US2579181A - Enclosed gravure fountain - Google Patents

Description

Dec. 18, 1951 H. w. FAEBER ENCLOSED GRAVURE FOUNTAIN kFiled July 28, 194

VENT-0Q. HARRY W. EBm

4/! FIG. 2.

Patented Dec. 19,1951

- 2,57 9,181 ENCL ED 'GRAVURETQUN A Harry- W-. -Faeber, La-rchmont, N. I1, assignor to Time, I hmorp r wl xlsnNl X-na sc i lration ofNew. York Application July 28, 1948,- Seria1-No:41;051

" The present invention relates to an enclosed grav-ure fountain, suitable -particu-lar1y in rotary intaglio -printing-machines, having as its novel features a construction designed --=te completely enclosethe fountain, one element of which is a fluid pressure *means capable ef -"actin-gupon a-dector iolade"bearingon the peripheral surfaee-of'the printing cylinder in a manner designed to compensate for the uneven --wear of the-doctor blade. I

in intaglio ;.prihting-, the printing surface has formed in depressionscorresponding to the design to be printed. is --conventional practice in-the rotary intaglio printing wart to ;mount a rotatable printing.- cylinden. the. neripheralssure chines thisreguires immediate i'eplacement of the duster blade to avoid uneven sw ping of t Peripheral surface .because the i intionfof, a film of printing fluid on thelririntingc surface after it passes the doctor 'iolade would result atransfer of the fluid 'to the web at plages not'corresponding to the" depressions and would therefore 'eifectiveiy destroy the valueflor desirabilityof the print.

It has alsobeen found thattheprinting fluid inthe fountain tends to change'in consistency during "the "printingnperation due to the evaporation thereof from the fountain "and to the accumulationtherein offoreign -particles. The latter phenomenon is -'particu1arly undesirable because the presence of foreign'particles in'the printing *fiuid accelerates ---t-he uneven wearing 'of ahe -doctor "blade and-results "in a scratching of the --printing surface to such an extent that the number of copies that cam-be *printed with itbeeomesquite limited.

- Attempts have been-madein the past to over- :eomes*these difficulties. Thus-tor example, it has been proposed to mount the doctor blade underneath a second blade that-does not come {into contact "with the P inta-glio -printihg surface but serves Jmerely'as .a spring to press the dodtor loladeagainst thatsu-rface. Itlhas also :been suggested to seal the printing fountain :.-from the outside atmosphere by means of a resiliently mounted sealing blade in .Wiping engagement withithe peripheral surface .-.of the printing cylinder "in :such almannerr-that a given point on the :cylinder successively 1-,comes into .contact with ".the doctor blade, the web and 'ilhBiSfiQil? ing '1 blade. Both suggestions have :resultedin cumbersome -and complicated 1 designs that have added to the maintenance. cost of rotarylinr tag lio printing .machines and .neither .of L-then l has .sheen entirely successful. The suggested spring nneans for pressing ithe. doctor zblade against .the :printing .'..cylinder is :not suii1ciently flexible 1:170 :comnensate for the uneven wearing of ithe doc-tor blade and .the sealing imeans thus far proposed have afforded vmerely lanotherline strument capable vof damaging, :by scratching, the intaglio printing surface. :In practice, the SOzCflllGd seal ialades, providedlto completelyenclose .the fountain, have ,-been rmoved .ontmrof .wiping engagement {with .the..-cyli-nder :to {avoid scratching.

:EEhe; present invention is concerned with an .e'ifort ato .overcome these .defects. The doctor tilade, in accordance with vthe presentrinvention, .is provided ,with Jan zoverlying fluid .pressure tube which, shy means of hydraulicror pneumatic pressureis capable of exerting a uni form pressurealong the entire length .of the :bladeeso; as. to maintain all parts? of the hearing .edgeagainst the peripheral .surfaceof thezprintr ing cylinder despite any uneven wear in the bearing edge. .The fountain is sealedin 'part byaavcomhination. of a sealing roll having :an accurately machined. peripheral surface in? roll? ingcontact with .izhe peripheral surface .of :the printing ;,cylinder and .a sealing blade in wipingrengagement with. the peripheral surface of the sealing roll and in part .by the doctor blade.

One of (the advantages of the present invention .is that .it .provides an extremely simple structure for automatically compensating for any .uneven wear of the doctor blade ah'd, at thesame time, reducing to a minimum the pos- :sihility of scratching or otherwise "marring the surface @of the printing cylinder. 1

Another advantage 'of the invention is that it'providesa true-seal for the fountain and requires aminimum of maintenance.

'These and other advantages, as well as the utility of the invention, will become more apparent from the detailed description that follows A fountain Ill having a bottom H, side walls l2 and i4 and end walls 16 and l! serves as a container for the printing fluid [9. A rotary intaglio printing cylinder 28 is mounted within the fountain l0 and the shaft 2| thereof may bejournaled in the end walls It and I! or in enclosing frame members 22 and 24, as shown in Figure 2. An impression roll 26 and a back-up roll 21 may be mounted above the printing cylinder 20, as shown schematically and by way of example in Figure 1. The elements thus far described with reference to the drawing are conventional and do not form a part of this in vention.

A carefully machined seal roll 30 having a non-abrasive peripheral surface is mounted in .the fountain it parallel to, and in rolling contact with, the printing cylinder 29 and means, such as gears a and 30a, are provided to drive the printing cylinder 20 and the seal roll 30 at substantially the same peripheral speed. The side l2 of the fountain I0 is provided with a hinged portion 3| carrying a sealing blade. 32 in wiping engagement with the seal roll 3! to complete the sealing of the fountain between the printing cylinder 20 and the side wall l2. The hinging of the hinged portion 3| is not required but is desirable for practical purposes, such as to facilitate inspection or filling of the interior of the fountain Ill and to permit convenient removal of the seal 30 and the cylinder 20.

The track 42 supports a slide 4| connected by means of a link Ma to an oscillating mechanism of conventional type (not shown).

The Standards Mb are carried on the slide 4| to support the shaft 410 which may be rotated by means of a hand wheel Md, a worm Me and a worm gear 4| The doctor support arms 40 are keyed to the shaft and the stop 40a determines their working position. Each of these arms 40 is provided, at its upper extremity, with an opening designed to receive a leg 44 of a doctor blade support 46, the position ofsaid support relative to the standard being maintained by means of one or more set screws 41 in the upper portion of the standard 48. A flexible doctor blade is secured to the underside, and a grooved memher or tube holder 5| is secured to the upper side, of the support 46 by means of one or more bolts or tap screws 52. A flexible, fluid pressure tube 54, connected to a source of fluid pressure 51, is positioned between the doctor blade 50 and the concave portion 5670f the tube holder 5|, the tube 54 and tube holder 5| overlying substantially the entire length of the doctor blade 50.

The side i l of the fountain I0 is provided with a hinged portion 60 having a sealing blade 6! aflixed thereto which is adapted to engage the bar 59 underneath the doctor blade support 46 to thus effectively seal the space between the printing roller 2|] and the side wall 14 of the fountain [0. The hinged joint between the portion 50 and the side I4 is sealed by a spring blade 60a which is secured to the portion 60 and bears resiliently against the wall [4. V

It is to be understood, of course, that the hinged portion 60 is pivotally mounted on the side wall M, to provide convenient access to the interior of the fountain and that suitable means may be provided to lock it into the operating position shown.

The end walls l6 and I! of the fountain l0 may suitably be provided with cover plates or lips 10 designed to cover and seal the end portions of the fountain. The cylinder 20 is ad ustable .endwise for lateral register and the cover plates 70 must extend inwardly a sufiicient distance to overlap the ends of the cylinder 20 in all of its ad usted portions.

. The gaps at the ends of the doctor blade and the cylinder 20 are closed by flexible sealing blades ll shown in Figures 1 and 3. A blade H is mounted on an angle bracket 12 by means of screws 13 extending through the blade for retaming the blade II in engagement with the lower surface or the doctor blade to and the end of the cylinder 20. The bracket I2 is secured to the wall ll of the fountain. A similar sealing blade is mounted in the same way on the wall lti for cooperation with opposite ends of v the doctor blade 50 and the cylinder 20.

which is in operation, the tune s4 is lined with a fluid under pressure so as to exert 'a predetermined hydraulic or pneumatic pressure on the doctor blade 50 with the result that every portion thereof will bear upon or be in wiping engagement with the peripheral surface of the printing cylinder 20. The fluid pressure tube, because of its flexible structure, will automatically operate to compensate for any uneven wear of the doc: tor blade and maintain the entire length of the wiping or bearing edge in wiping engagement with the peripheral surface of the printing cylinder and thus make unnecessaryan adjustment or replacement of the doctor blade during the operation of the machine. Furthermore, by controlling the amount of fluid pressure in the flexible 131110654, the operator can effectively control the pressure of the doctor blade 50, as a whole, against the peripheral surface of the printing cylinder 20 so as to obtain a maximum wiping action with a minimum of wear and scratching. The fluid pressure within the tube is COIIBIOliEd by means of a valve 54a, a bleeder valve 540 and is indicated by a gauge 540.

The fluid pressure means for maintaing the bearing edge of the doctor blade 50 against the peripheral surface of the cylinder 20 has the further function, in cooperation with the bar' 59, the seal blade 61 and the end seal blades H, of providing a substantially air tight cover over the fountain l0 between the printing cylinder 20 and the side wall I4.

The interposition of a seal roll 30 between the printing cylinder 20 and the sealing blade 32 effectively avoids a second wiping action on the printing cylinder and provides a substantially air tight covering over the fountain ill between the printing cylinder 20 and the side wall l2.. The sealing blade 32 has the additional function of removing from the peripheral surface of the seal roll 30 any foreign particles that may have become attached thereto and would tend to injure the peripheral surface of the printing cylinder 20 before the surface of the seal roll 30 comes into contact with the printing cylinder 20. v

It is to be understood that many alterations andmodifications will readily occur to those skilled in the art upon reading the description of this invention.

Thus, for example, it is immaterial whether the shafts for the printing cylinder and the seal roll are journaled in the end walls of the fountain 01' in an enclosing frame. The fluid within the flexible tube may be a gas or liquid and any suitable means may be employed to control the pressure thereof. ing the doctor blade and the elements cooperating therewith may be mounted on the frame or on the fountain itself. The modification illustrated and described specifically is preferred merely because it provides an extremely simple way ofobtaining access to the fountain from the side.

The fluid pressure tube may be of substantially uniform cross section throughout its effective length or it may be tapered. It is also possible to provide the sealing blade 32 that is in wiping engagement with the seal roll 30 with a flexible, fluid pressure tube arrangement similar to that provided for the doctor blade in order to still more effectively wipe the seal roll clean and thus still further minimize the possibility of scratching the peripheral surface of the printing cylinder.

These are but a few of the many modifications that will readily occur to those skilled in the art and are intended to be included within the scope of this invention as defined in the appended claims.

I claim:

1. An enclosed gravure fountain comprising a housing having side and end walls for a printing fluid, a rotatable printing cylinder in the housing parallel to and spaced from said side walls and having configurations thereon formed by depressions extending below the peripheral surface thereof, a unitary and flexible doctor blade having a wiping edge bearing on the peripheral surface of the cylinder, an inflatable fluid pressure tube overlying the doctor blade and capable of exerting pressure on said blade to maintain substantially the entire length of the wiping edge against the peripheral surface of the cylinder, means for supporting said flexible doctor blade and said fluid pressure tube, sealing means for covering the space between said supporting means and one of said side walls, a seal roll parallel to said printing cylinder and in rolling contact with the peripheral surface thereof, said roll being disposed between said cylinder and the other of said side walls, means for rotating the printing cylinder and the seal roll at substantially the same peripheral speed, a second seal blade be tween said other side wall and said seal roll and having a bearing edge in wiping contact with said seal roll, said seal roll and said second seal blade cooperating to cover the space between said cylinder and said other side wall, and sealing means between the end walls and the adjacent ends of the cylinder and seal roll for sealing gaps at the ends of the cylinder and seal roll.

2. In an enclosed gravure fountain comprising a housing having side and end walls for a printing fluid, a rotatable printing cylinder in the housing parallel to and spaced from said side The standards for support walls and having configurations thereon formed 3 by depressions extending below the peripheral surface thereof, a unitary and flexible doctor blade having a wiping edge bearing on the peripheral surface of the cylinder, and means for supporting said flexible doctor blade, the combination of sealing means for covering the space between said supporting means and one of said side walls, a seal roll parallel to said printing cylinder and in rolling contact with the peripheral surface thereof, said roll being disposed between said cylinder and the other of said side walls, means for rotating the printing cylinder and the seal roll at substantially the same peripheral speed, a second seal blade between said other side wall and said seal roll and having a bearing edge in wiping contact with said seal roll, said seal roll'and said second seal blade cooperating to cover the space between said cylinder and said other side wall and sealing means on the end walls of the housing overlapping the ends of the printing cylinder and the seal roll to cover the spaces between the ends of the cylinder and roll and the adjacent end walls.

3. In an enclosed gravure fountain comprising a housing having side and end walls for a printing fluid, a rotatable printing cylinder in the housing parallel to and spaced from said side walls and having configurations thereon formed by depressions extending below the peripheral surface thereof, a unitary and flexible doctor blade having a wiping edge bearing on the peripheral surface of the cylinder, and means for supporting said flexible doctor blade, the combination of sealing means for covering the space between said supporting means and one of said side walls, sealing means on the end walls of said housing engaging said doctor blade and the adjacent ends of said cylinder for sealing gaps at the ends of said cylinder, a seal roll parallel to said printing cylinder and in rolling contact with the peripheral surface thereof, said roll being disposed between said cylinder and the other of said side walls, means for rotating the printing cylinder and the seal roll at substantially the same peripheral speed, and a second seal blade between said other side wall and said seal roll and having a bearing edge in wiping contact with said seal roll, said seal roll and said second seal blade cooperating to cover the space between said cylinder and said other side wall.

HARRY W. F'AEBER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 511,934 Cottrell Jan. 2, 1894 1,458,860 Solomon June 1-2, 1923 1,566,358 White Dec. 22, 1925 1,598,819 Hill Sept. 7, 1926 1,812,920 Ballard July 7, 1931 1,837,702 Canfield Dec. 22, 1931 2,115,725 Koch May 8, 1938 2,141,978 Greenhill Dec. 27, 1938 2,274,166 Roesen Feb. 24, 1942 2,278,138 Paardecamp Mar. 31, 1942 FOREIGN PATENTS Number Country Date 699,931 Germany Dec. 10, 1940

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