US1812884A - Combined ink eliminator and doctor blade - Google Patents

Description

July 7, 1931. R. B. LEECH I COMBINED INK ELIMINATOR AND DOCTOR BLADE Filed Sept. 4. 1929 2 Sheets-Sheet 1 July 7, 1931. R. B. LEECH COMBINED INK ELIMINATOR AND DOCTOR BLA DE I Filed Sept. 4. 1929 2 Sheets-Sheet 2 WE n h Patented July 7, 1931 UNITED STATES PATENT OFFICE RUSS B. LEECH, OF CHICAGO, ILLINOIS, ASSIGNOR TO STANDARD PROCESS CORPORA- TION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE COMBINED INK ELIMINATOR AND DOCTOR BLADE Application filed September 4-, 1929. Serial No. 390,385.

The present invention relates to an imeliminator for rotogravure and similar printing presses.

As is well known, it is the practice in rotogravure and similar printing to have the printing cylinder revolve while partly 1mmersed in an ink receptacle so that a quantity of ink will adhere to its surface, and to remove all ink from the polished surface of the printing cylinder by means of a doctor blade, leaving ink only in the depressed or engraved portions of the cylinder. The means at present generally utilized for this purpose consists merely of a blade extending lengthwlse of the cylinder and generally capable of being moved toward and from the cyllnder, the edge of the blade being yieldingly pressed into engagement with the cylinder by pressure means tending to bodily bend the blade itself. Such pressure in most instances is provided by means of weights that tend to bring the edge of the blade into firm contact with the cylinder by flexing the blade and f suflicient pressure is applied to the blade 1t is flexed lengthwise. With this arrangement the applied pressure sometimes is suflicient to cause the flexible blade to bow or assume an arcuate form, if the blade is inherently suffieiently flexible, so that it does not present a satisfactory wiping edge to a cylinder, the surface of which does not present a perfectly straight line If the inherent flexibility of the blade is reduced to avoid the ob ection just stated, the blade becomes too stiff to readily conform to the cylinder surface resulting in an uneven and, accordingly, unsatisfactory removal of the surplus ink. Furthermore, unless the blade is flexibleto a high degree particles of grit may collect beneath the blade scratching the cylinder. Such grit particles will simply be carried beneath a truly flexible blade without damage to the cylinder.

In order to function perfectly the doctor blade should be just as flexible as possible, consistent with adequate strength, in order that it will readily conform to and evenly wipe the entire cylinder surface, though said surface be not truly cylindrical. This invention aims to secure such flexibility by the utilization of a very thin blade adapted to bear against the cylinder by pressure ap plied adjacent the edge of the blade itself, in a manner so as not to cause longitudinal flexing of the body of the blade so that the blade may readily bend suflieiently to accommodate itself to the cylindrical surface under such pressure and to improve the operation of such a blade by combining with it an ink eliminator that serves to remove most of the surplus ink from the printing surface of the form before it reaches the doctor blade. The doctor blade considered per se constitutes no part of the present invention, but said blade is claimed in an application of E. S. Ballard, Serial No. 455,878, filed on May 24, 1930. v

The primary object of the present invention accordingly, is to provide an improved combination of doctor blade and ink eliminator construction for rotogravure and similar printing press cylinders whereby the effectiveness of the wiping of the printing form is greatly increased without introducing factors that tend to mar or destroy the printing surface.

A still further object of the invention is to provlde a construction for removing surplus ink from printing cylinders comprising a highly flexible wiping blade in yieldable engagement with said cylinder in combination with means for removing a major portion of the ink from said cylinder in advance of said blade.

A still further object of the invention is to provide an improved construction for remov1ng surplus ink from printing cylinders comprising a flexible cylinder-engaging wipmg blade and an ink eliminator adapted to remove a major portion of the ink from said cylinder in advance of said blade, said blade and said eliminator being supported by an adjustable support with the effective edges of said blade and said eliminator disposed substantially equi-distant from a horizontal plane containing the axis of rotation of said cylinder whereby said blade and said eliminator are adapted, upon adjustment of said support, to be simultaneously brought into correct position by adjustn'lent with respect to printing cylinders of varying diameters.

face of a printing cylinder in advance of the engagement of said cylinder by the doctor blade.

With the above objects in view as well as 7 others that will become apparent during the course of the following disclosure reference will be had to the accompanying drawings forming part of same and wherein:

Figure 1 is a side elevational view of the improved construction in accordance with a preferred embodiment of my invention.

Figure 2 is a top plan view on a reduced scale of the construction illustrated in Figure 1 with certain parts removed for clearly illustrating the disposition of the ink eliminator.

Figure 3 is a top plan view of the doctor blade slide with the wiping or doctor blade by upon turning crank 23 each carriage 16 canbe advanced toward or away from cylinder 11 fora purpose hereinafter referred to. If desired both screws 19 can be connected by a shaft and bevel or similar gears utilized forsimultaneous rotation in which event only one proper operatively connected therewith, the

supplementary or pressure blade being I omitted for clearness of disclosure.

' I w1th1n an 111k pan 13 1n WhlCh according to Figure 4 is a view similar to Figure 3 disclosing the supplemental or pressure blade in top plan.

Figure 5 is anend elevational view of the printing cylinder disclosing the relation of the ink eliminator to the cylinder surface as well as one of the end wipers adjustably supported-by said eliminator. v

Figure 6 is a view similar to Figure 1 disclosing a modified embodiment of the invention.

' Referring to the drawings by reference characters in which like characters designate like parts, 11 designates a printing cylinder of usual constructionrotatably journaled in the usual frame 12 and with a portion of the circumference thereof atall times disposed common practice a quantity of ink is held whereby the printing'surface of cylinder 11 is completely inked upon continuous revolu- V tion of same in well'known manner.

The improved doctor blade'arrangement with ink reliminator constructed in accordance with the present invention comprises suitable supports 15 adapted to. be-secured to; the inner sides of the press frame 12 and on which supports are slidably disposed the carriages 16 which are provided -'with the transversely aline-d undercut doctor blade slide receiving grooves 17. Thecarriages 16 -each have swivelly connected thereto as indicated at 18 one end of a screw 19 which adjacent the opposite end thereof is threadedly engaged in a lug 21 on support 15 and eachof the screws 19 at said opposite end has detachably secured thereto by means of a nut 22 a hand crank 23 wherehand crank is attached to said shaft so that carriages 16 can be simultaneously adjusted by turning one crank handle from one side of the press.

Disposed within grooves 17 of carriages 16 are the opposite edges'of the doctor blade slide 25 which is preferably oscillatable parallel with cylinder 11 in well known manner. Carried by slide 25 inwardly of the opposite ends thereof are a pair of apertured lugs 26 to which are pivotally secured by means of pintles 27 the rear edge of a doctor blade clamp support 28, between the removable portions 29 and 30 of which a substantial portion of the doctor blade 31 is detachably clamped by means of screws 32. The doctor blade 31 is constructed of very thin metal preferably corresponding to the thickness and temper of a Gillette razor blade in order to possess high flexibility. The blade 31 is supportedin such manner that it is disposed at a relatively sharp or acute angle to a tangent to the surface of cylinder 11 with the free edge thereof in wiping contact with the cylinder, which cylinder revolves in the direction indicated by the arrow in Figure 1.

The blade 31 through the'weight ofsupport 28 normally contact the surface of cylinderi 11 but with insuflicient pressure to have the necessary wiping action and with insuflicient pressure to cause the blade to flex longitudinally. The blade 31, in accordance with the present invention is constructed of such thin material that it would not withstand direct pressure thereto, in accordance with present practices and besides such pressure if applied as before stated, would defeat the desirable extreme flexibility of the free wiping edge of blade 31. According to the present invention means for maintaining the edge of blade 31 in full wiping contact with cylinder 11 while maintaining the high flexibility of said blade are provided. Such means comprises a supplementary or pressure blade 34 preferably supported independently of .thewiper blade. Oneedge of the pressure blade is detachably supported by means of bolts 35 between the sections 36 and 37 0f a clamp support 38 which support is provided with terminal lugs 39 that are fixed vidual spring fingers 43 for contacting blade 31 closely adjacent the free Wiping edge thereof. It may be noted that it is desirable that blade 34 be substantially heavier and stiffer than blade 31 because of the pressure applied thereto in a manner about to be described. By the provision of the yieldable fingers 43 a highly flexible edge is provided even though blade 34 be constructed of heavier material. Secured to one end of shaft 40 is a ratchet wheel 44 to the periphery of which is secured a handle 45, whereby shaft 40 can be rotated through wheel 44 upon manual movement of handle 45 for applying pressure to blade 34. Wheel 44 is maintained in any adjusted position with the desired pres sure by engagement therewith of a pawl 46' pivotally secured at 47 to an extension 48 of one of the brackets 41.

In the construction just disclosed the portions of the edge of a highly flexible wiping blade 31 are separately maintained in pressure engagement with the surface of cylinder 11 regardless of any inequalities therein, because the yieldable spring fingers 43 on blade 34 will individually yield to any inequalities in the cylinder surface opposite certain of them while at the same time they place suflicient pressure on the cylinder contacting edge of blade 31 to cause an even wiping action. The pressure of the separate fingers can be readily regulated by rotating shaft 40 through handle 45.

This invention further comprises means for removing the major portion of surplus ink from cylinder 11 in advance of blade 31 7 whereby blade 31 is relied on merely for "form, that is it may be round or rectan ular effecting complete wiping of the cylinder. The arrangement about to be described removes any large surplus of ink adhering to the cylinder after leaving the pan. Such means comprises an ink eliminator 51 which includes an elongated member preferably in the form of a bar disposed substantially parallel with blade 31 and with a corner edge thereof in slightly spaced relation to the surface of cylinder 11 as indicated at 52 in Figure 1. Such eliminator may assume any 1n cross section, or it may be ofblade-like character.

The ink eliminator 51 is suitably secured to carriages 16 by means of screws 53,

whereby both the blade 31 and eliminator 51 may simultaneouslybe adjusted toward and from the surface of cylinder 11 through screws 19 hereinbefore described. It will be observed upon inspection of Figure 1 that the arrangement of blade 31 and eliminator 51 is such that the wiping edges thereof are on opposite sides of.and equi-distant from the horizontal plane of the, axis of cylinder 11, as indicated bythe dot and dash line in Figure 1, whereby blade 31 andeliminator 51 will be brought in proper operative rela tion to a printing cylinder of any diameter upon adjustment of carriages 16 that support said blade and eliminator.

Carried by U-shaped clamps 55 preferably attached to eliminator 51 are end wipers 56 preferably constructed of leather. Said wipers are adapted to wipe the ends of cylinder 11 to prevent the presently experienced throwing or splashing of ink from the cylinder edges caused by the fast revolving of the printing cylinderin the ink pan. The clamps 55 are movably secured to eliminator 51 by means of thumb screws 57, whereby wipers 56 can readily be adjusted longitudinally of eliminator 51 for engaging the opposite ends of various length printing cylinders.

It will be seen that by the provision of the ink eliminator, which wipes most of the sur plus ink from the cylinder the doctor blade is relied upon to remove only a thin film of ink which has been been left evenly applied to the cylinder. It will be seen further that the doctor blade and the cooperative pressure means, as well as the ink eliminator, are supported by adjustable means, whereby same may be simultaneously adjusted for operative relation with printing cylinders of various diameters.

While the means above disclosed are at present preferred for placing blade 34 under pressure, the supplemental blade 34 may be subjected to pressure by means similar to that now used, but app-lied directly to the doctor blade. Such means are illustrated in Figure 6, wherein blade 34 is supported by a clamp 61 carried on a shaft 62 j ournaled in brackets 63 of slide 25. The clamp 61 is provided with an arm 64 to the free end of which is secured a rope or cable 65 which passes around pulley 66 and has secured to the free end thereof weights 67 for subjecting blade 34 and fingers 43 carried thereby to pressure for holding blade 31 in yielding pressure wiping engagement with cylinder 11. The

"weights 67 are removable whereby the pressure on blade 34 may be varied according to the number of weights supported by cable 65.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment istherefore to be considered in'all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather thanby the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are there fore intended to be embraced therein.

hat I claim and desire to secure by United States Letters Patent is 1. In combination, a support for the doctor blade of a printing press, a. yielding doctor blade mounted on said support and an ink eliminating member mounted on said support in slightly spaced relation to said form in position to remove some of the sur plus ink on a printing form in advance of the operation .of the doctor blade. and with out wear on said g V 2. The combination ,definedin claim in which said support is mounted for adjustform.

mounted on said support, an ink eliminating member mounted on said support in slightly spaced relation to said form in position to v remove'some ofthesurplus ink on a printing form in advance of the operation'o-f the doc- 'tor blade and without wear on said form,

and means to adjust said support to: and from the printing rollwherebysaid blade and bar may besimultaneously adjusted.

4. The combination defined in claim 3 in which said member is provided with wipers arranged to Contact with the ends of printing cylinders so as to prevent the throwing'of ink bv centrifugalfforce; from the ends of' said cylindersg" v v 5. In combination, a support for the doctor we blade of a printing press,f-a highly resilient d ctor blade mounted on 'saidsupport, means associatedwithsaid doctoi blade .tojcauselit to yieldingly contact with the printing form, said last namedmeans comprising in epend- 1 ent yielding elements engaging ,the blade at 1' points alongthe length and adjacent the edge thereof that contact with said form, and an ink eliminating member mounted ,on said ink eliminating member mounted on said sup- 1 support in position to remove some of the surplus ink on a printing form in advance of the operation of the doctor blade on said form, said eliminating bar serving to limit the excess of ink to be removed by said doctor blade. V

6. The combination defined in claim 5 in which said eliminator member and doctor blade are mounted on a supportjthat is capable of being bodily adjustable toward and from the printing form and in which the 50'- eliminator member and operative edge of the doctor blade are spaced substantially equidistantly above and below a horizontal plane that contains the axis of rotation of the printing form.

7. In combination, a support for the doctor blade of a printing press, a yieldingly mounted doctor blade mounted onsaid support, an

port in position to remove some of the surplus ink on a printing form in advance of the operation of thedoctorblade on said form, and means carried by the support and arranged to wipe over the ends ofthe printing form to remove ink adhering thereto.

8. The combination defined in claim 7 in which said last named means are adjustably mounted on said ink eliminating member so 'as to be individually adjustable along the length thereof so as to be brought into con blades, comprising a member constructed so that it may be applied to said press for reducing surplusink from a printing form before it engages said doctor blade, said member being designed to be arranged so as not to contact with said form.

10. An ink eliminating means for a printing press embodying a doctor blade, comprising a member designed for attachment and simultaneous adjustment with the support for the doctor blade of the press, said member being elongated and designed to almost engage the printing form from end to end thereof in advance of the doctor blade so as to remove most of the surplus ink from said form before it contacts with said doctor blade.

11. The combination defined in claim 10 including a pair of wipers designed to be atvided with means to attachit to the support that "carries said doctor bladeso that the member is out of contact with but in close proximity to the printing surface of a printing form, andapair of wipers attached to said member and designed to firmly engage the end of the printing form and to wipe the ink'therefrom.

13. The combination defined in claim 12 in which said wipers are provided with a covering of yieldable material so as to-readily 1 conform to the end surfaces of the printing form.

14. In combination a printing form, a 4

highly flexible doctor blade and an ink elimi-' nator member arranged to almost engage said form in advance of said blade, said blade contacting with said form and conforming to its surface while said member is slightly spaced from said form.

15. The combination defined in claim 14 in which said member and blade are mounted for adjustment as a unit toward said form so that the operative edges of said member and blade are substantially equi-distantly spaced above and below a horizontal plane passing through the axis of rotation of said form.

In testimony whereof I afiix my signature.

' RUSS B. LEECH.

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