US3727536A - Exposed printing plate washer - Google Patents

Abstract

An apparatus for washing away water soluble areas of a plastic emulsion covering a plate used in printing operations. Portions of the normally water soluble plastic emulsion become insoluble in water when exposed to ultra violet light through a light dark master. The apparatus consists of a housing wherein circulating heated water is sprayed uniformly over the printing plate by an arrangement of nozzles to remove the portions of the plastic emulsion remaining water soluble. The nozzles uniformly wash all areas of the emulsion coating, developing thereon, in plastic relief, a representation of the light dark master. The housing of the apparatus also contains air jets and heat lamps arranged for drying the developed plate. Exposed printing plates are carried within the apparatus housing by a continuously slowly revolving drum to which an operator releasably mounts each printing plate by spring clamps through an access opening in the housing.

Description

United States Patent [191 Bunker EXPOSED PRINTING PLATE WASHER lnventor: Richard D. Bunker, Salt Lake City,

Utah

Assignee: Dyna-Flex Corporation, Salt Lake City, Utah Filed: Jan. 3, 1973 Appl. No.: 214,736

US. Cl ..95/98, 95/93 Int. Cl. ..G03d 3/10 Field of Search ..95/89 R, 93, 97,

References Cited UNITED STATES PATENTS Primary Examiner-Samuel S. Matthews Assistant Examiner-Fred L. Braun Attorney-B. Deon Criddle [4 1 Apr. 17, 1973 [57] ABSTRACT An apparatus for washing away water soluble areas of a plastic emulsion covering a plate used in printing operations. Portions of the normally water soluble plastic emulsion become insoluble in water when exposed to ultra violet light through a light dark master. The apparatus consists of a housing wherein circulating heated water is sprayed unifon'nly over the printing plate by an arrangement of nozzles to remove the portions of the plastic emulsion remaining water soluble. The nozzles uniformly wash all areas of the emulsion coating, developing thereon, in plastic relief, a representation of the light dark master. The housing of the apparatus also contains air jets and heat lamps arranged for drying the developed plate. Exposed printing plates are carried within the apparatus housing by a continuously slowly revolving drum to which an operator releasably mounts each printing plate by spring clamps through an access opening in the housing.

5 Claims, 7 Drawing figures 0* {I //a 45 l 43 16 l l 2 I l6 17 2 /7 I I i //a r I Patented April 17, 1973 3,727,536

3 Sheets-Sheat 1 Patented April 17, 1973 3,727,536

15 Sheets-Sheet 2 Patented April 17, 1973 3 Sheets-Sheet 3 1 EXPOSED PRINTING PLATE WASHER BRIEF DESCRIPTION OF THE INVENTION continuously and completely washing such plates.

SUMMARY OF THE INVENTION It is a principal object of the present invention to provide a washing apparatus for removing the water soluble areas of the plastic emulsion covered printing plate of the type disclosed in my aforesaid application for United States Patent.

Another object is to provide a continuously operating washing apparatus whose construction allows a number of such printing plates to each be processed in turn with only a single operator required to mount ac tivated plates onto a revolving drum of the apparatus and to remove washed plates therefrom.

Another object is to provide a water recycling arrangement within the apparatus wherein water sprayed is caught and reheated as needed for reuse therein.

Still another object is to provide means within the apparatus for the removal of moisture from the developed plate.

Still another object is to provide a means for easily and releasably securing the aforesaid printing plates to the revolving drum of the apparatus.

Principal features of the present invention include a housing wherein a number of compartments are arranged around a drum revolving therein, one of said compartments providing an access aperture through the housing to the drum. Some of the compartments contain nozzles directed towards the revolving drum and uniformly spraying, with temperature controlled water, a plastic emulsion covered printing plate mounted thereon. Spring clamps on the drum are used to releasably position the printing plates as the clamps move past the access aperture. The spray nozzles in each compartment are stationary and are arranged in a pattern that will provide overlapping coverage to uniformly wash the entire face of each printing plate moving past the nozzles.

The revolving drum carries each printing plate from the compartment containing the water sprays to a compartment containing apparatus for drying the washed printing plate. The drying apparatus consists of a number of air jets and an arrangement of heat lamps all of which are directed against the revolving drum so as to remove water from the relief surface of a printing plate mounted thereon.

Continued drum revolution passes the washed and dried printing plate back to the access aperture where it is removed before another unwashed, exposed plate is placed thereon.

The heated water sprayed in the apparatus is collected into a storage tank through drains in the housing,

is reheated to the extent necessary to maintain the desired wash temperature, and is recirculated by again pumping it through the spray nozzles.

Brush seals are provided at the sides of the access aperture in the apparatus to allow free rotation of the drum while preventing water and air spray from coming into the access aperture and at a divider installed between washing and drying compartments.

Sets of swivelling spring clamps are mounted to the revolving drum to secure the corners of the printing plates to the outer wall of the drum.

Additional objects and features of the invention will become apparent from the following detailed description and drawings disclosing what is presently contemplated as being the best mode of the invention.

THE DRAWINGS FIG. 1 is a front elevation view of the continuous printing plate washer of the invention;

FIG. 2, a top plan view;

FIG. 3, a horizontal sectional view taken on the line 33 of FIG. 1;

FIG. 4, a vertical sectional view taken on the line 4- 4 of FIG. 3;

FIG. 5, an enlarged sectional view taken on the line 55 of FIG. 4, showing a typical spring clamp with which a printing plate is releasably held to the rotating drum of the invention;

FIG. 6, an enlarged vertical sectional view taken within the line 66 of FIG. 3, showing a typical water wash nozzle arrangement of the invention; and

FIG. 7, a horizontal sectional view taken on the line 77 of FIG. 1.

DETAILED DESCRIPTION Referring now to the drawings:

In the illustrated preferred embodiment, the continuous plastic relief printing plate washing apparatus is shown generally at 10 and includes a housing 11 that when viewed from above has a hexagon shape, sup ported by legs 14a of a framework shown generally at 14. A circular drum I2 is arranged to rotate within the housing 11. A motor 13 mounted below the housing 11, on a beam 14b on frame 14 and is held in place by bolts, not shown, slowly drives drum 12 through a transmission 15 that is also supported by beam 14b.

Spray nozzle assemblies 16 are arranged between the inner surfaces of walls 11a of housing 11 and the outer wall of drum 12 in a compartment 17. Compartment 17 is formed by partitions 17b extending inward from walls Ila towards the drum, such that the spray assemblies within the compartment 17 are separated from an ad joining plate drying chamber and an access aperture. The spray nozzle assemblies 16 are of identical construction so only one will be hereafter described in detail.

Each spray nozzle assembly 16, shown best in FIG. 6, consists of four upstanding manifold pipes 18 that extend from a common header pipe 18a, in parallel arrangement with one another. Nipples 19 extend from each pipe 18 towards the drum l2 and a spray nozzle 20 is mounted on the end of each nipple. Each nozzle 20 is mounted to spray water over a defined segment of a printing plate 21 secured to the drum 12, as will be hereinafter described in detail. Each nozzle 20 is mounted to be diagonally offset with respect to its adjacent nozzles so that a uniform spraying occurs at all areas of each printing plate 21.

Water passing through nozzles impinges on drum 12 and on printing plates 21 mounted thereon, and then flows from the compartment 17 through a common drain 22 provided in the compartment bottom 17a. The compartment bottom 17a is shown inclined towards the drain 22 to insure proper draining. Drain 22 is connected by a line 23 to a reservoir tank 24, mounted below housing 11, on tank supports 25 so as to be supported within the framework 14. Water temperature within tank 24 is maintained at a desired level by a conventional calrod-type, electrical heating unit that extends into the tank. As best seen in FIG. 7, a water line 26 extends from reservoir 24 to the intake of a pump 27. Water pumped through pump 27 goes through valve 27b and then through a pipe 27c and common header pipe 28 into stand pipes 280 to be again forced through common header pipe 180 into upstanding pipes 18 and sprayed from nozzles 20. Since the water within the washing apparatus is constantly being reused only a minimum heat input is required to maintain the water at a desired temperature. An inlet line, not shown, provides make up water to tank 24 from a pressure water source, not shown, and a conventional float valve, not shown, within the tank regulates the amount of make up water admitted.

Drum 12, shown best in FIG. 4, is arranged within housing 11. The drum rests on rollers 29, and is turned through an axle 30 which projects upwardly from gear box 15 therebelow. The path of revolution of the outer wall of the drum begins at an access aperture 31 through a wall 11b of housing 11 and continues through the wash compartment 17, and a drying .chamber 32, before returning to the access aperture 31.

Drying chamber 32, like the chamber 17, is formed in the area provided between the inner housing wall 110 and the outer wall of drum 12. Chamber 32 has a partition 17b forming one side wall and another partition 32a forming the other side wall. The bottom 17a is common to all of compartment 17 and chamber 32. While no water is sprayed in the drying chamber 32, it is desirable to have a drain 22 through bottom 17a therein connected into the drain structures of the wash compartments, so the water blown from the plates, as will be hereinafter described, will drain from chamber 32. Chamber 32 contains a system of air jets 33 and an arrangement of infra-red type heat lamps 34 mounted so as to be directed against the rotating drum l2 and the printing plates 21 mounted thereon. As shown best in FIG. 3, the system of air jets 33 consists of 'four distributor tubes 35, each directed towards the drain and connected to a common air line 36 that extends from the bottom 17a to a midpoint in compartment 32. Each air tube has a number of nozzles 37 projecting outward therefrom pointing towards drum 12. Nozzles 37 distribute air supplied through the tubes 35 such that it covers all portions of the printing plates 21 as they are moved past the nozzles by drum 12. Air forced through nozzles 37 thus blows off most of the water clinging to drum 12 and the passing printing plates 21, and the conventional heat lamps 34, shown best in FIG. 3, further dries away water from the plates. The heat lamps are preferably fixed within wall 1 1c to a reflector 34a that focuses lamp energy in the direction of the drum. While only one bank of air nozzles and one bank of heat lamps are shown, it should be obvious that more than one bank of each could be used if necessary or desirable.

As shown best in FIGS. 1 and 7, a source of compressed air enters the system through a valve 38 mounted on the framework 14, below housing 11 and supplies compressed air through an air line 38a and valve 38b to a heater 380 from where heated and compressed air passes through lines 39 and 36 to the individual nozzles 37. Electricity is supplied to the bank of heat lamps 34 through a junction box 40 and a thermostat 40a both located beneath the bottom of housing 11. Conventional electrical conduits and switches, not shown, supply electrical energy to operate the motors and valves as herein described.

The access aperture shown at 31 in housing 11 provides an operator access to the outer wall of the revolving drum 12. Seals 41 and 42, shown in this embodiment as brushes, extend along the opening sides of the access aperture to respectively seal the aperture from the adjacent compartment 17 and chamber 32.

As has been disclosed previously printing plates 21 are releasably secured to the revolving drum 12 for transport through the washing apparatus. As removal and installation of each plate must be accomplished while a portion of the drum turns within the access aperture 31, it is necessary that plate attachment means be provided which will hold each plate securely while affording quick securement and easy rapid removal of the plates.

The holding means shown in FIG. 5, has proven very effective. The holding means, shown generally at 43, comprises a wire clamp 42 comprising a sear or hairpin spring 44 swivel mounted at 44a to the outer wall of the drum 12. One leg 440 of each spring 44 extends through the wall of drum 12 and has a loop 44b formed in the end thereof to prevent withdrawal of the leg 44c and the other leg 44d is held resiliently against the wall of drum 12 by the action of the spring. The set of clamps includes two clamps spaced and arranged such that the leg 44d of each top can be positioned to clamp a corner of a printing plate 21 to the drum. A number of sets of clamps are spaced around the drum so that plates to be processed can be continually placed on the drum and processed plates can be removed as the drum rotates.

A defoaming agent contained within a reservoir 45 is pumped by pump 46, as needed, into tank 24 through lines 46a and into tank 24 to eliminate foam within the tank 24 and the valves in the system.

In operation, the start switch located on junction box 40 is activated thereby activating motor 13, pump motor 27a, air compressor and heater 38c, illuminating heat lamps 34, the water heater unit in the water tank 24 and opening water flow valve 27b. Motor 13, through transmission 15, rotates the drum 12 on the bearings 29. An operator clamps a printing plate 21 on the revolving drum by turning wire clamps 43 to position the ends of legs 44d on the top corners of the plate. The revolving drum 12 carries plate 21 into the chamber 17 where water that has been collected and heated in tank 24 is forced by liquid pump 27 through spray nozzles 20, of each manifold 16, in turn, against the surface of the printing plate. The water sprayed onto the plate 21 dissolves the soluble portions of the emulsion coating thereon, and drains through drains 22 and line 23 back to tank 24. As the plate continues to revolve on the drum, it moves past partition 17!) into drying chamber 32 where the plate 21 on drum 12 is subjected to the high pressure heated air forced through by nozzles 37.-The thermostatic control 40a regulates the temperature of the air as it is passed through air heater 380. The heat lamps 34 further dry the plate 21. The continuously revolving drum 12 then carries plate 21 past brush seal 41 and back into opening 31 where the developed plate 21 can be removed from drum l2, and an undeveloped plate 21 can be installed in place thereof. The entire drum peripheral face can be covered by printing plates and as plates are being removed from and placed on the drum other plates are being processed. Thus a continuous plate processing operation can be performed. Alternatively, a single plate can be processed should this be desired.

Although a preferred form of my invention has been herein disclosed, it is to be understood that the present disclosure is made by way of example and that variations are possible without departing from the scope of the hereinafter claimed subject matter, which subject matter I regard as my invention.

I claim: 1. An exposed plastic relief image printing plate washer comprising a framework; a drum rotatably mounted to said framework; means for revolving said drum; means for releasably mounting an exposed plastic reliefimage printing plate on a portion of said drum; a housing having walls surrounding said drum and mounted on said frame; an access aperture through a wall of the housing exposing a portion of said drum; at least one water spray assembly mounted between said drum and the walls of said housing, said assembly having spray nozzles arranged to uniformly spray said portion of said drum to which an exposed plastic relief image printing plate is mounted; means for supplying water to the nozzles under pressure; means for collecting and removing sprayed water from said housing; means mounted within said washer between said drum and the walls of said housing for removing water clinging to each plastic relief image printing plate after it emerges from the water spray assembly; and divider means within said housing for separating said water spray arrangement from said water removing means and from said access aperture in said housing. 2. An exposed plastic relief image printing plate washer as recited in claim 1, wherein the means for releasably mounting an exposed plastic relief image printing plate on a portion of said revolving drum consists of at least one sear spring having one leg swivel mounted to said drum, and with the other leg thereof resiliently held against the drum. 3. An exposed plastic relief image printing plate washer as recited in claim 1, wherein the means for removing clinging water from the plastic relief image printing plate comprises an assembly of airjets mounted so as to direct air from a compressed air source against the surface of the drum mounted plastic relief image printing plate. 4. An exposed plastic relief image printing plate washer as recited in claim 3, further including means to heat the compressed air.

5. An exposed plastic relief image printing plate washer as recited in claim 4, wherein the means for removing clinging water from the plastic relief image printing plate further includes an arrangement of heat lamps mounted to radiate against each printing plate.

Claims (5)

1. An exposed plastic relief image printing plate washer comprising a framework; a drum rotatably mounted to said framework; means for revolving said drum; means for releasably mounting an exposed plastic relief image printing plate on a portion of said drum; a housing having walls surrounding said drum and mounted on said frame; an access aperture through a wall of the housing exposing a portion of said drum; at least one water spray assembly mounted between said drum and the walls of said housing, said assembly having spray nozzles arranged to uniformly spray said portion of said drum to which an exposed plastic relief image printing plate is mounted; means for supplying water to the nozzles under pressure; means for collecting and removing sprayed water from said housing; means mounted within said washer between said drum and the walls of said housing for removing water clinging to each plastic relief image printing plate after it emerges from the water spray assembly; and divider means within said housing for separating said water spray arrangement from said water removing means and from said access aperture in said housing.

2. An exposed plastic relief image printing plate washer as recited in claim 1, wherein the means for releasably mounting an exposed plastic relief image printing plate on a portion of said revolving drum consists of at least one sear spring having one leg swivel mounted to said drum, and with the other leg thereof resiliently held against the drum.

3. An exposed plastic relief image printing plate washer as recited in claim 1, wherein the means for removing clinging water from the plastic relief image printing plate comprises an assembly of air jets mounted so as to direct air from a compressed air source against the surface of the drum mounted plastic relief image printing plate.

4. An exposed plastic relief image printing plate washer as recited in claim 3, further including means to heat the compressed air.

5. An exposed plastic relief image printing plate washer as recited in claim 4, wherein the means for removing clinging water from the plastic relief image printing plate further includes an arrangement of heat lamps mounted to radiate against each printing plate.

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