bafliing means including a plurality of walls arranged in the ink trough parallel with the axis of the fountain roller and each having one of its edges in slightly spaced relation with the cylindrical surface thereof, and means for equalizing the level of the ink in the trough.

3. In or for a printing press adapted to be used with thin fluid inks, an inking mechanism including, in combination, an ink trough, a rotatable fountain roller arranged during its rotation to dip into the ink, a second roller cooperating constantly with the fountain roller to control the amount of ink passed along for use in printing, said fountain roller being adapted as it rotates to carry along to said second roller an even supply of ink from the ink trough, and bathing means including a plurality of walls extending to the bottoni of the ink trough and arranged parallel with the axis of the fountain roller and each having one of its edges in slightly spaced rela- WALTER MATUSCHKE.

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