US2276525A - Apparatus for inking plate cylinders - Google Patents

Description

.March 17, 1942. H. R. TROTTER I APPARATUS FOR INKING PLATE CYLINDERS s Sheets-Sheei 1 Filed March 7, 1940 March 17, 1942. H. R. TROTTER APPARATUS FOR INKING PLATE CYLINDERS 3 Sheets-Sheet 2 Filed Manon '7, 1940 Mai-ch 17, 1942. H. R. TROTTER 3 I APPARATUS FOR INKING PLATE CYLINDERS Filed March 7, 1940 3 Sheet sP-Sheet s o o o a O O o W h W 02. a) W? fig 3kg Patented Mar. 17, 1942' 2,276,525 APPARATUS FOR INKING PLATE CYLINDERS Henry R. Trotter, Glencoe, Ill., assignor to R. R.

Donnelley & Sons Company, Chicago, 111., a corporation of Illinois Application March 7, 1940, Serial No. 322,798

3 Claims.

My invention relates to the inking of the printing cylinders, as for example the plate cylinders, of rotary presses commonly involving the provision of an ink fountain from which the ink is fed to th printing cylinder through the medium of a train of inking rollers, the ink being transferred from the fountain, by a series of steps, to the form roller constituting the terminal roller of the train.

The printing face of such a cylinder'commonly presents printing areas of widely differing densities clue, as for example, to the differences between solid characters of type and small characters of type, the heavier printing areas requiring, in the continuing operation of the press,the supplying thereto of a greater volume of ink than in the case of the areas of lesser density.

a sufficient supply of ink, in the continuing operation of the press, to insure on the'form roller the requisite quantity of ink.

The means referred to commonly involve the use of an oscillating ductor roller which conveys dabs or batches of ink from the fountain roller to the roller next to it and an adjustable metering device in the ink fountain which, under the control of the operator, operates to vary the feed of ink across the inking rollers in accordance with the requirement of the form.

Such a character of means presents a number of disadvantages certain of which are that considerable dexterity and skill, calling for a high degree of. expertness on the part of the pressmen and constant attention, is required for effecting the proper adjustments; the applying of the ink in the form of dabs and batches to the roller as stated necessitates the provision of a long train of ink rollers intermediate the fountain and the form roller thus necessitating,

especially in the production of quality work,

where heat-drying inks are used, the employment of a high boiling point ink to avoid the drying of the ink before its transfer to the printing cylinder, which results in the necessity for an extremely high heat to be applied to the printed surface to evaporate the ink solvents after passing through the printing unit.

One of my objects is to provide a novel method ink from the fountain roller to the form roller permitting a lower boiling point ink to be used and avoiding high heating of the printed material after passing it through the printing unit.

Furthermore, as inking mechanism has hitherto been provided and in accordance with prior methods, serious difiiculties have been presented by reason'of the tendency of the ink to dry, on

the rollers of the inking mechanism especially during the periods when the press is idle even when of short duration, necessitating the taking of measures such as for example the application of protecting coatings to the ink on the rollers, to prevent such drying; it being another of my objects to provide a novel method and apparatus for preventing the drying of the ink on the rollers of the inking mechanism not only during its operation in supplying ink to the printing cylin-, der but also when the press is not operating.

As a preface to the following description it may be stated that my invention as to one phase thereof is based on the hypothesis that all portions of the printing face, regardless of variations in density, require the same thickness of ink film to produce the desired impressions on the paper to be printed and in its broadest aspect as to this phase consists in providing a clearance between the form roller and the roller which delivers 'ink thereto and continuously supplying to such clearance a suificient volume of inkto maintain the clearance filled with ink at all times; the clearance being such that the film of ink transferred to the printing cylinder from the form roller be of uniform thickness andof th thickness of the ink film desired to be presented by the printing surfaces of the printing cylinder to the sheet to be printed.

As to the phase of my invention relating to the avoiding of the drying of the ink on the rollers, it may be stated that, as to one of its aspects it consists in providing for the supplying to the form roller an amount of ink in excess of that which should be presented by this roller to the printing cylinder and removing such excess from the form roller before it contacts the printing cylinder and preferably returning such excess to the ink supply for recirculation in which latter case the ink is. caused to flow through a continuous circulatory. course. I

Referring to the accompanying drawings:

Figure 1 is a view in side elevation of the inking mechanism and associated printing and impression cylinders of a rotary printing press, embodying my invention, and by which my improved method may be practiced.

Figure 2 is an enlarged broken sectional view taken at the line 2 on Fig. 1 and viewed in the direction of the arrow.

Figure 3 is a plan view, reduced in size, of the structure shown in Fig. '1, with the printing and impression cylinders and their mountings omitted.

Figure 4 is a section taken at the line 4 on Fig. 3 and viewed in the direction of the arrow,

the dams cooperating with the scraper bars for certain of the rollers being removed.

Figure 5 is a fragmentary sectional view taken at the line 5 on Fig. 4 and viewed in the direction of the arrow; and

Figure 6, a broken plan view of the structure shown in Fig. 5.

In the arrangement shown 5 represents a rotary printing cylinder, as for example a plate cylinder, which may be mounted in the main frame 6 of the press and positively driven from the drive of the press in accordance with cornmon practice, the cylinder 5 having a gear I, by means of which the ink-transferring rollers of the inking mechanism to be described, are driven. 8 represents the impression cylinder cooperating with the printing cylinder; and 9 the paper web to be printed.

The inking mechanism comprises a carriage ||l slidable on the main frame 6 of the press toward and away from the printing cylinder 5 and having side plates spaced apart and connectedtogether by the tie-rods |2, I3 and I4. Themainframe 6 is equipped with a pair of parallel racks IS with which gears l5 fixed on a shaft journaled in the carriage l0, mesh. By means of a hand-wheel l8 fixed on the shaft lkthis shaft may be rotated in either direction to move the carriage, toward or away from the printing cylinder 5, as desired, and thus into and out. of engagement with drive means hereinafter described operated by the press.

The carriage I3 is equipped with an ink-pan ,8 into the ink in which a roller 20, commonly termed a fountain roller, journaled in the side plates ll, extends.

Journaled in the side plates H is a form roller 2| to which ink from the pan i9 is transferred by means of the fountain-roller 20 and an intermediate transfer roller 22 joumaled in the side plates II, the rollers 20,2l and 22, being disposed in parallel relation to each other and to the printing cylinder 5.

The rollers 20 and 22 may, be ,made of steel whereas at least the circumferential' surface of the form roller 2| is made of a composition presentingm somewhat yieldable ink-receiving surfacer-suitable for the reception of ink and its transfer to the printing sur aces of the printing cylinder 5, as for example accordance with the common practice of groviding form rollers.

The printing cylinder 5 and the several rollers referred to are driven in the directions of the byway of example,

respective arrows, these rollers being driven from v the printing cylinder 5 by the means shown and comprising the following mechanism:

A shaft 23 journaled in the side plates H and having a gear 24 meshing with the gear lon the printing cylinder 5; a sprocket 25 on the shaft 23 and engaging an endless sprocket chain I 25 which meshes with a gear 21 on the intermediate roller 22; and also a gear 23 on the. fountain roller 20 and a gear 29 on the shaft 3|! journaled in the sideplates II, the shaft 30 I having a gear 3| meshing with gears 32 and 33 on'vibratory rollers 34 and 35, as for example of steel, which extend parallel with, and alongside of the form roller 2| and in contact therewith, the form roller in the particular arrangement shown being driven by the rollers 34 and The vibratory rollers 34 and 35 are joumaled in a frame 36 located in the space between, and in spaced relation to, the side plates this frame comprising side plates 31, in which the rollers 34 and 35 are joumaled, and tie rods 38, 39 and 40 connecting together the side plates 31 the frame 38 being slidable crosswise of the machine on the rod l3 and on a shaft 4| journaled in the side plates The frame 36 cooperates with means for re ciprocating it, together with the vibratory rollers 34 and 35, shown as comprising a cam 42 mounted on one end of the shaft 43 of the foun- -tain roller 20 and containing a cam groove 44 described. The roller45 runs in contact with the printing cylinder 5 and with the roller 41, the shaft 4| carrying the roller 47 being driven by a gear 48 on this shaft meshing with the gear 24 on the shaft 23.

The rollers 20 and 22 are shown as separately adjustable vertically by mounyting the boxes 49 and 50 in which these rollers are journaled, in

vertical ways 5| and 52 on the side plates 7 with adjusting screws 53 and 54 engaging these boxes; and the form roller 2| adjustable relative to the printing cylinder, as by mounting its journal boxes '55 in horizontal ways on the side plates H, with adjusting screws 51 and 58 engaging these boxes; and the roller 35 adjustable, as by journaling it in arms 59 at its opposite ends screwed-tothe-side plates H, .by bolts 80, with the bolt-openings in the arms somewhat larger than the bolts 5!).

The fountain roller 2D-is shown as having associated therewith a plate 6|, forming a dam, mounted on a shaft 62' carried by the side plates II to control the thickness of the film of ink carried by this roller from the pan l9; adjustment of this plate being effected by means of the adjusting screw 64carried'on an arm 33 on the shaft 52. a

Associated with the vibratory'rollers 34 and 35 are scraper means, comprising scraper plates and 65 preferably of spring steel, carried by, and rotatably adjustable on, the tie rods I 3 and M, respectively.

The scraper plates 65 and 86 are carried on bars 51 and 58, respectively, each of substantially the same length as the rollers 34 and 35, secured to spaced apart bracket arms 69 and 10 connected to the tie rods l3 and i4, respectivegether in any suitable way.

The scraper means referred to for each roller 34 and 35 also comprise portions of plates, which are of the same form for the scraper means for each roller 34 and 35,, superposed on, and secured to, the opposite ends of the bars 61 and 68,the"

plates on the-bar 61 being shown at T3 and the plate on one end of the bar 68 at 14. These scraper portions on the plates 13 are represented at 15 and, with the main scraper plate 65 between. them, form a scraper surface effective over the entire length of the vibratory roller 34 in the rotary and reciprocatory movements of the latter, the scraper portions 15 being shown as,

formed by milling out concave pockets 16 in the upper surfaces of the plates 13. The scraper portions for the plates 14 are similarly provided for forming, with the scraper plate 66, a scraper I shown in the drawings, but sufliciently spaced from the ends of the rollers 34 and 35 to permit of the reciprocal'movement of the latter without interference from these plates. I

The pockets l6 and TI reach short of the outer ends of the plates 13 and 14 thus forming dams at the opposite ends of the scraper means for each roller 34 and 35, the dams on the plate 13 being shown at 80 and the dam on theone of the plates 14 shownat 8|.

Adjustment of the scraper means above de scribed about the tie rods I3 and I4 is effected by means of adjusting screws 82 and 83 mounted in a cross-plate 84 secured to the side plates H, and bearing, respectively, at their ends against the bracket-arms 69 and 10.

In accordance with one of the principal features of my invention as above set forth in the preamble, the roller 22 is spaced from the form roller 22 and likewise this .016"-fi1m on the roller 22 would be divided in the space between this roller and the form roller.2l, causing an inkfilm of .008" thickness to be deposited on, and This ,008"

carried over by, the form roller 2|. thick film is then successively halved by the vibratory rollers 35 and 34, whereby the form roller 2| carries over to the printing surfaces of the printing cylinder 5 an ink film of .002" thickness which divides in the space between-the form roller 2| and the printing cylinder 5, causing an ink.

film of .001" thickness to be deposited on the printing surfaces of the plate cylinder 5 for presentation to'the sheet 9 to be printed.

As will be understood, the clearance between the rollers 2| and 22 is greater than thesthickness roller 2| to provide a clearance between these rollers which is maintained at all times full of ink.

For the sake of illustration, assuming the apparatus to comprise the various rollers described and that the ink film between the various cooperating rollers and between the printing cylinder and the form roller will be halved in the operation of the inking mechanism, as I believe occurs, and it is desired that the ink film delivered to the printing surfaces of the printing cylinder 5 be .001 thick, the dam 6| would be set to cause, the fountain roller 20 to carry to the intermediate roller 22 an ink film .032" thick; the rollers 20 and 22 would be spaced apart to provide a .032" clearance therebetween and the roller 22 would be spaced from the form roller 2| .016.

Thus in the operation of the rollers the .032" thick film on the fountain roller 20 would be divided in the space between this roller and the roller 22 causing an ink film of .016 in thickness to be deposited on, and carried over, by the of the ink film on the form roller 2|}after pass-' ing beyond the printing cylinder 5 and this remnant of ink film thus carried over by the form roller to the clearance between the form roller and the roller 22 augments the ink delivered by the roller 20 to this clearance thus building up an excess of ink behind such clearance, as indicated at 10. Thus, regardless of the amount of ink carried over by the form roller 2| after leavingthe printing cylinder 5 the clearance space between the rollers 2| and 22 is maintained at all times full of ink and insures a uniform thickness f lm of .008 on the form roller after leaving the roller 22. In other words, a reservoir, so to speak, of ink is'caused to be maintained at the clearance between the. rollers 2| and 22 and regardless of the areas of the circumferential surface of the form .ioller from which ink was removed by the printing cylinder, the form roller receives, and carries over, from the roller 22 a uniform thickness of ink film-in the example given, of .008"

. and thence through the'spacesbetween the bracket-arms to the pan l9 thus establishing a closed circulatory course for the ink within the apparatus.

The- rollers 46 and 41 are provided for'the purpose of smoothing out any irregularities of application of the ink which'might result from imperfections in the surface of the form roller 2|, the rollers 46 and 41 neither adding to, nor taking away, any ink from the form. While in the example given the ink film is described as halved by the cooperating rollers and A the printing cylinder and the form roller it will be understood that even should such halving not take place, a dividing of such films would nevertheless occur and the principle of my invention in so far as one phase thereof is concerned and involving theprovision of clearance between the form roller and the roller by which ink is supplied to the form roller resulting in the supplying to the form roller of a uniform ink film for uniform application to the printing surfaces of the printing cylinder, would nevertheless obtain.

As will be understood, the primary purpose of the vibratory rollers, with the cooperating scraper means, is .to remove excess ink from the form roller 2|. However, these rollers and scraper means are merely an example of a form of excess-removing means which may be used, it being within my invention to employ any suitable means for this-purpose. Thus by way of example, these rollers need not be of the vibratory type; nor need they, regardless -of whether they are vibratory or non-vibratory, be provided of the particular number shown, as the number used. may be greater or less than two as shown.

The feature of supplying to the form roller an amount of ink in excess of that which it is desired be presented by this roller to the printing cylinder and involving, as it does, rather copious fiow of ink in the inking apparatus, and removing such excess before the form roller contacts the printing cylinder is of great advantage not only from the standpoint of ensuring the delivery to the printing surfaces of the printing cylinder a uniform film of ink of the desired thickness but also from the standpoint of preventing drying of the ink on the rollers of the inking apparatus. When the press is operating this feature is of advantage particularly as relatively large quantities of ink course through the apparatus militating against the drying of the ink.

This feature may also be'availed of for preventing drying of the ink when the press is shut down for any reason, in which case, in accordance with common practice, the inking apparatus is shifted out of operative relationship to the, printing cylinder and the means which drive the inking apparatus. This contemplates the provision of means separate from the drive of the inking apparatus from the press, for continuing the operation of'the inking apparatus after the press has stopped. As a portion of the ink in such operation is removed from the form roller by the vibratory rollers and scraper means in the particular illustrated embodiment of the invention, ink is continuously circulated through the apparatus from its source to a point beyond the form roller. Preferably, though not of necessity, this circulatory course is a closed course, as shown and above described, the ink removed from the form roller thus being returned for transfer by the fountain roller 20in the arrangement shown returned to the pan l9, but in any event returned to the roller mechanism of the inking apparatus at such a point as to ensure flowing of ink to all of the inking rollers in the operation of the inking apparatus.

Provision is made inthe construction shown for driving the inking apparatus when the press is stopped, by providing a gear 85 on a shaft 85 joumaled in thestationary frame of the press and driven from any suitable power device (not shown), the gear 85 being so disposed that when the inking apparatus is .drawn back, out of the operating position shown, the gear 24 will mesh with the drive gear 85 and thus be driven therefrom.

While have illustrated and described certain particular steps in the practicing of my novel method, and have shown anddescribed a particular apparatus, including modifications there'-.

of, for practicing the method and as embodying.

What I claim as new and desire to secure by Letters Patent, is:

1. An apparatus for applying an ink film of uniform,,-predetermined thickness to a printing cylinder, comprising a form roller mounted to transfer an ink film therefrom to said printing cylinder, an ink supplying roller, a transfer roller operating at the same peripheral speed as the form roller and arranged to transfer from the supplying roller to the form roller suificient ink, in excess of the amount suitable for printing purposes, to obliterate the effects on the form roller of previous contact of the printing cylinder therewith, means comprising a hard,

smooth roller and adevice arranged to continuously remove the accumulated ink therefrom for removing a portion of said excess ink and converting the remainder on the form roller into a smooth film of predetermined thickness greater than desirable for printing purposes, and means comprising a second hard, smooth roller and-a device arranged to continuously remove the accumulated ink therefrom, for removing the remainder of said excess ink to thereby leave upon the surface of the formroller for application to the printing cylinder a smooth, evenly distributed ink film of uniform predetermined thickness suitable for printing purposes.

2. An apparatus for applying an ink film of uniform desired thickness to a printing cylinder,

comprising a form roller disposed in cooperative relation to said printing cylinder, means for applying to the surfaces of said form roller after contact with said printing cylinder sufiicient ink, in excess of that required for uniform printing purposes, to obliterate the effects of contact ofsaid form roller with the printing cylinder, and means for removing from said form roller the applied ink-in excess of an evenly distributed film of uniform, predetermined thickness suitable for uniform printing, said removing means including a plurality of rollers operating in sequence upon said form roller to remove said ex-, cess ink therefrom in successive increments and means for removing from said last mentioned rollers said removed increments ofexcess ink to thereby ensure the production ofa smooth, uniform ink film of predetermined thickness upon the form-roller.

3. An apparatus for applying an ink film of uniform desired thickness to a printing cylinder,

comprising a form roller disposed in cooperative relation to said printing cylinder, means for applying to the surfaces of said form roller after contact with said printing cylinder suflicient ink,

in excess of that required for uniform printing purposes, to obliterate the effects of contact of said form roller with the printing cylinder, and means for producing upon the form roller for presentation thereby to said printing cylinder an evenly distributed ink film of'a uniform and predetermined thickness suitable for printing purposes by removing from the roller the previously applied excess ink, said last' named means including rollers acting sequentially upon the form roller to reduce by successive increments the thickness of the ink film on said form roller, and means for continuously clearing from said last mentioned rollers the ink removed thereby from said form roller.

' HENRY R. 'I'ROTTER.

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