US3455763A - Etching apparatus - Google Patents

Description

1969 A. J. SARKA ET AL ETCHING APPARATUS 6 Sheets-Sheet 1 Filed May 25, 1965 INVENTORS A LBE R T J. SAR KA BY LOU IS F! 10TH ATTOR N E Y5 July 15, 1969 A. J. SARKA ETAL momma APPARATUS 6 Sheets-Sheet 2 Filed May 25, 1965 INVENTORS ALBERT J. SARKA LOUIS P. TOTH ATTORNEYS y 1969 A. J. SARKA ETAL ETCHING APPARATUS 6 Sheets-Sheet 3 Filed May 25, 1965 mdE INVENTOR5 ALBERT J. SARKA BY LOUIS P. TOTH July 15, 1969 A. J. SARKA ETAL 3,455,763

ETCHING APPARATUS.

Filed May 25, 1965 e Sheets-Sheet 4 INVENTORS F! G. 5

ALBERT J. SARKA BY LOUIS E TOTH ATTORNEYS 6 Sheets-Sheet 5 INVENTORS ALBERT J. BY LOUIS P. TOTH W SARKA ATTORNEYS y 5, 1969 A. J. sARKA ETAL momma APPARATUS Filed May 25, 1965 July 15, 1969 A. J. SARKA AL 3,455,763

ETCHING APPARATUS Filed May 25, 1965 6 Sheets-Sheet 6 IN VENTORS ALBERT J. SARKA BY LOUIS F? TOTH WWW? ATTORNEYS United States Patent 3,455,763 ETCHING APPARATUS Albert J. Sarka, Fairview Park, and Louis P. Toth, Broadview Heights, Ohio, assignors to Harris-Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Filed May 25, 1965, Ser. No. 458,549 Int. Cl. C23f 1/02 US. Cl. 156-345 13 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to the art of etching and more particularly to a method of and apparatus for etching a plate.

The present invention is particularly useful in the production of die plates to be used in cutting and creasing as in the formation of paperboard carton blanks. A complete disclosure of die plates of this type and the manner in which they are used to form a paper carton blank can be found in the patent to Downie No. 3,142,233, issued July 28, 1964.

The patent also discloses in considerable detail the manner in which the plates are prepared for etching. Briefly, the plate preparation involves the application of a coating which is etch resistant to the areas of the plate which are not to be etched. As the etchant contacts the plate surface it etches the uncoated areas of the plate to relieve the latter.

It has been discovered that in etching plates on which close pattern tolerances must be maintained, such as the die plate patterns disclosed in the previously identi fied patent to Downie, the etchant must be applied in uniform strength and quantity to all areas of the plate surface. To achieve this desired application of etchant,

the present invention provides a plurality of spray tubes movable through the cabinet in a substantially linear path and delivers the etchant to the plate surface in the form of a spray in the course of their movement along the path. This moving spray application, due to the continuous mixing of the etchant as it is circulated through the system, maintains the strength of the etchant spray susbstantially uniform. To insure that the spray is uniformly applied to all areas of the plate surface, the plate is mounted for rotation about an axis extending substantially normal to the path of tube movement so that periodically, such as after a pass or passes of the spray, the plate can be rotated about this axis so that succeeding passes of the spray move across the plate in different paths. For example, in the case of etching a rectangnlarly shaped plate, the plate may be located successively in four positions, with each position being oriented 90 relative to the preceding and succeeding positions so that all edges of the plate are exposed to the leading edge of the spray as it is moved thereacross, consequently insuring uniform spray application to all portions of the emerging pattern.

One problem which arises in connection With etching plates is that of inspecting the plate' without removing i substantially along line 4-4 of FIG..3;1- ':T

truck taken substantially along line 6-6 ofF IGL S;

-men, particularly when it-is recognized that 3,455,763 Patented July 15, 1969 it from the plate holder of the etching apparatus. The plates are often of large size and it is difficult for the workman to inspect the entire plate if it is maintained in the same orientation as during the etching process and when it is moved out of the etching area ,for inspec' tion purposes, particularly when such orientation is horizontal. It the plate is in or shifted to avertical positionfor inspection, the upper portion of the plate maybe too high to allow convenient inspection b'yihe workthe inspec ion is a microscopic type inspection. i

Accordingly an important object ot' the present invention is to provide a new and :improved apparatus .for etching plates in which the plate. may be readily and conveniently inspected without removing the plate from the support for holding it in etching position.- :1

Another object of the'present invention is the provision of a new and improved method of etching a plate by making a plurality of passes with a sprayof etching fluid across the surface of the plate and angularly rotating the plate between passes. i

Another object of the present invention is the provision of a new and improved apparatus for etching a plate wherein a rectangularly moving spray of etching fluid is directed onto a plate which is mounted for rotation about an axis extending substantially normal to the path of movement of the spray.

Another object of the present invention is the provision of new and improved etching apparatus in which a plate to be etched is supported in a substantially horiontalr position in an enclosure to expose the plate to a spray of etching fluid and in a position inclined to the horizontal as it is withdrawnsfrom the enclosure to receive a water spray which is directed onto the, surface of the inclined plate to remove any etching fluid remaining on the plate and drain the fluid into the enclosure prior to emerging therefrom.

A further object of the present invention. is the pro vision of a new and improved etching apparatus in which a plate,.which is etched in a generally horizontal position, can be moved outside of the etching: area, rotated about a generally horizontal axis to position the plate in an upstanding position for inspection purposes with the plate being rotated about an axis generally perpendicu- A vision of a new andrirnproved means for producing a spray of etching fluid in an enclosure and which "com prises a plurality of hollow tubes having discharge open ings therein and which are bodily movable to'- produce a moving spray of etching fiuid. 1 a

Further objects and advantages of the presentinvention will be apparent froinf the followingdetailed description of the preferredembodiment thereof made with refer ence to the accompanying drawingsforming a part olithe present specification for all subject matter disclosed therein and in-which: Y i

FIG. 1 is a perspective view of the apparatus embodying the present invention;

FIG.- 2 is a sectional view of the apparatus embodying the present invention taken substantially along line 2+2 of FIG. 1; FIG. 3 is a sectional view of the apparatussembody ing the present invention takensubstantially' along. line 3-3 of FIG-2; t FIG. 4is a sectional view showing' the tube truck taken FIG. 5 is a sectionalaview-taken substantially along line 5-5 of FIG. 4; i 2 in FIG; 6' is a sectional view'of aportion of thtube prises a plurality of spray tubes 102 mounted at their snares respective ends on trucks 104 having wheels 106'dis'-- posed to "run in tracks orguideways '108-supportedon' opposite side Walls of the cabinet 10. A drive means 110* is operatively conne'cted'to the trucks and adaptedto move 5 the spray' tubes backand' forth a'cross -the cabinet bea neath the plate A supported'by the plate'handling meansz" 22.'The plate handling means and the. spray tubes are arranged in the preferred embodiment in. move in directions normal to one another. Thespraytubes 102.have a1 by'asuitable power means- 116.'"The pump .means ing cludes suitable'piping 1I8 for. connecting the pump with v the reservoir 20 and with the trucks-104. The piping 118 has suitablevalves and flow indicator anda T-section- 120 disposed in cabinet (FIG. 3). A flexiblehose 122 is connected to each end of the T-section 120' and extends therefrom to the trucks104. The etching fluid in"- reservoir 20 is removed by pump 114 and circulated through piping 118, hoses122, trucks 104, suitablepassageways in the trucks into the spray tube 102 where it.v

is dispersed through openings 112 as a spray. The etch ing fluid after being dispersed by tubes 112 accumulates in reservoir 20 and is recirculated to the tubes. Periodi-. cally the etching fluid loses its strength and has to .be replaced. By manipulation of certain valves the etching. fluid can be directed into a drain and a cleaning liquid,- such as water, is circulated through the tubes 102 and the piping. Water can also be delivered to the tank through pipe 119 to rinse the surfaces of the tank. 12.

Disposed above the tubes 102 is a baflie. 124 definingan opening having generally the same configuration as, but smaller than, the plate support means 86. The bafiiev 124 and plate support means 86 cooperate to form a barrier across the tank to preventthe spray of fluid from entering into the section of the tank above plate A as the spray tubes traverse the cabinet. Theprecise configuration of the opening defined by baflie 124 preferably conforms to the plan configuration of plate 86. The configuration in the preferred embodiment: is square with cut out corners similar to a Swiss-cross. The cut out corner configuration facilitates rotation of the plate support means relative to the cabinet when the former is disposed. in etching position in the latter.

The trucks 104 supporting the spray tubes 102 for movement in cabinet 10 and the tubes are preferably con-. structed from acid resistant material, such as Teflon, and each truck comprises a lower body section 126 of unitary construction and four upper body sections 128 which are removably secured to lower section 126.by a plurality of threaded fasteners 130. Each upper section 128 is capped by a metal plate 132, preferably of stainless steel,. and the lower section 126 has a single plate 134 which also is preferably made from stainless steel. The threaded fasteners 130 extend through openings in the upper plate 132, the associated upper section 128, lower section 126 and plate 134. To facilitate mounting the innermost two fasteners 130 of plates 132, a metal plate 184 (FIGS. 5 and 6) is welded to the upper side of plate 134 and extends across opening 174 and has the head of the bolts 130 Welded or otherwise secured to the upper edge thereof and the threaded ends ofthe bolts extend through the Teflon body sections 126, 128 and upper plate 132 and threadedly receives the associated nuts 186. This arrangement, of course,..-is necessitated due to the connection of collar 176 to plate 134 at the area Where these bolts or fasteners 130 would normally extend. through plate 134.

Disposed along the back side of lower section 126 (FIG. 5) is a' plate 136 which is secured at its lower end by Teflon section 126. A pairof axles 138 are secured to backing plate 136 and onto which the truckwheels 140 are rotatably mounted. The rollers 140 also are preferably constructed from Teflon.- A suitable guideway, or

track, 142 is welded, or otherwise secured, tothe sides of cabinet 10 and along which the truck wheels 140 are adapted to run. 1

The tubes are secured to the trucks by rneans of anw inner pipe or conduit 143 which extendsthrough the Teflon 'truck body between the upper sections 128 and lower section 126. The inner pipe 143 isfsecuredat one end in abutting relationship toback plate 136 =by-a threaded fastener 144 and the other end-is secured concentric relationship to an end-of the tribe-102 by. a

suitable bushing 146 mounted in the end of tubeQ102.

The end of tube'102' is arranged to extend partiallyinto the upper andilower'Teflonsections between-plates' 128 and plate 134, as is clearly shown in FIG. 5 ofthedrawings. The tube mounting arrangement is such as to permit quick removal thereof from the trucks by removing the associated plate 132 and upper body-section 128 of each truck.

The drive means 110 for the trucks 104 comprises a suitable motor means 148 which is mounted on a shelf sprockets 156 which are keyed or otherwise fixedly secured to rotate with the shaft. Disposed at the opposite end of cabinet 10 is an idler shaft 158 having a pair ofsprockets 160 mounted on respective ends thereof in alignment with sprockets 156. Drive shaft 152 extends through one side of cabinet 10 and has mounted thereon a sprocket 162 which is driven from motor sprocket 164 through a suitable drive belt 166 such as a link chain belt. A pair of link chains 166 are disposed about sprockets 156 and 160 and the respective ends of each chain are connected to plate 168 depending from bottom plates 134 of the trucks. A pair of chain guide plates 170 project upwardly and are secured to guideways 142 by means of suitable fasteners 172 and functions to support the upper runs of the chains. Upon actuation of'motor means 148, power is transmitted therefrom through sprockets 164, 162 and 156 to chains 166 to propel the trucks 104 along guideways 142 to move the tubes in a substantially linear path.

Means are provided for establishing fluid communication through each of the trucks from the flexible hoses 122 to the spray tubes 102 and comprises an opening 174 in bottom plate 134 and a circular collar 176 depending from plate 134 from Within opening 174 and onto which the end of hose 122 is connected. The upper and lower Teflon body sections 126 and 128 have formed therein suitable passageways for providing fluid communication between collar 176 and tubes 102 and comprisesa main fluid passageway 178 in the lower Teflon section 126, and a series of annular passageways 180 formed in the upper and lower Teflon sections 126 and 128 to provide communication between each inner pipe 143 and the main passageway 178. Each inner pipe'1'43 has an opening 182 in the upper portion thereof disposed in the annular passageway 180 so as to provide fluid communication therebetween. As fluid is pumped through hoses 122 it flows :under pressure through collar 176, main passageway 178, annular passageways 180', opening 182 in the inner I pipe 143 and into each end of tubes 102 where it is dispersed therefrom through openings 112. The etchant flow through the trucks is shown by thearrows in FIG. 6.

The operation of the etching'apparatuswill now be described. The machine is initially; set in the position il-,- lustrated in FIG. 1 with the plate holder means 28 oriented substantially vertically which is the plate, attaching and removal position. The plate holder means is fixed. in this position while the plate A is attached to the plate support means '86 by the latch means 64 engaging notch 46 of 7 plate 42. The plate is delivered to the machine by a suitv;

.ablematerial handling means such as an overhead crane, conveyor, etc., and is locked in position by adjustment of locking dogs 100 with the side to be etched exposed. After the plate A has been secured to the plate holder means,.the operator grasps cable actuator 68 and exerts a force thereon which disengages the bolt of the latch means 64 from notch 46 and thereafter the operator .rotates the base 26 relative to frame 24 by handle means 56.until the plate assumes -the position illustrated in FIG. 9-. This position is characterized by the spring latch means being positioned slightly below notch 44 of plate 42 which is the position in which, the plate is substantially horizontal. With the plate in this position, the operator pushes on member 62 which moves frame 24 along telescoping slides' 34 and 36 to locate the plate within the cabinet in't'he position illustrated in FIG. 7. To assure proper alignment of the plate handling means relative to the cabinet and also to maintain the plate A in the horizontal position while the etching is accomplished, the bolt of latch means 76 is aligned to extend into key slot 82 of the angle 84. With the plate in this position, the door 16 is closed. Suitable motor control means in control panel 188 mounted on cabinet 10 is actuated along with suitable pumpcontrol means which also is mounted in control panel 188 and function to deliver the etching fluid under pressure to the tubes 102 through pump 114, piping 118, T-joint 120, hoses 122, collars 176, main passageways 178 of the trucks 104 and through the annular passageways 180 into the openings 182 in the inner pipes 143 and out pipes 143 into tubes 102 where it is subsequently dispensed in the form of a spray through openings 112 in the top side of the tubes 102. After sufficient etching fluid has been pumped to the tubes 102 so that an even spray is dispensed therefrom, the drive means 110 for the trucks is actuated including motor 148, sprockets 164, 162, 156, 160 and chain 166 and which move the tubes 102 across the cabinet below the face of plate A and delivers to the plate a spray of etching fluid which corrodes the plate according to the established pattern thereon. As the tube trucks 104 complete their etching pass by reaching the opposite side of cabinet 10', one of the trucks engages the switch actuator of a suitable switch 190 which functions to shut off the drive means 110 and reverse the motor 148. Upon subsequent actuation of the drive means 110, the tubes will be moved in the opposite direction to the opposite side of the cabinet where they will be stopped by one of the trucks engaging a second limit switch 190 similar to the other limit switch but disposed at the opposite side of the cabinet. The switches referred to are limit switches wherein the switch is mounted on the exterior of the cabinet with only the switch actuator mechanism projecting into the cabinet in position to be engaged by the trucks at opposite ends of their path of travel. In order to insure even quality of etching on plate A, it is desirable to'rotate plate A 90 between passes of the etching spray tubes 102. To accomplish this rotation, the operator opens door 16, grasps one end of plate support means 86 and rotates same 90 until latch means 96 drops into recesses 98 in the bushing 90 which secures the plate relative to the base 26 in the new position. Door 16 is then closed, whereupon the controls are again act-uated to drive tube true-ks 104 to make another etching pass at the plate. After each pass or after several passes, the plate is again rotated relative to base 26 heretofore described so as to present all sides of the pattern being formed on plate A to the etching spray. This minimizes the streaking effect and uneven chemical etching of the plate by the movable spray.

Periodically the operator will want to inspect the etching progress on plate A. To accomplish this, he open .door 16 of cabinet 10, grasps rod actuator 80 and disengages latch means 76 from slot 82 in angle 84 and the base is rotated by handle 56 until the latch means 64 of plate A duringwithdrawal thereof from cabinet 10. As noted in FIG. 10, this portion holds plate ,A at an inclined relationship relative to; frame 24 and as the plate handling means is withdrawn from the cabinet a water spray is directed againstfthe etchedsurface of plate A to wash any etchant remaining on the plate there.- from prior to emerging from thecabinet, The water spray is dispersed through a water spray tube 192 located at the entrance end of the opening in cabinet 10. .The

cabinet has an inclined plate 194;located adjacent tube 192 and. which slopes into a collection trough 196. The water sprayed onto theetched surface of plate A drains off the plate face due to the inclined relationship of the plate and the water and.etchant mixture flows down plate 194 into trough 196. Suitable drainage means such as a hose is connected totrough 196 to drain the mixture which accumulates in trough 1 96.. After the plate A has been completely removed from cabinet 10 .and is in front of the cabinet, base member 26 can be rotated by handle 56 to a convenient inspection position which could be the position illustrated in FIG. 1 wherein the latch 64 is in engagement with slot 46, or alternatively a third notch 198 could be provided in plate 42 so as to hold plate A in the inspection position illustrated in FIG. 11. This position permits manipulation of the plate to facilitate precise measurement of the depth of etch of the plate to determine the progress of the etching operation thereon. Of course, as mentioned previously, any number of notches might be provided in plate 42 to provide more fixed positions of adjustment of base member 26 relative to the frame 24.

A pair of vents 200 are provided in the cabinet 10 and are adapted to be connected to .an exhaust system to vent the fumes and gases produced by the chemical etching operation.

While the preferred embodiment of the present invention has been described in considerable detail, it is hereby my intention to cover further constructions, modifications and arrangements which fall within the ability of those skilled in the art and within the scope and spirit of the present invention.

Having described our invention, what we claim is:

1. In an etching apparatus, an enclosure for holding an etching solution and having a front exterior wall at least partially defining an opening in said enclosure, plate handling means connected to said enclosure and adapted to support a plate to be etched, means mounting said plate handling means for moving said plate through said opening between an inspection station at which the plate is disposed exteriorly of said enclosure and forwardly of said front wall and an etching station at which the plate is disposed within said enclosure with the surface to be etched exposed for etching, and means for impinging the etching solution against said surface of the plate to thereby effect an etching of said surface, said plate handling means including means supporting the plate for rotation about a first axis and a second axis normal to said first axis with the plate in an upended condition with said surface facing away fromsaid enclosure when said plate is at said inspection station, whereby the plate erigagesnotch 44 on plate 42. This position of adjustment can be adjusted to facilitate inspection of said surface.

2. The apparatus defined in claim 1 including means supporting said plate for rotation about said first and second axes when at said etching station to facilitate manipulation thereof for etching.

3. The apparatusas defined in claim 2 including means for releasably securing said plate in a selected one of aplurality of positions of rotation about said axes when said plate is disposed at said inspection and etching stations. 7

,4. The apparatus defined in claim 1 including means supporting said plate in a substantially horizontalposition when atsaid etching station and meanssuporting said plate in .a position inclined to the horizontal as the plate is moved fromysaid etching to said inspection station.

5. The apparatus defined in claim 1 including means Supporting said plate for rotation about one of said axes at said etching station.

6. In an etching apparatus, an enclosure for holding an etching solution and having an opening along one side thereof, plate handling means adapted to support a plate to be etched and arranged to move said plate through said opening between an inspection station at which the plate is exterior of said enclosure and an etching station at which the plate is disposed in said enclosure with the surface to be etched exposed for etching, and means for impinging the etching solution against said surface of the plate to thereby effect an etching of said surface, said plate handling means comprising a frame member slidably mounted on said enclosure and arranged to move through said opening, a base member mounted on said frame member for rotation relative thereto about a first axis, a plate holder member mounted on said base member for rotation relative thereto about a second axis normal to said first axis, means on said plate holder member to secure a plate thereto, first locking means associated with said base member in a selected effective to releasably lock the base member in a selected one of a plurality of positions relative to said frame member and second locking means associated with said base member and said plate holder member to secure the latter relative to the former in a selected one of a plurality of positions.

7. The apparatus described in claim 6 wherein said first locking means comprises an arcuate-shaped plate carried by said frame member and having a plurality of notches disposed about the periphery thereof, a latch mechanism on said base member and having a latch means biased into contact with the periphery of said arcuate plate and adapted to engage said notches to secure the base member relative to the frame member in a selected one of a plurality of positions, said latch mechanism further including means connected to said latch means and operable to move said latch means against its bias out of engagement with its associated notch to free said base member to rotate relative to said frame.

8. The apparatus as described in claim 6 wherein said second locking means comprises latch means on said base member and a plurality of mating recesses on said plate holder member and means for biasing said latch means into engagement with said recesses.

9. The apparatus defined in claim 1 wherein said means for impinging etching solution against the plate includes a plurality of tubes having discharge openings therein, means for delivering etching fluid to said tubes under pressure to be dispersed through said openings in the form of a spray, means mounting said tubes for movement in said enclosure and drive means for moving said tubes.

10. The apparatus as described in claim 6 wherein said means for impinging etching solution against the plate includes a plurality of tubes having discharge openings therein, trucks supporting the opposite ends of said tubes and movable along guideways supported by said enclosure, drive means operatively connected to said trucks and effective to move said trucks along said guideways, each of said trucks having fluid passageway means therein in communication with the associated tube ends,

and means for delivering said etching fluid under pressure to said passageway means and discharged through said openings in said tubes to establish said spray.

11. In an etching apparatus adapted to etch a pattern on a plate surface, an enclosure having a front wall, means for producing a spray of etching fluid in said enclosure, means mounting said spray producing means for movement in a linear path in said enclosure, drive means for moving said spray producing means along said path, and plate handling means adapted to support .a plate at an etching station in said enclosure with the surface to be etched arranged to intercept said spray as said spray producing means is moved along said path by said drive means and to move said plate to an inspection station forwardly of said front wall, said plate handling means including means for supporting said plate for rotation at said etching station about an axis normal to said linear path of movement of said spray producing means whereat rotation of said plate about said axis presents different portions of the pattern being etched on said plate to said spray and for rotation at said inspection station about an axis extending generally along said path of movement whereat rotation of said plate about said last named axis facilities inspection of different portions of the pattern being etched on said plate.

12. In an etching apparatus, an enclosure having an opening therein, means for producing a spray of etching fluid in said enclosure, plate handling means connected to said enclosure and adapted to support a plate to be etched and arranged to move said plate through said opening between an inspection position in which the plate is disposed exteriorly of said enclosure and forwardly of the front wall of said enclosure to an etching position in which the plate is disposed within said enposition in which thep late is disposed within said enclosure with the surface to be etched aranged to intercept said spray, means supporting the plate on said plate handling means for rotation about an axis from a generally horizontal position to a position inclined relative to said horizontal position when in said etching position mean for maintaining the plate in said horizontal position when in said etching position, means for maintaining the plate in said inclined position as it is moved from said etching position to said inspection position, and means effective to direct a water spray on the surface of the plate when in said inclined position whereby etching fluid remaining on the plate will be washed off prior to the plate reaching said inspection position.

13. The apparatus as defined in claim 12, including means supporting said plate for rotation about an axis normal to said first axis.

References Cited UNITED STATES PATENTS 2,669,048 2/1954 Easley et a1. 15414 2,266,502 8/1961 Dirats 134144 3,266,502 8/1966 Copeland 13457 JACOB H. STEINBERG, Primary Examiner US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent: No. 3 55, T63 Dated J y 5, 9 9

Inventor(s) Albert J. Sarka & Louis P. Toth It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

r. In the claims, Column 9, line 22, after "base" insert and frame--, also in the same line change "member to --members-- and delete the rest of the line.

In the claims, Column 10, line 35, delete the entire line 3).

m Sill! M6 4910 Atteat:

WILLIAM E. SGHUYLER, JR. Awaiting officfif Cowl-Banner of Patents

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