US3608464A - Apparatus for developing lithographic plates - Google Patents

Apparatus for developing lithographic plates Download PDF

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Publication number
US3608464A
US3608464A US729040A US3608464DA US3608464A US 3608464 A US3608464 A US 3608464A US 729040 A US729040 A US 729040A US 3608464D A US3608464D A US 3608464DA US 3608464 A US3608464 A US 3608464A
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Prior art keywords
plate
rubbing
belt
reach
developer
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US729040A
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English (en)
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Robert E Harrell
Arthur E Essmueller
Roy C Bax
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Western Litho Plate and Supply Co
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Western Litho Plate and Supply Co
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/16—Coating processes; Apparatus therefor
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03D—APPARATUS FOR PROCESSING EXPOSED PHOTOGRAPHIC MATERIALS; ACCESSORIES THEREFOR
    • G03D3/00—Liquid processing apparatus involving immersion; Washing apparatus involving immersion
    • G03D3/02—Details of liquid circulation
    • G03D3/06—Liquid supply; Liquid circulation outside tanks
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/26—Processing photosensitive materials; Apparatus therefor
    • G03F7/30—Imagewise removal using liquid means
    • G03F7/3085—Imagewise removal using liquid means from plates or webs transported vertically; from plates suspended or immersed vertically in the processing unit

Definitions

  • SHEET 3 [IF 5 PATENIEB swam SHEET k UF 5 Tut APPARATUS FOR DEVELOPING LITHOGRAPHIC PLATES
  • the invention relates to apparatus for postexposure treatment of lithographicplates to press-ready condition by the additive process.”
  • the additive process of lithographic plate treatment is applicable to both negative-working and positive-working plates.
  • increments are added during the postexposure treatment to the light-reacted areas of the plate
  • increments are added during the postexposure treatment to the nonlight-reacted areas of the plate.
  • the additive process is to be distinguished from the subtractive process" wherein the postexposure treatment involves subtracting increments of nonlight-reacted areas in :the case of negatively working plates, and subtracting increments of light-reacted areas in the case of positive-working plates.
  • the plate is provided on its active surface with a coating of material which reacts upon exposure to light, so as to change its wettability characteristic.
  • the active surface of such a plate is usually exposed to light through a photographic transparencyhaving dark areas and clear areas. Upon exposure, the areas on the active surface of the plate which correspond in location to the clear areas are light struck (and,
  • the negative-working additive process necessitates that the light-struck areas on the active surface of the plate become organophilic and hydrophobic, while the nonlight-struck areas on the active surface of the plate remain hydrophilic and organophobic.
  • the postexposure treatment of such plates involves a series of steps.
  • a developer" emulsion or suspension is spread uniformly readily spreadable.
  • the light-struck areas on the active surface of the plate have a preferential affinity for the organophile components of the developer, while the nonlight-struck areas of the plate have a preferential affinity for the hydrophilic components of the developer, are loosened and, at least to" some extent, washed away by the hydrophile components of the developer.
  • the time consumed in rubbing the developer on a large plate is usually sufficient to permit evaporation of enough of the organic vehicle to harden the lacquer, but in the case of small plates, such hardening is frequently expedited by fanning, with resultant vaporization of the organic vehicle.
  • the second step is to wash away, with water, all of the developer which is not adhered to the light-struck areas, and then to, at least partially, dry the active surface of the plate.
  • the third step in the hand operation is optional, but nonetheless the prevailing practice in the art. lt involves the application of a preservative to the hydrophile areas, and, in some cases, the application of a different preservative to the organophile areas of the plate. This increases the storage life of the plate prior to printing, and involves an operation manipulatively comparable to the first step, but with a less viscous emulsion or suspension which, for example, may contain an organophile grease and a water-soluble gum in a mixture of oil and water. Such components have preferential affinity, respectively, for the light-struck and the nonlight-struck areas of the plate. After appropriately spreading the composition and rubbing it until the plate is again dried at least to a substantial extent, the plate is ready for the press. 1
  • the three steps of the hand operation just described require an elapsed time of 10 minutes or more per plate, more time being required for large plates than for small ones.
  • One object of the invention is to expedite the postexposure treatment of lithographic plates.
  • Another object of the invention is to provide an apparatus for performing automatically the postexposure treatments of such plates, and to reduce the consumption of materials employed in such treatments.
  • a machine having an endless belt for moving the exposed lithographic plate successively to, through and beyond, stations at each of which one of the steps of the above-described hand operation is performed, and preferably without interrupting the movement of the endless belt or moving the plate relative to the belt.
  • the endless belt is preferably smooth enough and held flat enough that when a thin flexible sheet of' metal, such as a common lithographic plate, is laid upon it, air is excluded from the interface, and the two stick" together so long as the flat coincidence is maintained, an action which is facilitated if either contacting face is damp with a liquid which, at least to some extent, wets both.
  • the belt is preferably made of a material which is, at least to some extent, phillic to liquids which are phillic to the reverse (nonactive) surface of the plate, and the belt is preferably of a material, for example neoprene, which may be vulcanized into endless condition in situ, i.e., while trained around one or more drive, or'guide, rollers forming a permanent part of the apparatus; and means is provided for assuring that the'belt is damp, but substantially devoid of unabsorbed or flowable liquid atthe time it receives a plate.
  • a salient feature of the invention is the provision of mechanism which both spreads the developer on a plate and rubs it. This is accomplished, in accordance with the present invention, by providing a continuously circulating pressurized system for supplying the developer liquid in metered quantities to a plate, and immediately thereafter to subject the plate to the action of a plurality of rubbing heads spaced apart a distance sufficient to enable at least part of the liquid components of the developer to evaporate from a given increment of the plates active surface before making contact with the succeeding head.
  • Each head is equipped with a plurality of spaced rubbing members which are essentially porous, nonabrasive'and possessed of at least enough resiliency to compress, albeit slightly without permanent deformation.
  • the rubbing members may have some, but preferably little, absorptivity toward the viscous developer.
  • Any natural or synthetic sponge may be used as a rubbing member, but is is preferable that it be one whose average pore size is large, such as the so-called coarse-grain cellulose sponge of commerce.
  • the coarse grain sponge is characterized by the fact that many of its pores are a quarter-inch or more in diameter, the average pore size being greater than three thirty-seconds of an inch with relatively few as small as one thirty-second inch, as distinguished from fine grain sponges whose pores are predominately on the order of one thirty-second inch in diameter, and, according to commercial practice, must be no greater than three thirty-seconds of an inch.
  • the spacing of the rubbing members on the leading rubbing head is more important than to space them on the succeeding rubbing head.
  • Such spacing of the rubbing members on the leading rubbing head is calculated to permit at least some of the developer deposited upon the plate, prior to reaching the leading rubbing head, to pass through the latter and be operated upon by the succeeding rubbing head. Consequently the invention contemplates that the developer be deposited upon a plate on the moving belt at a position ahead, and preferably immediately ahead, of the leading rubbing member.
  • the developer is deposited by dropping it in metered quantities from a plurality of outlets aligned in spaced relation transversely of the direction of movement of the plate.
  • the respective rubbing heads have their several rubbing members under slight, but substantially uniform, compression, e.g., enough to compress a coarse-grain cellulose sponge normally 1 inch thick to a thickness of about seven-eighths inch.
  • a curvilinear orbit herein termed a doubly cranked link motion, which is the type of planar motion undergone by a link whose opposite ends are pivotally connected respectively to rotating cranks having the same throw.
  • a wiping member of the squeegee type makes water-sealing engagement against the active surface of the plate.
  • a squeegee may be either a roller or a blade, in either event having a contacting part of rubber, or other relatively soft material, which makes a substantially watertight seal with the plate traveling therebeneath.
  • the plate passes under another rubbing head, which may be of like character to the two previously mentioned, for rubbing the developer, but prior to passing under the third rubbing head, there is dropped upon the dewatered moving plate metered quantities of the preservative composition.
  • a series of spaced metering devices is arranged so as to drop the requisite quantity (usually less than that of the developer) of the preservative composition upon the subjacent plate.
  • the preservative composition then undergoes rubbing of like character to that which the developer previously underwent.
  • the plate is squeegeed to remove excess preservative (including entrained water and organic solvent).
  • the series of postexposure treatment operations requires an elapsed time which is but a small fraction of that required when the operations are carried out by hand, and the drying aspect of the development operation, as well as that of the preservative application, is expedited by the air circulation induced by the doubly cranked link motion of the several rubbing heads.
  • FIG. 1 is an isometric view taken from a front or input corner of one embodiment of the apparatus, with portions of the covers and other parts broken away to reveal the relationship of working parts;
  • FIG. 2 is a plan view of the apparatus shown in FIG. 1 with the covers removed;
  • FIG. 3 is an end elevation of the apparatus shown in FIG. 1 with the covers removed,'some parts broken away, and taken from the front end, addressed toward the reader in FIG. 1;
  • FIG. 4 is a side elevation of the apparatus shown in FIGS. 1, 2 and 3, taken from the right side, addressed toward the reader in FIG. 1;
  • FIG. 5 is a partial sectional view taken along line 5+5 of FIG. 4, and showing the mechanism associated with one of the rubbing heads of said apparatus;
  • FIG. 6 is a bottom plan view showing the preferred arrangement of plate rubbing members on the pair of rubbing heads at the developer station of said apparatus;
  • FIG. 7 is a somewhat diagrammatic view showing the system for supplying developer to plates at the developer station
  • FIG. 8 is a partial end view on enlarged scale and showing, in detail, a manner of securing a demountable rubbing assembly on a rubbing head;
  • FIG. 9 is a somewhat diagrammatic view showing the system for supplying preservative composition to plates at the preservative station.
  • the apparatus shown in the drawings has an endless belt 1, the front loop of which is trained about an idler roller 2, and the rear loop of which is trained about a driven roller 3, so that the upper reach of the belt 1 moves from the roller 2 toward roller 3 to, through, and beyond, a superimposed front idler roll 4, a developing station 5, a washing station 6, a preservative station 7, and a rear squeegee roll 8, in succession.
  • the endless belt 1 is preferably made of neoprene, or other material which is flexible, substantially nonstretchable, and wettable by liquids which wet the reverse (inactive) surface of a lithographic plate to 'be' treated.
  • Such wetting liquid is usually water, but, under certain circumstances, may be organophile, so it is preferred that the beltmaterial be, at least to a substantial extent, amphiphilic, which condition is satisfied by neoprene.
  • a lithographic plate 9 to be treated is fed into the apparatus across a feed apron 10 into the nip between front idler roll 4 and the upwardly addressed exterior surface of the upper reach of belt 1.
  • a platen 11 in the nature of a tabletop, extends continuously beneath the upper reach of belt 1 through stations 5, 6 and 7, and terminates just short of squeegee roll 8, thereby sustaining the upper reach of the belt in a substantially level or slightly sloping course, and providing a firm base for sustaining any vertical load imposed upon the upper reach of the belt as the plate 9 is transported on the belt 1 from the front end'of the apparatus to the rear end thereof.
  • two spaced rubbing heads 12 and 13 are mounted for planar movement relative to, but parallel with, the plane of the upper reach of belt 1.
  • a series of metering devices 14 which periodically measure and drop charges of developer liquid upon the active surface of a lithographic plate, such as 9, traveling on the belt therebeneath.
  • some of the metering devices may be equipped with tubes 114 to lead their discharge onto the idler roll 4, or into the nip between that roll and an incoming plate.
  • FIG. 7 An advantageous system for supplying developer liquid to the several metering devices 14 is shown in FIG. 7, and consists of a supply tank 141 connected to deliver liquid developer to the intake of a pump 142, which discharges through tube 143 to a header 144 to which the several metering devices 14 are connected. From the end of header 144 (remote from tube 143), a tube 145 extends back to tank 141.
  • a stream of liquid developer is continuously moving under pressure through header 144 at all times during operation of the apparatus, and hence is available in well-agitatedcondition to supply developer liquid to all metering devices 14 simultaneously as demanded.
  • Each of the metering devices has an electrically controlled valve which opens and closed in predetermined coordination with the movement of a plate therebeneath, or for preconditioning the cranked link motion, of the character above described, y
  • the driving force is imparted by an. endless chain 15 which engages sprockets 16 and 17 on rubbing head 12, and sprockets 18 and 19 on rubbing head 13.
  • endless chain 15 which engages sprockets 16 and 17 on rubbing head 12, and sprockets 18 and 19 on rubbing head 13.
  • all four sprockets are rotated clockwise, as seen in FIG. 2, but the general arrangement provides for numerous variations.
  • all sprockets may be rotated in the counterclockwise direction; the sprockets on one of the rubbing heads may be rotated in the clockwise direction, while the sprockets on the other rubbing head are rotated in the counterclockwise direction; the respective rubbing heads may be driven in phase (wherein the respective rubbing heads maintain the same spaced relationship between each other, and occupy no position which is not parallel with all other positions during a cycle), or out of phase (i.e., the respective rubbing heads occupy no position which is not parallel with every other position occupied during v a cycle, but the spaced relationship between the two does vary during a cycle).
  • the respective sprockets on the same rubbing head may be rotated in opposite senses, a condition in which the given rubbing head occupies a multiplicity of positions in the course of a cycle which are not parallel with any other position, and the spacing from the companion rubbing head is constantly varying at opposite ends of the given rubbing head.
  • the rubbing heads 12 and 13 are driven as shown in the drawings, i.e., with all sprockets rotating in the same direction, but with rubbing head 13 moving 180 out of phase with the movement of rubbing head 12.
  • each ofthe rubbing heads 12 and 13 is provided, at its lower extremity, with a platen 20 to the lower face of which there is detachably mounted an assembly of rubbing members.
  • Such assembly preferably consists of a flat plate 21, to which there is appropriately secured, as by cementing, a series of seven rubbing members 22 each spaced from its neighbor, as shown in FIG. 6.
  • the individual rubbing members are preferably a rectangular slab of coarse-grain cellulose sponge, or other comparable material, and the spaces between them preferably approximate half the amplitude of movement of the rubbing head in the horizontal direction which is at right angles to the movement of belt 1.
  • Such spaced relationship of the individual rubbing members one from the other permits some increments of developer liquid deposited on a plate ahead of the leading rubbing head 12 to pass through the space between adjacent rubbing members on the leading rubbing head, and thus to be available at the trailing rubbing head 13.
  • the spaced relationship of the rubbing members, coupled with the motion of the rubbing head, also induces turbulence in the circumambient air which expedites evaporation of the volatile components in the developer liquid being'rubbed.
  • Angular orientation of the respective rubbing elements 22-relative to their supporting plate 21 is preferred,
  • the rubbing assembly 23 for the trailing rubbing head 13 is identical with that employed on the leading rubbing head 12, but with opposite slope.
  • a continuous slab of cellulose sponge, or equivalent material, having dimensions substantially corresponding with its supporting plate has some advantage over the spaced and angularly oriented arrangement shown in the drawings, but has the disadvantage that, in the field an attendant may inadvertently put the wrong rubbing assembly on the leading rubbing head.
  • Such disadvantage assumes overriding importance because the rubbing members are expendable, and require frequent replacement.
  • the mechanism for moving the respective rubbing heads with the doubly cranked link motion aforesaid is shown in detail in FIG. 5, and is identical for each of the rubbing heads, as well, in the embodiment shown, as being identical at opposite ends of a given rubbing head.
  • Such mechanism comprises a shaft 24 joumaled in a stationary part of the apparatus, and connected in rotational force-transmitting relationship with sprocket 16.
  • a crank arm 25 At the lower end of shaft 24, a crank arm 25 is connected in rotational force-transmitting relationship.
  • An eccentric stub shaft 26, projecting from crank arm 25, is journaledin a bearing 27 fixedly secured to rubbing head 12.
  • the same organization of parts is provided for cooperation with sprocket 17.
  • every individual point on rubbing head 12 revolves in a circular orbit about a center which is different from that about which any other point (in the same horizontal plane) in the rubbing head revolves.
  • the throw of crank 25 and its counterpart is substantially the same as the spacing between the respective rubbing members 22 on the leading rubbing head.
  • the several rubbing members 22 are resiliently compressible, and since greater pressure of the rubbing members is desirable on fine grained plates than on coarse-grained plates, means is provided for adjusting the degree of compression of the rubbing members and hence the pressure exerted by them upon a plate being operated upon.
  • Such means is also shown in FIG. 5, and consists of a disc 28 fixed to a shaft 29, and secured for rotation within an annular cage 30 affixed to the upper side of platen 20.
  • the shaft 29 is externally threaded to mate with internal threads on nut 31, which latter is affixed to the same part 32 of the rubbing head to which bearing 27 is affixed.
  • a handwheel 33 or other manipulating device, whereby, upon turning shaft 29, the displacement between platen 20 and rubbing-head part 32 is varied.
  • An identical arrangement is provided at the other end of the rubbing head, save that the counterpart of shaft 29 is foreshortened and provided with a sprocket 34 which is interconnected by a chain 35 with a sprocket 36 secured for rotation with shaft 29. Consequently, upon turning shaft 29, both ends of platen 20 are moved vertically relative to rubbing-head part 32 to the same extent, thereby to regulate the degree of compression in rubbing members 22, and the load imposed by them on a subjacent lithographic plate.
  • the platens 20 of each rubbing head are provided with a pair of strips 37 extending along the opposite long sides thereof.
  • Each of the strips 37 has a lip 38 which respectively extend toward each other in spaced relationship to the lower face of platen 20, as shown in FIG. 8.
  • the spaced relationship approximates the thickness of rubbing assembly plate 21, so that a given plate 21 may be slid into and out of the raceway defined by the opposite lips 38.
  • tag-shaped keepers 39 are connected eccentrically by bolts 40 to opposite ends of platen 20, so that when in the position shown in FIG.
  • the keepers 39 prevent removal of plate 21, but when it is desired to remove the latter, one of the bolts 40 can be relaxed sufficiently to permit its associated tag-shaped keeper 39 to be rotated l80 out of the way of removing plate 21 by the sliding action above described.
  • the endless chain 15, which drives the several sprockets 16, 17, 18 and 19, is driven by a motor 41 in the conventional manner, and is engaged not only with the sprockets mentioned, but also with idler sprockets 42 appropriately positioned and equipped withb any suitable means for adjusting the axis of rotation of at least one of them, so as to properly regulate the tension on the endless chain.
  • the endless chain also engages a pair of sprockets 43 and 44, which drive a comparable rubbing head 45 at the preservative station later to be described.
  • a squeegee member 47 delineates the rear of the washing station, but one or more additional squeegee members, such as 48, may be provided if desired.
  • Each of the squeegee members is equipped with a wiping blade, of resiliently flexible material such as rubber, or the like, which rides upon, and makes substantially water-sealing contact with, the subjacent increments of belt 1 or a lithographic plate thereon as the case may be.
  • Such blade on the squeegee members 47 and 48 form dams to prevent the water released within the washing station from flowing to the rear past squeegee member 47.
  • a water supply header 49 having a plurality of nozzles 50 from which there issues a shower of water directed toward the active surface of a subjacent plate, such as 9, as it passes therebeneath.
  • the streams of water are so controlled and directed that substantially all increments of the active surface of the plate will be subjected to the rinsing and, to a minor extent, eroding action of the water streams, thereby to remove the hydrophile components of the developer liquid previously applied at the developing station, to the extent that the solids thereof are not already adhered to the already-hardened lacquer-forming components of the developer.
  • the water released within the washing station is prevented from flowing back toward the developing station by tilting the entire apparatus, or at least the portion of platen 11 subjacent the washing station, in a direction such as to make it almost two degrees uphill from the squeegee 47 to the developing station.
  • Water accumulated ahead of squeegees 47 and 48 flows sidewise of belt I, and if desired, the entire apparatus, or at least the portion of platen I1 beneath the washing station, may be tilted about 1 sidewise so that the water, squeegeed off, will flow by gravity over the opposite longitudinal edges of the belt and platen.
  • the tabletop platen 11, or a part thereof, has greater width than the belt 1
  • perforations may be provided in the portion of platen 11 which lies outboard of belt 1 so as to permit the escape of water therethrough, but in the embodiment shown, the squeegee members 47 and 48 extend for the full width of belt 1, the water released in the washing station flows over the edges of the belt, and is caught by a sink 51 disposed beneath the lower reach of belt 1.
  • the active surface thereof is substantially denuded of water by the squeegees.
  • the lithographic plate Upon emerging from the washing station 6, the lithographic plate, such as 9, passes under a proximity switch 52, which senses the presence of a subjacent plate on belt 1, and closes an electrical circuit whichactuates a plurality of metering devices 53, and results in the dropping of measured charges of preservative composition at predetermined intervals onto the active surface of a subjacent plate as it moves on belt I therebeneath into and through preserving station 7.
  • the several metering devices 53 are connected at spaced intervals of about five to six inches in the widthwise direction (of the belt) to a header 54, which is fixedly mounted upon the framework of the apparatus, and connected through tube 55 to a pump 56 which receives the preservative composition from tank 57.
  • tank 57 is vented to prevent the pump 56 from drawing a vacuum. While the tank 57 is shown with an open top, it will be understood that a lid may be applied to reduce evaporation of volatile components of the developer.
  • a drain line 58 having a valve 59, is provided for draining the contents of tank 57 when operation of the apparatus is to be discontinued for a substantial period of time.
  • the rubbing head 45 also included within the preserving station 7 is the rubbing head 45 previously mentioned, whose construction and mode of operation is, in the embodiment shown, identical with that of developer rubbing head 12, except that where a single rubbing head is provided as at the preserving station, it is preferred that the shafts thereof, corresponding to 24 in FIG. 5, be provided at their upper ends with counterweights 61, or other balancing means, to minimize vibration, which balancing means is not necessary with rubbing heads 12 and 13 when driven in the same sense of rotation, but out of phase, as previously described.
  • the counterweights 61 are mounted on the upper extremities of shafts corresponding to 24 in FIG. 5, and so oriented that the mass centers of the respective counterweights are in 180 displacement from the pivot axis of bearing 27 about stub shaft 26.
  • the rubbing head 45 performs the same type of operation on an subjacent plate with preservative composition, as rubbing heads 12 and 13 performed at the developing station with developing composition, and rubbing head 45 is driven by the endless chain 15 in engagement with sprockets 43 and 44 in like manner to that previously described.
  • a lithographic plate such as 9, is transported on the belt 1 into the nip between the belt 1 and a squeegee roller 8 which squeegees off any excess of preservative composition on the active surface of the plate, and accumulates it ahead of the nip between the belt and idler roll 8, so that it may drain sidewise of the belt and flow into sink 57, as in the case of the water discharged at the washing station 6.
  • any suitable device such as an oven, for expediting the natural evaporation of water and organic solvent from the preservative on the plate is recommended.
  • Such an oven or other drying device is preferably arranged to receive the plates, one by one, as they emerge from squeegee 8, dry them, and automatically deliver them to a stacking device from which they may be removed at will in multiple.
  • both spray head 62 and squeegee 63 are arranged so that the drainage therefrom is accumulated in sink 51.
  • the residual water on an increment of belt 1 which has just passed squeegee 63 is substantially all adsorbed by the belt so that the belt is damp when the reserve (inactive) surface of an incoming plate, such as 9, first makes contact with the belt.
  • Such dampness is enough to exclude air from the.plate-belt interface when the two are squeezed together bythe idler roll 4, and the resultant interfacial tension holds the plate in position on the belt, without relative movement, while the active (obverse) surface of the plate is undergoing the rubbing action of the heads 12, 13 and 45, and undergoing the wiping action of squeegees 47 and 48.
  • the water supply while potable, contains solutes which have a deleterious efiect when such water is brought into contact with the active face of an un-.
  • the input apron 10 is equipped with means for sensing the presence, on the apron, of an incoming exposed lithographic plate, such as 9.
  • a plate-presence sensor is in the form of a whisker switch 65, which normally projects above the level of plate 10, but is pressed down into electrical-oircuit-closing position when an incoming plate engages it.
  • the apparatus is started manually to precondition it for operation, a few seconds before a plate, such as 9, is inserted.
  • a plate such as 9
  • the several components of the apparatus are actuated in sequence.
  • the pumps 142 and 56 are energized to build up a head of developer composition in the developer header 144, and a head of preservative composition in header 54.
  • the movement of belt 1 is initiated simultaneously with turning on the water to headers 49 and 62.
  • the several metering devices 14, which control the discharge of developer liquid, are opened to deposit on the belt a sufficient amount of developer liquid to impregnate at least the surface increments of the several rubbing members 22 on the developer heads 12 and 13.
  • the metering devices 53 are opened to deposit a charge of preservative composition on the belt for .LLL
  • the electrical control circuitry may be automated to interrupt the continued movement of the belt and'rubbing head upon either the lapse of a chosen increment of time, or belt travel for a chosen distance, since the last actuation of the whisker switch.
  • the metering devices 14 will be automatically energized to deliver a charge from each of the metering devices, and to drop that chargeupon the subjacent plate near the leading edge thereof, as well as to auto matically drop succeeding charges on the plate every four or six inches.
  • the control circuitry for metering devices 53 is-energized to cause periodic discharge of preservative after the plate has reached aposition to intercept the dropping discharges;
  • the electrical circuitry and equipment for so controlling the metering devices 14 can take any form well known in the art, and forms no part of the present invention.
  • the time at which movement of the rubbing heads l2, l3 and 45 is initiated is not critical, save that such initiation of each such rubbing head should occur prior to the time the leading edge of an approaching plate reaches it.
  • the discharge of water from nozzles 50 may be continuous once motion of the belt 1 has been initiated, but, if desired, means for sensing the approach of a plate can be provided to turn the water discharge on when there is need for it, and off when there is no need for it.
  • the discharge of preservative composition from metering devices 53 is under the control of proximity switch 52, so that discharge of preservative liquid commences after the leading edge of a plate undergoing processing has reached a position below the metering devices 53, continues periodically as long as a plate is present beneath proximity switch 52, and is terminated when there is no plate beneath proximity switch 52.
  • the frequency of the discharges from metering devices 14 and 53 depend, to some extent, upon the developer and preservative compositions employed, as well as the character of the plate being treatedand its area. Accordingly, it is contemplated that the timing of such discharges be adjustable to best suit the prevailing conditions of operation, but the specific means for accomplishing such variation are well known in a variety of forms for-comparable situations, and form no part of the present invention.
  • Apparatus for developing lithographic plates comprising a moving endless belt having a substantially horizontal upper reach, a lithographic-plate-receiving station adjacent one end of said reach, said upper reach supporting and transporting a received plate to, through and beyond a succession of operating stations located along said reach, said belt having an exterior surfacefacing upwardly in said upper reach, means for applying liquid to said exterior surface, and means engaging said exterior surface ahead of said plate receiving station for removing substantially all but absorbed and adsorbed liquid from successive increments of said exterior surface, and wherein one of said operating stations has:'
  • a. means above said upper reach for measuring charges of developer liquid and dropping them upon a subjacent lithographic plate transported on said upper reach;
  • a rubbing head having a resiliently compressible porous rubbing member arranged to engage a lithographic plate moving on said belt beneath said head;
  • Apparatus for developing lithographic plates comprising a moving endless belt having a substantially horizontal upper reach, a lithographic-plate-receiving station adjacent one end of said reach,*said upper reach supportingandtransporting a" received plate to, through and beyond a succession of operating stations located along said reach, said belt having an exterior surface facing upwardly in said upper reach, means for applying liquid to said exterior surface, and means engaging said exterior surface ahead of said plate receiving station for removing substantially all but absorbed and adsorbed liquid from successive increments of said exterior surface, and wherein one of said operating stations has:
  • a. means above said upper reach for measuring charges of developer liquid and dropping them upon a subjacent lithographic plate being transported on said upper reach;
  • Apparatus for processing exposed lithographic plates comprising:
  • the plate-conveying means comprises an endless belt having an upper reach for conveying a plate along said path, the plate being applied to the upper reach of the belt adjacent one end thereof constituting its starting end, and having means for wetting the belt ahead of said one end of its upper reach for holding a plate flat on the belt.
  • the belt-wetting means comprises means for spraying water on the bottom surface of the lower reach of the belt, and means for wiping off excess water from the lower reach.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photosensitive Polymer And Photoresist Processing (AREA)
  • ing And Chemical Polishing (AREA)
  • Printing Plates And Materials Therefor (AREA)
US729040A 1968-05-14 1968-05-14 Apparatus for developing lithographic plates Expired - Lifetime US3608464A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US72904068A 1968-05-14 1968-05-14
DE1756378A DE1756378C2 (de) 1968-05-14 1968-05-14 Anlage zur Herstellung druckfertiger Mehrmetallplaften für Offset-Druckmaschinen
US11261971A 1971-02-04 1971-02-04

Publications (1)

Publication Number Publication Date
US3608464A true US3608464A (en) 1971-09-28

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US729040A Expired - Lifetime US3608464A (en) 1968-05-14 1968-05-14 Apparatus for developing lithographic plates
US00112619A Expired - Lifetime US3782532A (en) 1968-05-14 1971-02-04 Apparatus for developing lithographic plates

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Application Number Title Priority Date Filing Date
US00112619A Expired - Lifetime US3782532A (en) 1968-05-14 1971-02-04 Apparatus for developing lithographic plates

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US (2) US3608464A (id)
BE (1) BE719497A (id)
DE (1) DE1756378C2 (id)
FR (1) FR1581882A (id)
GB (1) GB1269281A (id)
NL (3) NL6809863A (id)

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3682078A (en) * 1968-07-18 1972-08-08 Western Litho Plate & Supply Apparatus for post-exposure treatment of lithographic plates
US3719133A (en) * 1972-02-18 1973-03-06 E Haracz Lithographic plate developing apparatus
US3771428A (en) * 1971-10-21 1973-11-13 Azoplate Corp Apparatus for processing two sides of a printing plate
US3809105A (en) * 1972-01-05 1974-05-07 Hoechst Co American Apparatus for processing two sides of a printing plate
US3846816A (en) * 1971-10-21 1974-11-05 Hoechst Co American Printing plate processor and means for opening and closing the same
US3846817A (en) * 1972-09-04 1974-11-05 Asahi Chemical Ind Apparatus for conveying synthetic resin-made articles in the sheet form
US3896470A (en) * 1973-04-11 1975-07-22 Buckler Ind Inc Automatic processor for offset plates
US3906536A (en) * 1971-07-27 1975-09-16 Robert C Graham Apparatus for processing printing plates precoated on both sides
US3936853A (en) * 1974-06-06 1976-02-03 Mart Milam E Developer apparatus for lithographic plate processing system
US3953225A (en) * 1973-08-08 1976-04-27 Buckler Industries, Inc. Basic unit processor for offset plates and method of processing them
US3981583A (en) * 1973-08-23 1976-09-21 Nippon Paint Co., Ltd. Apparatus for automatically processing photopolymer plates
US4069791A (en) * 1976-10-01 1978-01-24 E. I. Du Pont De Nemours And Company Automatic toning device
US4119991A (en) * 1977-04-08 1978-10-10 Peter Vincent Martino Horizontal one step automatic plate processor
US4128326A (en) * 1977-06-02 1978-12-05 Astro Engineering Co. Chemical dispensing system
US4145135A (en) * 1977-09-01 1979-03-20 Beach Manufacturing Corporation Lithographic plate processor
US4148576A (en) * 1978-08-09 1979-04-10 Martino Peter V Apparatus for continuously processing film in a horizontal through-put manner
US4178097A (en) * 1977-09-06 1979-12-11 Beach Manufacturing Corporation Automatic lithographic plate processor
US4179208A (en) * 1977-04-08 1979-12-18 Martino Peter V Horizontal one step automatic plate processor
US4222656A (en) * 1979-03-09 1980-09-16 Western Litho Plate & Supply Co. Apparatus and method for processing exposed lithographic plates
US4367940A (en) * 1980-06-16 1983-01-11 Mart Milam E Chemical application and developer apparatus for lithographic plate processor
US4627698A (en) * 1983-10-03 1986-12-09 Dainippon Screen Mfg. Co., Ltd. Processing apparatus for printing plates
EP0323836A2 (en) * 1988-01-07 1989-07-12 Fuji Photo Film Co., Ltd. Method for manufacturing lithographic printing plates
US5079580A (en) * 1989-07-28 1992-01-07 Konica Corporation Apparatus for processing a silver halide photographic light-sensitive material
US10139731B2 (en) * 2017-01-05 2018-11-27 Boe Technology Group Co., Ltd. Conveyor, developing system and method

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3248411C2 (de) * 1982-12-28 1986-03-27 Fritz Dipl.-Ing. 8000 München Knollmann Vorrichtung zum mehrstufigen Behandeln von Fotodruckplatten
DE102009032928A1 (de) * 2009-07-14 2011-01-20 Gmg Grafische Maschinen Gesellschaft Mbh Vorrichtung zur Prüfung von mit magnetischen Elementen versehenen Substraten, insbesondere zur Prüfung von mit magnetischer Druckfarbe bedruckten Druckprodukten

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US2496947A (en) * 1945-10-20 1950-02-07 Eastman Kodak Co Film processing machine with film operated control means for a fluid applicator
US2555874A (en) * 1946-12-23 1951-06-05 John S Swift Co Inc Photolithographic plate inking, drying, and developing machine
US3059560A (en) * 1958-03-20 1962-10-23 Intercompany Corp Production of lithographic printing plates
US3088391A (en) * 1958-01-23 1963-05-07 Fairchild Camera Instr Co Liquid treatment apparatus for photopolymer sheet material
US3271226A (en) * 1963-08-09 1966-09-06 Eastman Kodak Co Etching apparatus for making a cellulosic printing plate

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US2482882A (en) * 1945-06-11 1949-09-27 Carl O Swanson Self-cleaning door mat
DE969425C (de) * 1953-05-22 1958-05-29 August Weickinger Fa Verfahren und Vorrichtung zum UEberziehen von Druckformzylindern mit einer lichtempfindlichen Schicht
US2855094A (en) * 1955-03-21 1958-10-07 Gordon Johnson Equipment Compa Stainless belt inspection table
DE1141182B (de) * 1960-03-26 1962-12-13 Pako Corp Filmentwicklungs- und -behandlungsgeraet
DE1205831B (de) * 1962-05-22 1965-11-25 Donka App Nfabriek N V Verfahren und Vorrichtung zur Bearbeitung fotografischen Materials
US3219339A (en) * 1962-07-25 1965-11-23 Fmc Corp Article separating apparatus

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Publication number Priority date Publication date Assignee Title
US2496947A (en) * 1945-10-20 1950-02-07 Eastman Kodak Co Film processing machine with film operated control means for a fluid applicator
US2555874A (en) * 1946-12-23 1951-06-05 John S Swift Co Inc Photolithographic plate inking, drying, and developing machine
US2677320A (en) * 1946-12-23 1954-05-04 John S Swift Co Inc Developing head for phtolithographic plate treating machines
US3088391A (en) * 1958-01-23 1963-05-07 Fairchild Camera Instr Co Liquid treatment apparatus for photopolymer sheet material
US3059560A (en) * 1958-03-20 1962-10-23 Intercompany Corp Production of lithographic printing plates
US3271226A (en) * 1963-08-09 1966-09-06 Eastman Kodak Co Etching apparatus for making a cellulosic printing plate

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3682078A (en) * 1968-07-18 1972-08-08 Western Litho Plate & Supply Apparatus for post-exposure treatment of lithographic plates
US3906536A (en) * 1971-07-27 1975-09-16 Robert C Graham Apparatus for processing printing plates precoated on both sides
US3771428A (en) * 1971-10-21 1973-11-13 Azoplate Corp Apparatus for processing two sides of a printing plate
US3846816A (en) * 1971-10-21 1974-11-05 Hoechst Co American Printing plate processor and means for opening and closing the same
US3809105A (en) * 1972-01-05 1974-05-07 Hoechst Co American Apparatus for processing two sides of a printing plate
US3719133A (en) * 1972-02-18 1973-03-06 E Haracz Lithographic plate developing apparatus
US3846817A (en) * 1972-09-04 1974-11-05 Asahi Chemical Ind Apparatus for conveying synthetic resin-made articles in the sheet form
US3896470A (en) * 1973-04-11 1975-07-22 Buckler Ind Inc Automatic processor for offset plates
US3953225A (en) * 1973-08-08 1976-04-27 Buckler Industries, Inc. Basic unit processor for offset plates and method of processing them
US3981583A (en) * 1973-08-23 1976-09-21 Nippon Paint Co., Ltd. Apparatus for automatically processing photopolymer plates
US3936853A (en) * 1974-06-06 1976-02-03 Mart Milam E Developer apparatus for lithographic plate processing system
US4069791A (en) * 1976-10-01 1978-01-24 E. I. Du Pont De Nemours And Company Automatic toning device
US4119991A (en) * 1977-04-08 1978-10-10 Peter Vincent Martino Horizontal one step automatic plate processor
US4179208A (en) * 1977-04-08 1979-12-18 Martino Peter V Horizontal one step automatic plate processor
US4128326A (en) * 1977-06-02 1978-12-05 Astro Engineering Co. Chemical dispensing system
US4145135A (en) * 1977-09-01 1979-03-20 Beach Manufacturing Corporation Lithographic plate processor
US4178097A (en) * 1977-09-06 1979-12-11 Beach Manufacturing Corporation Automatic lithographic plate processor
US4148576A (en) * 1978-08-09 1979-04-10 Martino Peter V Apparatus for continuously processing film in a horizontal through-put manner
US4222656A (en) * 1979-03-09 1980-09-16 Western Litho Plate & Supply Co. Apparatus and method for processing exposed lithographic plates
US4367940A (en) * 1980-06-16 1983-01-11 Mart Milam E Chemical application and developer apparatus for lithographic plate processor
US4627698A (en) * 1983-10-03 1986-12-09 Dainippon Screen Mfg. Co., Ltd. Processing apparatus for printing plates
EP0323836A2 (en) * 1988-01-07 1989-07-12 Fuji Photo Film Co., Ltd. Method for manufacturing lithographic printing plates
EP0323836A3 (en) * 1988-01-07 1990-02-07 Fuji Photo Film Co., Ltd. Method for manufacturing lithographic printing plates
US5079580A (en) * 1989-07-28 1992-01-07 Konica Corporation Apparatus for processing a silver halide photographic light-sensitive material
US10139731B2 (en) * 2017-01-05 2018-11-27 Boe Technology Group Co., Ltd. Conveyor, developing system and method

Also Published As

Publication number Publication date
US3782532A (en) 1974-01-01
NL7404201A (id) 1974-06-25
FR1581882A (id) 1969-09-19
DE1756378C2 (de) 1975-05-22
BE719497A (id) 1969-01-16
NL6809863A (id) 1969-11-18
DE1756378B1 (de) 1971-07-15
GB1269281A (en) 1972-04-06
NL7404202A (id) 1974-06-25

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